Stability of hydroalcoholic extracts of two species of guaco; Mikania glomerata SPRENG. and Mikania laevigata SCHULTZ. (Asteraceae), by UHPLC-MS

It is important to study the stability of plant extracts used as active ingredients in phytotherapic medicine, as degradation of the active principles directly affects the efficacy and safety of these products. Therefore, a stability study of the hydroalcoholic extract of the species: Mikania glomerata and Mikania laevigata was conducted in order to determine the speed of degradation and shelf life of these extracts, which are incorporated in cough syrup in Brazil. Leaves of both species were dried in an oven or by lyophilization (freeze-dried). Hydroalcoholic extracts underwent both accelerated stability study of six months and long-term stability study for 12 months. Samples were stored at different temperatures and every three months were analysed by ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) to monitor their chemical profile, quantifying coumarin and chlorogenic acid. For all conditions of the study, a reduction of the content of the chemical marker of this species, coumarin, greater than 5% was observed, so a shelf life of two years cannot be assigned to the hydroalcoholic extracts of these species as observed in commercial extracts.

Evaluation of genotoxicity and coumarin production in conventional and organic cultivation systems of Mikania glomerata Spreng.

Mikania glomerata Sprengel, popularly known as "guaco," is used in Brazilian folk medicine for several inflammatory and allergic conditions. Besides, the popular use "guaco" is indicated by the Brazilian Ministry of Health as a safe and effective herbal medicine. The biological activity of M. glomerata extracts is due to the presence of the coumarins, a large family of phenolic substances found in plants and is made of fused benzene and α-pyrone rings. Considering that there are few data on the biological effects of the extracts of M. glomerata, mainly in genetic level, this work aims to evaluate, in vitro, the genotoxicity and coumarin production in M. glomerata in conventional and organic growing. The data showed that the organic culture system showed double the concentration of coumarin being significantly more productive than the conventional system. Besides, the results of comet assay suggest that extracts of M. glomerata cultivated in a conventional system was genotoxic, increased DNA damage levels while the organic extracts seem to have antigenotoxic effect possibly due to the concentration of coumarins. Additional biochemical investigations are necessary to elucidate the mechanisms of action of M. glomerata extracts, which were found to have a role in protection against DNA damage.

Influence of environmental factors on the volatile composition of two Brazilian medicinal plants: Mikania laevigata and Mikania glomerata.

INTRODUCTION: Mikania laevigata Sch.Bip. ex Baker and Mikania glomerata Spreng. are medicinal plants popularly known as guaco, used for inflammatory diseases of the respiratory system, included in pharmaceutical formularies and often used without distinction. However, several studies show that the chemical composition varies between these species, as well as in plants are subjected to different environmental stresses. Few studies have been carried out with the volatile compounds of guaco, even less about the changes in volatile composition due to abiotic variation. OBJECTIVE: The aim of this work was to evaluate how volatile compounds vary according to the seasons and at different times of the day and if these compounds are influenced by the variations in the growth conditions such as: temperature, luminosity and water. METHODS: The headspace volatiles of the leaves were sampled by solid phase micro extraction and analyzed by gas chromatography-mass spectrometry. Untargeted metabolomic analysis of the resulting chromatograms and chemometrics was applied. The chemical profile of the volatiles of M. laevigata and M. glomerata were different; being clearly separated in the exploratory grouping analyzes (PCA), followed by analysis of variance of the marker compounds of both species. RESULTS: Only M. laevigata contained coumarin, considered to be the chemical marker of both species and to be responsible for the therapeutic activities. There was no significant difference between the morning and afternoon collections of either species. Coumarin, α-pinene and bicyclogermacrene were more intense in the volatiles of M. laevigata throughout the year and responsible for grouping the samples of this species. For M. glomerata, hexanal and 2-hexenal were responsible for grouping the samples and were more intense in all months. The growth conditions tested affected the intensity of specific compounds in the chromatograms. Some compounds were less intense with the increase of the temperature and in the plants subjected to full sunlight. However, certain volatile compounds-such as pinenes-were more intense in plants suffering drought. CONCLUSION: The variation in composition between species of guaco was greater than those observed in the seasonal and cultivation studies, indicating that these species cannot be used indistinctly.

Radiation levels of UV-A and UV-B on growth parameters and coumarin content in guaco / Níveis de radiação UVA e UVB sobre parâmetros de crescimento e conteúdo de cumarina em guaco

ABSTRACT: Guaco is a medicinal plant species containing coumarin, a secondary metabolite whose concentration is influenced by various factors, such as the level of exposure to UVA (315-400 nm) and UVB (280-315 nm) radiation, age of the plant, and position of the storage organ in the plant. This study aimed to assess the effect of different blocking levels of UVA and UVB radiation on growth parameters and coumarin content of two guaco accessions. Treatments did not affect any of the growth parameters assessed, except leaf area. Coumarin content was higher in leaves collected from the upper canopy and with unblocked exposure to UVA and UVB.

RESUMO: Guaco é uma espécie medicinal que apresenta em sua composição a cumarina, um metabólito secundário cuja concentração no vegetal é influenciada por fatores como os níveis de radiação UV-A (315-400 nm) e UV-B (280-315 nm) incidentes, bem como pela idade e posição do órgão de armazenamento na planta. O objetivo deste estudo foi o de avaliar o efeito de diferentes níveis de bloqueio das radiações UV-A e UV-B sobre parâmetros de crescimento e teor de cumarina em dois acessos de guaco. Os tratamentos não apresentaram efeito sobre os parâmetros de crescimento avaliados, com exceção dos valores de área foliar. Em relação aos teores de cumarina, estes foram superiores nas folhas coletadas do dossel superior, bem como no tratamento sem bloqueio das radiações UV-A e UV-B incidentes.

Mikania glomerata Sprengel extract and its major compound ent-kaurenoic acid display activity against bacteria present in endodontic infections.

The search for new, effective and safe antimicrobial compounds from plant sources has continued to play an important role in the maintenance of human health since ancient times. Such compounds can be used to help to eradicate microorganisms from the root canal system, preventing/healing periapical diseases. Mikania glomerata (Spreng.), commonly known as "guaco," is a native climbing plant from Brazil that displays a wide range of pharmacological properties. Many of its activities have been attributed to its phytochemical composition, which is mainly composed of diterpenes, such as ent-kaurenoic acid (KA). The present study evaluated the potential activity of an ent-kaurenoic-rich (KA) extract from Mikania glomerata (i.e. Mikania glomerata extract/MGE) and its major compound KA against bacteria that can cause endodontic infections. Time-kill assays were conducted and the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), anti-biofilm activity, and synergistic antimicrobial activity of MGE and KA were determined. The MGE exhibited MIC and MBC values, which ranged from 6.25 to 100 µg/mL and 12.5 to 200 µg/mL respectively. The MIC and MBC results obtained for the KA, ranged from 3.12 to 100 µg/mL and 3.12 to 200 µg/mL respectively. Time-kill and anti-biofilm activity assays conducted for KA at concentrations between 3.12 and 12.5 µg/mL exhibited bactericidal activity between 6 and 72 h of incubation and 50% inhibition of biofilm formation for Porphyromonas gingivalis (clinical isolate), Propionibacterium acnes (ATCC 6919), Prevotella nigrescens (ATCC 33563), P. melaninogenica (ATCC 25845), Aggregatibacter actinomycetemcomitans (ATCC 43717). For synergistic antimicrobial activity, KA combined with chlorhexidine dichlorohydrate (CHD) had an additive effect with increased efficacy against P. gingivalis (clinical isolate) compared to CHD alone. It was concluded that M. glomerata extract and its major compound ent-kaurenoic acid (KA) showed in vitro antibacterial activity, the latter being a potential biofilm inhibitory agent. They may play important roles in the search for novel sources of agents that can act against bacteria present in endodontic infections.

ent-Kaurenoic acid-rich extract from Mikania glomerata: In vitro activity against bacteria responsible for dental caries.

Many studies have reported that medicinal plant extracts can inhibit oral pathogen growth or adhesion to surfaces and therefore reduce dental caries formation. The addition of these extracts to oral products like mouthwashes and dentifrices is considered an important strategy in caries control. In this sense, we have developed a Mikania glomerata extract with high ent-kaurenoic acid content (KAMg). So, this work describes the preparation of such extract and the development of a validated HPLC-DAD method to determine its ent-kaurenoic acid (KA) content. Herein it is also described the KAMg in vitro antibacterial evaluation against several cariogenic bacteria in comparison with KA and the investigation of further aspects of the KAMg activity. Toxicological aspects of the developed extract were evaluated by assessing its cytotoxicity and genotoxicity. KA and a KA-rich extract like KAMg showed to inhibit the growth of microorganisms responsible for dental caries at relatively low MIC (Minimum inhibitory concentration) values, albeit not as low as the MIC value obtained for chlorhexidine digluconate (CHD), the golden anticariogenic standard approved by the American Dental Association Council on Dental Therapeutics. However, KAMg was more effective to inhibit the formation of a Streptococcus mutans biofilm with four times lower MICB50 (minimum inhibitory concentration that reduces 50% of the biofilm) value as compared with CHD. Taking into account all these data and considering the absence of genotoxic and cytotoxic activity under the tested conditions, it is suggested that KAMg is a natural product to be considered as active ingredient in oral care products.

Toxic effects of the administration of Mikania glomerata Sprengel during the gestational period of hypertensive rats.

Herbal medicine is an ancient practice that has been gaining acceptance of the medical class through scientific studies that prove its effectiveness. However, its use should still be cautious. Medicinal plants have potential toxic effects not yet discovered, and may have unproven interactions with other medications. The use of drugs during pregnancy is still very dangerous and vigorously studied; however, there are few studies of herbal medicines in pregnant women. Existing studies prioritize on teratogenic or abortifacient effects. The aim of this study was to analyze the toxic effects of Mikania glomerata Sprengel administration, popularly known as "guaco" during the gestational period of hypertensive rats. For this experimental groups consisting of pregnant Wistar rats received treatments with guaco extract (1 to 2 mL). In order to analyze the possible toxic effects of guaco during pregnancy, weight gain of rats was assessed during pregnancy; reproductive performance of rats, morphological parameters, and fetal placental histology were compared. Although some parameters presented significant differences, we can conclude that changes prioritized by literature, such as toxicity, vasodilation and hypotension, have not been caused by guaco. The only fetal changes observed were due to the maternal hypertension. Some studies have reported vasodilator and hypotensive effects of guaco. However, only a few studies exist, and its actual effects remain unknown. Specific studies should be developed with higher doses of guaco for a definitive conclusion of its toxic and non-toxic effects.

Fitoterápicos na Rede Pública de Saúde (SUS) no Brasil: Um estudo toxicológico de Mikania glomerata em fetos de ratas Wistar / Herbal Medicines in the Brazilian Public Health System (SUS): A toxicological study of Mikania glomerata in Wistar rat fetuses

Embora seja notável o avanço no uso popular de plantas com finalidade terapêutica, estudos são necessários para demonstrar seus potenciais tóxicos, já que grande parte dos usuários de fitoterápicos os considera inócuos. Durante a gestação, a maioria das alterações no feto é decorrente da exposição da mãe a agentes químicos, podendo ocorrer efeitos abortivos, teratogênicos e citotóxicos. A relevância deste trabalho se deve a escassez de estudos sobre os efeitos tóxicos do extrato de Mikania glomerata, popularmente conhecida como guaco, durante o período gestacional. Foram estudadas ratas Wistar prenhes (normotensas e espontaneamente hipertensas) sob tratamento com extrato seco de M. glomerata (2mL) e avaliada a morfologia do fígado dos fetos. Todos os grupos apresentaram fetos vivos sem alterações macroscópicas, perda pré-implantação e reabsorção fetal normal. Não houve alterações anatômicas nos fígados, apenas presença de monócitos e linfócitos nas veias-centrolobulares. Conclui-se que o extrato, na concentração e formulação estudadas, não apresentou toxicidade aos fetos.(AU)

Although remarkable advances in the use of herbal medicine were observed, studies are needed to demonstrate the toxic potential of their compounds, since most of their users consider them effective and safe. During pregnancy, most of the abnormal changes in the fetus is mainly due to the mother's exposure to chemicals, resulting in abortion or teratogenic and cytotoxic effects to the mother and neonate. The relevance of this research is due to the lack of studies on the toxic effects of Mikania glomerata. popularly known as "guaco" - extract administration during the gestational period. Experimental groups of normotensive and spontaneously hypertensive pregnant Wistar rats were studied. The animals were treated with M. glomerata extract (2 ml) and the morphology of fetal liver was evaluated to evaluate the possible toxic effects of M. glomerata to fetuses. In all groups the live fetuses were without macroscopic changes and the pre-implantation loss or normal fetal reabsorption were physiologically normal (data not shown). There were no anatomical or histological changes in the livers of fetuses studied, which showed centrilobular veins with the presence of monocytes and lymphocytes. The results lead the conclusion that M. glomerata extract, at the tested concentration, did not show toxicity to rats' fetuses.(AU)

UHPLC–MS quantification of coumarin and chlorogenic acid in extracts of the medicinal plants known as guaco (Mikania glomerata and Mikania laevigata)

Abstract In Brazil, Mikania glomerata Spreng. and M. laevigata Sch. Bip. ex Baker, Asteraceae, known popularly as guaco, are widely used for colds and asthma. Although coumarin is adopted as the chemical marker of both species, it was not always detected in M. glomerata, for which chlorogenic acid was identified and quantified instead. The purpose of this study was to develop and validate a method to quantify both coumarin and chlorogenic acid and apply it to extracts of plants identified as M. glomerata, M. laevigata, or as guaco, to determine the pattern of composition of these two species and to observe differences between oven-dried and lyophilized leaves. A method using ultra-high resolution liquid chromatography–mass spectrometry (UHPLC–MS) in the full scan mode was validated for selectivity, matrix effect, linearity, limits of detection and quantification, precision and accuracy. The concentration of coumarin varied between species and samples, therefore these two species should not be used interchangeably. The concentration of chlorogenic acid was also determined for all samples. The UHPLC–MS method permitted the quantification of coumarin and chlorogenic acid in 16 samples of guaco and several commercial samples were possibly misidentified.

Quantificação de citocinas no soro e homogenato da pata na intoxicação experimental com veneno de Bothropoides jararaca em ratos Wistar tratados com soroterapia e Mikania glomerata / Quantification of cytokines in serum and paw homogenate of experimental intoxication for venom of the Bothropoides jararaca in Wistar rats treated with antivenom and Mikania glomerata

O presente estudo teve como objetivo quantificar os níveis de citocinas pró-inflamatórias, entre as quais TNF-α, interleucina-1β (IL-1β), IL-6, e anti-inflamatórias, como IL-10, interferon-γ (INF-γ), bem como comparar o efeito do tratamento convencional com o efeito do tratamento complementado pelo extrato da planta Mikania glomerata, na intoxicação experimental por Bothropoides jararaca. Foram usados ratos Wistar,divididos em três grupos: C - controle, VB - veneno botrópico + soro antiofídico e VBM - veneno botrópico + soro antiofídico + Mikania glomerata. As citocinas foram quantificadas, no soro e no homogenato desses animais, pelo teste ELISA, em três momentos (M1 - 30 minutos, M2 - seis horas e M3 - 24 horas após a inoculação do veneno). Os resultados obtidos evidenciaram que a intoxicação por veneno botrópico estimula principalmente a produção de IL-6 no soro e TNF-α, IL-1β, IL-6 no homogenato da pata de animais experimentalmente intoxicados. O tratamento complementar, com o extrato da planta Mikania glomerata, teve influência principalmente na produção de IL-6, IL-10 e IFN-γ no soro e IL-6, IL-1β e IFN-γ no homogenato. Porém, são necessários novos estudos com o extrato de Mikania glomerata para que se possa entender a ação dessa planta sobre a intoxicação botrópica, bem como verificar qual a melhor via para administrá-lo...

This experiment aimed to quantify the pro-inflammatory cytokine levels, including TNF-α, interleukin-1β (IL-1β) and IL-6 as well as the anti-inflammatory ones such as IL-10 and INF-γ. It was also proposed to compare the effect of the conventional treatment to a treatment in which was added the Mikania glomerata plant in the experimental intoxication using Bothropoides jararaca venom. It was used Wistar rats that were randomly divided into 3 groups: C - control; VB - Bothrops venom + antivenom serum; and VBM - Bothrops venom + antivenom serum + Mikania glomerata. Cytokines were quantified in the serum and paw homogenate using ELISA test in three different moments (M1- 30 minutes, M2- 6 hours and M3- 24 hours after venom injection). The intoxication by Bothropoides jararaca venoms mainly stimulated the production of IL-6 in the serum and TNF-α, IL-1β, IL-6 in paw homogenate of animals experimentally intoxicated. Adjunctive treatment with the extract of the Mikania glomerata plant mainly influenced the production of IL-6, IL-10 and IFN-γ in the serum and IL-6, IL1β and IFN-γ in paw homogenate. Further research is necessary with the extract of Mikania glomerata in order to understand the action of this plant on the Bothropoides poisoning and also to verify the best way to manage it...

Estudo das propriedades físico-químicas e avaliação da toxicidade aguda do extrato etanólico das folhas de Mikania glomerata Sprengel / Study of the physicochemical properties and acute toxicity evaluation of the ethanolic extract of the leaves of Mikania glomerata Sprengel

A Mikania glomerata é uma planta pertencente à família Asteraceae que é bastante utilizada na medicina popular devido às suas ações broncodilatadora, antiasmática, expectorante e antitussígena. O objetivo do presente estudo foi determinar as propriedades físico-químicas do pó obtido a partir das folhas de M. glomerata, bem como, avaliar a toxicidade em camundongos após tratamento agudo com doses repetidas do extrato etanólico padronizado preparado a partir das folhas dessa espécie. Durante o estudo das propriedades físico-químicas do pó obtido a partir das folhas de M. glomerata foram feitas as determinações da densidade bruta e de compactação, do teor de cinzas totais, do teor de umidade, e da granulometria. De acordo com os resultados obtidos podemos sugerir que o pó pode ser usado na formulação de uma forma farmacêutica sólida. Na segunda parte do estudo foi determinada a Dose Letal 50% (DL50), bem como, realizada a análise morfológica macroscópica e avaliados a toxicidade aguda com doses repetidas e os parâmetros bioquímicos e hematológicos de camundongos. De acordo com os dados obtidos na segunda parte deste estudo podemos sugerir que o extrato etanólico pode ser usado de forma segura em humanos, uma vez que apresentou valor de DL50 de aproximadamente 3000 mg Kg-1), bem como, não produziu nenhuma alteração morfológica nos principais órgãos, e nem provocou alterações nos parâmetros bioquímicos e hematológicos de camundongos.

The Mikania glomerata is a plant belonging to the Asteraceae that is widely used in folk medicine because of its bronchodilator, antiasthmatic, expectorant and antitussive actions. The aim of this study was to determine the physicochemical properties of the powder obtained from the leaves of M. glomerata, and to evaluate its toxicity in mice after acute treatment with repeated doses of standardized ethanol extract prepared from the leaves of this plant species. We determined the bulk and packing density, the total ash content, the moisture content and the particle size. The results suggest that the powder can be used in the formulating of a solid pharmaceutical form. In the second part of this study, we determined the 50% lethal dose (LD50), performed the gross morphological analysis and evaluated the acute toxicity from the use of repeated doses and the biochemical and hematologic parameters in mice. The data obtained in this part suggest that the ethanol extract can be used safely in humans, since it has a LD50 value of approximately 3000 mg kg -1 and produced no morphological changes in the major organs, or caused alterations in the biochemical and hematological parameters in mice.

Propriedades físicoquímicas e avaliação da toxicidade aguda do extrato etanólico padronizado a 70% das folhas de Mikania glomerata (Asteraceae) / Physicochemical properties and acute toxicity evaluation of ethanol extract of the leaves from Mikania glomerata Sprengel

Mikania glomerata (Asteraceae) é bastante utilizada na medicina popular devido às suas ações broncodilatadora, antiasmática, expectorante e antitussígena. O objetivo do presente estudo foi determinar propriedades físicoquímicas do pó obtido a partir das folhas de M. glomerata, bem como avaliar a toxicidade em camundongos após tratamento agudo com doses repetidas do extrato etanólico padronizado a 70% preparado durante 30 dias consecutivos. No estudo das propriedades físicoquímicas fez-se a determinação da densidade bruta e de compactação, do teor de cinzas totais, do teor de umidade e da granulometria. De acordo com os resultados obtidos o pó pode ser usado na formulação de uma forma farmacêutica sólida, uma vez que suas propriedades físico-químicas são compatíveis com o desenvolvimento desse tipo de formulação. Na segunda parte do estudo foi determinada a dose letal 50% (DL50) em camundongos, e na análise morfológica macroscópica dos principais órgãos e avaliada a toxicidade aguda com doses repetidas em parâmetros bioquímicos e hematológicos de camundongos. Os resultados sugerem que o extrato etanólico padronizado a 70% pode ser usado de forma segura, uma vez que apresentou um valor para a DL50 (~3000 mg kg-1) que pode ser classificado na categoria nociva, e não produziu nenhuma alteração morfológica nos principais órgãos e em parâmetros bioquímicos e hematológicos de camundongos.

Mikania glomerata Sprengel is a plant from the Asteraceae family and it is widely used in folk medicine because of its bronchodilating, anti-asthmatic, expectorant and antitussive effects. The purpose of this study was to determine the physicochemical properties of the powder obtained from the leaves of M. glomerata, and to evaluate the toxicity in mice after an acute treatment with repeated doses of standardized 70% ethanol extract prepared from the leaves during 30 consecutive days. To study the physicochemical properties of the powder, we conducted a determination of the bulk density and compaction, the total ash content, the moisture content and particle size. According to the results obtained, we suggest that the powder can be used to formulate a solid dosage form, since its physicochemical properties matches the development of this type of formulation. In the second part of the study, it was determined a lethal dose in the order of 50% (LD50), along with a gross morphological analysis and the evaluation of the acute toxicity with repeated doses, in the terms of biochemical and hematological parameters of mice. According to the results from the second phase, we suggest that the 70% ethanol extract can be used safely in humans, since it presented a value for the LD50 (~ 3000 mg kg-1) that can be classified as 'harmful'. It also did not produce any morphological changes in the major organs and in the biochemical and hematological parameters of mice.

Rendimento extrativo de cumarina de folhas de guaco (Mikania glomerata Sprengel) submetidas a diferentes temperaturas de secagem / Extraction yield of coumarin from guaco (Mikania glomerata Sprengel) leaves subjected to different drying temperatures

O objetivo deste trabalho foi avaliar o efeito da temperatura do ar de secagem no rendimento extrativo da cumarina de folhas de guaco. Foram empregados 6 tratamentos de secagem, sendo ar ambiente, ar aquecido a 40, 50, 60, 70 e 80ºC. Utilizou-se secador de bandejas, tendo como fonte de aquecimento o gás liquefeito de petróleo (GLP). Os rendimentos extrativos da cumarina, depois de realizada a secagem, foram comparados com os valores obtidos da planta fresca (tratamento testemunha). A extração da cumarina foi realizada pelo método a quente, em banho-maria a 65ºC, sendo a identificação e quantificação realizada por cromatografia líquida de alta eficiência (CLAE). Em função dos resultados obtidos, pôde-se concluir que a temperatura do ar de secagem a 50ºC possibilitou o melhor resultado para o rendimento extrativo de cumarina em folhas de guaco.

The aim of this study was to evaluate the effect of drying on the extraction yield of coumarin from guaco leaves. Six drying treatments were used, being room air, heated air at 40, 50, 60, 70 and 80ºC. A tray dryer was used with liquefied petroleum gas (LPG) as heating source. The extraction yield of coumarin, after drying, was compared to the values obtained from the fresh plant (control treatment). Coumarin extraction was carried out by using the heat method, in water bath at 65ºC, and identification and quantification were done by means of high performance liquid chromatography (HPLC). Considering the obtained results, the temperature of the drying air at 50ºC led to the best result for the extraction yield of coumarin in guaco leaves.

Toxicological screening of Mikania glomerata Spreng., Asteraceae, extract in male Wistar rats reproductive system, sperm production and testosterone level after chronic treatment / Triagem toxocológica do extrato de Mikania glomerata Spreng., Asteraceae, no sistema reprodutor, produção espermática e nível de testosterona em machos de ratos Wistar após tratamento crônico

Some compounds present in therapeutic plants may be responsible for the occurrence of adverse side effects. Coumarin and flavonoids are substances found in many plant species that showed antifertility activity in female rats and dogs, respectively. Mikania glomerata Spreng., Asteraceae, known as guaco in Brazil, is a plant largely used in folk medicine and its leaves are reported to have coumarin and flavonoids. This work analyzes the effect of chronic administration of M. glomerata on the reproductive system of male rats. Thirty-day-old Wistar rats were treated with M. glomerata hydroalcoholic extract at a dose of 3.3 g/kg of body weight for ninety days. Body and organ weights, gamete concentration on the epididymis cauda, serum testosterone level and food consumption were evaluated. No significant alteration was observed in any of the variables analyzed, suggesting the absence of toxic action or antifertility activity of the M. glomerata hydroalcoholic extract.

As plantas medicinais podem apresentar na sua constituição compostos capazes de causar efeitos adversos no organismo. Cumarina e flavonoides são substâncias encontradas em muitas espécies vegetais, cuja interferência na fertilidade de ratas e cadelas, respectivamente, foi evidenciada em estudos prévios. Mikania glomerata Spreng., Asteraceae, (guaco) é uma planta usada no tratamento de doenças respiratórias e em suas folhas foi detectada a presença de cumarina e flavonoides. Neste estudo, avaliou-se o efeito do extrato hidroalcoólico, preparado com partes aéreas de guaco, no sistema reprodutor de ratos submetidos a tratamento crônico. Ratos Wistar (trinta dias de idade) foram tratados com extrato hidroalcoólico de guaco na dose de 3,3 g/kg de peso corporal durante noventa dias. O peso corporal e de órgãos, a produção de espermatozoides, a concentração de testosterona plasmática e o consumo de ração foram avaliados. Não foi observada nenhuma alteração significativa das variáveis analisadas e o tratamento não afetou o consumo de ração. Estes dados sugerem que, na dose utilizada, o extrato hidroalcoólico de guaco não teve efeito tóxico e nem interferiu com a fertilidade de ratos Wistar submetidos a um tratamento de longa duração.

Avaliação do efeito de polietilenoglicóis no perfil de extratos de Mikania glomerata Spreng., Asteraceae, e Passiflora edulis Sims, Passifloraceae / Evaluation of PEG effects on the extracts obtaining from Passiflora edulis Sims, Passifloraceae, and Mikania glomerata Spreng., Asteraceae

Os polietilenoglicóis (PEG) são polímeros hidrossolúveis capazes de reduzir a constante dielétrica de solventes como a água, e assim são utilizados como cossolventes para solubilização de diferentes fármacos. Atualmente, o PEG tem sido empregado satisfatoriamente na obtenção de extratos de matérias-primas vegetais por favorecer a extração de substâncias com polaridades semelhantes às extraídas pelos solventes hidroetanólicos. O objetivo deste trabalho foi avaliar o efeito da concentração e da massa molar de PEG (400 e 4000 g/mol) sobre a extração de flavonoides totais a partir de Passiflora edulis Sims, Passifloraceae, (maracujá) e de cumarina a partir da Mikania glomerata Spreng., Asteraceae, (guaco). Este estudo revelou que o aumento da concentração de PEG promoveu um aumento na capacidade extrativa de flavonoides totais e cumarina a partir da Passiflora edulis e Mikania glomerata respectivamente, comportamento atribuído a alterações da constante dielétrica. Apesar de elevar a capacidade extrativa, os líquidos extratores contendo PEG exigiram elevada relação planta:solvente para alcançar teores extrativos semelhante ao solvente hidroetanólico utilizado, com exceção da extração de flavonoides totais com PEG 4000 g/mol a partir da Passilfora edulis.

Polyethylene glycols (PEG) are hydrosoluble polymers able to reducing dielectric constant of solvents like water and thus are used as cosolvents to enhance the aqueous solubility of several drugs. Actually, the PEG have been successful applied to obtain extracts of plant raw material once can facilitate the extraction of substances with polarities similar to those extracted by hydroethanol solvents. In this study, the objective was to evaluate the effect of PEG concentration and molecular weight (400 and 4000 g/mol) on the extraction of total flavonoids from Passiflora edulis Sims, Passifloraceae, and coumarin from Mikania glomerata Spreng., Asteraceae. The results showed that increasing PEG concentration promoted an increase in the extractive capacity of total flavonoid and coumarin from Passiflora edulis and Mikania glomerata respectively. This behavior was attributed to changes in dielectric constant. Despite raising the extractive capacity, the solvent containing PEG required high plant/solvent ratio to reach levels similar to hydroethanol solvents used, except for the extraction of total flavonoids from Passiflora edulis using PEG 4000 g/mol.

Mikania glomerata Spreng. e M. laevigata Sch. Bip. ex Baker, Asteraceae: estudos agronômicos, genéticos, morfoanatômicos, químicos, farmacológicos, toxicológicos e uso nos programas de fitoterapia do Brasil / Mikania glomerata Spreng. e M. laevigata Sch. Bip. ex Baker, Asteraceae: agronomic, genetic, anatomical, chemical, pharmacological, toxicological studies and its use in herbal therapy programs in Brazil

No Brasil as espécies de Mikania glomerata Spreng. e M. laevigata Sch. Bip. ex Baker, Asteraceae, popularmente conhecidas como guaco, são amplamente utilizadas com evidências pré-clínicas para o tratamento de doenças onde estejam envolvidas suas ações broncodilatadoras, antialérgicas, antiasmáticas, anti-inflamatórias, antiulcerogênicas e relaxantes da musculatura lisa. Em virtude das propriedades terapêuticas atribuídas as essas espécies, ambas foram oficializadas na farmacopéia brasileira, e por serem bastante semelhantes, dificilmente são diferenciadas. Com o objetivo de contribuir com novas pesquisas, a presente revisão descreve, de forma sistematizada, sobre os aspectos farmacológicos, toxicológicos, químicos, agronômicos, morfoanatômicos, genéticos e o uso nos programas de fitoterapia do Brasil destas espécies. As principais diferenças e semelhanças entre as duas espécies são evidenciadas através da comparação das informações baseadas na literatura específica.

In Brazil the species of Mikania glomerata Spreng. and M. laevigata Sch. Bip. ex Baker, Asteraceae popularly known as guaco, are widely used with preclinical evidence for the treatment of diseases whose actions involve bronchodilators, antiallergic, anti-asthmatic, anti-inflammatory, antiulcerogenic and smooth muscles relaxant. Due to the therapeutic properties attributed to these species, both were included in the official Brazilian Pharmacopoeia, and because of their similarity, they are hardly differentiated. In order to contribute to the new research, this review describes their several aspects: pharmacology, toxicology, chemical, agricultural, anatomical, genetics and the use in herbal medicine programs in Brazil, in a systematic way. The main differences and similarities between the two species are evidenced by comparing the information based on literature.

Effect of Mikania glomerata (Asteraceae) leaf extract combined with anti-venom serum on experimental Crotalus durissus (Squamata: Viperidae) envenomation in rats

Crotalic envenomation represents the highest number of deaths when compared to other snakebite envenomations of medical interest. Crotalic venom has important characteristics such as neurotoxicity, myotoxicity, nephrotoxicity, and clotting and hemolytic action. We evaluated the clinical and laboratory aspects of Crotalus durissus terrificus experimental envenomation in Wistar rats treated with antivenom and the aqueous extract of the plant Mikania glomerata. The animals were divided into three groups: Group C (control); Group VS-venom and antivenom; Group VSM-venom, antivenom and aqueous extract of M. glomerata. Crotalic poison caused clinical and laboratory alterations in Wistar mice. Significant linical alterations were: temperature decrease, edema in the venom inoculated member, sedation and a locomotion decrease in groups VS and VSM when compared with group C. A faster recovery from sedation was observed only for animals of group VSM when compared to VS. There was an increase in the number of leukocytes, neutrophils and creatine kinase in the VS and VSM groups, compared to group C. Wistar rats showed a high resistance to crotalic venom. Additional studies with different doses, time of treatment, different administration methods and histopathological and immunological studies are necessary to understand the action of M. glomerata in crotalic accidents. Rev. Biol. Trop. 57 (4): 929-937. Epub 2009 December 01.

El envenamiento crotálico representa el número más alto de muertes cuando es comparado con envenenamientos por mordeduras de otras serpientes de interés médico. El veneno crotálico tiene importantes características de acción neurotóxica, miotoxicidad, nefrotoxicidad, coagulación y acción hemolítica. Este trabajo evaluó los aspectos clínicos y de laboratorio del envenenamiento experimental con el veneno de la serpiente Crotalus durissus terrificus en las ratas Wistar tratadas con suero antiofídico y extracto acuoso de M. glomerata. Los animales fueron separados en tres diferentes grupos: grupo control (C); grupo veneno+suero (VS), grupo veneno+suero+extracto acuoso de M. glomerata (VSM). El veneno crotálico causó alteraciones clínicas y diferencias en los análisis sanguíneos practicados a los ratones Wistar evaluados. Las alteraciones clínicas más importantes fueron una disminución de la temperatura, edema en el miembro inoculado de veneno, la sedación y una disminución de la locomoción en los grupos VS y VSM comparado con el grupo C. Una rápida recuperación de la sedación estadísticamente significativa fue observada en los animales del grupo VSM al compararse con los del grupo VS. Los análisis sanguíneos mostraron un aumento en el número de leucocitos, neutrofilos y creatina quinasa en los grupos VS y VSM comparados con el grupo C. Los ratones Wistar mostraron una alta resistencia al veneno del crótalo. Estudios adicionales con variación en las dosis, tiempo de tratamiento, y métodos de administración, así como la realización de estudios histopatológicos e inmunológicos son importantes para comprender la acción de M. glomerata en accidentes crotálicos.

Determinação do teor de cumarina no xarope de guaco armazenado em diferentes temperaturas / Coumarin content of guaco syrup stored at different temperatures

A produção magistral do xarope de guaco, obtido a partir do extrato fluido do guaco (Mikania glomerata Spreng., Asteraceae) e comercializada na Farmácia Universitária da UFJF/MG, gerou um projeto de pesquisa com o objetivo principal de estudar a estabilidade do produto acabado, tendo como ponto de referência a determinação do teor de cumarina das amostras armazenadas em diferentes temperaturas. O método aplicado para realizar a análise do teor de cumarina presente no xarope em estudo foi espectrometria no UV com comprimento de onda de 275,4 nm. Utilizou-se como veículo para efetuar as diluições da amostra uma mistura de metanol/água destilada, na proporção de 80 por cento v/v. A curva de calibração foi obtida diluindo-se 100 mg de cumarina padrão em 100 mL da solução descrito acima, obtendo-se sete concentrações distintas com variação de 2 µg a 20 µg. Os resultados obtidos demonstraram que a temperatura de armazenamento de 45 °C foi considerada ótima para desenvolver a conversão do isômero trans em cis com subseqüente conversão deste a cumarina. Os valores de cumarina encontrados na forma farmacêutica em estudo foram de 1,19 a 1,37 mg/mL, sendo que o valor mais alto refere-se às amostras armazenadas a 45°C durante seis meses.

The production of guaco syrup, obtained from guaco (Mikania glomerata Spreng., Asteraceae) fluid extract, and commercialized by the University Pharmacy of the Federal University of Juiz de Fora-MG, Brazil, led to a research project whose main aim was to study the stability of the finished product, with reference to the coumarin content of samples stored at different temperatures. UV spectrophotometry (275.4 nm) was used to assess the coumarin content of the study syrup. An 80 percent v/v methanol/distilled water mixture was used for sample dilution. The calibration curve was constructed by the dilution of 100 mg standard coumarin in 100 ml of the aforementioned solution, with seven distinct concentrations (ranging from 2 µg a 20 µg) being obtained. The results showed the 45 °C storage temperature to be optimum for the development of trans-cis isomerization, with subsequent conversion of the latter into coumarin. Coumarin content in the studied pharmaceutical presentation ranged from 1.19 to 1.37 mg/mL, the highest value corresponding to the samples stored at 45 °C for six months.

Estudo comparativo da composição química das espécies vegetais Mikania glomerata Sprengel e Mikania laevigata Schultz Bip. ex Baker / Comparative study of the chemical composition of the species Mikania glomerata Sprengel and Mikania laevigata Schultz Bip. ex Baker

Adulterações da matéria-prima vegetal ocorrem comumente no mercado de fitoterápicos, sob a forma de substituições e/ou falsificações. Muitas vezes, espécies distintas são comercializadas em substituição à farmacopéica devido à dificuldade de obtenção desta, ou mesmo pelo emprego intencional de espécies de menor valor econômico que apresentem características morfológicas semelhantes. Portanto, faz-se necessária a realização de estudos que busquem identificar a constituição química das espécies de amplo uso medicinal, que são alvos de adulterações. Mikania glomerata e Mikania laevigata, conhecidas popularmente como "guaco", são comercializadas indistintamente. Buscando-se avaliar a composição química das duas espécies, realizou-se uma prospecção fitoquímica por CCD e foram obtidos os perfis cromatográficos por CLAE-FR. Fez-se a quantificação da cumarina empregando-se o mesmo método. Na prospecção fitoquímica por CCD, foi detectada, nas duas espécies, a presença de cumarina, triterpenos/esteróides e heterosídeos flavônicos. Os perfis cromatográficos, obtidos por CLAE-FR, mostraram-se semelhantes, observando-se a predominância de compostos polares. Na quantificação da cumarina, obtêve-se um teor de 0,30 por cento para M. glomerata e 0,43 por cento para M. laevigata, teores de acordo com o preconizado na monografia do guaco-cheiroso (mín. 0,1 por cento). M glomerata e M. laevigata apresentaram composição química semelhante e teores de cumarina próximos, sugerindo que estas podem ser utilizadas de forma indistinta.

Adulterations of plant raw materials often occur in the marketing of herbal medicine, usually in the form of substitutions and/ or fakes. Many times, different plant species are commercialized in the place of the one recognized by the pharmacopoeia. This may occur due to the difficulties of obtaining the authentic plant material, or by an intentional use of a plant species that has less economic value but shows similar morphologic features. Therefore, it is necessary to carry out studies that can identify the chemical composition of those species of wide medicinal use, which are the targets of adulterations. Mikania glomerata and Mikania laevigata, popularly known as "guaco", are indistinctly commercialized in Brazil. A phytochemical screening by TLC was carried out to evaluate the chemical composition of both species. The RP-HPLC profiles were obtained and the quantification of coumarin was determined by the same method. A phytochemical screening has shown that coumarin, triterpenes/ steroids and flavonic heterosides are the constituents detected in both species. The RP-HPLC profiles were similar between the two species and revealed the predominance of polar compounds. In the quantification of coumarin, a content of 0.30 percent (w/w) was obtained for M. glomerata and 0.43 percent (w/w) for M. laevigata. These values are in accord with the contents (min. 0.1 percent, w/w) described by the monograph of "guaco-cheiroso" in the Brazilian Pharmacopoeia. Therefore, the results indicated similar chemical profiles for M. glomerata and M. laevigata, as well as comparable coumarin contents, thus suggesting that the species might be used indistinctly.

A validated capillary gas chromatography method for guaco (Mikania glomerata S) quality control and rastreability: from plant biomass to phytomedicines / Método validado por cromatografia gasosa capilar para o controle de qualidade e rastreabilidade de guaco (Mikania glomerata S): da matéria-prima ao fitoterápico

Este trabalho descreve a validação completa de metodologia analítica empregando cromatografia gasosa capilar com padronização interna para quantificação da cumarina (1,2-benzopirona) em produtos contendo guaco (Mikania glomerata Spreng - Asteraceae): xarope, planta e extrato padronizado, além do estudo de estabilidade do fitoterápico em questão. Utilizou-se uma coluna capilar HP-5 (30 m x 0,32 mm x 0,25 µm), hidrogênio a 1,8 mL/min e rampa de temperatura de 100 ºC a 250 ºC, a 15 ºC/min. A temperatura do injetor (split 1:20) foi de 250 ºC, enquanto a do detector foi de 270 ºC. Os tempos de retenção dos padrões foram: 2,86 minutos para o 1, 2, 3, 4-tetrametilbenzeno, 4,45 minutos para o piperonal (padrões internos) e 5,36 minutos para a cumarina. Após o procedimento de extração da planta in natura, a recuperação da cumarina foi de 101,6 por cento, enquanto que para o xarope esta foi de 100,8 por cento. Os limites de detecção e quantificação foram 0,5 µg/mL e 1,5 µg/mL, respectivamente. A precisão, determinada para todas as amostras, apresentou desvios padrões relativos menores que 2,5 por cento. Os teores de cumarina presentes nas folhas, extrato e xarope foram de 0,38 por cento m/m, 1,33 mg/mL e 0,143 mg/mL, respectivamente.

This work describes a full validation of a capillary gas chromatography analytical methodology using internal standardization for the quantification of coumarin (1,2-benzopyrone) in guaco (Mikania glomerata Spreng - Asteraceae) products: syrup, plant and its extract, including the stability study of the phytomedicine. For the analysis, it was used an HP-5 capillary column (30 m x 0.32 mm x 0.25 µm), hydrogen at a flow rate of 1.8 mL/min and the increasing temperature gradient was: 100 ºC to 250 ºC, 15 ºC/min. The temperature of injector (split 1:20) and detector were kept at 250 ºC and 270 ºC, respectively. The retention times of the standards for the above conditions were 2.86 minutes for 1, 2, 3, 4-tetramethylbenzene, 4.45 min for piperonal (internal standards), and 5.36 minutes for coumarin. After extraction procedure, the recovery of coumarin determined for plant raw material was 101.6 percent, while for syrup it was 100.8 percent. Detection and quantification limits were 0.5 µg/mL and 1.5 µg/mL, respectively. Precision was determined for all samples and the results were lower than 2.5 percent. The total amount of coumarin in plant raw material, its extract and syrup were 0.38 percent w/w, 1.33 mg/mL and 0.143 mg/mL, respectively.