Effect of Temperature and Water Stress on the Antioxidant and Antidiabetic Activities of Thymus vulgaris Essential Oil
Abdelouahid Laftouhi, Meriem Slimani, Amal Elrherabi, Mohamed Bouhrim, Mohamed Adil Mahraz, Amine Mounadi Idrissi, Noureddine Eloutassi, Zakia Rais, Abdslam Taleb, Mustapha Taleb
Abstract
Thymus vulgaris L. (family Lamiaceae) is an aromatic medicinal plant well-known for its essential oil and therapeutic values. It thrives across Europe, Western Asia, the Mediterranean, and Northwestern Africa. This study aims to investigate the effect of climate change on the chemical composition, antioxidant, and antidiabetic activities of Thymus vulgaris essential oil. Essential oils were extracted from three distinct Thymus vulgaris samples (S1 – S3) cultivated under different climatic conditions. S1 was cultivated under normal seasonal condition; S2 and S3 were cultivated under controlled conditions; 5°C temperature increase and 50% precipitation (S2), 10°C temperature increase and 75% precipitation (S3). Chemical constituents of the essential oils were identified using Gas Chromatography-Mass Spectrometry (GC-MS). The antioxidant activity was assessed using the 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, and Ferric Reducing Antioxidant Power (FRAP) assays. The antidiabetic activity was assessed via the α-glucosidase and α-amylase inhibitory activities. GC-MS analysis identified 23 compounds with varying proportions in the three essential oil samples. The findings showed that S1 had the most potent antioxidant activity with IC50 values of 461.83±10.49 µg/mL and 1508.83±7.22 µg/mL in the DPPH and ABTS assays, respectively, while S3 exhibited the highest antioxidant activity in the FRAP assay, with IC50 value of 244.64±1.34 µg/mL. For the antidiabetic activity, S1 showed the highest α-amylase inhibitory activity, while S2 exhibited the highest α-glucosidase inhibitory effect. This study sheds light on Thymus vulgaris' adaptability and therapeutic potential under changing climatic conditions. These findings underscore the importance of understanding these dynamics for future applications.