PLA2-MjTX-II from Bothrops moojeni snake venom exhibits antimetastatic and antiangiogenic effects on human lung cancer cells.

Phospholipases A2 (PLA2s) from snake venom possess antitumor and antiangiogenic properties. In this study, we evaluated the antimetastatic and antiangiogenic effects of MjTX-II, a Lys49 PLA2 isolated from Bothrops moojeni venom, on lung cancer and endothelial cells. Using in vitro and ex vivo approaches, we demonstrated that MjTX-II reduced cell proliferation and inhibited fundamental processes for lung cancer cells (A549) growth and metastasis, such as adhesion, migration, invasion, and actin cytoskeleton decrease, without significantly interfering with non-tumorigenic lung cells (BEAS-2B). Furthermore, MjTX-II caused cell cycle alterations, increased reactive oxygen species production, modulated the expression of pro- and antiangiogenic genes, and decreased vascular endothelial growth factor (VEGF) expression in HUVECs. Finally, MjTX-II inhibited ex vivo angiogenesis processes in an aortic ring model. Therefore, we conclude that MjTX-II exhibits antimetastatic and antiangiogenic effects in vitro and ex vivo and represents a molecule that hold promise as a pharmacological model for antitumor therapy.

Antiangiogenic properties of BthMP, a P-I metalloproteinase from Bothrops moojeni snake venom by VEGF pathway in endothelial cells.

Angiogenesis is a process that is controlled by a delicate combination of proangiogenic and antiangiogenic molecules and can be disrupted in various illnesses, including cancer. Non-cancerous diseases can also have an abnormal or insufficient vascular growth, inflammation and hypoxia, which exacerbate angiogenesis. These conditions include atherosclerosis, psoriasis, endometriosis, asthma, obesity and AIDS. Based on that, the present work assessed the in vitro and ex vivo antiangiogenic properties stemming from BthMP, a P-I metalloproteinase from Bothrops moojeni snake venom, via the VEGF pathway. BthMP at a concentration of 5 and 40 µg/mL showed no toxicity to endothelial cells (HUVEC) in the MTT assay and was not able to induce necrosis and colony proliferation. Interestingly, BthMP inhibited adhesion, migration and invasion of HUVECs in Matrigel and arrested in vitro angiogenesis by reducing the average number of nodules in toxin-treated cells by 9.6 and 17.32 at 5 and 40 µg/mL, respectively, and the number of tubules by 15.9 at 5 µg/mL and 21.6 at 40 µg/mL in a VEGF-dependent way, an essential proangiogenic property. Furthermore, BthMP inhibited the occurrence of the angiogenic process in an ex vivo aortic ring test by decreasing new vessel formation by 52% at 5 µg/mL and by 66% at 40 µg/mL and by increasing the expression of an antiangiogenic gene, SFLT-1, and decreasing the expression of the proangiogenic genes VEGFA and ANGPT-1. Finally, this toxin reduces the production of nitric oxide, a marker that promotes angiogenesis and VEGF modulation, and decreases the protein expression of VEGFA in the supernatant of the HUVEC culture by about 30 %. These results suggest that BthMP has a promising antiangiogenic property and proves to be a biotechnological mechanism for understanding the antiangiogenic responses induced by snake venom metalloproteinases, which could be applied to a variety of diseases that exhibit an imbalance of angiogenesis mechanisms.

Antileishmanial effects of γCdcPLI, a phospholipase A2 inhibitor from Crotalus durissus collilineatus snake serum, on Leishmania (Leishmania) amazonensis.

BACKGROUND: Leishmaniasis, a neglected disease caused by the parasite Leishmania, is treated with drugs associated with high toxicity and limited efficacy, in addition to constant reports of the emergence of resistant parasites. In this context, snake serums emerge as good candidates since they are natural sources with the potential to yield novel drugs. OBJECTIVES: We aimed to show the antileishmanial effects of γCdcPLI, a phospholipase A2 inhibitor from Crotalus durissus collilineatus snake serum, against Leishmania (Leishmania) amazonensis. METHODS: Promastigotes forms were exposed to γCdcPLI, and we assessed the parasite viability and cell cycle, as well as invasion and proliferation assays. FINDINGS: Despite the low cytotoxicity effect on macrophages, our data indicate that γCdcPLI has a direct effect on parasites promoting an arrest in the G1 phase and reduction in the G2/M phase at the highest dose tested. Moreover, this PLA2 inhibitor reduced the parasite infectivity when promastigotes were pre-treated. Also, we demonstrated that the γCdcPLI treatment modulated the host cell environment impairing early and late steps of the parasitism. MAIN CONCLUSIONS: γCdcPLI is an interesting tool for the discovery of new essential targets on the parasite, as well as an alternative compound to improve the effectiveness of the leishmaniasis treatment.

Antileishmanial effects of γCdcPLI, a phospholipase A2 inhibitor from Crotalus durissus collilineatus snake serum, on Leishmania (Leishmania) amazonensis

BACKGROUND Leishmaniasis, a neglected disease caused by the parasite Leishmania, is treated with drugs associated with high toxicity and limited efficacy, in addition to constant reports of the emergence of resistant parasites. In this context, snake serums emerge as good candidates since they are natural sources with the potential to yield novel drugs. OBJECTIVES We aimed to show the antileishmanial effects of γCdcPLI, a phospholipase A2 inhibitor from Crotalus durissus collilineatus snake serum, against Leishmania (Leishmania) amazonensis. METHODS Promastigotes forms were exposed to γCdcPLI, and we assessed the parasite viability and cell cycle, as well as invasion and proliferation assays. FINDINGS Despite the low cytotoxicity effect on macrophages, our data indicate that γCdcPLI has a direct effect on parasites promoting an arrest in the G1 phase and reduction in the G2/M phase at the highest dose tested. Moreover, this PLA2 inhibitor reduced the parasite infectivity when promastigotes were pre-treated. Also, we demonstrated that the γCdcPLI treatment modulated the host cell environment impairing early and late steps of the parasitism. MAIN CONCLUSIONS γCdcPLI is an interesting tool for the discovery of new essential targets on the parasite, as well as an alternative compound to improve the effectiveness of the leishmaniasis treatment.