Evaluation of Preliminary Cytotoxic Potency of Aqueous and Ethanolic Extracts of Sargassum wightii Greville & Stoechospermum marginatum (C. Agardh) Kutzing

Seaweeds are an abundant reservoir of bioactive compounds with prospective utilization in multidisciplinary domains, particularly in pharmacology. Algal samples were collected from the Southeastern coast of India. Extracts were prepared using water and ethanol as solvents. BSLA can be considered a propitious preliminary toxicity test, as the brine shrimp is acutely responsive to a variety of chemical substances. Trypan blue exclusion method can be described as a straightforward and cost-conscious method for the preliminary cytotoxic examination of natural extracts, using DLA cells and normal spleen cells, in which the degree of cytotoxicity is evaluated concerning the percentage of mortality of cell lines. A dose-dependent increase in the percentage of dead cells demonstrates cytotoxic competence of the extract. Conversely, a higher percentile of live cells reveals the selective cytotoxicity of the extract against cancer cells, which is a favorable attribute of anticancer drugs. The aqueous and ethanolic extracts of Stoechospermum marginatum, with an LC₅₀ value of 460 and 420 µl/mL, respectively, had the highest cytotoxicity on the brine shrimp larvae compared to aqueous and ethanolic extracts of Sargassum wightii. Strikingly, the ethanolic extracts of both algae demonstrated the highest cytotoxic capability against DLA cells, with LC₅₀ values of 30.61 and 10.75 µl/mL, while exhibiting comparatively low toxicity towards normal spleen cells. These inferences signify that the ethanolic extracts of Sargassum wightii and Stoechospermum marginatum possess bioactive compounds with promised anticancer properties and minimal toxicity against normal spleen cells, justifying intensified inspection for the isolation and characterization of the active constituents responsible for the remarked cytotoxic effects.