Antioxidant Potency of Kaempferia galanga Linn and Zingiber officinale var. Rubra rhizomes

Reactive oxygen species (ROS) include radical and non-radical oxygen species produced by partial reduction of oxygen. Consumption of antioxidants is necessary to prevent damage to cells, tissues, and organs due to ROS. Red ginger (Zingiber officinale) and kencur (Kaempferia galanga) are known as potential natural antioxidants. The purpose of this research is to determine the potency of antioxidant in ginger red extract (RGE) and kencur extract (KE). The extract characteristics were assayed including total phenol content (TPC) using gallic acid standard and total flavonoid content (TFC) using quercetin standard. The antioxidant potency was assayed namely 2,2 diphenyl 1 picrylhydrazyl (DPPH), hydrogen peroxide (H2O2), Nitrogen oxide (NO), 2,2'-Azinobis(3-Ethylbenzthiazoline-6-Sulfonate) (ABTS) scavenging activities, and ferric reducing antioxidant power (FRAP) methods. TPC of RGE and KE were 4.83 and 10.93 μg GAE/mg extract respectively. Meanwhile, the TFC of RGE was 2.68 QE μg/mg extract and KE was 5.67 QE μg/mg extract. The Median Inhibitory Concentration (IC50) in DPPH, ABTS, NO, H2O2 scavenging activities of RGE were 79.88; 67.33; 140.35; 212.26 μg/ml respectively and KE were 197.01; 145.16; 52.42; 155.52 μg/ml respectively. The FRAP method shows that KE was greater antioxidant activity compared to RGE. In conclusion, RGE and KE are potential as natural antioxidants.