Evaluation of phytochemical indices and antioxidant properties of Salvia sclarea for functional food applications

Clary sage (Salvia sclarea L., Lamiaceae) has long been valued as a medicinal and aromatic plant, and its biological activity is attributed mainly to phenolic acids, flavonoids, and terpenoids. Despite growing interest in sage as a functional food ingredient, part-by-part comparisons of phytochemical composition and radical scavenging capacity across the whole plant are scarce. Leaf, stem, flower, and root extracts of S. sclarea were prepared by maceration in 80% methanol (1:10 w/v, 24 h). Total phenolic content (TPC) was measured by the Folin–Ciocalteu method (mg GAE/g DW), total flavonoid content (TFC) by the aluminium chloride colorimetric procedure (mg QE/g DW), and antioxidant capacity by DPPH and ABTS radical scavenging assays (% inhibition; IC₅₀ in μg/mL). Each plant part was represented by a single composite sample analysed in analytical triplicate (n = 3). Because no biological replication was available, plant parts were compared descriptively, and Pearson correlation and simple linear regression were applied to the four plant-part means as exploratory tools. Leaf extracts showed the highest values for all parameters: TPC 48.32 ± 2.14 mg GAE/g DW, TFC 15.87 ± 0.93 mg QE/g DW, DPPH inhibition 82.4 ± 1.63% (IC₅₀ = 38.5 μg/mL), and ABTS inhibition 85.1 ± 1.42%, followed by flowers, stems, and roots. Across the four plant-part means, TPC was positively associated with DPPH (r = 0.975) and ABTS (r = 0.977) inhibition and explained 95.0–95.4% of their variance in simple regression models. As these results derive from one composite sample per plant part, they are preliminary and do not establish biological differences among plant parts. The in vitro findings suggest that S. sclarea leaf extracts merit further investigation as candidate natural antioxidant ingredients for functional foods, subject to biologically replicated sampling, food-grade extraction, and in vivo validation.