Biochemical and molecular docking-based assessment of Spirulina platensis's bioactive constituents for their potential application as natural anticancer drug

Abstract

Spirulina platensis and its extracts possess positive benefits for human health indications from malnutrition, antioxidant properties, and therapeutic properties. This study investigates the antioxidant activity of Spirulina platensis extracts and their cytotoxicity against the breast cancer cell line (MCF-7). The antioxidant and cytotoxicity properties of C- phycocyanin (C-PC) were directly compared with the diethyl ether extract of S. platensis (DEE). Results indicated that C-PC exhibited superior antioxidant activity compared to DEE extract. The observed values for C-PC are 1.453 μg/mL (IC₅₀-value), 299.6 μM AA eq/mL, 86.68 μM TE eq/mL, and 179 μg/g for ABTS assay, DPPH, FRAP and total antioxidant activity, respectively. Moreover, C-PC also demonstrated enhanced cytotoxic activity against MCF-7 tumor cells with IC₅₀ values of 100 μg/mL and 630 μg/mL for C-PC and DEE; respectively. C-PC treatment downregulated the expression of PI3K, Akt, mTOR, and Wnt. C-PC treatment to MCF-7 cells significantly induced caspase 3, caspase 8, and caspase 9. Similar effects, with lower tendency, were also observed for DEE extracts of S. platensis. Molecular docking studies suggest that S. platensis' bioactive constituents can induce apoptosis through intrinsic pathways. The current findings provide evidence for the medical importance of Spirulina platensis active constituents as promising natural anticancer drugs.