Antioxidant Activity and HPLC Fingerprinting Profile of Ethanolic Extract of Euphorbia cotinifolia Bark from Bangladesh

Aims: The present study was designed to investigate the antioxidant activity and High Performance Liquid Chromatography (HPLC) fingerprinting profiles of the ethanolic stem bark extract of Euphorbia cotinifolia growing in Bangladesh.

Methodology: In-vitro antioxidant activity of the ethanol extract was carried out using ABTS (2, 2'-Azino-Bis-3-Ethylbenzothiazoline-6-Sulfonic Acid) radical scavenging activity, reducing power assay, total antioxidant activity, total phenolic and flavonoid content determination. The polyphenolics content in the ethanol extract was identified and quantified through HPLC with Diode-Array Detection method.

Results: The ABTS radical scavenging activity demonstrated an IC50 (Inhibitory concentration 50) of 18.50 ml, while the maximum absorbance of reducing power was found to be 0.1148 at 250 ml, respectively. The total antioxidant capacity, total phenolic and flavonoid contents were found at significant level (347.8 mg of ascorbic acid/g, 56.24 mg/g of gallic acid, and 137.4 mg/g of quercetin equivalent), respectively. Catechin, caffeic acid, epicatechin, p-coumeric acid, ellagic acid and quercetin were quantified in the ethanol extract by reverse-phase HPLC (175.50, 4.61, 67.73, 4.01, 558.31 and 4.35 mg/100g of dry extract, respectively).

Conclusion: These results may be due to the higher polyphenolics content of the ethanol extract of Euphorbia cotinifolia bark, which also accounts for the significant antioxidant activity observed. Hence, it can be suggested that bioactive polyphenolics compound in Euphorbia cotinifolia might be responsible for the antioxidant activities.