Extracts from Microalgae and Archaea from the Andalusian Coast: A Potential Source of Antiproliferative, Antioxidant, and Preventive Compounds

Abstract

Marine and extreme environments harbor a huge diversity of microorganisms able to produce new bioactive metabolites with beneficial health effects. In this study, ethanol, aqueous, methanol, and acetone extracts and protein hydrolysates were obtained from five different microalgae species and two haloarchaea. An in vitro study of cytotoxicity, migration, angiogenic effect, antioxidant capacity, and modulation of detoxifying enzyme expression was carried out using resistant (HCT-15) and non-resistant (T84) colon cancer tumor lines. Our results showed that the aqueous extract of the microalga Chlorella sorokiniana induced the greatest cytotoxic effect in both cell lines, while the ethanolic extracts of the archaea Haloarcula hispanica and Halobacterium salinarum caused the greatest inhibition on the migratory capacity. Meanwhile, the protein hydrolyzate and the aqueous extract of the microalga Chlorella sorokiniana significantly protected cells against hydrogen peroxide damage. Moreover, the aqueous extracts of Haloarcula hispanica and Halobacterium salinarum resulted in inducing the greatest increase in the activity of the detoxifying enzymes enzyme quinone oxidoreductase and glutathione S-transferase. These preliminary results suggest that aqueous extracts of some microalgae and haloarchaea may be promising candidates for an adjuvant therapy against colorectal cancer. However, additional research is required to identify the active principles and elucidate the mechanisms of action involved.