The Promising Free Radical Scavenging Activity of Some Fabaceae Flowers

Oxidative stress caused by free radicals is a key contributor to the development of chronic diseases. As a natural defense strategy, the identification of plant-based free radical scavengers has become increasingly important. This study investigates the antioxidant potential of selected flowers from the Fabaceae family, plants which common in Indonesia and contain phenolic, one of the chemicals with antioxidant properties. The objective of this study is to ascertain the total phenolic content and free radical scavenging activity of ethanol extracts of a number of Fabaceae flowers that are frequently found in the neighborhood, including Arachis pintoi, Crotalaria retusa L., Crotalaria pallida Aiton, and Sesbania grandiflora L. All samples were extracted with 70% ethanol, which was subsequently analyzed for total phenolic content and free radical scavenging activity by Folin-Ciocalteu and DPPH reagents. As the results, the highest total phenolic content was 62.962 + 0.679 mg GAE/g sample (A. pintoi), while the lowest one was 23.986 ± 0.613 mg GAE/g sample (S. grandiflora L.). In line with the total phenolic compound, the activities of the highest free radical scavenging which is indicated by IC50 of those plants is 68.570 ± 1.476 µg/mL (A. pintoi), and the lowest value is 203.371 ± 4.706 µg/mL (S. grandiflora L.). These findings indicate that among the tested Fabaceae flowers, A. pintoi exhibits the strongest antioxidant potential, likely due to its high total phenolic content. This highlights its promise as a natural source of free radical scavengers and supports further exploration for potential therapeutic applications.