Protective effect of Berberis vulgaris fruit extract against Paraquat-induced pulmonary fibrosis in rats.

BACKGROUND: Pulmonary fibrosis induced by paraquat (PQ) has caused a large number of human fatalities all over the world, especially in Asian region. The main potential mechanism of PQ toxicity has been thought to be mediated by ROS. The present study was designed to evaluate the efficacy of the Berberis vulgaris fruit extract (BVFE) against PQ-induced pulmonary fibrosis in rats.

METHODS: Forty male rats were randomly divided into five experimental groups each containing eight rats. Groups 1 and 2, served as a negative and positive control and received a single dose of intratracheal instillation of saline and PQ (20mg/kg), respectively. Groups 3-5 were treated with different doses of BVFE (100, 200, 400mg/kg/day, orally) 1 week before the PQ injection and continued for 3 weeks. The rats were sacrificed 21days after PQ. Malondialdehyde (MDA), Hydroxyproline, inflammatory and fibrogenic cytokine tumor necrosis factor (TNF)-α, interleukin (IL)-6 and transforming growth factor (TGF)-β1 in lung tissue were determined. Presence of fibrosis, inflammatory cells, connective tissue and collagen deposition in lung were evaluated microscopically by hematoxylin and eosin (H&E) staining. Dried extract was standardized by amount of berberine by HPTLC methods by silica gel plate.

RESULTS: The results showed that PQ could significantly increase the lung MDA, hydroxyproline, TNF-α, IL-6 and TGF-β1 levels. BVFE ameliorated the biochemical and histological lung alterations induced by PQ.

CONCLUSIONS: The present study indicates the hydroalcolic extract of Berberis vulgaris fruit has beneficial effects in rat pulmonary fibrosis induced by PQ in a dose-dependent manner, possibly by anti-oxidant and anti- inflammatory properties, which might be due to its berberine alkaloid content.