Biological screening of herbal extracts and essential oil from Plectranthus species: α-amylase and 5-lipoxygenase inhibition and antioxidant and anti-Candida potentials

Abstract The phenolic compound content, the antioxidant and α-amylase inhibition potentials of different extracts of the Plectranthus amboinicus, P. barbatus and P. ornatus were evaluated. We also evaluated the influence of plant growth and harvest time on the chemical composition of the essential oil (EO) of P. amboinicus, its antioxidant and anti-Candida activities and the α-amylase and lipoxygenase inhibitions. The turbo-extract of P. barbatus showed the greatest phenolic compound content and antioxidant activity. No α-amylase inhibition activity was observed in the analyzed extracts, but the turbo-extraction and refluxing extracts possessed high antioxidant activities. Protected cultivation and morning harvest conditions gave the best antioxidant activities, which was associated to the highest carvacrol content. P. amboinicus EO antioxidant activity could contribute to the reduction of oxidative stress in diabetes. Causal Candida strains of diabetic foot ulcers showed sensitivity to P. amboinicus EO. C. albicans and C. dubliniensis were the most sensitive of the selected Candida strains. Turbo-extracts or refluxing of the three species extracts and the EO of P. amboinicus should be considered as a potential candidate for the management the complications of type 2 diabetes.

Antibacterial and anti-biofilm potential of Plectranthus amboinicus (Lour) Spreng essential oil and Carvacrol against Staphylococcus aureus and Escherichia coli / Potencial antibacteriano e anti-biofilme do óleo essencial de Plectranthus amboinicus (Lour) Spreng e carvacrol frente a Staphylococcus aureus e Escherichia coli

Introduction: Staphylococcus aureus and Escherichia coli are pathogens that cause chronic infections due to antibiotic resistance mechanisms and their ability to adhere to surfaces and to form biofilms. The search for new agents from natural resources to counter microbial biofilms is an urgent priority in healthcare. Objetive: chemical composition, antibacterial and anti-biofilm activity of Plectranthus amboinicus essential oil (PAEO) and carvacrol were investigated against E. coli and S. aureus. Methodology: PAEO was chemically analyzed using gas chromatography coupled to a mass spectrometer. Antimicrobial activity was assessed by the disc diffusion method and broth microdilution method to determine minimum inhibitory concentrations (MICs). Antibiofilm activity was investigated using 96-well plates with a crystal violet assay. Results: carvacrol (85.25%) was the major component of PAEO. The disc diffusion test confirmed the ability of PAEO and carvacrol in inhibiting bacteria in their planktonic form. The MICs of PAEO against S. aureus and E. coli were 0.31 and 1.25%, respectively, with bactericidal effect. Carvacrol demonstrated a significant antibacterial property (MIC = 0.31%), exhibiting bacteriostatic effects against S. aureus and bactericidal effects against E. coli. Carvacrol considerably inhibited E. coli biofilm formations (58.9%). Moreover, carvacrol inactivated the mature biofilms. Conclusion: the data obtained are promising, and facilitates the development of new therapeutic alternatives. These results indicate the potential of carvacrol in treating diseases caused by E. coli and S. aureus

Introdução: Escherichia coli e Staphylococcus aureus são patógenos que podem causar infecções persistentes devido aos mecanismos de resistência e à sua capacidade de aderir e formar biofilme. A busca por novos agentes a partir de recursos naturais para combater o biofilme é uma prioridade na área da saúde. Objetivo: a composição química, a atividade antibacteriana e anti-biofilme do óleo essencial de Plectranthus amboinicus (PAEO) e do carvacrol foram investigadas frente a S. aureus e E. coli. Metodologia: a análise química do PAEO foi realizada por cromatografia gasosa acoplada a espectrômetro de massa. A atividade antimicrobiana foi avaliada por difusão em disco e microdiluição em caldo para determinar as concentrações inibitórias mínimas (CIMs). As atividades do anti-biofilme foram investigadas usando placas de 96 poços pelo ensaio de cristal violeta. Resultados: o carvacrol (85,25%) foi o principal componente do PAEO. A capacidade do PAEO e do carvacrol para inibir bactérias planctônica foi confirmada por difusão em disco. A CIM do PAEO para S. aureus e E. coli foi de 0,31 e 1,25%, respectivamente, com efeito bactericida. O carvacrol demonstrou uma propriedade antibacteriana significativa (CIM=0,31%), exibindo efeito bacteriostático frente a S. aureus e efeito bactericida para E. coli. O carvacrol inibiu significativamente a formação de biofilme de E. coli (58,9%) e promoveu a desestabilização do biofilme maduro. Conclusão: os dados obtidos são promissores, possibilitando o desenvolvimento de novas alternativas terapêuticas e revelam a potencialidade do carvacrol como fonte para o tratamento de doenças causadas por E. coli e S. aureus.

Phytochemical characterization and biological activities of Plectranthus barbatus Andrews / Caracterização fitoquímica e atividades biológicas de Plectranthus barbatus Andrews

Plectranthus barbatus Andrews (Lamiaceae) is widely distributed in the world and has a range of popular therapeutic indications. This work aimed to evaluate the phytochemical characterization of two leaf extracts of P. barbatus, and their antimicrobial, antineoplastic and immunomodulatory potential. After collection, herborization and obtainment of the P. barbatus aqueous extract (PBA) and acetone:water 7:3 P. barbatus organic extract (PBO), the phytochemical characterization was performed by high-performance liquid chromatography (HPLC). The antimicrobial activity was performed to determine the minimum inhibitory concentration (MIC) against eight bacterial strains using the microdilution test and the fungus Trichophyton rubrum by disc diffusion assay and microdilution test. Cytotoxicity was assessed by MTT and trypan blue methods in normal peripheral blood mononuclear cells (PBMCs) at concentrations ranged between 0.1 to 100 µg.mL-¹ and in neoplastic cell lines Toledo, K562, DU-145 and PANC-1 at 1, 10 and 100 µg.mL-¹ . Immunomodulatory activity, was evaluated by sandwich ELISA of proinflammatory cytokines at BALB/c mice splenocytes cultures supernatant. Both extracts presented flavonoids, cinnamic derivatives, steroids and ellagic acid. PBO showed bacteriostatic activity against Acinetobacter baumannii (MIC = 250 µg.mL-¹) clinical isolate and PBA fungistatic activity against Trichophyton rubrum (MIC = 800 µg.mL-¹). The extracts did not exhibit toxicity to PBMCs and neoplastic cells (IC50 > 100 µg.mL-¹). Additionally, PBO at 100 µg.mL-1 significantly inhibited IFN-γ and IL-17A cytokines (p = 0.03). Plectranthus barbatus is a potential candidate for therapeutic use due to its low toxicity in healthy human cells and exhibits biological activities of medical interest as bacteriostatic, fungistatic and immunomodulatory.

Plectranthus barbatus Andrews (Lamiaceae) é amplamente distribuída no mundo e com uma série de indicações terapêuticas populares. Este trabalho teve como objetivo avaliar a caracterização fitoquímica de dois extratos da folha de P. barbatus e seu potencial antimicrobiano, antineoplásico e imunomodulador. Após coleta, herborização e obtenção do extrato aquoso (PBA) e acetona: água 7: 3 (orgânico) (PBO) de P. barbatus, a caracterização fitoquímica foi realizada por cromatografia líquida de alta eficiência (CLAE). A atividade antimicrobiana foi realizada para determinar a concentração inibitória mínima (CIM) contra oito cepas bacterianas usando o teste de microdiluição e o fungo Trichophyton rubrum por ensaio de difusão em disco e teste de microdiluição. A citotoxicidade foi avaliada por métodos MTT e azul de tripan em células normais mononucleares do sangue periférico (CMSP) em concentrações variadas entre 0,1 a 100 µg.mL-¹ e nas linhagens celulares neoplásicas Toledo, K562, DU-145 e PANC-¹ em 1, 10 e 100 µg.mL-¹ . A atividade imunomoduladora foi avaliada por ELISA sanduíche de citocinas pró-inflamatórias em sobrenadante de culturas de esplenócitos de camundongos BALB/c. Ambos os extratos apresentaram flavonoides, derivados cinâmicos, esteróides e ácido elágico. O PBO mostrou atividade bacteriostática contra Acinetobacter baumannii (CIM = 250 µg.mL-¹) e atividade fungistática do PBA contra Trichophyton rubrum (CIM = 800 µg.mL-¹). Os extratos não apresentaram toxicidade para CMSP e células neoplásicas (IC50 > 100 µg.mL-¹). Além disso, o PBO a 100 µg.mL-¹ inibiu significativamente as citocinas IFN-γ e IL-17A (p = 0,03). Plectranthus barbatus é um candidato potencial para uso terapêutico devido à sua baixa toxicidade em células humanas saudáveis e exibe atividade de interesse médico como bacteriostática, fungistática e imunomoduladora.

Phytochemical characterization and biological activities of Plectranthus barbatus Andrews / Caracterização fitoquímica e atividades biológicas de Plectranthus barbatus Andrews

Plectranthus barbatus Andrews (Lamiaceae) is widely distributed in the world and has a range of popular therapeutic indications. This work aimed to evaluate the phytochemical characterization of two leaf extracts of P. barbatus, and their antimicrobial, antineoplastic and immunomodulatory potential. After collection, herborization and obtainment of the P. barbatus aqueous extract (PBA) and acetone:water 7:3 P. barbatus organic extract (PBO), the phytochemical characterization was performed by high-performance liquid chromatography (HPLC). The antimicrobial activity was performed to determine the minimum inhibitory concentration (MIC) against eight bacterial strains using the microdilution test and the fungus Trichophyton rubrum by disc diffusion assay and microdilution test. Cytotoxicity was assessed by MTT and trypan blue methods in normal peripheral blood mononuclear cells (PBMCs) at concentrations ranged between 0.1 to 100 µg.mL-1 and in neoplastic cell lines Toledo, K562, DU-145 and PANC-1 at 1, 10 and 100 µg.mL-1 . Immunomodulatory activity, was evaluated by sandwich ELISA of proinflammatory cytokines at BALB/c mice splenocytes cultures supernatant. Both extracts presented flavonoids, cinnamic derivatives, steroids and ellagic acid. PBO showed bacteriostatic activity against Acinetobacter baumannii (MIC = 250 µg.mL-1) clinical isolate and PBA fungistatic activity against Trichophyton rubrum (MIC = 800 µg.mL-1). The extracts did not exhibit toxicity to PBMCs and neoplastic cells (IC50 > 100 µg.mL-1). Additionally, PBO at 100 µg.mL-1 significantly inhibited IFN-γ and IL-17A cytokines (p = 0.03). Plectranthus barbatus is a potential candidate for therapeutic use due to its low toxicity in healthy human cells and exhibits biological activities of medical interest as bacteriostatic, fungistatic and immunomodulatory.

Plectranthus barbatus Andrews (Lamiaceae) é amplamente distribuída no mundo e com uma série de indicações terapêuticas populares. Este trabalho teve como objetivo avaliar a caracterização fitoquímica de dois extratos da folha de P. barbatus e seu potencial antimicrobiano, antineoplásico e imunomodulador. Após coleta, herborização e obtenção do extrato aquoso (PBA) e acetona: água 7: 3 (orgânico) (PBO) de P. barbatus, a caracterização fitoquímica foi realizada por cromatografia líquida de alta eficiência (CLAE). A atividade antimicrobiana foi realizada para determinar a concentração inibitória mínima (CIM) contra oito cepas bacterianas usando o teste de microdiluição e o fungo Trichophyton rubrum por ensaio de difusão em disco e teste de microdiluição. A citotoxicidade foi avaliada por métodos MTT e azul de tripan em células normais mononucleares do sangue periférico (CMSP) em concentrações variadas entre 0,1 a 100 µg.mL-1 e nas linhagens celulares neoplásicas Toledo, K562, DU-145 e PANC-1 em 1, 10 e 100 µg.mL-1 . A atividade imunomoduladora foi avaliada por ELISA sanduíche de citocinas pró-inflamatórias em sobrenadante de culturas de esplenócitos de camundongos BALB/c. Ambos os extratos apresentaram flavonoides, derivados cinâmicos, esteróides e ácido elágico. O PBO mostrou atividade bacteriostática contra Acinetobacter baumannii (CIM = 250 µg.mL-1) e atividade fungistática do PBA contra Trichophyton rubrum (CIM = 800 µg.mL-1). Os extratos não apresentaram toxicidade para CMSP e células neoplásicas (IC50 > 100 µg.mL-1). Além disso, o PBO a 100 µg.mL-1 inibiu significativamente as citocinas IFN-γ e IL-17A (p = 0,03). Plectranthus barbatus é um candidato potencial para uso terapêutico devido à sua baixa toxicidade em células humanas saudáveis e exibe atividade de interesse médico como bacteriostática, fungistática e imunomoduladora.

Evaluation of tissue repair using phytotherapeutic gel from Plectranthus neochilus, Schlechter (boldo-gambá) and Cnidoscolus quercifolius Pohl (favela) in Wistar rats / [Avaliação da reparação tecidual do gel fitoterápico de Plectranthus neochilus, Schlechter (Boldo-gambá) e Cnidoscolus quercifolius Pohl (Favela) em ratos Wistar]

The objective of this study was to investigate the effects of a gel formulation from the association of Plectranthus neochilus and Cnidoscolus quercifolius on tissue repair in cutaneous wounds in rats. A surgical wound was induced in 35 Wistar rats and treated according to group: G1 - commercial phytotherapeutic gel; G2 - Carbopol gel 1%; G3, 4, 5 - gel formulation from Boldo-gambá and Favela (FGBF) at 2.5%, 5%, and 10%, respectively. 1ml of the product was applied topically daily, for 14 days. Macroscopic evaluation of the wound showed inflammation, granulation, and epithelization in all groups. The FGBF 2.5% group showed greater angiogenic potential. There was a significant difference between the surgical area of the wounds treated with FGBF 2.5%, 5%, or 10% compared to the group with the commercial phytotherapeutic gel. On histomorphometry of the skin, there were reepithelization of the epidermis and superficial dermis, longitudinal collagen fibers, fibroblasts, and blood vessels, and in the deeper dermis, fibroblasts, transverse and longitudinal collagen fibers, blood vessels, and inflammatory cells. The 2.5% formulation had the greatest increase in fibroblast proliferation and most intense collagenization on day 14 of treatment.(AU)

Este trabalho objetivou investigar os efeitos de uma formulação em gel da associação da Plectranthus neochilus e da Cnidoscolus quercifolius no processo de reparação tecidual em feridas cutâneas de ratos. Foi induzida uma ferida cirúrgica em 35 ratos Wistar, sendo tratadas de acordo com os grupos: G1 - fitoterápico comercial; G2 - gel de carbopol 1%; G3, G4 e G5 - formulação gel boldo-gambá mais favela (FGBF) 2,5%, 5% e 10%, respectivamente. Aplicou-se 1mL do produto, via tópica, diariamente, durante 14 dias. Na avaliação macroscópica das feridas, verificou-se inflamação, granulação e epitelização em todos os grupos. O grupo FGBF 2,5% apresentou maior potencial angiogênico. Houve diferença significativa entre as áreas cirúrgicas das feridas tratadas com os FGBF 2,5%, 5% ou 10%, comparados ao grupo com o gel fitoterápico comercial. Na histomorfometria da pele, observou-se reepitelização da epiderme e da derme superficial, fibras colágenas longitudinais, fibroblastos e vasos sanguíneos e, na derme profunda, fibroblastos, fibras colágenas transversais e longitudinais, vasos sanguíneos e células inflamatórias. A formulação a 2,5% teve o maior aumento na proliferação de fibroblastos e mais intensa colagenização no dia 14 de tratamento.(AU)

Ethnobotany of Plectranthus neochilus Schltr (Meprobamate) in Cuba / Estudio etnobotánico de Plectranthus neochilus Schltr (Meprobamato) en Cuba

Chloroform extract (CE) and fractions obtained from Aldama arenaria roots were evaluated for their in vitro antiproliferative activity against 10 human tumor cell lines [leukemia (K-562), breast (MCF-7), ovary expressing a multidrug-resistant phenotype (NCI/ADR-RES), melanoma (UACC-62), lung (NCI-H460), prostate (PC-3), colon (HT29), ovary (OVCAR-3), glioma (U251), and kidney (786-0)]. CE presented weak to moderate antiproliferative activity (mean log GI50 1.07), whereas fractions 3 and 4, enriched with pimaranetype diterpenes [ent-pimara-8(14),15-dien-19-oic acid and ent-8(14),15-pimaradien-3ß-ol], presented moderate to potent activity for most cell lines, with mean log GI50 of 0.62 and 0.59, respectively. The results showed promising in vitro antiproliferative action of the samples obtained from A. arenaria, with the best results for NCI/ADR-RES, HT29, and OVCAR-3, and TGI values ranging from 5.95 to 28.71 µg.ml -1, demonstrating that compounds of this class may be potential prototypes for the discovery of new therapeutic agents.

El extracto de cloroformo (CE) y las fracciones obtenidas de las raíces de Aldama arenaria fueron evaluadas por su actividad antiproliferativa in vitro contra 10 líneas celulares tumorales humanas [leucemia (K-562), mama (MCF-7), ovario que expresa un fenotipo resistente a múltiples fármacos (NCI/ADR-RES), melanoma (UACC-62), pulmón (NCI-H460), próstata (PC-3), colon (HT29), ovario (OVCAR-3), glioma (U251) y riñón (786-0)]. CE presentó actividad antiproliferativa débil a moderada (log GI50 promedio de 1.07), mientras que las fracciones 3 y 4, enriquecidas con diterpenos de tipo pimarane [ent-pimara-8 (14), ácido 15-dien-19-oico y ent-8 (14), 15-pimaradien-3ß-ol], presentaron actividad moderada a potente para la mayoría de las líneas celulares, con un log GI50 promedio de 0.62 y 0.59, respectivamente. Los resultados mostraron una prometedora acción antiproliferativa in vitro de las muestras obtenidas de A. arenaria, con los mejores resultados para NCI/ADR-RES, HT29 y OVCAR-3, y valores de TGI que van desde 5.95 a 28.71 µg.ml -1, lo que demuestra que los compuestos de esta clase pueden ser prototipos potenciales para el descubrimiento de nuevos agentes terapéuticos.

Pretreatment of hepatetctomized rats with Coleus forskohlii did not interfere with the course of hepatic hyperplasia

Abstract Purpose Coleus forskohlii Briq., a medicinal plant originally from India, has been indicated against heart disease, expiratory disorders, convulsions, and hepatic changes, among others. In view of the broad pharmacological potential of the plant and the scarce information about its effects, the objective of the present study was to investigate the effect of its use for pretreatment of partially hepatectomized rats. Methods The animals were divided into two experimental groups: Control (CG) receiving physiological saline for 10 days before partial hepatetctomy, and Treated (TG) receiving 40 mg Coleus forskohlii/kg/day for 10 days before partial hepatectomy. The treatments were performed by gastric gavage. After the surgical procedure, treatment was continued according to the following groups: CG 24 h, CG 48 h, TG 24 h, and TG 48 hs, and liver tissue and intracardiac blood samples were obtained for histological and biochemical analysis, respectively. Results No significant differences were observed in mitotic or apoptotic index or in the concentrations of the enzymes AST, ALT and alkaline phosphatase, and no areas of fibrosis were detected. Conclusion Treatment with Coleus forskohlii did not interfere with the course of hepatic hyperplasia.

Seasonal effect in essential oil composition and antioxidant activity of Plectranthus amboinicus leaves / Efeito sazonal na composição e atividade antioxidante do óleo essencial de malvarisco (Plectranthus amboinicus)

In view of the increasing search for natural products with biological activities, such as essential oils are of high quality because of their therapeutic and economic importance and represent the second class of natural compounds with the largest number of active constituents and production through Plants minimizes the environment and sanitary impacts . The objective of the present work is to assess the seasonal effect on the composition and antioxidant activity of essential oil in leaves of Plectranthus amboinicus (Lour.) Spreng using hydro and steam distillation techniques. With regarding to the extraction methodology of essential oils from the P. amboinicus, the hydrodistillation technique is the most efficient in obtaining the volatile product with the best features for the determination of antioxidant activity. The analyses of the essential oil indicated a similarity in their composition, being observed the Carvacrol as major compound in almost all analysis, except in January 2015 using steam distillation extraction. Regarding antioxidant activity and seasonality, it was verified that in October 2014 obtained the best value of inhibitory concentration, with IC50 = 124.97 ppm. However, it was possible to obtain the essential oil from the P. amboinicus leaves through hydro and steam distillation methodologies, but also noted the seasonality influence on it's the context of antioxidant capacity.

Tendo em vista a crescente busca de produtos naturais com atividades biológicas, os óleos essenciais apresentam alta qualidade devido à sua importância terapêutica e econômica e representam a segunda classe de compostos naturais com o maior número de constituintes ativos com produção através das plantas, o que minimiza os impactos ao meio ambiente. O objetivo do presente trabalho foi avaliar o efeito sazonal na composição e na atividade antioxidante do óleo essencial presente nas folhas da Plectranthus amboinicus (Lour.) Spreng utilizando as técnicas de hidrodestilação e arraste a vapor d'água. No que se refere à metodologia de extração dos óleos essenciais do malvarisco, constatou-se que a técnica de hidrodestilação é a mais eficiente na obtenção do produto volátil com as melhores características para a determinação da atividade antioxidante. Quanto à sazonalidade, verificou-se que no mês de Outubro/2014 obteve-se o melhor valor da concentração inibitória com CI50=124,97 ppm. Este trabalho mostra que é a obtenção do óleo essencial das folhas do malvarisco, utilizando as metodologias de hidrodestilação e arraste a vapor de água, como também, constatar a influência da sazonalidade na determinação da capacidade antioxidante do mesmo.

Antibiotic activity of Plectranthus ornatus Codd, a Traditional Medicinal Plant

ABSTRACT The dichloromethane extract of Plectranthus ornatus Codd., a tradicional medicinal plant, showed antibiotic activity with minimum inhibitory concentration (MIC) values of 0.4 mg.mL-1 and 100 percent of biofilm inhibition against Staphylococcus aureus strains isolated from animals with mastitis infections. Based on these antibacterial activities, in addition to ethnopharmacological reports from healing men and farmers in Brazil, an herbal soap was produced from this active extract and was tested both in vitro and in vivo. In vivo assays conducted on these herbal soaps led to results similar to those previously conducted with the active extract. These results indicated the great potential of this plant for use as an excipient by preparing herbal antibacterial soaps as an alternative veterinary medicine aimed at controlling bovine mastitis infections on small Brazilian farms.

Parâmetros de qualidade físico-químicos e avaliação da atividade antioxidante de folhas de Plectranthus barbatus Andr. (Lamiaceae) submetidas a diferentes processos de secagem / Quality of the leaves of Plectranthus barbatus Andr. (Lamiaceae) dried in solar dryer and oven

RESUMO O presente trabalho descreve a composição físico-química, a avaliação da atividade antioxidante pelo método de sequestro de radicais livres DPPH, determinação de flavonoides e de fenóis totais dos extratos etanol, acetona e aquoso de Plectranthus barbatus Andr. (Lamiaceae), desidratadas em secador solar e em estufa de circulação de ar a 60 oC. Os valores de atividade de água encontrados para as duas secagens foram inferiores ao mínimo necessário para o crescimento e produção de toxina de patógenos de importância alimentar. Os resultados das análises físico-químicas demonstraram que ambos os processos mostraram-se eficientes na desidratação de P. barbatus. Os resultados demonstraram que os extratos acetona (estufa) e etanol (estufa e secador solar) foram os que apresentaram maior conteúdo de fenóis totais. O extrato etanólico (estufa) apresentou maior quantidade de flavonoides e melhor potencial antioxidante (IC50 = 75,71 ± 10,57 µg mL-1).

ABSTRACT This paper describes the physicochemical composition, the evaluation of the antioxidant activity by free DPPH radicals using the scavenging method, the determination of flavonoids and total phenolic compounds of ethanol, acetone and aqueous extracts of the medicinal plant Plectranthus barbatus Andr. (Lamiaceae), dehydrated in solar dryer and circulation oven at 60 °C. Water activity rates for two drying methods were below the minimum necessary for growth and toxin production of important food pathogens. Physicochemical results showed that both processes were effective in the dehydration of P. barbatus. The results demonstrated that the acetone (over) and ethanol (over and solar dryer) extracts showed the highest content of total phenols. The ethanol extract (over) showed the highest amount of flavonoids and better antioxidant activity (75.71 ± 10.57 µg L-1).

Indole acetic acid production by fluorescent Pseudomonas spp. from the rhizosphere of Plectranthus amboinicus (Lour.) Spreng. and their variation in extragenic repetitive DNA sequences.

Fluorescent Pseudomonas (FP) is a heterogenous group of growth promoting rhizobacteria that regulate plant growth by releasing secondary metabolic compounds viz., indole acetic acid (IAA), siderophores, ammonia and hydrogen cyanide. In the present study, IAA producing FPs from the rhizosphere of Plectranthus amboinicus were characterized morphologically, biochemically and at the molecular level. Molecular identification of the isolates were carried out using Pseudomonas specific primers. The effect of varying time (24, 48, 72 and 96 h), Trp concentrations (100, 200, 300, 400 and 500 µg.ml-1), temperature (10, 26, 37 and 50±2 °C) and pH (6, 7 and 8) on IAA production by 10 best isolates were studied. Results showed higher IAA production at 72 h incubation, at 300 µg.ml-1 Trp concentration, temperature 26±2 °C and pH 7. TLC with acidified ethyl acetate extract showed that the IAA produced has a similar Rf value to that of the standard IAA. Results of TLC were confirmed by HPLC analysis. Genetic diversity of the isolates was also studied using 40 RAPD and 4 Rep primers. Genetic diversity parameters such as dominance, Shannon index and Simpson index were calculated. Out of 40 RAPD primers tested, 9 (2 OP-D series and 7 OP-E series) were shortlisted for further analysis. Studies using RAPD, ERIC, BOX, REP and GTG5 primers revealed that isolates exhibit significant diversity in repetitive DNA sequences irrespective of the rhizosphere.

Proteção do dano oxidativo hepático induzido por ferro pelo extrato aquoso da planta Plectranthus barbatus / Protection against hepatic oxidative damage induced by iron by the aqueous extract of Plectranthus barbatus

Plectranthus barbatus Andrews (Lamiaceae) é uma planta muita utilizada na medicina popular para o tratamento de doenças gastrointestinais e hepáticas. O objetivo do presente trabalho foi estudar o efeito protetor do extrato aquoso de P. barbatus (EAPB) sobre os danos hepáticos causados pela sobrecarga de ferro provocada pelo ferro-dextran em ratos. O tratamento com ferro-dextran induziu uma redução significativa na concentração de glutationa reduzida nos animais tratados em relação ao grupo controle e o tratamento prévio dos animais com o EAPB protegeu o fígado do efeito provocado pelo ferro neste parâmetro. Com relação à lipoperoxidação, houve aumento significativo na concentração de malondialdeído (MDA) nos animais tratados em relação ao controle, entretanto, quando os animais receberam o tratamento prévio com o EAPB, houve redução significativa na concentração do MDA. A análise histopatológica mostrou que o grupo tratado com ferro-dextran apresentou grânulos de ferro no citoplasma das células de Kupffer com alargamento das mesmas e algumas com os núcleos hipertróficos. O tratamento prévio com EAPB resultou no desaparecimento dos sinais de danos às células de Kupffer sem nenhum núcleo hipertrófico, mas com a presença de grânulos de ferro totalmente fagocitados, o que demonstra uma aparência morfológica normal. Portanto, o EAPB pode ser útil na prevenção de danos hepáticos induzidos por sobrecarga de ferro.

The Plectranthus barbatus Andrews (Lamiaceae) is a plant largely used in folk medicine to treat gastrointestinal and liver diseases. The objective of this work was to study the protective effect of the aqueous extract of P. barbatus (EAPB) against damage caused by iron overload induced by iron dextran in rat liver. Treatment with iron-dextran induced a significant reduction in the glutathione levels in treated animals compared to control group, and the pretreatment of animals with EAPB protected the liver from the effects caused by iron in this parameter. With respect to lipid peroxidation, a significant increase in the malondialdehyde (MDA) levels in treated animals compared to control was observed; however, when the animals were pretreated with EAPB, there was a significant reduction in the MDA levels. Histopathological analysis showed that the group treated with iron-dextran showed iron granules in the cytoplasm of the Kupffer cells and some of them presented enlarged nuclei. The group previously treated with EAPB showed the disappearance of the signs of damage to the Kupffer cells with no nucleus hypertrophy but with the presence of iron granules completely phagocytosed by these cells, which showed a normal morphological appearance. Therefore, the EAPB may be useful in the prevention of liver damage induced by iron overload.

Chemical composition and antimicrobial activity of the essential oil of Plectranthus mollis (Lamiaceae) from Western Ghats region, Karnataka, India / Composición química y actividad antimicrobiana del aceite esencial de Plectranthus mollis (Lamiaceae) de la región de los Ghats occidentales, Karnataka, India

Plectranthus is a large and widespread genus with a diversity of ethnobotanical uses. In traditional medicine P. mollis has been used against snakebites, respiratory stimulant and vasoconstrictor, cardiac depressant, cure for haemorrahage, treatment of mental retardation and rheumatism. P. mollis is reported to exhibit relaxant activity on smooth and skeletal muscles, and has cytotoxic and anti-tumour promoting activity, and can be used in the treatment of cancer. The aim of the present study was to identify chemical composition of the essential oil of P. mollis and to evaluate antimicrobial efficacy of the oil. The essential oil of the flowering aerial parts of P. mollis as obtained by hydro-distillation and analyzed by gas chromatography equipped with a flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS). Twentyseven compounds were identified, which comprised 98.6% of the total constituents. The main compound was identified as fenchone (32.3%), followed by α-humulene (17.3%), piperitenone oxide (8.5%), cis-piperitone oxide (6.0%) and E-β-farnesene (5.9%). The oil was found rich in oxygenated monoterpenes type constituents (52.0%), followed by sesquiterpene hydrocarbons (40.2%), oxygenated sesquiterpenes (4.9%), and monoterpene hydrocarbons (1.5%). Antimicrobial activity of the essential oil of P. mollis was tested against six Gram-positive and eight Gram negative bacteria, and three fungi, by using the tube dilution method. The oil was active against the tested Gram-positive and Gram-negative bacteria, and fungi at a concentration range of 0.065±0.008-0.937±0.139mg/mL, 0.468±0.069-3.333±0.527 mg/mL and 0.117±0.0170.338±0.062mg/mL respectively. The present study revealed that the oil constituents somehow were qualitatively similar and quantitatively different than earlier reports from different parts of the world. The essential oil of P. mollis has found to be antimicrobial activity which can be usefulness in the treatment of various infectious diseases caused by bacteria and fungi.

Plectranthus es un género grande y extenso con una diversidad de usos etnobotánicos. En la medicina tradicional P.mollis se ha utilizado contra las mordeduras de serpiente, como estimulante respiratorio y vasoconstrictor, depresor cardiaco, cura para hemorragias, tratamiento del retraso mental y el reumatismo. Se informó que P. mollis presenta actividad relajante sobre los músculos lisos y esqueléticos, y tiene actividad promotora citotóxica y anti - tumoral, además puede ser utilizado en el tratamiento del cáncer. El objetivo del presente estudio fue identificar la composición química del aceite esencial de P. mollis para evaluar la eficacia antimicrobiana del aceite. El aceite esencial de las partes aéreas de las flores de P. mollis se obtuvo por hidro - destilación y se analizó por cromatografía de gases equipado con un detector de ionización de llama (GC-FID), y cromatografía de gases acoplada a espectrometría de masas (GC/MS). Se identificaron veintisiete compuestos, que comprenden el 98.6% de los constituyentes totales. El compuesto principal se identificó como fencona (32.3%), seguido de α-humuleno (17.3%), óxido de piperitenona (8.5 %), óxido de cis piperitona (6.0 %) y E-β-farneseno (5.9%). Se encontró que el aceite es rico en monoterpenos oxigenados de tipo constituyentes (52.0%), seguido de hidrocarburos de sesquiterpeno (40.2%), sesquiterpenos oxigenados (4.9%), e hidrocarburos monoterpenos (1.5 %). La actividad antimicrobiana del aceite esencial de P.mollis se ensayó frente a seis bacterias Gram-negativas y ocho Gram-positivas, y tres hongos, utilizando el método de dilución en tubo. El aceite fue activo contra las bacterias Gram-positivas y Gram-negativas y hongos ensayados, en un intervalo de concentración de 0.065±0.008 a 0.937±0.139mg/ml, 0.468±0.069 a 3.333±0.527mg/ml y 0.117±0.017 a 0.338±0.062mg/ml, respectivamente. El presente estudio reveló que los constituyentes del aceite de alguna manera fueron cualitativamente similares y cuantitativamente diferentes de los informes anteriores de diferentes partes del mundo. Se encontró que la actividad antimicrobiana del aceite esencial de P. mollis puede ser de utilidad en el tratamiento de diversas enfermedades infecciosas causadas por bacterias y hongos.

Crescimento e tolerância à salinidade em três espécies medicinais do gênero Plectranthus expostas a diferentes níveis de radiação / Growth and salinity tolerance in three medicinal species of the genus Plectranthus exposed to different levels of solar radiation

No cultivo de plantas medicinais as condições de salinidade e de luz podem exercer influência no rendimento e na qualidade final da produção de biomassa. O objetivo deste trabalho foi avaliar o efeito de diferentes luminosidades e níveis de salinidade na água de irrigação sobre o crescimento e tolerância de três espécies de plantas do gênero Plectranthus. O ensaio foi conduzido em parcelas subsubdivididas com cinco repetições, sendo as parcelas referente ao fator ambiente (pleno sol e telado), as subparcelas aos níveis de salinidade na água de irrigação - CEa (0,7; 1,9; 3,1; 4,3 e 5,5 dS m-1), e as subsubparcelas às três espécies do gênero Plectranthus (P. amboinicus, P. barbatus e P. grandis). As variáveis de resposta foram: índice relativo de clorofila (IRC), área foliar (AF), razão de área foliar (RAF), área foliar específica (AFE), matéria seca da parte aérea (MSPA), matéria seca das raízes (MSR), matéria seca total (MST), relação MSR/MSPA, grau de tolerância à salinidade, e teor dos íons Na+ e K+. O estresse salino reduziu o crescimento das plantas, sendo as maiores reduções observadas nas plantas expostas a pleno sol. A salinidade influenciou a partição de matéria seca, sendo as raízes mais afetadas do que a parte aérea. Com o aumento da CEa houve aumento expressivo no teor foliar de Na+, enquanto o teor de K+ e o IRC foram reduzidos. Entretanto, o acúmulo de Na+ foi menor em P. grandis. Considerando-se a MST, verificou-se que as três espécies se mostraram moderadamente tolerantes à salinidade de até 3,1 dS m-1, exceto P. grandis cultivada em telado, classificada como tolerante. Em relação ao grau de redução na produção MSPA (parte de interesse comercial), poderia se recomendar o cultivo de P. grandis quando a água de irrigação contiver CEa de até 3,1 dS m-1.

In the cultivation of medicinal plants, salinity and light can affect the yield and quality of biomass. The objective of this study was to evaluate the effect of light and salinity levels of the irrigation water on the growth and salt tolerance of three medicinal plant species of the genus Plectranthus. A completely randomized split-plot design with five repetitions was used. The plots were formed by the environment of cultivation (full sunlight and greenhouse), the subplots by the salinity in the irrigation water - ECw (0.7, 1.9, 3.1, 4.3 and 5.5 dS m-1), and the subsubplots by the three plant species (P. amboinicus, P. barbatus and P. grandis). The following variables were evaluated: relative chlorophyll index (RCI), leaf area (LA), leaf area ratio (LAR), specific leaf area (SLA), shoot dry mass (SDM), root dry mass (RDM), total dry mass (TDM), RDM/SDM ratio, relative salt tolerance, and concentration of Na+ and K+ in leaves. Salinity reduced plant growth, with the greatest reductions observed in plants exposed to full sunlight. Salinity affected the dry matter partitioning, and the roots were more affected than the shoot. With increasing ECw, there was a significant increase in the concentration of Na+ in the leaves, while K+ and RCI decreased. However, the increase in Na+ accumulation was lower in P grandis. The three species were moderately tolerant to salinity up to 3.1 dS m-1, considering the total dry mass production, except the P. grandis grown in greenhouse, classified as tolerant. Regarding the relative reduction in shoot dry mass (part of commercial interest), we could recommend the cultivation of P. grandis when the available irrigation water presents values of ECw up to 3.1 dS m-1.

Variação sazonal na alelopatia de extratos aquosos de Coleus barbatus (A. ) Benth. sobre a germinação e o desenvolvimento de Lactuca sativa L. / Seasonal variation in the allelopathy of aqueous extracts from Coleus barbatus (A. ) Benth. on the germination and development of Lactuca sativa L.

O objetivo deste trabalho foi avaliar o efeito alelopático de extratos de Coleus barbatus sobre a germinação e desenvolvimento de plântulas de alface. Os experimentos foram conduzidos em laboratório, em diferentes concentrações de extratos obtidos de folhas de falso-boldo (0; 7,5; 15; 22,5; 30%), coletadas nas quatro estações do ano, obtidos por trituração, maceração, infusão e decocção. As sementes de alface foram distribuídas sobre placas de petri umidecidas com 10 mL de solução. Os resultados mostraram que os extratos de folhas afetaram a germinabilidade de sementes de alface apenas na concentração de 30% do extrato preparado por decocção de folhas coletadas no inverno. O índice de velocidade de germinação apresentou redução significativa nos extratos triturados preparados no outono e inverno; na maceração de folhas coletadas no verão e outono e no extrato de decocção preparado no inverno. Os extratos estimularam o crescimento da parte aérea das plântulas de alface, ao passo que, o comprimento das raízes foi afetado pelos extratos, ora inibindo, ora estimulando o crescimento das mesmas. Os extratos de folhas de falso-boldo coletadas nas quatro estações do ano apresentaram efeito alelopático sobre a germinação e o desenvolvimento da alface, sendo que estes variaram em função da sazonalidade da coleta, da forma de obtenção dos extratos e das concentrações testadas.

The aim of this study was to evaluate the allelopathic effects of extracts from Coleus barbatus on germination and seedling growth of lettuce. The experiments were conducted in the laboratory using different concentrations (0, 7.5, 15, 22.5, 30%) of aqueous extracts from "falso-boldo" leaves harvested in all four seasons; extracts were obtained by grinding, maceration, infusion and decoction. Seeds were distributed on Petri dishes moistened with 10 mL solution. Results showed that the leaf extracts affected the germination of lettuce seeds only at the concentration of 30% extract prepared by decoction of leaves harvested in the winter. Germination speed index showed significant reduction for ground extracts prepared in the fall and winter, as well as for macerated leaves harvested in the summer and fall and for extracts prepared through decoction in the winter. The extracts stimulated the growth of shoots of lettuce seedlings, whereas root length was affected by the extracts, which either stimulated or inhibited its growth. Extracts of "falso-boldo" leaves harvested in all four seasons had allelopathic effect on germination and development of lettuce, and the latter varied depending on the harvest season, the form of preparing the extracts and the tested concentrations.

Composição do óleo essencial de quatro espécies do gênero Plectranthus / Essential oil composition of four Plectranthus species

O gênero Plectranthus é considerado um dos mais ricos em óleos essenciais dentro da família Lamiaceae, compreendendo muitas espécies com propriedades medicinais. Algumas destas são conhecidas popularmente como boldo, as quais possuem semelhanças taxonômicas e diversas sinonímias, possuindo ações anti-dispépticas, analgésicas e digestivas. O objetivo deste estudo foi avaliar quantitativa e qualitativamente os óleos essenciais presentes nas folhas das espécies P. amboinicus, P. barbatus, P. grandis e P. neochilus. A extração do óleo foi realizada por hidrodestilação, utilizando pentano como solvente extrator, repetida por três vezes para cada uma das espécies. A análise dos componentes dos óleos essenciais das quatro espécies de Plectranthus, através da CG/EM, permitiu identificar 14 componentes químicos, sendo a maioria sesquiterpenos. O trans-cariofileno se apresentou em elevada concentração nos óleos estudados. Alguns componentes químicos demonstraram ser específicos para cada espécie e outros apresentaram ocorrência comum a todas as quatro, possibilitando a diferenciação das mesmas em dois grupos, um formado por P. amboinicus e P. neochilus e o outro por P. grandis e P. barbatus. Conclui-se que as quatro espécies de boldo apresentam diferenças significativas quanto ao teor e à constituição química do óleo essencial.

Plectranthus has been considered one of the richest genera in essential oils within the Lamiaceae family, which includes several species with medicinal properties. Some of them are commonly known as boldo and present taxonomic similarities and several synonymies, with antidyspeptic, analgesic and digestive actions. The aim of this study was to evaluate quantitatively and qualitatively the essential oils from P. amboinicus, P. barbatus, P. grandis and P. neochilus leaves. The oil was extracted by hydrodistillation using pentane as extracting solvent and was repeated three times for each species. The analysis of essential oil components by GC/MS in the four Plectranthus species identified 14 chemical components, mostly sesquiterpenes. High concentration of trans-caryophyllene was found in the studied oils. Some chemical components were specific for each species and other components had common occurrence in all four species, allowing their differentiation into two groups, one composed of P. amboinicus and P. neochilus and another one by P. grandis and P. barbatus. In conclusion, the four boldo species had significant differences as to essential oil yield and chemical composition.

Constituintes voláteis de Mentha pulegium L. e Plectranthus amboinicus (Lour.) Spreng / Volatile constituents of Mentha pulegium L. and Plectranthus amboinicus (Lour.) Spreng

Nesse trabalho foi investigado a composição química de óleos essenciais de duas plantas medicinais cultivadas em Ilhéus, Brasil, Plectranthus amboinicus (Lour.) Spreng. (hortelã-grosso) e Mentha pulegium L. (poejo). Os óleos essenciais foram extraídos das folhas frescas por hidrodestilação e foram analisados por CG/FID e CG-EM, na primavera e no inverno. P. amboinicus forneceu, tanto na primavera como no inverno, 0,10 por cento de óleo sendo timol o componente majoritário. M. pulegium forneceu na primavera 0,20 por cento de óleo e no inverno 0,09 por cento. Os componentes majoritários dos óleos foram pulegona e trans-cariofileno; borneol, mentol e piperitona foram identificados em menores quantidades. No inverno foram observados maiores quantidades de mentol e isomentol. Acetatos de neoisomentila, de mentila e de isometila foram observados somente no inverno. Esse trabalho contribui para o conhecimento das espécies vegetais cultivadas na região do sul da Bahia.

This work investigated the chemical composition of the essential oils of two medicinal plants grown in Ilhéus Municipality, Bahia State, Brazil: Plectranthus amboinicus (Lour.) Spreng (Mexican mint) and Mentha pulegium L. (pennyroyal). The essential oils were extracted from fresh leaves by hydrodistillation and analyzed by GC-FID and GC-MS, in the spring and in the winter. In both seasons, P. amboinicus yielded 0.10 percent oil and had thymol as major component. M. pulegium yielded 0.20 percent and 0.09 percent oil in the spring and winter, respectively. The major components were pulegone and trans-caryophyllene, whereas borneol, menthol and piperitone were identified at small quantities. Higher menthol and isomenthol levels were detected in the winter. In addition, neoisomenthyl, menthyl and isomenthyl acetates were only observed in the winter. This work contributes to the knowledge of plant species grown in southern Bahia.

Métodos de secagem e rendimento dos extratos de folhas de Plectranthus barbatus (boldo-da-terra) e P. ornatus (boldo-miúdo) / Methods estimated drying and percentage of extracts in leaves of Plectranthus barbatus (Brazilian bold) and P. ornatus (false bold)

Plectranthus sp. pertence à família Lamiaceae e inclui cerca de 300 espécies. Duas delas, P. barbatus (PB) e P. ornatus (PO) destacam-se pelo interesse medicinal. As principais substâncias encontradas em Plectranthus sp. são os diterpenóides, óleos essenciais e compostos fenólicos. A melhor forma de utilizar as folhas de PB e PO é a fresco; porém, na comercialização há necessidade de recorrer a processos de secagem. Entretanto, isto pode interferir no princípio ativo, desta forma, estudos para determinar o melhor método gravimétrico são importantes. O objetivo deste estudo foi avaliar qual o melhor método de secagem, onde haja maior perda de água possível, e calcular os rendimentos dos extratos visando avaliar se o método gravimétrico interfere na quantidade de extrato produzido. Desta forma, utilizou-se quatro métodos de secagem e após evaporação do solvente, fez-se o cálculo do rendimento dos extratos secos. O percentual de água foi superior em PB e PO (média geral de 90,12±8,22 por cento). Dentre as secagens, em estufa de ventilação forçada (EVF) foi mais eficiente em PB (88,87 por cento) e em estufa convencional (ECO) foi melhor em PO (95,13 por cento). O maior rendimento do extrato seco em PB foi na secagem em camada delgada (CD) (20,96 por cento), enquanto que em PO foi ECO (41,34 por cento). Não houve correlação entre o método de secagem e o rendimento de extrato obtido.

Plectranthus sp. belongs to the family Lamiaceae and includes about 300 species. Two of them, P. barbatus (PB) and P. ornatus (PO), have medicinal interest. The main substances found in Plectranthus sp. are the diterpenoids, essential oils and phenolic compounds. The best way to use the leaves of PB and PO is cool; but for marketing there is a need of resort to drying processes. However, this may interfere on the values of active principle; thus, studies to determine the best gravimetric methods are important. The objective of this study was to evaluate the best method of drying, where there the greater loss of water possible, and calculate the percentage of the extracts to assess whether the gravimetric method interferes with the amount of extract produced. To this was done by drying four different methods ventilated dry (EVF), conventional drying (ECO), microwave (MCO) and layer thing (CD) and after evaporation of the solvent, was made the calculation the percentage of the dried extract. The water content was higher in PB and PO (overall average of 90.12±8.22 percent). Among the drying, EVF was more efficient for PB (88.87 percent) and ECO was better for PO (95.13 percent). The highest content of dry extract was for PB in to CD (20.96 percent), whereas for PO was in to ECO (41.34 percent). There is no relationship between the drying method and in the quantity of extract obtained.

Actividad expectorante de formulaciones a partir de plectranthus amboinicus (lour) spreng (orégano francés) / Expectorant activity of formulations from plectrantus amboinicus (lour) spreng (french oregano)

La administración de extracto acuoso y extracto fluido, así como de los jarabes obtenidos de los extractos, produjeron incrementos significativos de la concentración de rojo fenol en la secreción traqueobronquial de ratón. Tanto el extracto acuoso como el hidroalcohólico presentan actividad expectorante; el jarabe preparado con extracto acuoso fue efectivo a dosis de 50 mL/kg, con una dosis efectiva media de 41,91 mL/kg; el jarabe preparado con extracto fluido fue efectivo a dosis de 50 y 37,5 mL/kg, con dosis efectiva media de 34,64 mL/kg; y las tabletas de 100 mg ejercieron efecto expectorante a las dosis de 34 y 68 mg/kg. A su vez la administración aguda de tabletas de 100 mg ejerció un efecto expectorante, similar al de la bromhexina y el salbutamol...

Administration of aqueous extract and of fluid extract as well as the syrups produced from the extracts resulted in significant increase of red phenol concentration in the tracheobronchial secretion of mice. Both the aqueous and the hydroalcohol extracts have expectorant activity; the aqueous extract-made syrup was effective at 50 mL/kg dose, with an effective mean dose of 41,91 ml/kg; fluid extract-made syrup was effective at 50 and 37,5 mL/kg, being 34,64 mL/kg the effective mean dose and finally 100 mg tablets showed their expectorant action at doses of 34 and 68 mg/kg. In turn, the acute administration of 100mg tablets had the same expectorant effect as bromhexine and salbutamol...

In vivo antimalarial activity of leaves of Plectranthus amboinicus (lour) spreng on Plasmodium berghei yoelii.

An invivo study of aqueous extract of the leaves of Plectranthus amboinicus on Plasmodium berghei yoelii was conducted on laboratory infected albino mice and compared with standard drug chloroquine. Reduction of parasitemia at 250 mg/kg and 500 mg/kg of aqueous extract for 24 hrs, 48 hrs, 72 hrs and 96 hrs were determined. The reduction of parasitemia after 96 hrs was 100%, 67.9% and 76.2% for standard, 250 mg/kg and 500 mg/kg of aqueous extract respectively. The isolation of active principle responsible for the reduction of parasitemia may give a promising drug molecule.