The Effect Of Allicin On Bleomycin-induced Pulmonary Fibrosis Rats

Objective:To investigate the influence of allicin on the Pulmonary Fibrosis rats and clarify the mechanism underlying the preventive effect of allicin on fibrosis in lungs.Methods:Wistar rats were given a instillation of bleomycin to make a pattern of pulmonary fiborsis,while normal group given a instillation of NS instead. The rats were divided into four groups randomly: normal group(a single intratracheal instillation of NS plus i.p.injection of NS),allicin group (intratracheal instillation of BLM,plus i.p.injection of allicin),Colchicine group(intratracheal instillation of BLM, plus i.p.injection of colchicine)and model group(intratracheal instillation of BLM, plus i.p.injection of NS).All the i.p. injections were performed once a day.The lungs were harvest on 7d and 28d for HE-staining and Masson-staining.The contents of hydroxyproline in lungs were analyzed by the hydroxyproline assay.the expressions of alpha -smooth muscle actin(α-SMA) and transforming growth factor beta-1 (TGF-β1) were detected by immunohistochemical staining.The expressions of MMP-2 and TIMP-2mRNA were detected by RT-PCR method.Results:Pulmonary alveolitis and fibrosis in allicin and colchincine groups ameliorated comparing model group on 7d by HE-staining and 28d by Masson- staining.The contents of hydroxyproline showed no significant difference in each group on 7d,which were remarkly decreased in pulmonary tissues of allicin group and colchincine group compared with that in model group on 28d.Compared with the model group,the rats in allicin group and colchincine group showed lower levels ofα-SMA and TGF-β1 expression.The expressions of MMP-2 and TIMP-2mRNA in allicin group and colchincine group were increased than normal group,which were decreased compared with that in model group on both 7d and 28d. Conclusion:Allicin could prevent pulmonary fibrosis,the mechanism may contributed to the regulation of MMP-2 and TIMP-2 mRNA balance.It could also prevent the up-regulation ofα-SMA and TGF-β1 expressions in fibrotic lungs of rats,which might be another of the mechanisms underlying the preventive effect of allicin on pulmonary fibrosis.