Anti-biofilm activity against Staphylococcus aureus MRSA and MSSA of neolignans and extract of Piper regnellii

ABSTRACT Many infections worldwide are associated with bacterial biofilms. The effects of isolated neolignans (conocarpan and eupomathenoid-5) and the dichloromethane extract of Piper regnellii (Miq.) C. DC., Piperaceae, were tested against isolates of methicillin-resistant Staphylococcus aureus and methicillin-sensitive S. aureus biofilms and S. aureus planktonic cells. The dichloromethane extract presented better results than isolated neolignans against all of the biofilms tested, with a minimum inhibitory concentration <400 µg/ml for preformed biofilms and minimal biofilm inhibitory concentration of 15.6 µg/ml for biofilm formation. The minimum inhibitory concentration to planktonic cells was <12.5 µg/ml. These results indicate a good effect of the dichloromethane extract against methicillin-resistant S. aureus and methicillin-sensitive S. aureus biofilms and efficient prophylaxis.

Antiviral activity of fractions from leaves of Piper regnelli var. pallescens

This study investigated the antiviral potential of fractions and eupomatenoid-5 obtained from Piper regnelli (Miq.) C. DC., Piperaceae, leaves against bovine herpesvirus-1 (BHV-1) and poliovirus. VERO cell monolayers in 96-well cell culture plates were infected with BHV-1 or poliovirus and incubated in the presence and absence of samples for 48 h. The cells were then fixed and stained with sulforhodamine B, and the virus-induced cytopathic effect was measured in a 96-well plate reader at 530 nm. Cytotoxicity was assessed by incubating the cell monolayers with samples for 72 h. The hexane, chloroform, chloroform/ethyl acetate (19:1), and chloroform/ethyl acetate (9:1) fractions showed activity against BHV-1. The chloroform, chloroform/ethyl acetate (19:1), chloroform/ethyl acetate (9:1), chloroform/ethyl acetate (1:1), and ethyl acetate fractions were active against poliovirus. The chloroform/ethyl acetate (9:1) fraction presented the best selectivity index for both viruses. The present study reports the antiviral activity of the extract and fractions of P. regnelli leaves.

Quantification of β-ecdysone in differents parts of Pfaffia glomerata by HPLC

Pfaffia glomerata (Spreng.) Pedersen, Amaranthaceae, is widely distributed in Brazil. Roots are considered as the world's greatest supplier and β-ecdysone is the most important compound extracted from roots of Pfaffia glomerata. So, the aim this study was analyze the presence of β-ecdysone in the inflorescences and stems and compared with the content from roots of Pfaffia glomerata and determine the best extractive method of β-ecdysone this plant. The crude extracts were obtained by Soxhlet method, reflux, maceration, percolation and turbolyse. Compound extracts were quantified by High Performance Liquid Chromatography (HPLC). The analysis were carried out a Phenomenex Column C18, 5 µm, 250x4,6mm, maintened at 30 ºC, gradient system using as mobile phase a mixture of methanol and water, flow rate 1,0 mL and detection at 245 nm. Results showed Soxhlet method with ethanol:water (90:10 v/v) presented the higher concentration of β-ecdysone in P. glomerata and inflorescences showed higher amount of this active substance (3,06%), compared with stems (2,37%) and roots (1,63%), showing that the inflorescences and plant stems may also be used as a rich source of β-ecdysone.

Hypoglycemic effect of the hydroalcoholic extract of leaves of Averrhoa carambola L. (Oxalidaceae) / Efeito hipoglicemiante do extrato hidroalcoólico de folhas de Averrhoa carambola L. (Oxalidaceae)

O efeito do tratamento via oral (20 mg/kg x day) com extrato hidroalcoólico de folhas de Averrhoa carambola L. (EHFC) sobre a glicemia de jejum (15 h) foi examinada ao compararmos ratos que receberam veículo (Grupo controle) ou EHFC (Grupo EHFC) durante 15 dias. O grupo EHFC apresentou menor glicemia de jejum (p<0,05). Em contraste, o grupo EHFC apresentou maior (p<0,05) produção hepática glicose a partir de L-alanina (5 mM). Este efeito foi mediado, pelo menos parcialmente, pela ativação do catabolismo da L-alanina, inferido pela maior produção hepática de uréia (p<0,05) e L-lactato (p<0,05). Diferente da L-alanina, a produção hepática de glicose a partir de L-glutamina (5 mM), L-lactato (2 mM) e glicerol (2 mM) no grupo EHFC foi similar ao grupo controle. Adicionalmente, o efeito do tratamento com EHFC sobre a captação de glicose no músculo soleus, inferida pela incorporação de [14C]-glicose em glicogênio (síntese de glicogênio) e produção de [14C]-lactato foi investigada, verificando-se resultados semelhantes nos dois grupos. Assim, concluiu-se que a redução da glicemia de jejum promovida pelo tratamento com EHFC não foi mediada por inibição da gliconeogenese hepática e/ou aumento da captação muscular de glicose.

The effect of the oral treatment (20 mg/kg x day) with the hydroalcoholic extract of leaves of Averrhoa carambola L. (HELAC) on fasting glycemia (15 h) was examined. For this purpose, rats that received vehicle (Control group) or HELAC (HELAC group) during 15 days were compared. HELAC group showed lower fasting glycemia (p<0.05). In contrast, livers from HELAC group showed higher (p<0.05) glucose production from L-alanine (5 mM). This effect was mediated, at least part of it, by an activation of the catabolism of L-alanine inferred by the increased hepatic urea (p<0.05) and L-lactate (p<0.05) production. Differently of L-alanine, the glucose production from L-glutamine (5 mM), L-lactate (2 mM) and glycerol (2 mM) was similar (Control group vs. HELAC group). In addition, the HELAC treatment did not change the glucose uptake in soleus muscles, inferred by the incorporation of [14C]-glucose to glycogen (glycogen synthesis) and [14C]-lactate production. Thus, we can conclude that the reduction of fasting glycemia promoted by the treatment with HELAC was not mediated by an inhibition of hepatic gluconeogenesis and/or an increased glucose uptake by muscles.

Antifungal activity of the extracts and saponins from Sapindus saponaria L

Extracts from the dried pericarp of Sapindus saponaria L. (Sapindaceae) fruits were investigated for their antifungal activity against clinical isolates of yeasts Candida albicans and C. non-albicans from vaginal secretions of women with Vulvovaginal Candidiasis. Four clinical isolates of C. albicans, a single clinical isolated of each of the species C. parapsilosis, C. glabrata, C. tropicalis, and the strain of C. albicans ATCC 90028 were used. The hydroalcoholic extract was bioactivity-directed against a clinical isolate of C. parapsilosis, and showed strong activity. The n-BuOH extract and one fraction showed strong activity against all isolates tested. Further column-chromatography on silica gel separation of this fraction afforded two pure triterpene acetylated saponins: 3-O-(4-acetyl-beta-D-xylopyranosyl)-(1->3)-alpha-Lrhamnopyranosyl-(1->2)-alpha-L-arabinopyranosyl-hederagenin (1) and 3-O-(3,4-di-acetyl-beta-D-xylopyranosyl)-(1->3)-alpha-L-rhamnopyranosyl-(1->2)-alpha-L-arabynopyranosyl-hederagenin (2). The structures of the compounds were based on spectral data (¹H and 13C NMR, HSQC, HMBC and MS), and on with literature. The saponins isolated showed strong activity against C. parapsilosis.

Extratos do pericarpo de frutos de Sapindus saponaria L. (Sapindaceae) foram testados para a atividade antifúngica sobre isolados clínicos de leveduras de Candida albicans e C. não-albicans obtidos de secreção vaginal de mulheres com Candidíase Vulvovaginal. Foram avaliados quatro isolados clínicos de C. albicans, um de cada uma das espécies C. glabrata, C. parapsilosis, C. tropicalis e uma cepa referência de C. albicans ATCC 90028. O extrato hidroalcoólico foi biomonitorado contra um isolado clínico de C. parapsilosis, apresentando forte atividade. O extrato butanólico e uma fração apresentaram forte atividade contra todos os isolados testados. Posterior análise desta fração via cromatografia em sílica gel (CHCl3:CH3OH, 1:1, v/v) resultou no isolamento de duas saponinas triterpênicas puras mono e diacetiladas, 3-O-(4-O-acetil-O-beta-D-xilopiranosil)-(1 -> 3)-alfa-L-ramnopiranosil-(1 -> 2)-alfa-L-arabinopiranosil-hederagenina (1) e 3-O-(3,4-di-O-acetil-beta-D-xilopiranosil)-(1 -> 3)-alfa-L-ramnopiranosil-(1 -> 2)-alfa-L-rabinopiranosil-hederagenina (2) respectivamente. A elucidação estrutural das substâncias foi baseada em dados espectrais (RMN de ¹H e de 13C, HSQC, HMBC, ESI/MS) e comparados com dados da literatura. As saponinas triterpênicas isoladas (1) e (2) apresentaram forte atividade contra C. parapsilosis.

Atividade antileishmania do extrato hidroalcoólico e de frações obtidas de folhas de Piper regnellii (Miq.) C. DC. var. pallescens (C. DC.) Yunck / Antileishmanial activity of hydroalcoholic extract and fractions obtained from leaves of Piper regnellii (Miq.) C. DC. var. pallescens (C. DC.)

A atividade biológica do extrato bruto e as várias frações obtidas de folhas de Piper regnellii (Miq.) C. DC. var. pallescens (C. DC.) Yunck foi avaliada em Leishmania amazonensis. Este estudo incluiu o processo de extração e o fracionamento biomonitorado pelo método de cromatografia de adsorção. Um aumento progressivo no efeito antileishmania foi observado durante o processo de purificação. O extrato hidroalcoólico solúvel em água (EBA) apresentou concentração inibitória 50 por cento (IC50) igual a 167 µg/mL enquanto o extrato hidroalcoólico solúvel em acetato de etila (EBAcOEt) mostrou um IC50 de 30 mg/mL sobre o crescimento de formas promastigotas após 48 h de cultivo. A fração hexano (FHex) apresentou uma atividade antileishmania maior que o EBAcOEt com IC50 de 21,5 µg/mL. Análises de citotoxicidade indicaram que as concentrações tóxicas do EBA, EBAcOEt e das frações foram maiores para macrófagos J774G8 do que para os protozoários.

Biological activity of the crude extract and several fractions obtained from Piper regnellii var. pallescens was assessed on Leishmania amazonensis. This study included the extraction process and bioassay-guided fractionation by the adsorption chromatography method. A progressive increase in the antileishmanial effect was observed in the course of the purification process. The hydroalcoholic extract water soluble (EBA) had a 50 percent inhibitory concentration (IC50) at 167 µg/mL whereas the hydroalcoholic extract acetate soluble (EBAcOEt) showed an IC50 of 30 µg/mL against the growth of promastigote forms after 48 h of culturing. The hexan fraction (FHex) showed an antileishmanial activity greater than EBAcOEt with IC50 at 21.5 µg/mL. Analysis of cytotoxicity indicated that the toxic concentrations of the EBA, EBAcOEt, and fractions were higher for J774G8 macrophages than for the protozoans.

Ausência de efeito hipolipemiante da Solanum melongena L. (berinjela) em pacientes hiperlipidêmicos / Absence of hypolipidemic effect of Solanum melongena L. (eggplant) on hyperlipidemic patients

Neste estudo, investigamos o potencial hipolipemiante do extrato seco do fruto de berinjela (Solanum melongena), o qual tem sido comercializado no Brasil para o tratamento da hiperlipidemia humana. Assim, um estudo duplo-cego randomizado, objetivando avaliar a eficácia da Solanum melongena (SM) administrada oralmente, foi realizado. Este estudo consistiu de 41 voluntários hiperlipidêmicos alocados para tratamento com SM (n= 21) ou placebo (n= 20). Cada voluntário recebeu duas cápsulas contendo SM (450mg) ou placebo (450mg) duas vezes ao dia, sendo acompanhados mensalmente. A dose de SM utilizada corresponde ao empregado para tratar hiperlipidemia no Brasil. Após 3 meses de tratamento, os valores séricos de colesterol total, LDL-c e LDL-c/HDL-c diminuíram (p<0,05) no grupo tratado com SM. Todavia, efeito similar foi observado no grupo placebo. Os demais parâmetros, incluindo valores séricos de triglicérides, HDL-c, VLDL-c, AST, ALT, gGT, glicose e índice de massa corpórea não apresentaram modificações significativas. Assim, podemos concluir que a SM, pelo menos na forma comercializada no Brasil (extrato seco do fruto), requer um maior volume de estudos clínicos antes de ser recomendada para tratar hiperlipidemia.