Essential oil content, in-vitro and in-silico activities of Hypericum triquetrifolium Turra, H. empetrifolium subsp. empetrifolium Willd., and H. pruinatum Boiss. & Balansa species

Background and Aims: The importance of Hypericum species that are used traditionally against many diseases is increasing day by day. Methods: In this study, the essential oil contents of Hypericum triquetrifolium, H. empetrifolium subsp. empetrifolium, and H. pruinatum species were determined with GC-MS/FID. This is the first study on the antioxidant, anticholinesterase, antiurease, antityrosinase, antielastase, and anticollagenase activities of these species. Also, in silico and in vitro enzyme inhibitory activities of the major compounds in the essential oil samples of the species have been evaluated. In addition, the cytotoxic effects of the essential oils were determined by the MTT method. Results: According to GC-MS/FID results, the major compounds were determined as caryophyllene oxide (16.76%) for H. triquetrifolium, [alpha]-pinene (21.67%) for H. empetrifolium subsp. empetrifolium, and germacrene D (22.47%) for H. pruinatum. Especially, H. pruinatum sample showed a high cytotoxic effect ([IC.sub.50] : 34.78 [+ or -] 0.22 and 29.06 [+ or -] 0.40 [micro]g/mL, respectively) on HT-29 and MCF-7 cell lines. It was determined that the same sample showed a promising inhibitory activity on acetyl (18.33 [+ or -] 2.79, 36.48 [+ or -] 2.40, and 56.97 [+ or -] 0.94, respectively) and butyryl (71.63 [+ or -] 2.78, 73.88 [+ or -] 1.16, and 56.97 [+ or -] 0.97, respectively) cholinesterase enzymes. Conclusion: Results of the in-vitro activity studies indicated that H. pruinatum essential oil could be used in the pharmaceutical industry. Keywords: Hypericum triquetrifolium, H. empetrifolium, H. pruinatum, essential oil, cytotoxicity, anti-aging, in silico