Viprutoxin, a snake venom serine proteinase inhibits platelet aggregation and selectively targets A549 cancer cells invitro.

Snake venom serine proteinases (SVSPs) are a well-studied group of toxins commonly found in the venoms of Viperidae, Elapidae and Crotalidae snakes. Serine proteinase toxins present in snake venoms are responsible for a wide variety of pathophysiological consequences in the victim. The problems range from coagulopathy to cytotoxicity. This paper discusses Viprutoxin (VPT), a 27 kDa serine proteinase isolated from Daboia russelli russelli venom (found in eastern India). Viprutoxin fragments obtained after trypsin digestion and Orbitrap High-Resolution Liquid Chromatography (O-HRLCMS) and Liquid chromatography Mass Spectrometry (LC-MS/MS) analyses showed similarities with a serine proteinase from Daboia russelli (UniProt ID: P18964 and P18965) and Crotalus horridus venom. Viprutoxin showed inhibition of adenosine di-phosphate (ADP) and collagen induced platelet aggregation, in vitro. Trypan blue dye exclusion assay and resazurin cell viability assay confirmed that Viprutoxin exerted cytotoxic and cytostatic effects on A549 (human alveolar adenocarcinoma) cells and MCF7 (human breast adenocarcinoma) cells. Exposure to Viprutoxin caused observable morphological changes and nuclear damage in A549 and MCF7 cells. However, Viprutoxin did not exhibit detectable cytotoxic effects on non-cancer HaCaT cells (human keratinocytes) in vitro making it a therapeutically promising candidate for future medicinal use.