ANALYSIS OF IN VITRO AND IN VIVO ANTIOXIDANT PROPERTIES OF HYDROPHILIC FRACTIONS FROM THE SEAWEED HALIMEDA MONILE L.

Abstract

ABSTRACT In this work, in vitro and in vivo antioxidant properties of the marine algae Halimeda monile were assessed and the levels of some of its compounds likely to be responsible for such properties were determined. The estimated contents of total polyphenols, chlorophylls a and b and carotenoids were 179.5, 356.3, 452.8 and 42.2 µg/g dry weight seaweed, respectively. The presence of terpenoids and flavonoids was also observed. The antioxidant activity of two polar fractions from H. monile (lyophilized aqueous extract and free phenolic acid fraction) was evaluated using three antioxidant assays: ferric reducing antioxidant power, 1,1-diphenyl-2-picrylhydrazyl and lipid peroxidation. Treatment of CCl4-induced liver damage in rats with extracts resulted in lower serum thiobarbituric acid-reactive substances levels and higher hepatic glutathione concentrations compared to those observed in the CCl4-treated group. Also, a significant increase in catalase activity was detected after treatment with the extracts. These results suggest that the seaweed H. monile could be a potential source for natural antioxidants. PRACTICAL APPLICATIONS Seaweeds have a broad chemical composition, consisting of bioactive molecules as chlorophyll, carotenoids, mycosporine-like amino acids, terpenoids, carbohydrates, vitamins and phenolic compounds. Different seaweed extracts have received increased attention, due to their pharmacological effects, particularly in vivo hypolipidemic, antioxidant, immunological and antitumoral activities. The phenolic compounds are powerful antioxidant molecules, and fractions rich in these compounds may be use as antioxidant complement in health states where oxidative state is damage. Results of this research with Halimeda monile L. fractions showed in experiments in vitro and in vivo the presence of different phenolic compounds and that the antioxidant activity is related to them. Therefore, the H. monile L. seaweed fractions have the potential to be developed into new health foods.