Chemical Contents and Bioactivities of Green Algae Ulva rigida C.Agardh and Red Algae Grateloupia turuturu Yamada Extracts

Edible seaweeds, valued for their rich content of bioactive compounds, have gained recognition in complementary medicine beyond their traditional role in the food and pharmaceutical sectors. Notable examples include Ulva rigida C.Agardh and Grateloupia turuturu Yamada. These seaweeds offer a promising avenue for exploring their bioactive potential in medical and dietary contexts.

Hexane extracts were prepared to elucidate the fatty acid composition of seaweeds via Gas Chromatography-Mass Spectrometry analyses. Subsequently, investigations were conducted to assess the cytotoxicity on human breast cancer cell lines (MCF-7 and MDA-MB-231), as well as examine the antimicrobial and anti-cholinesterase activities of extracts obtained using hexane, dichloromethane:methanol (CH2Cl2:MeOH, 1:1), methanol (MeOH), and water solvents.

The most abundant substances for the U. rigida and G. turuturu species were hexadecanoic acid, octadecenoic acid, and erucic acid compounds. The CH2Cl2:MeOH (1:1) extract of G. turuturu was found as the highest toxicity on MCF-7 and MDA-MB-231 breast cancer cells (IC50: 28.7 µg/mL). G. turuturu extracts showed inhibition on E. coli and C. albicans. The hexane extracts of U. rigida and G. turuturu inhibited AChE enzyme in both algae species.

The results highlight seaweeds’ bioactive potential for therapeutic and dietary products. Further research can explore medical and nutritional applications.