Antioxidant activity of mature leaves, young leaves and bark of Syzygium polyanthum

Antioxidants are substances that inhibit oxidation of biomolecules. Syzygium polyanthum plant was used in this study to determine the antioxidant activity at different parts of plants. The samples were extracted using 100% ethanol and antioxidant activity were evaluated using 2,2 diphenyl-1-picrylhydrazyl (DPPH) scavenging activity assay, then analyses by Thin Layer chromatography (TLC)-DPPH total phenolic content (TPC) using Folin-Ciocalteau method and total flavonoid content using Down Colorimetric method. Thin Layer Chromatography (TLC)was used to provide the profile of the samples. The results showed the antioxidant activity of mature leaves (91.73±0.35%) was highest, followed by young leaves (87.34±0.29%) and bark (78.41±0.44%). The purple background with yellow spots on TLC-DPPH also indicated the presence of antioxidant in the samples. The total phenolic content was the highest in mature leaves (8.77±0.59 mg GAE/g extract), followed by young leaves (7.22±1.23 mg GAE/g extract) and bark (4.96±1.18 mg GAE/g extract). The highest flavonoid contents was in mature leaves (2.05±0.58 mg QE/g extract), followed by young leaves (1.81±0.76 mg QE/g extract) and bark (1.47±0.50 mg QE/g extract). The antioxidant activity of samples extract investigated suggests that Syzygium polyanthum plant especially the leaves shows great potential to be a natural antioxidant.