In vitro Antioxidant and Anti-Tyrosinase Activities Along with Phytochemical Constituents of Brittle Wort (Chara corallina) Extracts

Abstract

Brittle wort (Chara corallina), a widespread freshwater green macroalga found in southern Thailand, is one of the most widely consumed edible species. Recently, many studies revealed potential of freshwater algae for use as a dietary supplement. This study aimed to screen the phytochemicals and assess the biological activity of C. corallina as an anti-tyrosinase and antioxidant, as well as the total phenolic and flavonoid contents. Samples of C. corallina was extracted using ethanol and distilled water. Crude extracts were screened for the phytochemicals as well as evaluated for total phenolic content, total flavonoid content, antioxidant and anti-tyrosinase activity. The yields of the aqueous and ethanolic crude extracts were 10.84% and 12.27%, respectively. The phytochemical screening of the ethanolic extract revealed the presence of terpenoids, flavonoids, saponins, and alkaloids, whereas anthraquinones, flavonoids, saponins, and alkaloids were identified in the aqueous extract. Aqueous extract had higher total phenolic content (9.3±0.2 mg gallic acid equivalent ^· mg^-1 crude extract) and total flavonoid content (1.9±0.2 mg quercetin equivalent ^· mg^-1 crude extract) compared to ethanolic extract. Through DPPH and ABTS scavenging activities, the biological activities of C. corallina aqueous extract demonstrated its potential as an antioxidant whereby tyrosinase inhibition activities showed an IC₅₀ of 231.6±3.8 µg·mL^-1 and 555.8±12.1 and 611.5±8.7 µg·mL^-1, respectively. The present study suggests that C. corallina is the potential source of antioxidants and anti-tyrosinase substances and is vital in the development of new skin-lightening substance for the cosmetics industry.