In Vitro Antioxidant and Antimicrobial Activıties of Methanolic Extracts of Selected Herbal Teas Commonly Consumed in Turkiye

Objective: This study aims to investigate the antioxidant and antimicrobial effects of sage, olive leaf, green tea and linden plant extracts consumed as tea in our society. Methods: For determination of antioxidant activity, DPPH radical scavenging activity determination, ABTS radical scavenging activity determination, Fe+3 TPTZ reduction capacity determination and Cu+2 –Cu+ reduction capacity determination studies were carried out. The antimicrobial activities of the plant extracts were determined by microdilution method using bacterial strains Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 700603), Proteus mirabilis (ATCC 29906), Pseudomonas aeruginosa (ATCC 9027) and Staphylococcus aureus (ATCC 29213). Results: According to the results of the study, it was observed that olive leaf extract had the highest DPPH free radical scavenger capacity, ABTS cation radical scavenger, iron and copper ion reducing antioxidant power capacity. In addition, it was determined that all plant extracts showed antioxidant activity in various concentration ranges. According to the antimicrobial activity test results, all plants showed the best antimicrobial activity against S. aureus, while the weakest antimicrobial activity was against P. aeruginosa. It was determined that linden and olive leaf extracts, which draw attention with their high antioxidant capacities, were weak in terms of antimicrobial activity. Conclusion: The high antioxidant activity of methanol extracts of sage, olive leaf, green tea and linden plants, whose teas are frequently consumed in our society, draws attention as a beneficial feature for health. It is believed that the results of this study will contribute to the studies on therapeutic natural medicines that have increased recently.