Evaluating the Therapeutic Potential of Common Sage (Salvia officinalis L.): Antioxidant Capacity, Cytotoxicity and Dose-Dependent Effects on Gastric Smooth Muscle Viability and Function.

Salvia officinalis L. (S. officinalis) or common sage has long been valued in traditional medicine for its broad therapeutic properties. Our study explored the antioxidant potential, the cytotoxic activity and the effects on smooth muscle (SM) contractility of a traditionally prepared sage aqueous infusion. A chromatographic analysis revealed the major phenolic constituents of the infusion, rosmarinic acid being the most abundant compound (38.16 mg/mL), followed by rutin (3.58 mg/g), caffeic acid (3.00 mg/g) and hesperidin (1.84 mg/g). Three spectrophotometric methods were used to determine the antioxidant potential of the plant extract: a DPPH assay for radical scavenging activity (IC50 21.77 ± 0.98 µg/mL), a CUPRAC assay (2.32 ± 0.04 mmol Trolox equivalents/g) and a total reducing capacity assay (1.92 ± 0.01 mmol Trolox equivalents/g) for evaluating reducing properties. A cytotoxicity was assessed in primary SM cells (isolated from rat gastric tissue) using the xCELLigence real-time cell analysis system, where the infusion demonstrated dose-dependent cytotoxicity with an IC50 of 0.34 ± 0.12 mg/mL. Concentrations of 0.37 mg/mL rapidly reduced viability, while lower concentrations showed mild or negligible effects. Functional experiments with isolated rat gastric SM cells revealed a dose-dependent enhancement of both tonic and phasic contractile activity. Our results showed that the serotonergic pathways were mainly implicated in mediating these effects, while the cholinergic pathways were not involved with them. Together, these findings validate the traditional use of S. officinalis and point to its role in modulating SM function and providing antioxidant benefits, warranting further investigation into its mechanisms and therapeutic potential.