Activité antioxydante et anti-Candida des extraits des algues rouges Asparagopsis armata

Abstract

Marine algae are a valuable source of natural compounds with diverse biological activities, representing significant potential for the discovery of new therapeutic agents. Among them, Asparagopsis armata, an invasive red alga, is generating increasing interest due to its ability to produce bioactive molecules with promising antifungal and antioxidant properties. In this study, extracts of Asparagopsis armata were obtained by maceration using three different solvents: methanol, dichloromethane, and acetone, with the highest yield obtained using methanol. The polyphenol and flavonoid content of the extracts was determined using spectrophotometric methods, The dichloromethane extract showed the highest concentration of total polyphenols (3.843 mg/g), while the acetone extract exhibited the highest flavonoid content (0.113 mg/g). To evaluate antioxidant activity, DPPH and FRAP assays were conducted. The acetone extract showed the best DPPH free radical scavenging capacity, with an IC50 value of 0.2919 mg/ml, whereas the dichloromethane extract exhibited the highest reducing power according to the FRAP test. These results were compared with those of standard antioxidants such as Trolox, and vitamins C and E. Antifungal activity was evaluated in vitro against Candida albicans AM16 using disk and well diffusion methods. The dichloromethane extract showed the strongest inhibition, with inhibition zones of 12.66 mm (disk method) and 45 mm (well method), depending on the volumes and concentrations tested. The acetone extract showed moderate activity, while the methanolic extract revealed no inhibition. Positive controls (fluconazole, cycloheximide) were used for comparison.