Protective Effect Of Curcumin On Lung Injury In Diabetic Rats And Its Possible Mechanism

Objective: To establish the type2diabetic rats model induced by STZ, toinvestigate the protective effect and expression of protein P38MAPK of Curcuminon lung tissue injury in type2diabetic rats.To explore the possible mechanism, as toprovide theoretical basis for its clinical value.Methods: Male wistar rats were randomly assigned to three groups: controlgroup, diabetic group(DM) and diabetis received curcumin group(DM+C). Besidecontrol group, STZ was injected intraperitoneally to induce diabets model in the rats.DM+C group was intragastric administration with Curcumin one time every day afterthe success of the model, and blood glucose and body weight were determinedamong DM+C group and DM group at the fifteenth week. After sacrifice, the part ofthe mid-dle lobe of right lung was cryopreserved at-80℃,which was used toevaluate p38MAPK protein levels and TGF-β1protein levels by Western Blot andimmunohistochemistry(S-P dyeing). The inferior lobe were fixed with10%bufferedformalin for with H&E in order to study the histological changes in diabetes lunginjury.Results:1.Compared with control group rats, blood glucose levels were significantlyincreased while body weight levels were significantly decreased in DM group rats.However, in DM+CUR group, the blood glucose levels were significantly decreasedand body weight significantly increased than that in control group.2. Under light microscop, it was observed that the lung tissue structure was clear, andtube wall and mucosal epithelial were integrated in control group rats. However, inthe DM rats, the lung tissue structure was disordered, alveolar epithelial cells wasdegenerated, alveolar space was narrowed and alveolar walls structure wasincompleted. And In the alveolar interval, the capillary basement membranethicked, vessel narrowed, fibrous tissue proliferous and a few inflammatory cellsinfiltrated. Curcumin treatment group rats lung tissue injury weresignificantly alleviated compared with the diabetes group. 3. Immunohistochemistry (s-p dyeing) results showed that the brown particle in theDM was the most, the DM+CUR was next and the control was the least. showed thatp-p38MAPK express by immunofluorescence staining was similar with that by s-pdyeing. The expression of p38MAPK and TGF-β1by western blot in the DM groupwas higher than that in the control group（P<0.05）, while the expression ofp38MAPK and TGF-β1in the DM+CUR was significantly decreased compared withthat in DM group（P<0.05）.Conclusion: Curcumin can reduce the level of blood sugar, improve the weight andrelieve lung tissue pathological damage in diabetic rats, which may be relatedpartially by iinhibiting the expression of p38MAPK and TGF-β1protein.