Antibacterial and antiparasitic effects of Bothropoides lutzi venom.

The therapeutic potential of toxins has aroused great interest in the scientific community. Microbial resistance is a serious current public health problem, in part because of the wide use of antimicrobial drugs. Furthermore, there are several problems in the treatment of parasitic diseases such as leishmaniosis and Chagas' disease, including the low efficacy in some clinical phases of the diseases and the loss of effectiveness of benzonidazole in the chronic phase of Chagas' disease. In this context, the aim of this work was to study the antimicrobial and antiparasitic effects of Bothropoides lutzi total venom (BltTV). The venom exerted an antibacterial effect on S. aureus, with MIC=MLC=200 microg/mL. The inhibitory effects of BltTV on promastigote forms of Leishmania amazonensis and L. chagasi were assessed by counting of viable cells after incubation with BltTV. IC50 values of 234.6 microg/mL and 61.2 microg/mL, were obtained, respectively. Furthermore, the venom repressed epimastigote forms of Trypanosoma cruzi growth. Finally, BltTV was verified to affect murine peritoneal macrophages, causing a cytotoxic effect at the highest concentrations (100 and 50 microg/mL). In conclusion, Bothropoides lutzi venom demonstrated antibacterial and antiparasite effects, suggesting that the venom contains some substance(s) of therapeutic value.

Betulinic acid, a natural pentacyclic triterpenoid, prevents abdominal fat accumulation in mice fed a high-fat diet.

In the search for potential antiobese agents from natural sources, this study investigated the effects of betulinic acid (BA), a pentacyclic triterpene from Clusia nemorosa L. (Clusiaceae), in mice on a high-fat diet (HFD). Adult male Swiss mice (n = 8) treated or not with BA (50 mg/L, in drinking water) were fed a HFD during 15 weeks. Mice treated with BA and fed a HFD showed significantly (P < 0.05) decreased body weights, abdominal fat accumulation, blood glucose, plasma triglycerides, and total cholesterol relative to their respective controls fed no BA. Additionally, BA treatment, while significantly elevating the plasma hormone levels of insulin and leptin, decreased the level of ghrelin. However, it caused a greater decrease in plasma amylase activity than the lipase. These findings suggest that BA has an antiobese potential through modulation of fat and carbohydrate metabolism, and it may be a suitable lead compound in the treatment of obesity.