Chemical composition of endemic Hypericum bilgehan-bilgilii Basköse & Savran essential oil and its α-glucosidase antidiabetic, anti-inflammatory, cytotoxic and antioxidant potentials

Hypericum L. is a significantly important genus for flora of Türkiye due to its richness in phytochemicals possessing medicinal and cosmetic benefits. The essential oil composition and biological activities of Hypericum bilgehan-bilgilii Basköse & Savran (HEO) were analysed for the first time in the present study. The volatile oil of the whole parts of H. bilgehan-bilgilii was obtained by hydrodistillation with Clevenger-type apparatus. The chemical composition was analyzed by GC-MS using non-polar column.

α-glucosidase and 5-lipoxygenase inhibitory, cytotoxic, and DPPH radical scavenging activities were investigated. Forty-eight components were identified and represented 97.3% of the whole constituents. Interestingly, the major volatiles: 1-(2,4,5-trimethoxyphenyl)butan-1-one (27.7%) and 3-Methyl-1-(2,4,6-trihydroxyphenyl)butan-1-one (11.2%) were detected for the first time in Hypericum essential oils. The oil exhibited a significant activity against the 5-lipoxygenase enzyme with an IC50 value of 39 µg/mL.

Cytotoxicity potential of HEO was investigated, at different concentrations, towards four cell lines and, IC50 values underlies mild cytotoxicity. These results indicated that H. bilgehan-bilgilii essential oil may be considered as a valuable source for bioactive ingredients and anti-inflammatory agents.