HPLC Profiling and Antioxidant Properties of the Ethanol Extract of Hibiscus tiliaceus Leaf Available in Bangladesh

The aim of this research was to investigate the antioxidant activity and HPLC fingerprinting profiles of the ethanolic leaf extract of Hibiscus tiliaceus growing in Bangladesh. Catechin, rutin hydrate, ellagic acid and quercetin contents were quantified in the sample by HPLC-DAD (99.00±1.88, 79.20±1.59, 59.40±1.36 and 69.30±1.47 mg/100 g of dry extract), respectively. The antioxidant potential by 2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging activity, reducing power, total antioxidant capacity and total phenolic and flavonoid content were determined. In all the methods, the extract exhibited potent antioxidant activity. The IC50 value of the extract on ABTS radical was found to be 6.25±0.15 μg/ml, and at 250 µg/ml, maximum absorbance of reducing power was obtained 0.6475±0.021. The total antioxidant capacity, total phenolic and flavonoid contents were found in considerable amount (595.2±3.61 mg of ascorbic acid/g, 298.07±2.01 mg/g of gallic acid, and 13.69±0.06 mg/g of quercetin equivalent), respectively. Substantial amounts of phenols and flavonoids were noticed and thus, justify the free radical scavenging and antioxidant characteristics of the extract.