Study on the Mechanism of Curcumin Regulating Matrix Metalloproteinase to Improve Acute Pulmonary Embolism in Rats

OBJECTIVE To explore the therapeutic effect of curcumin on acute pulmonary embolism(APE) and its effect on the expression and activity of matrix metalloproteinases(MMPs) in APE rats, in order to provide experimental reference for clinical popularization of curcumin. METHODS SD rats were randomly divided into sham group, APE group, and curcumin treatment group in low, medium and high doses(50, 100, 150 mg·kg^-1), each group were re-divided into five groups(n=6):4 h, 1 d, and 3 d time point, for a total of 90 rats. After the APE model was established by autothrombotic transfusion into the pulmonary artery, curcumin treatment groups were administrated with curcumin at different dosages 2 h before the surgery. Then rats' mPAP and RVP, blood levels, gas analysis were detected in each group according to the corresponding time point. After anesthetized, blood samples and lung tissues were obtained. Lung tissues was stained by HE staining, serum ET-1, TXB₂, MMP-2, MMP-9 levels, lung tissues MDA content and SOD activity were determined. Western blotting analysis was also used to determine the protein expression of MMP-2 and MMP-9. RESULTS After inducing the APE animal model, the levels of mPAP and RVP were significantly increased, PaO₂ level were significantly decreased compared to those in sham group(P<0.01), significantly histological injury was also observed in lung tissues. Compared with the APE group, the levels of mPAP and RVP were obviously decreased, PaO₂ level were obviously increased in rats of each group treated with curcumin at different time point. HE staining also showed that lung histological injury was also attenuated with curcumin treatment. Oxidative stress results showed that curcumin treatment suppressed the content of MDA and activated the activity of SOD obviously. Serum ET-1, TXB₂, MMP-9 levels were obviously decreased in curcumin treatment groups compared to the APE group. Western blotting results also showed that the protein expression of MMP-9 were obviously suppressed in curcumin treatment groups. CONCLUSION Curcumin has potential protective effect against APE induced lung injury, this might contributed to the improving of lung function, blood gas indicators and vascular endothelial function, attenuating of lung histological injury, oxidative stress, and regulation of MMPs expression.