Salvia argentea L. extract inhibits the production of NO, and pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), alleviates the inflammatory response of LPS-induced macrophages cells, and reduces the CRP level on carrageenan-induced paw edema

Salvia argentea L. (Lamiaceae) is a medicinal plant originating from the Mediterranean region and has been used since ancient times for the treatment of various diseases. This study aimed to determine the phytochemical composition of S. argentea L. ethanol extract and to evaluate its in vitro and in vivo anti-inflammatory activity and its acute oral toxicity. The chemical constituents of the ethanol extract prepared from the aerial parts of the plant were identified using HPLC. The in vitro anti-inflammatory activity of the extract was evaluated in LPS-stimulated murine macrophage RAW 264.7 cells and the human monocytic cell line THP-1 by measuring the levels of nitric oxide (NO), pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α). Acute toxicity of the extract was assessed in accordance with OECD guideline no 423. In vivo anti-inflammatory activity was evaluated based on the inhibition of 1% carrageenan-induced paw edema in rats. Serum CRP levels as an inflammatory marker, were measured via ELISA. Histological and immunohistochemical assessments were performed to identify tissue changes in the paw. HPLC profiling revealed that the extract contained rosmarinic acid (11.334 µg/mg dry extract), and salvigenin (2.74 µg/mg of dry extract) as major compounds. The extract significantly inhibited the production of NO, IL-1β, IL-6, and TNF-α without affecting cell viability. In vivo, the extract treatment exhibited a dose-dependent reduction in paw edema and serum CRP levels, along with notable histological improvements. Administration of the extract resulted in dose-dependent decreases of NF-κB expressions in the paw tissues. No signs of acute toxicity were observed (oral LD₅₀ > 2000 mg/kg). These findings suggest that S. argentea L. ethanol extract possesses significant anti-inflammatory potential supporting its possible development as a natural therapeutic agent for inflammatory disorders.