Total phenol contents, total flavonoid contents, antioxidant activities of Methanol extracts of Amomum Subulatum, Lippia adoensis, Coriandram sartivum, and Ruta chalepensis sold from Jigjiga market, Ethiopia

Abstract This research work aimed to analyze the total phenolic, flavonoid contents, and antioxidant properties of four selected medicinal plants Amomum subulatum, Lippia adoensis, Coriandrum sativum, and Ruta chalepensis. The Folin-Ciocalteu method to measure total phenolic content, and the aluminum chloride colorimetric method to measure total flavonoid content, the DPPH(1,1-diphenyl-2-picrylhydrazyl), ABTS (2,2’-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)), and FRAP radical scavenging assay was used to measure the antioxidant activity. Results showed that Lippia adoensis (50 ± 0.23 mgGAE/g) and (20.5 ± 1.2 mgQE/g) and Ruta chalepensis (45 ± 0.76 mgGAE/g) and (17.3 ± 0.9 mgQE/g) have the highest phenolic and flavonoid content. The highest radical scavenging effect was observed in Lippia adoensis IC50 values 77.3 ± 2.8, 63.2 ± 2.3, and 15.8 ± 1.7 (µg/mL) DPPH, ABTS, and FRAP respectively. There is a positive correlation between total phenolic content, a flavonoid with antioxidant activity. Based on these results of the investigation, it could be concluded that Lippia adoensis is a rich source of phenolic compounds as natural antioxidants of high value.