effect of variety and method of extraction on antioxidant and antimicrobial activity of olive leaf extracts

the aim of this study was to extract phenolic compounds from olive leaves of cronaiky, roghani and mishen varieties by maceration and microwave-assisted extraction (mae) methods. our result revealed that effect of extraction method and variety was statistically significant (p<0.05) and mae-produced extracts have more total phenolics and antioxidant activity than traditional ones. the highest phenolic content (244.667±0.12 mg tae/g extract) and the lowest ic50 in dpph (74.19±0.15 µg/ml), reducing power (148.015±0.05 µg/ml) and total antioxidant capacity (160.391±0.02 µg/ml) indices were related to the mae extract of cronaiky. also, it was observed a highly linear correlation between the polyphenol contents and antioxidant activity. regarding the antimicrobial activity of olive leaf extract, we found the highest bactericidal activity was associated with mae extract of cronaiky and the lowest mbc was 625 and 2500 µg/ml against staphilococcus aureus and escherishia coli, respectively., showing e.coli as more resistant than s.aureus.