Dandelion alleviates Helicobacter pylori associated gastritis by inhibiting proteolytic activity of HtrA

Taraxacum officinale (dandelion) has been traditionally used in Chinese medicine for managing Helicobacter pylori (H. pylori) -associated gastritis, with documented anti-H. pylori, anti-inflammatory, and gastroprotective properties. The H. pylori virulence factor high-temperature requirement A (HtrA), which disrupts gastric epithelial integrity, represents a potential therapeutic target. However, the potential effect of dandelion on HtrA remains unexplored.

To clarify the potential mechanism by which dandelion extract alleviates H. pylori-induced gastritis through inhibition of HtrA.

The inhibitory effect of dandelion extract on recombinant HtrA was assessed using a casein hydrolysis assay and validated in AGS and GES-1 cell. A murine gastritis model was established using H. pylori strain 26695, and the underlying mechanisms related to HtrA inhibition were evaluated.

Dandelion extract (5 and 10 mg/mL) significantly inhibited HtrA proteolytic activity. In mice, oral administration of dandelion extract (0.5 and 1.0 g/kg) reduced H. pylori colonization, ameliorated gastric tissue injury and inflammation, inhibited macrophage infiltration and pro-inflammatory cytokine expression. In addition, it restored epithelial barrier function by upregulating Occludin and E-cadherin while down regulating β-catenin and PARP. Gastric HtrA and CagA levels were also markedly reduced. Furthermore, 78.125 μg/mL dandelion extract effectively suppressed HtrA-induced hyperproliferation, migration, and loss of junctional proteins in cellular models.

Dandelion extract may mitigate HtrA-mediated gastric epithelial damage, extending its mechanism of action from modulating host inflammation to regulating bacterial virulence. This finding provides a basis for further exploration of its potential as an adjuvant to antibiotic therapy.