Insecticidal activity and physiopathological effects of Cotula cinerea crude extract against Culex pipiens

@#The development of new alternatives strategies to synthetic insecticides aimed at reducing pest populations by developing pesticides based on plant extracts without negative effects in non target organisms and environment. The present study was undertaken in order to assess the insecticidal activity of the crude methanolic extract of the Algerian Asteraceae Cotula cinerea, against the larval and the pupal stage of Culex pipiens (Diptera: Culicidae). It is also to determine the chemical composition of the used extract, and to understand the mechanism of toxic action of the tested extract. Based on the preliminary tests, five concentrations of the crude methanolic extract of C. cinerea (0.62, 1.25, 2.50, 3.75, and 5 mg/mL) were tested for their insecticidal activity according to the protocol recommended by the World Health Organization. The chemical profile of the extract was also obtained by high performance liquid chromatography (HPLC). Histopathological effects and inhibition of acetylcholinesterase activity in treated mosquitoes with LC90 were examined to elucidate the mechanism of the toxic effect of the tested extract (48 h post treatment). Eight compounds have been identified by HPLC. That includes four flavonoids (rutin, quercetin, myrcetin and cathechin), three phenolic acids (benzoic acid, vanillic acid, p-coumaric acid) and one alkaloid (berberine). C. cinerea methanolic extract showed good larvicidal and pupicidal activities with LC50 and LC90 values of 1.10 and 4.37 mg/mL respectively against pupae, 24h post treatment and 1.26, 2.35 mg/mL respectively against the fourth instar larvae. Data of enzymatic assay performed on LC50 and LC90 pupae and larvae revealed prominent neurotoxic effects. C. cinerea extract reduced the activity of acetylcholinesterase (AChE) enzyme in a concentration dependent manner. Obtained inhibition percentages, 48 h after treatment, were 35.11 ± 7.44 and 51.83 ± 4.04% for pupal stage and 30.98 ± 2.97 % and 48.77 ± 4.72% for the fourth instar larvae for LC50 and LC90 values respectively. Treated larvae and pupae showed also histopathological damages in the pupal cuticle and larval midgut. The results of this study showed that C. cinerea crude methanolic extract could be considered as an eco-friendly alternative for mosquito control.

Evaluation of In vitro Activity of Antimicrobial Potential and Phytochemical Screening of Methanol Extract of Curcuma longa Linn against Some Clinical Isolates

Since ancient times, plants have been used as a source of medicinal compounds. This study was carried out to assess the antimicrobial potential of the methanol extract of Curcuma longa rhizome against some clinical isolates. A total of seven clinical isolates including Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Candida albicans, Aspergillus flavus, and Fusarium species were used. Different concentrations of the extracts were made. Agar well diffusion methods were used for bacterial and Candida albicans while agar dilution technique was used for the mold strains. Ciprofloxacin and Fluconazole were used as a standard positive control against the bacteria and fungi respectively. Dimethyl sulfoxide (DMSO) was used as a negative control. The result showed that methanol extract of Curcuma longa rhizome inhibited the growth of all tested organisms. The zone of inhibition of K. pneumoniae ranged from 9.33-13.33mm, S. aureus, 6.33-12.67mm, E. coli, 8- 11.67mm, P. aeruginosa, 7.67-10mm, and Candida albicans 8.33-13mm while the control drug Ciprofloxacin ranged from 25.33-41.33mm and fluconazole was 20mm. The percentage inhibition of diameter of growth of Fusarium spp ranged from 74.61-100% and that of A. flavus ranged from 32.44-100%. The positive control drug (Fluconazole) and 250mg/ml of the extract showed complete inhibition of the test organisms. Qualitative phytochemical studies of the extract of Curcuma longa in different solvents (N-hexane, water, methanol, and acetone) showed the presence of alkaloids, phenols, saponins, steroids, tannins, glycosides, and flavonoids. This result is indicative of its broad-spectrum antimicrobial potential and could be employed in the management and treatment of infections. This study corroborates the plant's historic use and lays the groundwork for potential therapeutic development.

In vitro antibacterial activity of endophytic fungus Aspergillus flavus IBRL-C8 from Senna siamea against Gram-bacteria

Aims@#To evaluate the antibacterial efficacy of ethyl acetate extract of Aspergillus flavus IBRL-C8 against Gram-positive and Gram-negative bacteria.@*Methodology and results@#In this experiment, an endophytic fungus which identified as A. flavus IBRL-C8 was extracted using ethyl acetate and methanol, from Senna siamea, prior to in vitro antibacterial test on eight Gram-bacteria. The results were significantly more enunciated to the ethyl acetate extract since the Gram-bacteria signified 9.0 to 20.0 mm of inhibition zones on Muller Hinton Agar (MHA) during disc diffusion assay. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the extract were ranged from 125-1000 µg/mL and 125-2000 µg/mL, respectively. Time-kill assay depicted the ethyl acetate extract of A. flavus IBRL-C8 exceptionally retarded methicillin-resistant Staphylococcus aureus (MRSA) and also manifested extended antibacterial activity. The maximum reduction in cell numbers occurred at 2MIC concentration (250 µg/mL) during the interval time of 16 h. The malformations noticed from microscopic observations where the transformation of structural annihilation from regular spherical morphology to non-spherical shape with an irregular surface and also disruption around the cell membrane when the MRSA treated with ethyl acetate extract of A. flavus IBRL-C8. @*Conclusion, significance and impact of study@#This study proposed the ethyl acetate extract of A. flavus IBRL-C8 as a potential antibacterial agent against MRSA infection, which can be useful in pharmaceutical application.

Comparative Study of Methanolic Extract of Banana, Ranitidine and Omeprazole on Total Acid Secretion and Gastric Ulcer Healing Effect in Albino Rats

Introduction: The commonest day to day ailment of humanbeings is the gastrointestinal diseases. Apart from traditionaluses, there are several reports on important pharmacologicalactions of musa sapientum. Study aimed to compare acidsecretion and ulcer healing effect of methanolic extract ofbanana, ranitidine, and omeprazole.Material and methods: The present study was carried out on30 albino rats for a period of 7 days. The animals were dividedrandomly into 5 groups of 6 animals each. Group I or controlgroup received 3% gum acacia suspension orally for 7 days.Group II, III, IV and V received 100mg/kg of aspirin orally asa single dose the 7th day. Group III was pretreated with 100mg/kg of MSE orally for 7 days. Group IV was pretreated with 20mg/kg omeprazole and Group V was pretreated with 150mg/kg of ranitidine orally for 7 days. After the administration ofthe drugs on the 7th Day, the albino rats were fasted for 24 hrsand then sacrificed after 4 hrs of pyloric ligation.Results: In the control group (n=6) the values of ulcer index(µmol tyrosin/ml), free acidity (mEq/l), total acidity (mEq/l),and volume of gastric juice (ml/4 hrs) were 0.22±0.01,53.25±2.59, 72.24±4.19 and 5.1±0.32 respectively. Whencompared to aspirin treated group, the MSE pretreated group(100 mg/kg) single dose orally on 7th day showed significantreduction (p<0.01, n=6) of ulcer index, free and total acidity(mEq/l), and volume of gastric juice (ml/4 hrs), whosevalues were 5.3±0.46, 71.31±4.15, 72.24±4.19 and 65.4±2.9respectively.Conclusion: The present study suggests that themethanolic extract of musa sapientum possesses significantulceroprotective effect, which is comparable to omeprazoleand ranitidine, except for gastric juice, where the effect ofomeprazole was more. The observations of the present studyputs forward omeprazole as a promising ulceroprotectiveagent, but further studies with more refined extracts andtechniques on animal and human subjects are requiredto establish the true potential in terms of therapeutic andeconomic viability of this herbal plant.

Improvement of endothelial function by Gunnera tinctoria extract with antioxidant properties

BACKGROUND: Gunnera tinctoria has been collected by Mapuche-Pewenche people for food and medicinal purposes. The high polyphenol content of methanolic extract from G. tinctoria leaves with chemical constituents such as ellagic acid and quercetin derivatives suggests its application to prevent endothelial dysfunction and oxidative stress. The aim of this study was to provide evidence of the protective effect of this extract on endothelial function by reducing oxidative stress induced by high D-glucose and H2O2, as well as by stimulating nitric oxide (NO) levels in human umbilical vein endothelial cells (HUVECs). RESULTS: A methanolic extract with a high content of polyphenols (520 ± 30 mg gallic acid equivalents/g dry extract) was obtained from G. tinctoria leaves. Its main constituent was ellagic acid. The results of Ferric reducing antioxidant power and 2,2-diphenyl-1-picrylhydrazyl radical scavenging assays of the extract confirmed its antioxidant activity by inhibition pathway of radical species. The incubation of HUVECs with the extract decreased the apoptosis and reactive oxygen species (ROS) synthesis induced by high extracellular concentration of D-glucose or hydrogen peroxide. The extract increased endothelial NO levels and reduced vasoconstriction in human placental vessels. CONCLUSIONS: This study provides evidence about the antioxidant and endothelial protective properties of methanolic G. tinctoria leaf extract. The extract improves the availability of NO in HUVECs, inhibiting the production of ROS and vasoconstriction.

Evaluation of Antipyretic and Anti-inflammatory Activity of Methonolic Extract of Andrographis paniculata in Albino Rats

The study was conducted to determine the antipyretic and anti-inflammatory activity of the methanolic extract of Andographispaniculata (APE) in albino rats. Acute oral LD50 of APE in female rats was more than 2000 mg/kg. The antipyretic activitywas studied by inducing pyrexia with Brewer’s yeast. A total number of thirty albino rats (200 g) were used for the study ofanti-pyretic activity they were divided into five groups of six rats in each group. Group I served as control Normal saline andGroup II were given brewer’s yeast alone (20 ml/kg), Group III was administered standard drug Aspirin @ 100 mg /kg bodywt. while groups IV and V were treated with 200 mg/kg and 400 mg/kg of Andrographis paniculata extract respectively.Pyrexia was induced by subcutaneously injecting 20% w/v brewer’s suspension in below the nape of the neck of the animals.The anti-inflammatory activity of APE was assessed by measuring the reduction in carrageenan-induced paw oedema in rats.A twenty four albino rats (200 g) were used for the study of anti-inflammatory activity. Four groups were divided with six ratsin each group. Group I served as control Normal saline solution and Group II was administered standard drug phenylbutazone@ 100 mg/kg While, groups III and IV were treated with 200mg/kg and 400mg/kg of APE respectively. APE (@ 400 mg/kghad significant antipyretic and anti-inflammatory activity against reduced brewer’s yeast induced pyrexia and carrageenaninduced rat paw edema in rats suggesting potent antipyretic effect of APE. From these results it may be concluded that crudemethanolic extract of Andrographis paniculata have significant antipyretic activity and anti-inflammatory activity that mightbe due to combined effect of active constituents present in plant extract this strongly support the ethno pharmacologicaluse of the plant for the management of fever and inflammation

Evaluation of antiatherogenic effect of Alternanthera brasiliana Linn kuntz in rats on atherogenic diet

Background: Hypercholesterolaemia is a major risk factor for systemic atherosclerosis and a well-known etiological factor for cardiovascular diseases and its complications which is a leading cause of mortality worldwide. In a recent study, the antihyperlipidemic activity of dried leaves extract of Alternanthera brasiliana has been evaluated. Hence, the present study was undertaken to investigate the anti-atherosclerotic potential of the methanolic extract of the leaves of Alternanthera brasiliana L. Kuntz (MEAB) in high fat diet induced hypercholesterolemic rat model.Methods: Thirty (30) wistar albino rats of either sex were randomly divided into five groups: first two groups received normal diet and high fat diet respectively and the remaining three groups received high fat diet supplemented with methanolic extract of Alternanthera brasiliana (MEAB) administered orally daily at two different doses: 200 mg/kg and 400 mg/kg and Atorvastatin 10 mg/kg/day orally as standard respectively. Serum total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL-C) and high density lipoprotein (HDL-C) was estimated after 12 weeks. Atherogenic index was calculated from the results of lipid profile. At the end, the aorta was removed for assessment of atherosclerotic plagues.Results: Our results showed that MEAB possessed significant cholesterol lowering potency as indicated by decrease in serum total cholesterol (TC), triglyceride (TG) and low density lipoprotein (LDL-C) accompanied by an increase in serum high density lipoprotein (HDL-C) and reduces the atherosclerotic lesion of aorta (p <0.05).Conclusions: These results strongly suggests that MEAB can prevent the progress of atherosclerosis likely due to the effect of A. brasiliana on serum lipoproteins and its antioxidant and anti-inflammatory properties. It could be a potential therapy for the prevention and treatment of atherosclerosis.

Anticancer activity of Mahonia leschenaultii methanolic root extract and berberine on Dalton's ascitic lymphoma in mice

To evaluate the effects of methanol root extract of Mahonia leschenaultii and berberine of Mahonia leschenaultii on Dalton's ascitic lymphoma in Swiss Albino mice. Methods: The methanol root extracts of Mahonia leschenaultii (200 and 400 mg/kg) were given orally, and berberines (10 and 20 mg/kg) were injected intra-peritoneally for 14 successive days in tumor bearing mice. Hematological parameters (white and red blood cells, haemoglobin level, granulocytes, and agranulocytes), lipid parameters (total cholesterol and triglycerides), serum enzymes (serum glutamate pyruvate transaminases, serum glutamate oxaloacetate transaminases, and alkaline phosphatise) and mean survival and solid tumor growth were determined and compared with untreated mice. 5-fluorouracil (20 mg/kg) was used as a reference standard drug. Results: Mahonia leschenaultii and berberine reduced the hematocrit significantly. Furthermore, Mahonia leschenaultii and berberine improved the survival of mice significantly and restored the affected hematological and lipid parameters similar to the normal levels. Conclusions: These observations show a strong anticancer effect of methanol root extract of Mahonia leschenaultii and berberine in suppressing Dalton's ascitic lymphoma cancer cell growth in a mouse model by controlling haematological, lipid, serum enzymes, and other derived parameters effectively.

Anticancer activity of Mahonia leschenaultii methanolic root extract and berberine on Dalton's ascitic lymphoma in mice

To evaluate the effects of methanol root extract of Mahonia leschenaultii and berberine of Mahonia leschenaultii on Dalton's ascitic lymphoma in Swiss Albino mice. Methods: The methanol root extracts of Mahonia leschenaultii (200 and 400 mg/kg) were given orally, and berberines (10 and 20 mg/kg) were injected intra-peritoneally for 14 successive days in tumor bearing mice. Hematological parameters (white and red blood cells, haemoglobin level, granulocytes, and agranulocytes), lipid parameters (total cholesterol and triglycerides), serum enzymes (serum glutamate pyruvate transaminases, serum glutamate oxaloacetate transaminases, and alkaline phosphatise) and mean survival and solid tumor growth were determined and compared with untreated mice. 5-fluorouracil (20 mg/kg) was used as a reference standard drug. Results: Mahonia leschenaultii and berberine reduced the hematocrit significantly. Furthermore, Mahonia leschenaultii and berberine improved the survival of mice significantly and restored the affected hematological and lipid parameters similar to the normal levels. Conclusions: These observations show a strong anticancer effect of methanol root extract of Mahonia leschenaultii and berberine in suppressing Dalton's ascitic lymphoma cancer cell growth in a mouse model by controlling haematological, lipid, serum enzymes, and other derived parameters effectively.

In vitro Antioxidant and Cholinesterase Inhibitory Activities of Methanolic Extract of Grewia nervosa L. (Family: Tiliaceae) Leaf

Aims: The methanolic extract of Grewia nervosa L. leaves belongs to the family of Tiliaceae. The purpose of this study was to evaluate total phenolics, total flavonoids, total proanthocyanidins, total antioxidant capacity, iron reducing power capacity, free radical scavenging activity, hydroxyl radical scavenging activity, Lipid peroxidation inhibition activity, anti-acetylcholinestrase activity, anti-butyrylcholinestrase activity, metal chelating activity, total flavonols, nitric oxide radical scavenging activity and phytochemical screening. Place and Duration of Study: The study was carried out between April 2015 to June 2015 in the Department of Pharmacy, Southeast University, Dhaka, Bangladesh. Methodology: Antioxidant activity and neuroprotective activities were determined by several standard methods. Phytochemical screening was done by characteristic colour changes or colour precipitate using standard phytochemical reaction methods. Results: The anti-acetylcholinesterase activity of different extracts of G. nervosa was assessed by a slightly modified Ellman coupled enzyme assay. IC50 of the crude extract and its fractions petroleum ether fraction (PEF), chloroform fraction (CLF), ethyl acetate fraction (EAF) and aqueous fraction (AQF) was found to be 17.07 µg/ml, 15.08 µg/ml, 135.57 µg/ml, 274.78 µg/ml respectively. In butyrylcholinesterase inhibitory assay, the lowest activity was found in PTEF with IC50 value 15.79 and the highest activity was found in CLF with IC50 value 7.55. The crude methanol extract and its different fractions showed considerable total antioxidant activity and reducing capacity. In DPPH scavenging assay and hydroxyl radical scavenging assay, the crude methanol extract showed 79.54% and 89.54% scavenging having IC50 of 11.36 and 15.06 μg/ml respectively. Among the fractions, ethyl acetate exhibited the highest DPPH scavenging activity with IC50 of 14.98 μg/ml, while the petroleum ether fraction exhibited the lowest activity with IC50 of 553.09 μg/ml. In hydroxyl radical scavenging activity aqueous fraction exhibited the highest scavenging activity with IC50 of 14.84 μg/ml, while petroleum ether fraction exhibited the lowest activity with IC50 of 33.39 μg/ml. In the lipid peroxidation assay, crude methanol extract showed significant inhibition of peroxidation at all concentrations, with IC50 of 54.41 μg/ml. Among the fractions, ethyl acetate fraction demonstrated the highest activity with IC50 of 33.46 μg/ml. Conclusion: Observing the in-vitro studies, it can be concluded that the methanolic extract of G. nervosa leaves could be used in different diseases because of its effective pharmacological properties. So, further studies are recommended to isolate the exact compounds responsible for this activity and their efficacy needs to be tested.

Evaluation of the analgesic and antipyretic properties of African Cleome viscosa

Background: Cleome viscosa Linn a plant from the family Capparaceae has been used in traditional medicine in Asia and Africa for the treatment of various diseases including diarrhea, cardiac stimulant, anthelmintic, carminative, anti-inflammatory and antiseptic. Decoction of the whole plant has been used for the treatment of inflammation and as a stimulant while the leaves have been applied externally on wounds and ulcers. The objective of this study is to investigate and evaluate the antipyretic and analgesic properties, toxicity profile and the phytochemical study of the methanolic leaf extract of African Cleome viscosa.Methods: The antipyretic study was performed by adopting the Baker’s yeast induced pyrexia in rats while the analgesic study was performed adopting the tail immersion or tail flick technique. Data generated was analyzed as appropriate using the analysis of variance (ANOVA).Results: The methanolic extract of the leaves of the African Cleome viscosa had a significant (P<0.05) antipyretic and analgesic effects at different time intervals and varying doses when compared with the negative control groups in the respective studies. The preliminary phytochemical study showed the presence of alkaloids, tannins, steroids, glycosides and flavonoids. The extract also proved to be non-toxic in the acute toxicity study carried out at the highest dose of 5000mg/kg body weight administered to the albino rats.Conclusions: The methanolic leaf extract of the plant showed significant antipyretic and analgesic activity in albino rats thus supporting its use in traditional medicine.

Evaluation of antidiabetic activity of fruit of Coriandrum sativum. Linn methanolic extract in Streptozocin induced diabetic wistar Albino rats

Background: Diabetes prevalence is estimated to increase annually. Numerous people use traditional medicine, such as India also considered as the diabetic capital in the world. Diabetes is a metabolic disorder characterized by disturbances in lipid, carbohydrate and protein metabolism. The present study to evaluate the antidiabetic potential of coriandrum sativum. linn fruits methanolic extract in streptozocin induced diabetic wistar albino rats model.Methods: Diabetes induction in wistar albino rats by administration of streptozocin (50mg/kg, i.p.) in citrate buffer. 30 wistar albino rats were divided into 5 groups (A, B, C, D, E). Group A: served as normal control, whereas Group B: diabetic control, Group C, D methanolic coriandrum sativum Linn. fruits extract (CSFME) at a dose of 100, 200mg/kg orally, Group E was given standard drug Glibenclamide (0.5mg/kg) orally. All groups are administered for the period of 14 consecutive days and blood sugar levels was measured at regular intervals up to end of the study.Results: This present research study confirms that the test drug compound CSFME has sustained oral hypoglycaemic activity and statistically significant (p ?0.05) and which is comparable with standard drug Glibenclamide.Conclusions: This research study confirms that the CSFME has antidiabetic activity against streptozocin induced wistar diabetic albino rats. It could be a novel antidiabetic agent and also a dietary adjunct in the type 2 diabetes management and its complication. Further studies are necessary required to confirm the antidiabetic activity of individual phytochemical compounds of Coriandrum sativum.

Inibição do sistema quorum sensing AI-1 por Capsicum frutescens e Capsicum annuum em bactérias Gram-negativas / Inhibition of AI-1 quorum-sensing system by Capsicum frutescens and Capsicum annuum in Gram-negative bacteria

A inibição do quorum sensing (QS) altera a comunicação bacteriana, reduzindo a expressão de fatores de virulência e a formação de biofilmes, o que pode conferir menor pressão seletiva em comparação aos antibióticos tradicionais. As frutas e hortaliças constituem uma fonte rica em compostos com propriedades potenciais de inibição do QS. Entretanto, há pouca referência sobre o potencial de pimentas do gênero Capsicum e de seus compostos isolados como inibidores do QS. Esse trabalho teve como objetivo avaliar o efeito de extratos orgânicos obtidos das variedades de pimenta-malagueta e pimentão vermelho sobre o sistema QS dependente do sinalizador AI-1 (acil homoserina lactona - AHL) em bactérias Gram-negativas. Os extratos foram obtidos por extração em fase sólida e separados em uma fração metanólica e outra amônica; sendo os compostos característicos identificados e quantificados por cromatografia líquida de alta eficiência (CLAE). A atividade antimicrobiana dos extratos foi avaliada pela determinação da concentração inibitória mínima (MIC) e pela curva de crescimento de Chromobacterium violaceum ATCC 12472, Serratia liquefaciens MG1 e Pseudomonas aeruginosa PAO1. O efeito anti-QS dos extratos foi avaliado pelos testes de difusão em ágar e quantificação da produção de violaceína em meio líquido por C. violaceum e sobre a formação de biofilme, avaliado pelo ensaio de cristal violeta e microscopia confocal, em S. liquefaciens e P. aeruginosa nas temperaturas 30 ºC e 37 ºC. Os resultados obtidos pela CLAE indicaram que o extrato metanólico de pimenta-malagueta (EMPM) continha capsaicinoides como a capsaicina e dihidrocapsaicina, luteolina e outros compostos não identificados; já o extrato amônico desta não continha os compostos capsaicinoides. Ambos os extratos de pimentão vermelho continham luteolina e compostos não identificados, mas não apresentaram capsaicinoides. Como o EMPM era representativo dos demais extratos, por conter tanto capsaicinóides quanto luteolina, o foco deste trabalho foi avaliar os efeitos do EMPM sobre fenótipos microbianos nas concentrações 5; 2,5; 1,25 e 0,625 mg/ml, além de utilizar a capsaicina como controle comparativo em concentrações equivalentes às do extrato (25, 50 e 100 µg/ml). Os resultados da atividade antimicrobiana mostraram inibição parcial do crescimento das bactérias nas concentrações sub-MIC (MIC >5 mg/ml) de 5 e 2,5 mg/ml de EMPM. A capsaicina também inibiu parcialmente o crescimento das bactérias a 100 µg/ml, com exceção de S. liquefaciens a 37 ºC, cujo crescimento foi induzido em 50 e 25 µg/ml. A produção de violaceína foi reduzida pelo EMPM a 1,25 e 0,625 mg/ml, sem afetar o crescimento de C. violaceum. Ensaios com C. violaceum CV026, estirpe biosensora capaz de produzir o pigmento na presença de AI-1 exógeno, sugerem que o possível mecanismo de atuação do extrato sobre o sistema QS em C. violaceum 12472 é sobre a síntese do sinalizador, já que não foi observada inibição da produção de violaceína em CV026 pelo extrato. Contrariamente, a capsaicina incrementou a produção do pigmento na estirpe 12472, mas ensaios com a estirpe CV026 indicaram que a capsaicina não atua como sinalizador do QS, uma vez que esta não induziu a produção de violaceína nesta estirpe. Já a formação de biofilme foi incrementada na presença do EMPM, sendo consideravelmente maior em P. aeruginosa a 30 ºC. Igualmente, observou-se indução da formação de biofilme por capsaicina em S. liquefaciens (37 ºC) e P. aeruginosa (30 ºC). Porém, a capsaicina não teve efeito sobre a formação de biofilme de S. liquefaciens quando cultivada a 30 ºC, nem P. aeruginosa a 37 ºC. Os resultados revelam que a produção de violaceína em C. violaceum ATCC 12472 é inibida pelo EMPM, mas não pela capsaicina. Já, o EMPM e a capsaicina, de forma geral, não inibem a formação de biofilme de S. liquefaciens MG1 nem P. aeruginosa PAO1. Outros estudos são necessários para elucidar os mecanismos pelos quais o EMPM e a capsaicina agem sobre os fenótipos avaliados neste trabalho

Quorum sensing inhibition alters bacterial communication by reducing virulence factors expression and biofilm formation, exerting less selective pressure compared to antibiotics. Fruits and vegetables are rich sources of compounds with potential QS-inhibition properties. However, there are few references about the potential of peppers belonging to the genus Capsicum and its isolated compounds as QS inhibitors. This study aimed to assess the effect of organic extracts obtained from Capsicum varieties, pimenta-malagueta (red chili) and pimentão vermelho (red bell pepper), on the AI-1 dependent QS system. The extracts were obtained by solid phase extraction and split into a methanolic and an ammonic fraction. Characteristic compounds were identified and quantified by high performance liquid chromatography (HPLC). The antimicrobial activity of the extracts was assessed by determining the minimal inhibitory concentration (MIC) and the growth curve of Chromobacterium violaceum ATCC 12472, Serratia liquefaciens MG1 and Pseudomonas aeruginosa PAO1. The anti-QS effect of the extracts was evaluated by the agar diffusion assay and the quantification of violacein production was assessed in liquid medium by C. violaceum, as well as in the biofilm formation test determined by the crystal violet assay and confocal microscopy with S. liquefaciens and P. aeruginosa at 30 ºC and 37 ºC. HPLC results showed that the methanolic extract of pimenta-malagueta (EMPM) contained capsaicinoids such as capsaicin and dihidrocapsaicin, luteolin and other unidentified compounds in lower concentrations; while its ammonic extract did not have capsaicinoids. Both pimentão vermelho extracts contained luteolin and other unidentified compounds in low concentrations, but they did not contain capsaicinoids. As EMPM was representative among the extracts because it contained capsaicinoids and luteolin, the focus of this work was to assess the effect of EMPM over microbial phenotypes at concentrations of 5, 2.5, 1.25 and 0.625 mg/ml, using capsaicin as a comparative control at equivalent concentrations to those in EMPM (25, 50 and 100 µg/ml). Antimicrobial activity assays showed a partial inhibition growth of bacteria at sub-MIC concentrations (MIC >5 mg/ml) of EMPM at 5 and 2.5 mg/ml. Similarly, capsaicin partially inhibited bacterial growth at 100 µg/ml, except for S. liquefaciens at 37 ºC in which growth was induced at 50 and 25 µg/ml. Violacein production was reduced by EMPM at 1,25 and 0,625 mg/ml without affecting C. violaceum growth. Assays with C. violaceum CV026, a biosensor strain that produces violacein in the presence of exogenous AI-1, suggest that EMPM reduced violacein production in C. violaceum 12472 by interfering with the AI-1 synthesis. In contrast, capsaicin incremented violacein synthesis in strain 12472, but experiments with strain CV026 revealed that capsaicin does not function as an analog of AI-1. Biofilm formation was increased in EMPM presence, being remarkably superior in P. aeruginosa cultivated at 30 ºC, as opposed to cultivation at 37 ºC. Similarly, capsaicin induced biofilm formation in S. liquefaciens (37 ºC) and P. aeruginosa (30 ºC). However, capsaicin did not affect biofilm formation on S. liquefaciens cultured at 30 ºC, neither on P. aeruginosa at 37 ºC. These results show that violacein production in C. violaceum ATCC 12472 is inhibited by EMPM, but not by capsaicin. In general, EMPM and capsaicin did not inhibit biofilm formation in S. liquefaciens MG1 neither in P. aeruginosa PAO1. More studies are necessary to elucidate the mechanisms by which EMPM and capsaicin affect the studied phenotypes in this work

Synthesis of silver and gold nanoparticles from leaf of Litchi chinensis and its biological activities

Objective:To synthesize and isolate silver and gold nanoparticles from Litchi chinensis leaf methanolic extract,and to evaluate its comparative biological activities including muscles relaxant,analgesic,anti-inflammatory and antidiarrheal.Methods:The gold and silver nanoparticles were synthesized by dissolving methanolic extract in gold chloride and silver nitrate solution separately which were confirmed by colour change and UV-Vis spectroscopy,and pellets were collected through centrifugation.Biological activities of the extract were conducted on BALB/c mice through various standard methods and the data were subjected to One-way ANOVA.Results:The colorless gold chloride solution changed to purple soon after the addition of plant extract,demonstrating that the reaction took place and gold ions were reduced to gold nanoparticles,while colorless silver nitrate solution changed to light and dark brown that was indicative of silver nanoparticles.The muscles relaxant activity showed that silver nanoparticles were more effective than gold nanoparticles and methanolic extract in traction test.The analgesic activity showed that silver and gold nanoparticles showed highest percentage decrease in acetic acid induced writhing at the doses of 50,100 and 150 mg/kg b.w.The highest anti-inflammatory activity was produced by gold nanoparticles followed by silver nanoparticles,while low activity was observed in methanolic leaf extract.Only the crude methanolic extract showed significant antidiarrheal activity as compared to the standard drug atropine sulphate,while antidiarrheal activities of gold and silver nanoparticles were non-significant.Contusions:The present work concludes that isolated silver and gold nanoparticles from leaf methanolic extract shows strong muscles relaxant,analgesic and antiinflammatory activities while crude methanolic extract possesses good antidiarrheal activity.

Synthesis of silver and gold nanoparticles from leaf of Litchi chinensis and its biological activities

Objective: To synthesize and isolate silver and gold nanoparticles from Litchi chinensis leaf methanolic extract, and to evaluate its comparative biological activities including muscles relaxant, analgesic, anti-inflammatory and antidiarrheal. Methods: The gold and silver nanoparticles were synthesized by dissolving methanolic extract in gold chloride and silver nitrate solution separately which were confirmed by colour change and UV-Vis spectroscopy, and pellets were collected through centrifugation. Biological activities of the extract were conducted on BALB/c mice through various standard methods and the data were subjected to One-way ANOVA. Results: The colorless gold chloride solution changed to purple soon after the addition of plant extract, demonstrating that the reaction took place and gold ions were reduced to gold nanoparticles, while colorless silver nitrate solution changed to light and dark brown that was indicative of silver nanoparticles. The muscles relaxant activity showed that silver nanoparticles were more effective than gold nanoparticles and methanolic extract in traction test. The analgesic activity showed that silver and gold nanoparticles showed highest percentage decrease in acetic acid induced writhing at the doses of 50, 100 and 150 mg/kg b.w. The highest anti-inflammatory activity was produced by gold nanoparticles followed by silver nanoparticles, while low activity was observed in methanolic leaf extract. Only the crude methanolic extract showed significant antidiarrheal activity as compared to the standard drug atropine sulphate, while antidiarrheal activities of gold and silver nanoparticles were non-significant. Conclusions: The present work concludes that isolated silver and gold nanoparticles from leaf methanolic extract shows strong muscles relaxant, analgesic and anti-inflammatory activities while crude methanolic extract possesses good antidiarrheal activity.

Phytoconstituents and antioxidant properties among commercial tea (Camellia sinensis L. ) clones of Iran

Background Tea (Camellia sinensis), a well-known beverage is consumed frequently worldwide due to its high antioxidant properties. The present study determines the amount of phytochemicals and antioxidant activities among 12 high yielding tea clones cultivated in Iran. Results Among the 12 clones studied, tea clone Iran 100 had the highest total phenolic content and total flavonoid content with values of 8.44 ± 1.03 mg gallic acid equivalents per gram dry weight and 4.50 ± 0.16 mg rutin equivalents per gram dry weight respectively. High performance Liquid Chromatography (HPLC) analysis of phenolics and flavonoids in 12 clones revealed the presence of (+)-catechin, (-)-epicatechin, (-)-epigallocatechin, (-)-epigallocatechin-gallate, (-)-epicatechingallate, gallic acid and caffeine. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay showed the existence of variation in the antioxidant activity ranging from 22.67 to 65.36%. The highest antioxidant activity with IC50 value of 218.24 µg/mL was observed in the leaf extract of the clone Iran 100, while the lowest was found in the clone Iran 482 with IC50 value of 234.44 µg/mL. The antioxidant activity had a positive correlation with total phenolic content, total flavonoid content, (-)-epigallocatechin-gallate, (-)-epicatechingallate and caffeine (0.59 = r = 0.97, P < 0.05). Conclusion From the study it can be concluded that the clone Iran 100 has a superior quality compared to any other clones studied due to occurrence of more phenolic compounds and a greater antioxidant activity. Hence, we recommend the use of tea clone Iran 100 for commercial planting.

Evaluation of acute and chronic toxic effects of Algerian germander in Swiss albino mice.

Germander (Teucrium polium) is commonly used as medicinal plant in Algeria against a variety of human diseases. This study aims to evaluate toxic effects of T. polium methanol extract (TPME) in Swiss albino mice. Biochemical parameters, organs morophology and histopathology were investigated. TPME gave a LD50 of 442.81 and 686.77 mg/kg of body weight (b.w.) in male and female mice, respectively. The acute treatment for seven days at a dose of 100 mg/kg of b.w. didn’t show any difference in body weight, relative mass and blood biochemical parameters. Histopathological examination revealed a moderate congestion in kidneys and an inflammatory infiltrate in liver. The chronic effect for 30 days at doses of 50 and 75 mg of TPME/kg of b.w. resulted in a significant increase of renal (urea), hepatic (aspartate aminotransferase and alanine aminotransferase) parameters, accompanied by a significant decrease of cholesterol level. Histopathological examination confirmed the biochemical tests by the observation of necrosis areas, ballooning degeneration and peliosis in liver sections and the presence of marked vascular congestion in kidneys in both sexes. In conclusion, the use of Teucrium polium L. may cause hepatotoxicity and nephrotoxicity after prolonged herb administration.

Antioxidant capacity of several Iranian, wild and cultivated strains of the button mushroom

The white button mushroom, Agaricus bisporus, is the most commonly grown mushroom in Iran; however, there is a significant shortage of research on its antioxidant activity and other medicinal properties. The aim of this study was to evaluate antioxidant capacity of the methanolic extracts from four cultivated strains and four Internal Transcribed Spacer (ITS)-identified, Iranian wild isolates of A. bisporus. Evaluations were made for total phenols, flavonoids and anthocyanins, and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity. Overall, results showed that all the wild isolates exhibited significantly lower DPPH-derived EC₅₀, compared to the cultivated strains (p < 0.05). A relatively high relationship was observed between total phenols and flavonoids or anthocyanins (r² > 0.60). However, these constituents could not statistically differentiate the group of wild samples from the cultivated ones, and there was low correlation with the DPPH-derived EC₅₀s (r² < 0.40). In conclusion, comparisons showed that wild isolate 4 and cultivated strains A15 and H1 had higher antioxidant capacity than the others (p < 0.05). This result identifies these mushrooms as good candidates for further investigation.

Anti-Toxoplasma activities of methanolic extract of Sambucus nigra (Caprifoliaceae) fruits and leaves / Actividad anti-Toxoplasma de extractos metanólicos de frutos y hojas de Sambucus nigra (Caprifoliaceae)

Toxoplasma gondii is an obligatory intracellular parasite that infects a wide range of warm-blooded animals and humans. Considering the severity of toxoplasmosis, side effects of current treatments, and the contribution of the ethnopharmacological knowledge for the treatment of parasitic infections, the aim of the present study was to investigate the efficacy of methanolic extracts from the fruits and leaves of Sambucus nigra against tachyzoite of T. gondii. For this, fruits and leaves of S. nigra were collected from Mazandaran province, Iran, were dried under the shade, and powdered using a commercial electrical blender. For extractions, methanol was used as solvent. Virulent RH strain of T. gondii was maintained in mice and macrophages containing tachyzoites were aspirated from the peritoneal cavity. Four concentrations (5, 10, 25 and 50mg/mL) of S. nigra extract were incubated with infected macrophages for 30, 60, 120 and 180 minutes and the viability of the tachyzoites were evaluated by trypan blue staining. Results showed that S. nigra fruit extracts at the concentrations of 5 and 10mg/mL killed 100% of T. gondii tachyzoites after 60 and 120 minutes, respectively; and concentrations of 25 and 50mg/mL killed 100% of the tachyzoites after 30 minutes. Additionally, extract of S. nigra leaves, at the concentrations of 5, 10 and 25mg/mL after 180 minutes, and concentration of 50mg/mL after 60 minutes, resulted with the highest efficacy. Our results showed that S. nigra has acceptable efficacy in vitro and the parasiticidal effect of fruit extract was significantly better than leaf extract. However, in vivo efficacy of this extract needs further investigation. Rev. Biol. Trop. 63 (1): 7-12. Epub 2015 March 01.

Toxoplasma gondii es un parásito intracelular obligatorio que infecta a una gran variedad de animales y seres humanos. Teniendo en cuenta la gravedad de la toxoplasmosis, los efectos secundarios de los tratamientos actuales, y la contribución de los conocimientos etnofarmacológicos para el tratamiento de infecciones parasitarias, el objetivo del presente estudio fue investigar la eficacia de los extractos metanólicos de los frutos y hojas de Sambucus nigra contra el taquizoito de T. gondii. Para esto, se recogieron frutos y hojas de S. nigra en la provincia de Mazandaran, Irán, se secaron a la sombra, y se pulverizaron con una batidora eléctrica comercial. Para las extracciones, se empleó metanol como disolvente. La cepa virulenta RH de T. gondii se mantuvo en ratones y los macrófagos con taquizoitos se aspiraron de la cavidad peritoneal. Cuatro concentraciones (5, 10, 25 y 50mg/ mL) de extracto de S. nigra se encubaron con los macrófagos infectados durante 30, 60, 120 y 180 minutos y la viabilidad de los taquizoitos se evaluó mediante tinción con azul de tripano. Los resultados mostraron que los extractos de frutos de S. nigra en las concentraciones de 5 y 10mg/mL mataron al 100% de los taquizoitos de T. gondii después de 60 y 120 minutos, respectivamente; y las concentraciones de 25 y 50mg/mL mataron al 100% de los taquizoitos después de 30 minutos. Además, el extracto de hojas de S. nigra, en concentraciones de 5, 10 y 25mg/mL después de 180 minutos, y una concentración de 50mg/mL después de 60 minutos, resultaron más eficientes. Nuestros resultados mostraron que S. nigra tiene una eficacia aceptable in vitro y el efecto parasiticida del extracto de frutos fue significativamente mejor que el del extracto de hoja. Sin embargo, la eficacia in vivo de este extracto necesita más investigación.

Behavioural and Electrophysiological Evidence of Impaired Learning and Memory in Male Sprague Dawley Rats following Subchronic Exposure to Standardised Methanolic Extract of Mitragyna Speciosa Korth

Background: Mitragyna speciosa (MS) or ketum is primarily found in Southeast Asia, particularly in northern Malaysia and Thailand. The medicinal value of this plant has attracted significant attention from both herbal medicine practitioners and scientists worldwide. Despite having illegal consumption status, the plant merits study. We conducted a series of experiments to test our hypothesis that ketum impairs both learning and memory in rats. Methods: Ketum leaves were extracted using methanol and standardised for the amount of its pure compound, mitragynine. Rats were divided into groups for a passive avoidance task and long-term potentiation (LTP) extracellular recording. In the extracellular recording condition, rats were grouped into control, MS100 (100 mg/kg of ketum extract), MS200 (200 mg/kg of ketum extract), and MS500 (500 mg/kg of ketum extract) groups. An additional group that received morphine was included in the passive avoidance task (10 mg/kg), and there were six animals per group. Rats received daily treatments orally for 28 days for both experiments. Result: Using a passive avoidance task, our data revealed that the rats' memory significantly increased with increasing doses of MS compared to the morphine-treated group. Our findings from LTP recordings showed that LTP was fully blocked by the higher doses of MS. Conclusion: We speculate on the possibility that additional factors were involved in the passive avoidance task because it was an in vivo animal study, while the LTP experiment solely involved brain slices.