Free radical scavenging activity of extract and fraction of Okra seeds determined by DPPH (2, 2-diphenyl-1-picrylhydrazy) method

Introduction: Okra, which belong to Malvaceae family, is well known used as a food ingredient due to its high fiber content. Objective: In this study, the antiradical strength of okra seed extracts and fractions was investigated. Methodology: Okra seeds were dried and macerated with ethanol. Further, it is fractionated by different solvents based on the level of polarity from the non-polar to the polar, including n-hexane, chloroform, ethyl acetate and water. The extracts and fractions were then tested for antiradical strength using DPPH and analysis of phenolic and flavonoid contents were performed. Results: Ethanol extract and fractions of okra seeds showed very strong free antiradical activity, and ethyl acetate fraction being strongest fraction with IC₅₀ value of 10.097±0.074μg/mL. Meanwhile, the phenolic and flavonoid contents of ethyl acetate fraction were the highest among other fractions with the values of 61.412±0.196 EAG and 97.933±0.222 EQ, respectively, with correlation values (R²) 0.9281 (phenolic) and 0.6229 (Flavonoids). Conclusion: Extract and ethyl acetate fraction of Okra seed had good radical inhibition properties, which indicated its potential for further development assays.