Phytochemical screening of Ulva rigida and evaluation of its antioxidant activity

Abstract

Ulva rigida is a green macroalga widely distributed in marine ecosystems, rich in essential nutrients such as fibers, minerals, proteins, vitamins, polysaccharides and secondary metabolites such as polyphenols and flavonoids. This marine macroalga has promising biological properties.  The aim of this study is to determine the main bioactive compounds of this macroalga and to evaluate its antioxidant power for use in the pharmaceutical, food and cosmetic sectors.

The extract was analyzed by Thin Layer Chromatography (TLC) and High-Performance Liquid Chromatography (HPLC), which were used to identify the bioactive compounds. The compounds of Ulva rigida contribute significantly to the antioxidant properties of the seaweed. The antioxidant activity of the extract was evaluated in vitro using DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azinobis-(3- ethylbenzothiazoline-6-sulfonic acid) reduction assays with ascorbic acid as a positive control. Extract analysis revealed the presence of gallic acid, rutin and luteolin.

The DDPH and ABTS assays showed significant antioxidant activity with IC50s of 0.242 mg/mL and 0.016 mg/mL, respectively. Ulva rigida is a versatile and promising marine resource due to its composition. Its exploitation could meet the growing demand for sustainable natural products in various industrial sectors. However, further research into its mechanisms of action, including in vivo studies, is needed to maximize its exploitation.