Chemical composition of leaf essential oil of Schinopsis lorentzii and its inhibitory effects against key enzymes relevant to type-2 diabetes: an emphasis on GC-MS chemical profiling and molecular docking studies

Schinopsis lorentzii (Griseb.) Engler is an aromatic plant belonging to Anacardiaceae family, and grown in Argentina, Paraguay, Brazil, and Bolivia. It is a rich source of essential oils and tannins as well as commercially available as vegetable-processed leather tanning and antiparasitic agent. This study was designed to explore the chemical composition of essential oil isolated from S. lorentzii leaves and elaborate on their significance as natural anti-diabetic, combined with molecular-docking studies. The leaf oil was chemically analysed using gas chromatography-mass spectrometry (GC-MS) method and investigated for inhibitory effects against alpha-amylase and alpha-glucosidase. Molecular-modelling study via Molecular Operating Environment-Docking (MOE-Dock) program was used to evaluate binding interactions of major components with the above-mentioned targets. The GC-MS analysis of the leaf oil revealed the predominance of beta-caryophyllene (21.63 +/- 0.36%), gamma-terpinene (13.53 +/- 0.74%), alpha-pinene (13.38 +/- 0.65%), and terpinen-4-ol (12.55 +/- 1.56%). The tested oil expressed a remarkable inhibitory effect against alpha-amylase with IC50 value of 2.27 +/- 0.19 mu g/mL, comparable to acarbose (IC50 = 0.52 +/- 0.18 mu g/mL) used as standard drug. Similarly, it significantly inhibited alpha-glucosidase (IC50 = 0.84 +/- 0.03 mu g/mL), compared to acarbose (IC50 = 0.38 +/- 0.02 mu g/mL). The in-silico molecular docking study revealed favorable binding affinities of beta-caryophyllene, terpinen-4-ol and sabinene with variable degrees with alpha-amylase and alpha-glucosidase. Thus, this study demonstrated valuable scientific data on the leaf oil of S. lorentzii as a potential candidate for the development of natural antidiabetic formulations.