Antioxidant and antimicrobial activity of the endemic Mentha longifolia subsp. cyprica growing in Cyprus

Abstract

Mentha longifolia subsp. cyprica (Heinr. Braun) Harley, endemic to Cyprus, is traditionally used to treat tonsillitis and as an inhalant for headaches. In this study, the essential oil components, antioxidant activity, total phenolic content of extracts, and antimicrobial activity of the essential oil and the extracts from the aerial parts of M. longifolia subsp. cyprica are reported for the first time. The essential oil profile was determined by GC and GC/MS, and 28 compounds were identified. The main components were pulegone (71.5 %), 1,8-cineole (9.5 %), menthone (5.0 %), and limonene (3.4 %). The methanol extract revealed the highest antioxidant activity (0.109 mg/ml) and phenolic content (60.9 ± 0.034 mg gallic acid/g extract) compared to the ethyl acetate (0.368 mg/ml, 24.3 ± 0.032 mg GAE/g extract) and n-hexane (1.737 mg/ml, 10.1 ± 0.023 mg GAE/g extract) extracts. The antimicrobial activity of the essential oil and extracts was screened for their antibacterial and anticandidal effects against selected microorganisms. Pseudomonas aeruginosa was the most sensitive bacterial strain to the tested samples (MIC, 500–1000 µg/ml). In contrast, better inhibition effects were shown against Candida species, with a MIC of 62.5 µg/ml against C. utilis. The results of this study may partially support the traditional use of M. longifolia subsp. cyprica and provide insight into an alternative species.