Cytotoxic, antioxidant and αlpha-amylase inhibitory activities of wild and Nabali olive leaf extracts from Jordan

Olive leaf extracts contain several phytochemical and pharmacological properties. This study evaluated the cytotoxic, antioxidant, α-amylase inhibitory activities of aqueous, ethanol and ethyl acetate extracts from the Nabali, Muhassan and wild olive leaves grown in Jordan. Total polyphenols, flavonoids and flavonols contents, chelating power activity, total antioxidant activity and DPPH free radical scavenging activity of each extract were evaluated. The α-amylase inhibitory activity of each extract was evaluated using CNP-G3 assay while cytotoxicity was assessed against viability of MCF7 and MB-MDA-231 breast cancer cell lines by MTT. The results showed that total polyphenol content was the highest in the ethanolic wild leaf extract (113.97 mg gallic acid equivalent/g of dry extract). At a concentration of 100µg/ml, the extracts from ethanolic wild leaf, ethyl acetate of wild leaf, and ethanolic Nabali leaf exhibited the highest chelating activity for ferrous ions (52.4%, 50.5%, and 47.2%). All olive leaf extracts significantly reduced MCF7 cell growth, while ethyl acetate wild leaf extract decreased MB-MDA-231 viability. The findings revealed a robust correlation between the antioxidant, cytotoxic and α-amylase inhibitory activities of various olive leaf extracts. Further investigations are needed to identify cytoprotective effects of olive leaf extracts and the evaluation of its efficacy in vivo.