Estimation of total phenolic and total flavonoid content and assessment of in vitro antioxidant activity of extracts of Hamelia patens Jacq. stems

Abstract

Background and Objective: Free radicals accumulation in the body causes many oxidative stress related diseases like arthritis, diabetes, inflammation, cancer and genotoxicity. The objectives of present study were to assess total phenolic and flavonoid content and to evaluate in vitro antioxidant activity of extracts of Hamelia patens stems. Methodology: Total phenolic and flavonoid content of the H. patens Jacq. stem extracts were determined by using the Folin-Ciocalteu method and aluminum chloride method, respectively. Antioxidant activities were performed by DPPH free radical, nitric oxide, hydrogen peroxide scavenging and metal chelating assay. Results: The total phenolic content of the petroleum ether extract (PHP), chloroform extract (CHP) and methanol extract (MHP) was 19.083±1.12, 30.58±1.28 and 99.25±1.39 mg gallic acid equivalent per gram of dried extract, respectively. The total flavonoid PHP, CHP and MHP was 8.47±0.67, 15.09±1.21 and 43.42±1.41 mg rutin equivalent per gram of dried extract, respectively. All extracts exhibited scavenging effect in concentration dependent manner. Chloroform extract showed good in vitro antioxidant activity as compared to other extracts. Antioxidant activities of the extracts were associated due to the total phenolic and flavonoid contents of the extract of H. patens. Conclusion: The present study showed that H. patens stems possess rich amounts of natural antioxidants and can be further explored for their possible use as a natural additive in food or in pharmaceutical products. These extracts can be regarded as a promising candidate for a plant derived antioxidant agent.