Leishmanicidal Metabolites from Cochliobolus sp., an Endophytic Fungus Isolated from Piptadenia adiantoides (Fabaceae)

Protozoan parasites belonging to genera Leishmania and Trypanosoma are the etiological agents of severe neglected tropical diseases (NTDs) that cause enormous social and economic impact in many countries of tropical and sub-tropical areas of the world. In our screening program for new drug leads from natural sources, we found that the crude extract of the endophytic fungus Cochliobolus sp. (UFMGCB-555) could kill 90% of the amastigote-like forms of Leishmania amazonensis and inhibit by 100% Ellman's reagent reduction in the trypanothione reductase (TryR) assay, when tested at 20 µg mL−1. UFMGCB-555 was isolated from the plant Piptadenia adiantoides J.F. Macbr (Fabaceae) and identified based on the sequence of the internally transcribed spacer (ITS) regions of its ribosomal DNA. The chromatographic fractionation of the extract was guided by the TryR assay and resulted in the isolation of cochlioquinone A and isocochlioquinone A. Both compounds were active in the assay with L. amazonensis, disclosing EC50 values (effective concentrations required to kill 50% of the parasite) of 1.7 µM (95% confidence interval = 1.6 to 1.9 µM) and 4.1 µM (95% confidence interval = 3.6 to 4.7 µM), respectively. These compounds were not active against three human cancer cell lines (MCF-7, TK-10, and UACC-62), indicating some degree of selectivity towards the parasites. These results suggest that cochlioquinones are attractive lead compounds that deserve further investigation aiming at developing new drugs to treat leishmaniasis. The findings also reinforce the role of endophytic fungi as an important source of compounds with potential to enter the pipeline for drug development against NTDs

Efeito do extrato aquoso de Sida cordifolia na regeneração hepática após hepatectomia parcial

Introdução: O uso de plantas medicinais para o tratamento de patologias humanas tem aumentado em todo mundo. Muitas delas são usadas por administração oral, e após a absorção podem afetar muitos órgãos. Objetivo: Esse estudo, tem como objetivo verificar o efeito do extrato aquoso de Sida cordifolia, popularmente conhecida no Brasil como “malva-branca”, na regeneração hepática. Métodos: Vinte ratos foram divididos em 4 grupos: controle, Sida 100, Sida 200 e Sida 400. Os animais foram submetidos a administração oral de água destilada, 100, 200 e 400 mg/kg de extrato aquoso de Sida cordifolia, respectivamente. Imediatamente após, foi realizada hepatectomia parcial 67%. Vinte quatro horas após, os fígados foram removidos. A regeneração hepática foi avaliada por imunohistoquímica (PCNA), usando o anticorpo monoclonal PC-10. Resultados: Os grupos Sida100 e Sida200 mostraram índices de regeneração hepática maiores que o grupo controle (p<0.001 e p<0.05, respectivamente). Conclusão: O extrato aquoso de Sida cordifolia estimula a regeneração hepática após hepatectomia parcial a 67% em ratos. _________________________________________________________________________________________ ABSTRACT: Purpose: The use of medicinal plants for the treatment of human diseases has increased worldwide. Many of them are used by oral administration and, after absorption, may affect many organs. Therefore, this study aimed at assessing the effects of the aqueous extract of Sida cordifolia leaves, popularly known in Brazil as “malva-branca”, on liver regeneration. Methods: Twenty rats were divided into four groups: control, Sida100, Sida200 and Sida400 groups. All animals were submitted to oral administration of distilled water, 100, 200 and 400 mg/kg of the aqueous extract of Sida cordifolia, respectively. Immediately after this, they underwent 67% partial hepatectomy. Twenty four hours later, their livers were removed. Hepatic regeneration was assessed by immunohistochemical staining for proliferating cell nuclear antigen (PCNA) using the PC-10 monoclonal antibody. Results: Sida100 and Sida200 groups disclosed higher liver regeneration indices than control group (p<0.001 and p<0.05, respectively). Conclusion: The aqueous extract of Sida cordifolia stimulates liver regeneration after 67% partial hepatectomy in rats

Endophytic fungi from the roots of horseradish (Armoracia rusticana) and their interactions with the defensive metabolites of the glucosinolate myrosinase – isothiocyanate system

K

BIOACTIVE AND OTHER PIPERIDINE ALKALOIDS FROM CASSIA-LEPTOPHYLLA

Four new piperidine alkaloids, leptophyllin A (4), 3-acetylleptophyllin A (5), leptophyllin B (8), and (-)-spectaline (1), and 3 known piperidine alkaloids, (-)-spectalinine (2), canavaline (3), and iso-6-canavaline (7), were isolated by a bioassay-guided fractionation of a leaf extract of Cassia leptophylla. The alkaloids 1 - 3 were active in a mechanism-based DNA-modifying yeast assay and 2 was moderately active in Vero monkey and Chinese hamster ovary cell cytotoxicity assays

A DNA-damaging sesquiterpene and other constituents from Frullania nisquallensis

Bioassay-guided fractionation of an MeCOEt extract of Frullania nisquallensis Sull. has furnished a DNA-damaging sesquiterpene, costunolide (1), and two inactive compounds, a sesquiterpene (-)-frullanolide (2) and a tridepside tenuiorin (3). C-13-NMR data of 3 are reported