Comparison of Essential Oils of Schinus molle L. Leaves Growing in Different Regions of Algeria in Terms of Their Chemical Compositions and Various Biological Activities

Abstract

This preliminary study investigated the chemical composition and biological properties of essential oils derived from Schinus molle L. leaves obtained from three specific regions in Algeria: Algiers (SMA), Djelfa (SMD), and Mascara (SMM). Gas chromatography (GC) and Gas chromatography–Mass Spectrometry (GC–MS) analyses confirmed the presence of 52 compounds (100.0%) in SMA essential oil, 50 compounds (100.0%) in SMD, and 72 compounds (100.0%) in SMM essential oils. The main components of SMA oil were camphene (31.82%), limonene (14.71%), and p-cymene (9.25%). In SMD and SMM oils, α-phellandrene (14.25% and 12.70%), limonene (13.02% and 11.90%), and germacrene D (10.62% and 10.15%) were the major components, respectively. The antioxidant characteristics were evaluated using five methods: β-carotene-linoleic acid, DPPH, ABTS+, CUPRAC, and Metal chelating assays. The results revealed a moderate to low anti-oxidant effect, with SMA essential oils exhibiting the highest activity. A moderate inhibitory effect against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-glucosidase, α-amylase, urease, and tyrosinase was observed, indicating anti-enzymatic activity. Nevertheless, all samples had higher IC₅₀ values for both antioxidant and anti-enzymatic activities than 200 μg/mL. It was determined that regional differences in the locations where S. molle grows showed both qualitative and quantitative differences in essential oil components. This difference was also detected in the biological activities of the essential oils. The anti-inflammatory capacities of the three samples were assessed using Human Red Blood Cell (HRBC) membrane stabilisation and egg albumin denaturation techniques. The results showed effective anti-inflammatory activity in all three samples. The antimicrobial efficacy was evaluated using a range of tests, such as anti-quorum sensing, violacein inhibition, anti-swimming, and anti-swarming assays, demonstrating moderate activity. No toxic effects were observed at the tested dosages when assessing cytotoxicity against a healthy cell line (CCD18-Co). This thorough examination provides valuable insights into the chemical composition and bioactive properties of essential oils derived from S. molle. These findings indicate the possible use of these essential oils in the food, medicinal, and cosmetic industries.