Lippia adoensis var. adoensis , locally known as Kesse , is a wild dietary herb that is endemic to Ethiopia and is used for medicinal purposes, flavoring, and preservation of food. This study investigated total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity, and antibacterial activity using various solvent extracts of the dietary herb. The strains of bacteria that were tested included four Gram‐negative strains ( Escherichia coli (ATCC‐25922), Salmonella typhimurium (ATCC‐14028), Klebsiella pneumoniae (ATCC‐13883), and Pseudomonas aeruginosa (ATCC‐43495)), and one Gram‐positive strain ( Staphylococcus aureus (ATCC‐25923)). The highest TPC (50.53 mg GAE/g of dried extract) and TFC (26.0 mg QE/g of dried extract) were revealed in methanol extract. Additionally, the extract showed the strongest 2, 2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity , Ferric ion (Fe 3+ ) reducing antioxidant power (FRAP) , and total antioxidant activity (2.12 mg BHTE/g) of dried extract. All bacterial strains showed the highest bacterial inhibition zones in methanol extract; however, E. coli , P. aeruginosa , and K. pneumoniae were resistant to chloroform and ethyl acetate extracts. The study demonstrated the antioxidant and antimicrobial properties of the herbal extracts that are used as natural antioxidants and antimicrobials in preventing various oxidative stresses and as food preservatives.
Dessalegn et al. (Thu,) studied this question.