Rhopalurus junceus scorpion venom has been identified as a natural extract with anticancer potential. Interestingly, this scorpion venom does not cause adverse symptoms in humans. However, there is scarce information about its composition and enzymatic activity. In this work, we determined the electrophoretic profile of the venom, the gelatinase and caseinolytic activity, and the phospholipase A2 (PLA2) and hemolytic activity. The effect of different venom doses (6.25, 12.5 and 25 mg/kg) on gastrocnemius muscle was also measured as CK and LDH activity in serum. The presence of hyaluronidase was determined by turbidimetric assay. The effect of different fractions obtained by gel filtration chromatography were evaluated at different concentrations (0.05, 0.1, 0.2, 0.4, 0.6mg/ml) against lung cancer cell A549 and lung normal cell MRC-5 using MTT assay. The electrophoretic profile demonstrated the presence of proteins bands around 67kDa, 43kDa, 18.4kDa and a majority band below 14.3kDa. The venom did not showed caseinolytic, gelatinase, PLA2 and hemolytic activity even at highest venom concentration used in the study. Scorpion venom only showed a significant toxic effect on gastrocnemius muscles identified by CK and LDH release after subcutaneous injection of 12.5 and 25mg/kg. Low molecular weight fractions (<4kDa) induced a significant cytotoxicity in A549 cells while high molecular weight proteins (45-60kDa) were responsible for hyaluronidase activity and toxic effect against MRC-5. Experiments indicate that Rhopalurus junceus scorpion venom has low enzymatic activity, which could contribute to the low toxic potential of this scorpion venom.
Keywords: Rhopalurus junceus; cancer cells; high molecular weight proteins; hyaluronidase; scorpion venom.