Vigna unguiculata Trypsin Inhibitor: A Protein with Versatile Biological Applications

Background: Trypsin Inhibitors are one of the most promising and investigated subject for their role in pharmacognostical and pharmacological studies. Aim: The paper describes purification and characterization of trypsin inhibitor obtained from blackeyed cowpea (Vigna unguiculata). Methods: The purification procedure of Vigna unguiculata trypsin inhibitor (VUTI) includes homogenization followed by ammonium sulphate precipitation. The protein thus precipitated was further dialysed and purified by ion exchange chromatography and gel permeation chromatography. The molecular weight was determined by SDS-PAGE. The protein thus purified was characterized biochemically to demonstrate curative potential as strong antioxidant, anti-inflammatory and antimicrobial agent. Results: The 15 kDa VUTI obtained showed IC50 values 490 μg/ml compared to standard which was 254μg/ml in 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay. Also, the highest ferric reducing antioxidant power (FRAP) results confirmed the highest FRAP value of 0.405 mM at 1000 μg/ml and the lowest value of 0.113 mM at 100 μg/ml which were quite comparable to ascorbic acid (standard). Anti-inflammatory activity of VUTI was depicted by the method of inhibition of albumin denaturation where, VUTI showed high IC50 value of 696.46 μg/ml. Also, VUTI showed good antibacterial potential by inhibiting all tested bacterial strains with maximum inhibition against Bacillus subtilis (99.62%) and minimum against Staphylococcus aureus (34.62%). The results were quite comparable with standard drug ampicillin (5 mg/ml). Unfortunately, VUTI failed to show any activity against fungi. Conclusion: Thus, the results obtained depict that VUTI additionally be a wonderful candidate for development of novel antibacterial drugs, and it can also be used to reduce the deletorious effects of free radicals.