Evaluation of antioxidant and antibacterial properties of dehydrocostus lactone isolated from Echinops kebericho root

Abstract

Background and Aim: Echinops kebericho, an endemic plant to Ethiopia, traditionally used to treat infectious as well as noninfectious diseases. The primary objective of this study was isolating dehydrocostus lactone (DHCL) from E. kebericho and evaluating antibacterial activities on selected human pathogenic bacteria. Methods: Extraction method used in this study was maceration. Based on the bioassay information methanol extract of the root of E. kebericho was subjected to column chromatography on silica gel by increasing solvent gradients to isolate DHCL. Optimized amount isolation of DHCL was done by dissolving methanol crude extract by hexane followed by recrystallization at room temperature in the dark place. Different concentrations of the extract were subjected by disc diffusion method against tested bacterial species and antioxidant activity test. Results: The phytochemical analysis of E. kebericho revealed a high presence of terpenoids, which are diverse natural compounds known for their antimicrobial and antioxidant properties. This suggests that terpenoids contribute significantly to the pharmacological effects of E. kebericho. In antibacterial testing, Escherichia coli was the most sensitive bacterium among all extracts and concentrations. The methanol extract displayed higher antioxidant activity compared to ethyl acetate and hexane extracts, indicating a higher concentration of antioxidant compounds. Notably, the isolated compound DHCL showed promising activity against tested pathogens and significant antioxidant activity. The higher activity of DHCL compared to the crude extracts suggests its responsibility for the observed effects, indicating that the isolation and purification process may have concentrated its beneficial properties. These findings highlight the potential of E. kebericho and DHCL as sources of bioactive compounds for therapeutic applications. Conclusion: All tested extracts and pure compound showed higher inhibition than positive controls in both bioassay. DHCL the principal bioactive component in the root extract of the plant and it displayed potent antibacterial and antioxidant activity.