Study on total phenolic content, total flavonoid content and free radical scavenging activity in herbal extracts

Abstract

This research aimed to study on total phenolic content, total flavonoid content and free radical scavenging activity of eight herbal extracts such as Terminalia arjuna, Terminalia chebula, Terminalia bellirica, Zingiber officinale, Nigella sativa, Aegle marmelos, Morinda citrifolia. and Coriandrum sativum. In this study, eight herbal extracts were prepared by maceration with 95 % ethanol. All extracts were investigated for free radical scavenging activity by DPPH assay and phytochemical analysis of extracts by determination of total phenolic content using Folin-Ciocalteu assay and the total flavonoid content was determined by aluminum chloride colorimetric assay. The result showed the highest yield at 29.62 % dry weight from Terminalia chebula extract. The Terminalia bellirica extract showed the highest antioxidant capacity with IC₅₀ value of 2.31 ± 0.10 µg/mL. However, Terminalia bellirica extract has significantly lower antioxidant capacity than ascorbic acid. Phytochemical analysis of extracts revealed that Terminalia arjuna extract showed the highest total phenolic content (89.97 ± 10.86 g gallic acid equivalent 100 g of extract) while Terminalia bellerica extract showed the highest total flavonoid content (13.11 ± 0.80 g quercetin equivalent 100 g of extract). The overall information obtained from this research supported the future development of herbs for medicinal purposes and dietary supplements.