Evaluation of Toxicity and Anti-Oxidation Activity of the Extracts from Halymenia durvillei

Abstract

Halymenia durvillei (HD), a marine red alga, is believed to have potentials for pharmacological, nutritional and cosmetic applications. However, such potentials are acceptable only when their extracts are devoid of any adverse effects on human health. No previous research has been conducted the toxicity and anti-oxidation capacity of HD. Thus, the aim of this work was to investigate toxicity and anti-oxidation activities of HD extracts. In this study, the toxicity and anti-oxidation capacity of 5 fractions of HD solvent extracts, i.e., ethanol (HDET), hexane (HDHE), ethyl acetate (HDEA), butanol (HDBU), and aqueous (HDAQ) were evaluated. The cytotoxicity was evaluated by MTT and LDH assays on 4 cell types, i.e., fibroblast, macrophage, hepatocyte and keratinocyte. The genotoxicity was evaluated by comet assay and micronucleus test using TK6 lymphoblastoid cell line. The anti-oxidation capacity was investigated by DPPH and ABTS assays. The toxicity studies showed that HDET, HDBU, HDAQ had very low to no toxicity as indicated by cytotoxicity and genotoxicity tests while HDEA, HDHE have some toxicity at high concentrations. HDAQ showed low antioxidant activity while HDET, HDEA, HDHE and HDBU possess relatively high antioxidant activity. Overall, our results indicated that HDET and HDAQ could be consumed as they are not toxic and HDHE, HDEA, and HDBU could be safely consumed at doses lower than 100 μg/mL. Further investigation using in vivo assays are needed to ensure the safety of HD extracts for animal and human consumptions.