BnSP-7 toxin, a basic phospholipase A sub(2) from Bothrops pauloensis snake venom, interferes with proliferation, ultrastructure and infectivity of Leishmania (Leishmania) amazonensis

• Published in: Parasitology 2013-06, Vol.140 (7), p.844-854
• Main Authors: Nunes, Debora CO, FIGUEIRA, MARCIA MNR, Lopes, Daiana S, DE SOUZA, DAYANE LNAVES, IZIDORO, LUIZ FERNANDO M, FERRO, ELOASA AV, Souza, Maria A, Rodrigues, Renata S, RODRIGUES, VERIDIANA M, YONEYAMA, KELLY AG
• Format: Article
• Language: English
• Subjects: Bothrops; Leishmania amazonensis
• ISSN: 0031-1820; 1469-8161
• DOI: 10.1017/S0031182013000012

This paper reports the effects of BnSP-7 toxin, a catalytically inactive phospholipase A sub(2) from Bothrops pauloensis snake venom, on Leishmania (Leishmania) amazonensis. BnSP-7 presented activity against promastigote parasite forms both in the MTT assay, with IC sub(50) of 58.7 mu g mL super(-1) of toxin, and a growth curve, inhibiting parasite proliferation 60-70% at concentrations of 50-200 mu g mL super(-1) of toxin 96 h after treatment. Also, the toxin presented effects on amastigotes, reducing parasite viability by 50% at 28.1 mu g mL super(-1) and delaying the amastigote-promastigote differentiation process. Ultrastructural studies showed that BnSP-7 caused severe morphological changes in promastigotes such as mitochondrial swelling, nuclear alteration, vacuolization, acidocalcisomes, multiflagellar aspects and a blebbing effect in the plasma membrane. Finally, BnSP-7 interfered with the infective capacity of promastigotes in murine peritoneal macrophages, causing statistically significant infectivity-index reductions (P < 0.05) of 20-35%. These data suggest that the BnSP-7 toxin is an important tool for the discovery of new parasite targets that can be exploited to develop new drugs for treating leishmaniasis.