In vitro evaluation of Rheum ribes extract on periodontal cells: cellular proliferation, biomarker modulation, and bioactivity assessment

Background This study aimed to evaluate the effects of Rheum ribes (R. ribes) extract on human periodontal ligament fibroblasts (hPDLF), human gingival fibroblasts (hGF), and human osteoblasts (hOB), to assess its bioactivity profile and explore its possible association with the Wnt/β-catenin signalling pathway. To the best of our knowledge, this is the first in vitro study evaluating R. ribes for periodontal applications. Methods The phenolic profile and bioactivity of the R. ribes extract were assessed using HPLC–DAD, FCR, DPPH, CUPRAC, FRAP, AChE inhibition and antimicrobial assays. The effects of R. ribes extract (2.5, 5, and 25 µg/mL) on cell viability were assessed using the MTT assay. The optimal dose (2.5 µg/mL) was further analysed by ELISA to measure levels of collagen type​-​​1 (Col-1), bone morphogenetic protein-2 (Bmp-2), axis inhibition protein-2 (Axin-2), and fibroblast growth factor-2 (Fgf-2). Results Syringic acid and quinic acid were identified using HPLC–DAD analysis. R. ribes extract exhibited higher copper(II) ion-reducing activity, but lower iron(III)-reducing activity, free radical scavenging capacity, and AChE inhibitory activity compared to the reference standards. Antimicrobial activity was detected against Staphylococcus epidermidis, Proteus mirabilis, and Candida albicans. In the MTT assay, 2.5 µg/mL significantly increased cell viability, whereas 25 µg/mL exhibited cytotoxic effects across all cell types. ELISA revealed significant increases in Col-1, Bmp-2, and Axin-2 levels in hPDLF and hOB cells treated with 2.5 µg/mL extract, while Fgf-2 levels significantly decreased in hOB cells ( p < 0.001). Conclusions R. ribes extract may support periodontal wound healing by enhancing cell viability and modulating key biomarkers. Further experimental and clinical assessments are necessary to corroborate these outcomes and clarify the extract's therapeutic potential.