Effect Of Curcumin On EPCS In Rats After Pulmonary Fibrosis

Introduction:Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive disease which is associated with lack of effective treatment and thus, poor survival. Despite extensive research, IPF pathogenesis remains unknown. Recently, there is a body of research suggesting that in IPF, the impairment of repair reendothelization mechanisms following alveolar injury may lead to destruction in lung architecture and fibrosis.Notably, failure of reendothelization may induce loss of the alveolar-capillary barrier integrity which might be considered as the point after which fibrosis may be inevitable.Endothelial progenitor cells (EPCs) are related to the maintenance of endothelial homoeostasis and in the process of new vessel formation. EPCs are embedded in the bone marrow,can be mobilized into the peripheral circulation and participate in the repair of damaged vessel. In recent years,some vitro and animal experiments have showed that curcumin can promote the proliferation and mobilization of EPCs,improve endothelial repair capabilities.However,the effects of curcumin on functional benefit of EPCs in pulmonary fibrosis have not been well reported.Objective:To explore the effect and mechanism of curcumin on endothelial progenitor cells (EPCs) in rats bone marrow and peripheral blood and the protein expression of eNOS.Methods:60 SD rats were randomly divided into control group (A), model group (B), curcumin group (C). There were 20 rats in each group. Lung fibrosis model was bulit by intratracheal injection of bleomycin (5mg/kg) in B, C group. A group in the same way intratrachealiy with saline. All groups after modeling were gavage administration the next day, 0.5% sodium carboxymethyl cellulose solvents(0.014 L/kg) in group A and B, curcumin suspension(200mg/kg) in group C. Every 10 rats were sacrificed from each group on the 14th and 28th day. The lung tissue were observed by HE staining and evaluated for the formation of lung fibrosis by using Ashcroft scoring system. Flow cytometer was used to detect the percentage of EPCs in bone marrow and peripheral blood. The protein expression of eNOS was detected by Western Blot.Results:The alveolitis and the pulmonary fibrosis were significantly alleviated in the curcumin group.In comparison with control group, the percentage of EPCs in bone marrow and peripheral blood and the protein expression of eNOS were significantly reduced in model group(p<0.01), In comparison with model group, the percentage of EPCs in bone marrow and peripheral blood and the protein expression of eNOS were significantly upregulated in curcumin group (P<0.05).Conclusions:Curcumin can effectively upregulate the percentage of EPCs in bone marrow and peripheral blood, and promote bone marrow EPCs migrate into peripheral blood through activating eNOS pathway after pulmonary fibrosis.