Phytochemical profiling and various biological activities of Phlomis tuberosa L.

In this study, antioxidant, anti-diabetic, anti-cholinesterase, anti-urease, anti-tyrosinase activities, chemical composition and vitamin content of extracts and essential oils obtained from flower, aerial part and roots of Phlomis tuberosa, which grows naturally in the Kazakhstan were investigated. Chlorogenic acid and ferulic acid were detected as major constituents in the methanol extracts of P. tuberosa flower (12.47 and 25.31 µg/g), aerial part (30.95 and 47.82 µg/g) and root (9.79 and 32.56 µg/g). The main vitamins in the extracts were vitamins B3, C, and E. The main constituents of the essential oils from flowers and aerial parts were n-octacosane (14.34% and 25.66%) and hexahydro farnesyl acetone (13.89% and 18.75%). Flower methanol extract exhibited the highest antioxidant activity according to β-carotene-linoleic acid, ABTS (2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) and CUPRAC (Cupric Reducing Antioxidant Capacity) methods with IC₅₀ values of 48.35 ± 0.84, 51.93 ± 0.85 and 65.43 ± 0.27 µg/mL, respectively. The roots hexane extract (IC₅₀:103.2 ± 0.99 µg/mL) showed greater α-glucosidase inhibition than acarbose (IC₅₀:128.5 ± 0.62 µg/mL). The anti-urease effect of both essential oils were higher compared to all the extracts, and the essential oil of the flowers demonstrated significant butyrylcholinesterase (BChE) inhibitory activity. This study contributes to the traditional therapeutic uses of P. tuberosa and emphasizes its value in the development of new therapeutic agents exhibiting antioxidant and anti-diabetic activity.