Comparative Evaluation of the Antioxidant Potential of Dolichandrone falcata Bark Extracts Using DPPH and FRAP Assay

Abstract

The present study evaluated the antioxidant potential of Dolichandrone falcata bark extracts using DPPH radical scavenging and ferric reducing antioxidant power (FRAP) assays. The bark was subjected to successive Soxhlet extraction using petroleum ether, chloroform, and methanol, yielding D. falcata petroleum ether extract (DFPE), chloroform extract (DFCE), and methanolic extract (DFME), respectively. The total phenolic and flavonoid contents of the extracts were determined, with DFME exhibiting the highest phenolic content (163.22 ± 0.17 mg GAE/g) and flavonoid content (95.98 ± 0.15 mg QE/g), followed by DFCE and DFPE. Antioxidant activity was assessed at different concentrations using FRAP and DPPH assays, with ascorbic acid used as the standard antioxidant. All three extracts demonstrated concentration-dependent ferric reducing activity, with DFME showing the highest reducing power, reaching an absorbance of 1.22 at 1000 µg/mL. Similarly, the DPPH radical scavenging activity increased with increasing extract concentration. DFME exhibited the highest scavenging activity, reaching 94.07% inhibition at 1000 µg/mL, followed by DFCE (78.45%) and DFPE (58.68%). The IC₅₀ values for DFME, DFCE, and DFPE were 429, 545, and 905 µg/mL, respectively, indicating greater antioxidant potency of the methanolic extract. The findings demonstrate that D. falcata bark possesses considerable antioxidant potential, particularly in the methanolic extract, which may be associated with its higher phenolic and flavonoid contents. These results support the potential of D. falcata bark as a promising natural source of antioxidant compounds.