Characterization and bioactivities of a novel copper–zinc superoxide dismutase from the marine snail Rapana venosa: antioxidant, antimicrobial, and anticancer effects

Background

Marine organisms, particularly snails, are rich sources of bioactive compounds with potential antioxidant, antimicrobial, and anticancer properties, offering promising avenues for drug discovery.

Methods

In this study, Rapana venosa extracts were evaluated for antioxidant enzyme activities and tested for antimicrobial and anticancer effects. Furthermore, a superoxide dismutase (SOD) isoenzyme, designated Rapana venosa superoxide dismutase 1 (RvSOD1), was purified from R. venosa using chromatographic techniques, characterized, and evaluated for its antimicrobial and anticancer activities.

Results

The crude R. venosa extract demonstrated substantial antioxidant activity, with measurable catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), and glutathione peroxidase (GPx) activities. It exhibited antimicrobial effects, inhibiting Escherichia coli by 71.2% and Candida albicans by 90.8%. The extract also showed cytotoxicity against human cancer cell lines MCF-7 (breast cancer), MDA-MB-231 (triple-negative breast cancer), and A549 (lung adenocarcinoma). The purified RvSOD1 displayed a specific activity of 600.7 U/mg (7.5-fold purification; 30.4% yield). Characterization indicated that RvSOD1 is a copper–zinc SOD, sensitive to potassium cyanide and activated by Zn²⁺ and Cu²⁺, with an optimum pH of 8.0 and an apparent molecular mass of ~ 90 kDa. Functionally, RvSOD1 showed antifungal activity against C. albicans (79.9% inhibition) and antibacterial activity against E. coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Staphylococcus aureus. In anticancer assays, RvSOD1 was active against MCF-7 and MDA-MB-231 cells but was less effective against A549 cells. Notably, the crude extract was more effective than purified RvSOD1 against all three cell lines, suggesting synergistic effects or additional bioactive compounds.

Conclusion

Both the R. venosa extract and the isolated RvSOD1 possess significant antioxidant, antimicrobial, and anticancer properties. These findings highlight their potential as promising multifunctional therapeutic candidates for future pharmaceutical and biomedical applications.