Effects of Bothrops moojeni venom on Leishmania amazonensis promastigote forms

In the present work, the effect of Bothrops moojeni venom fractions on Leishmania promastigotes was evaluated. The snake venom was fractionated into five protein fractions (E1 to E5), by ion exclusion chromatography, that were used to treat Leishmania amazonensis and Leishmania braziliensis promastigote forms whereas the viability and nitric oxide production were evaluated. It was observed that E5 venom fraction strongly inhibited Leishmania amazonensis nitric oxide production, while in Leishmania braziliensis the nitric oxide production was enhanced in all doses. Bothrops moojeni crude venom reduced the viability of both parasites in a dose-dependent manner and a peptide of 64 kDa was apparently degraded. Bothrops moojeni E5 venom fraction only reduced the viability and nitric oxide production of Leishmania amazonensis and no protein degradation was observed. Thus, these results suggest that Bothrops moojeni E5 venom fraction may offer components with a promising antileishmanial therapeutic application.

Down-modulation of nitric oxide production in murine macrophages treated with crude plant extracts from the Brazilian Cerrado.

Several plant species from the Cerrado biome in Brazil are popularly used as herbal medicines for its reputed analgesic, anti-acid, anti-microbial, anti-inflammatory and anti-tumoral properties, among others. It has been reported that some plant extracts interfere in the production of nitric oxide (NO), an important inflammatory mediator. In the present study, we investigated the effect of hexanic and ethanolic extracts from three plant species on NO production by LPS/IFN-gamma-activated J774 macrophages based on traditional use. The cytotoxic effect of the crude extracts was determined by the thiazolyl blue test (MTT) to measure cell viability. Serjania lethalis stem extracts and Cupania vernalis leaf extracts significantly inhibited NO production, while extracts from Casearia sylvestris var. lingua were inactive or showed low activity on NO production, or were very cytotoxic. The ethanolic stem bark and leaf extracts of Serjania lethalis and Cupania vernalis, respectively, almost completely inhibited the production of NO by J774 macrophages. It can be concluded that the selected extracts are potential sources of active compounds that might be used as anti-inflammatory agents.