Comparative study of Juniperus turbinata (Cupressaceae) cone and leaf based on GC-MS-Ms analysis and biological proprieties

Essential oils (EOs) extracted from leaves (JTEOL) and cones (JTEOC) of Juniperus turbinata leaves were analysed to determine their chemical composition and studied in vitro their antioxidant, antidiabetic, dermatoprotective, and neuroprotective effects. The results of GC-MS-MS characterization revealed significant qualitative and quantitative differences in volatile profiles between the two parts of the plant. JTEOC was dominated by α-pinene (81 %), followed by limonene (2.38 %), trans-verbenol (2.37 %), and α-terpinyl acetate (1.8 %), while JTEOL contained α-pinene (20.71 %), α-terpinyl acetate (19.87 %), and β-phellandrene (15.56 %) as major components. The antioxidant assays showed varying activities, with JTEOL showing superior radical scavenging capacity in DPPH and ABTS assays with 9.33 ± 0.55 mg TE/g and 41.16 ± 0.97 mg TE/g, respectively, while JTEOC exhibited higher reducing power in CUPRAC and FRAP assays as 85.69 ± 1.35 mg TE/g 47.78 ± 0.27 mg TE/g, respectively. In enzyme inhibition assays, both EOs showed significant α-amylase inhibition (JTEOC: 1.380 ± 0.019 mmol ACAE/g; JTEOL: 1.084 ± 0.055 mmol ACAE/g) but no α-glucosidase activity. JTEOL demonstrated superior tyrosinase inhibition (68.07 ± 3.74 mg KAE/g) compared to cone EO (17.14 ± 4.27 mg KAE/g). In cholinesterase inhibition assays, JTEOC specifically inhibited acetylcholinesterase (7.25 ± 0.16 mg GALAE/g), while both EOs showed butyrylcholinesterase inhibition, with JTEOL being more potent (2.85 ± 0.64 mg GALAE/g versus 1.52 ± 0.32 mg GALAE/g). Our current study suggests that J. turbinata EOs, particularly from leaves, possess a promising potential for applications in antioxidant, dermatoprotective, and neuroprotective treatments.