Polyphenol content, antioxidant and antibacterial activity of Salvia officinalis L. leaves from the Ouled Tebben Highlands, Algeria: a preliminary assessment

The present study provides a preliminary assessment of the total phenolic content, antioxidant activity, and antibacterial properties of aqueous (EA) and hydromethanolic (EHM) extracts obtained from Salvia officinalis L. leaves collected in the Ouled Tebben Highlands, Algeria. Total phenolic content was determined using the Folin-Ciocalteu method, while antioxidant activity was assessed via DPPH radical scavenging assay. The antibacterial activity was evaluated using the agar well diffusion method. The EHM extract showed higher phenolic content (TPC) with values of 179.00 ± 0.47, vs. 101.95 ± 0.76 mg GAE/g DW (EA). The EHM extract exhibited a more pronounced antibacterial effect against Gram-positive bacterial strains, namely Staphylococcus aureus and Bacillus sp., with inhibition zone diameters of 16.00 ± 0.47 mm and 16.00 ± 0.81 mm, respectively. In contrast, EA extract demonstrated a higher free radical scavenging activity than the EHM extract, with respective IC₅₀ values of 81.10 µg/mL vs. 114.86 µg/mL. These findings represent exploratory data and provide a basis for future studies incorporating biological replicates and inferential statistical analysis. Future studies focusing on geo-climatic variability and its impact on phenolic biosynthesis in Algerian sage populations are essential to better understand phytochemical variability and optimize its pharmacological potential.