Ophiopogon japonicus (L. f.) Ker Gawl. extract treats dry eye disease via anti-inflammatory, antioxidant, and goblet cell-stimulating effects

Objective To investigate the anti-inflammatory, antioxidant, and goblet cell-stimulating effects of a suspension of Ophiopogon japonicus (L. f.) Ker Gawl. ( O . japonicus , Mai Dong) extract combined with hyaluronic acid (HA) in the mouse model with dry eye disease (DED). Methods A DED mouse model was induced using benzalkonium chloride (BAK), followed by treatment with O. japonicus extract-containing eye drops at varying concentrations. Experimental groups included a normal control, a DED model control, a positive control, and an O. japonicus extract-treated group. Corneal fluorescein staining and tear break-up time (TBUT) were used to assess tear film stability and ocular surface integrity. Enzyme-linked immunosorbent assay (ELISA) measured inflammatory factor levels in corneal and conjunctival tissues, whereas western blot (WB) analyzed key antioxidant and inflammatory markers, including nuclear factor erythroid 2-related factor (2Nrf2) and heme oxygenase 1 (HO-1). Periodic acid-schiff (PAS) staining and immunofluorescence were used to evaluate goblet cell density and mucin secretion. Results O. japonicus extract significantly improved corneal damage, reduced fluorescein staining scores, prolonged TBUT, and increased tear secretion. It downregulated inflammatory markers, including interleukin-8 (IL-8), interleukin-1β (IL-1β), and interferon-γ (IFN-γ) while upregulating Nrf2, HO-1, and the interleukin-13 (IL-13)/IFN-γ ratio, alleviating oxidative stress and inflammation. PAS staining showed increased conjunctival goblet cell density and restored mucin secretion, enhancing tear film stability. Conclusion O. japonicus extract demonstrated significant anti-inflammatory, antioxidant, and goblet cell-stimulating effects in a DED model, with good biocompatibility and promising therapeutic potential. Future research should optimize extraction processes and validate their efficacy and safety in clinical settings.