In vitro leishmanicidal and cytotoxic activities of the glycoalkaloids from Solanum lycocarpum (Solanaceae) fruits.

Leishmaniasis is an infection caused by a protozoan parasite of the genus Leishmania and is the second most prevalent parasitic protozoal disease after malaria in the world. We report the in vitro leishmanicidal activity on promastigote forms of Leishmania amazonensis and cytotoxicity, using LLCMK2 cells, of the glycoalkaloids from the fruits of Solanum lycocarpum, determined by colorimetric methods. The alkaloidic extract was obtained by acid-base extraction; solamargine and solasonine were isolated by silica-gel chromatography, followed by reversed-phase HPLC final purification. The alkaloidic extract, solamargine, solasonine, as well as the equimolar mixture of the glycoalkaloids solamargine and solasonine displayed leishmanicidal activity against promastigote forms of L. amazonensis, whereas the aglycone solasodine was inactive. After 24 and 72 h of incubation, most of the samples showed lower cytotoxicities (IC50 6.5 to 124 µM) as compared to leishmanicidal activity (IC50 1.1 to 23.6 µM). The equimolar mixture solamargine/solasonine was the most active with an IC50 value of 1.1 µM, after 72 h. Likewise, solamargine was the most active after 24 h with an IC50 value of 14.4 µM, both in comparison with the positive control amphotericin B.

Zinc and pregnancy: Marked changes on the immune response following zinc therapy for pregnant females challenged with Trypanosoma cruzi.

BACKGROUND & AIMS: The occurrence of infectious disease processes during pregnancy has significant effects on maternal health and can lead to adverse pregnancy outcomes. The aim of the present study was to examine the potential role of zinc treatment during Trypanosoma cruzi infection in pregnant animals. METHODS: Female Wistar rats weighing 180-200 g were used in all experiments. Production of nitric oxide, peritoneal macrophages counts, and concentrations of IFN-γ and TNF-α were measured, and the potential protective effects of zinc on fetal development were assessed at 14-day post-infection. RESULTS: Nitric oxide concentrations were higher in pregnant zinc-treated animals than in their untreated counterparts, despite similar levels of the macrophages, IFN-γ and TNF-α. Zinc therapy was associated with a significant reduction in parasitemia and cardiac parasite burden. Higher placental and birth weights were observed in animals given prenatal zinc supplementation compared to untreated animals. CONCLUSIONS: These data confirm the critical importance of adequate zinc intake during the peri-conceptional period and indicate that zinc has an effective role in preventing adverse outcomes of pregnancy and reducing the risk of common infections such as Chagas' disease.