In Vitro Antioxidant Activity Test of Brown Algae (Sargassum polycystum) Ethanol Extract Using the DPPH Method

Oxidative stress due to the accumulation of free radicals plays an important role in the pathogenesis of various degenerative diseases, including cardiovascular disease. Brown algae (Sargassum polycystum) are known to contain bioactive compounds such as phenolics, flavonoids, and triterpenoids that have potential as natural antioxidants. This study aims to identify the phytochemical content and evaluate the antioxidant activity of Sargassum polycystum ethanol extract in vitro using the DPPH method. Extraction was performed using the Ultrasonic-Assisted Extraction (UAE) method with 95% ethanol. Antioxidant activity was tested using the DPPH method and compared with ascorbic acid as a positive control. Absorbance was measured at a wavelength of 517 nm and the IC₅₀ value was determined through linear regression analysis. The results showed that the antioxidant activity of the brown algae ethanol extract had an IC₅₀ value of 35.614 ppm, while ascorbic acid had an IC₅₀ of 3.875 ppm. Based on the results of the study, it can be concluded that the ethanol extract of brown algae (Sargassum polycystum) has very strong antioxidant activity.