M yrtus communis L.: essential oil chemical composition, total phenols and flavonoids contents, antimicrobial, antioxidant, anticancer, and α-amylase inhibitory activity

Abstract Background Myrtus communis L. leaves, due to their tonic and antiseptic properties, have been used as folk medicine in many communities to treat a variety of conditions such as inflammation, peptic ulcers, diarrhea, leucorrhoea, headaches, excessive perspiration, and skin diseases. In this study, we examined the chemical makeup and biological properties of M. communis essential oils (EOs) from two locations in Palestine, including Jericho, the world's deepest site and Jenin. The plant's methanol and ethyl acetate extracts' biological efficacy were also assessed. Results The GC–MS analysis revealed that the EO of M. communis leaves from Jenin included 39 components, the majority were 1,8-cineole (31.98%), linalool (21.94%), linalool acetate (11.42%), α-pinene (10.22%), and myrtenol (6.87%). While 33 compounds, were discovered in M. communis EO from Jericho, with cis-4-thujanol (27.37%), 1,8-cineole (24.32%), myrtenol (12.97%), and myrtenal (12.46%) being the main constituents. The EO, ethyl acetate, and methanol extracts were tested (in vitro) for antibacterial, anticancer, antioxidant, and α-amylase inhibitory properties. The EO from Jericho demonstrated greater antibacterial efficacy against Escherichia coli, Proteus vulgaris, Klebsiella pneumoniae, Staphylococcus aureus, and, methicillin-resistant Staphylococcus aureus (MRSA) with MIC values of 0.27, 0.135, 0.135, 0.27, and 0.135 mg/mL, respectively. MRSA, S. aureus and C. albicans were all susceptible to the antimicrobial efficiency of methanol and ethyl acetate extracts (MIC = 0.097–0.195, 0.097–0.195, and 0.049 mg/mL, respectively). Methanol and ethyl acetate extracts, in contrast to EOs, showed high DPPH activity, with IC50 values ranging from 3.60 ± 0.35 to 25.70 ± 0.48 µg/mL. Both oils showed moderate cytotoxic activity against HeLa, MCF7, 3T3, and LX-2 cell lines, with IC50 values ranging from 202.02 ± 2.27 to 592.40 ± 2.55 µg/mL for Jenin and 199.80 ± 3.41 to 914.54 ± 3.05 µg/mL for EO from Jericho. Furthermore, EO and methanol extracts from Jenin inhibited α-amylase with IC50 values of 950.48 ± 2.54 and 795.43 ± 1.88 µg/mL, respectively. Conclusions Our findings indicate that M. communis extracts and EOs contain a vast array of pharmacologically active compounds with potent antioxidant, antibacterial, and antifungal activities that can be exploited to develop new types of natural pharmaceuticals and warrant further in vivo investigation for their therapeutic potential. Graphical Abstract