Therapeutic Potential of Salvia absconditiflora Greuter&Burdet: From Polyphenol Screening to Antimicrobial, Antibiofilm and Anti-inflammatory Applications
Abstract
Abstract Plant extracts contain an extensive chemical profile that offers several benefits for well-being. Microbial burden and inflammation impair immune function and play key roles in the development of chronic diseases. This study investigated the phenolic profile and biological activities of an aqueous extract of Salvia absconditiflora Greuter&Burdet obtained by ultrasound-assisted extraction (UAE), a green and eco-friendly method. Phenolic characterization by LC–MS/MS identified luteolin-7-O-glucoside as the major compound. The extract demonstrated strong antioxidant activity, with an IC50 value of 0.0705 mg/mL in the DPPH assay and a FRAP value of 119.0877 mg Trolox/g. Anti-inflammatory effects were evaluated in LPS/IFNγ-stimulated RAW 264.7 macrophages. The extract significantly reduced nitrite levels at concentrations of 0.1–100 μg/mL and showed anti-inflammatory activity at 0.1–50 μg/mL without markedly affecting cell viability. Cytotoxicity assessments revealed selective anticancer potential. The extract significantly reduced cell viability in HCT-116 colon cancer cells across the 0.1–100 μg/mL range, while no significant cytotoxic effects were observed in HL60 acute myeloid leukemia cells or in healthy L929 mouse fibroblasts, indicating moderate selectivity toward colon cancer cells. Moreover, the aqueous extract exhibited selective antimicrobial activity, particularly against Gram-positive bacteria and certain Candida species. It showed a pronounced concentration-dependent effect on biofilm formation in Staphylococcus aureus (ATCC 29213 and ATCC 43300) and Staphylococcus epidermidis (ATCC 35984). Additionally, inhibition of violacein production in Chromobacterium violaceum ATCC 12472 suggested disruption of quorum-sensing pathways. Our research demonstrates the promise of S. absconditiflora as a source of novel antimicrobial agents and therapeutic leads.