Effect of oleanolic acid on expression of TNF-αand collagen in silicotic rats in vivo / 中国病理生理杂志

ABSTRACT

[ ABSTRACT] AIM:To observe the effect of oleanolic acid ( OA) on the expression of Tumor necrosis factor-α( TNF-α) and collagen in silicotic rats in vivo and its possible mechanism.METHODS:Male Wistar rats were divided in-to 4 groups according to the randomized block design:control group, model group, OA group and solvent control group (20 rats in each group) .Except control group, the rats in other groups were induced by intratracheal instillation of silicon di-oxide (SiO2;250 mg/kg).The rats in OA group were intragastrically administered with OA (60 mg/kg) from the second day of giving SiO2 .The rats in solvent control group were gavaged daily with 0.6%sodium carboxymethyl cellulose solution (10 mL/kg).The rats in control group were given normal saline under the same condition for 56 consecutive days.All rats were killed at the 7th, 14th, 28th and 56th days.The lung coefficient was detected and the morphological changes were ob-served.The serum contents of TNF-αwere detected by ELISA.The content of total collagen in the lung tissue was meas-ured.The protein level of nuclear factor-κB ( NF-κB) in the lung tissue was determined by immunohistochemical method. RESULTS:(1) According to the morphological changes, the silicosis model was successfully established.Compared with control group, the lung coefficient and total collagen increased obviously in model group and solvent control group.The lung coefficient and total collagen content in OA group at each time point reduced compared with those in model group and sol- vent group, and increased compared with those in control group at the corresponding time points.(2) The serum contents of TNF-αin model group and solvent control group significantly increased, peaking at the 14th day, slightly decreasing af-terward, and showing statistically significant difference at each time point compared with those in control group.No signifi-cant difference between model group and solvent group at different time points was observed.OA had inhibitory effect on the contents of TNF-αcompared with model group and solvent group at the corresponding time points.(3) NF-κB in model group and solvent control group significantly increased, peaking at the 28th day, and showing statistically significant differ-ence at each time point compared with those in control group.The NF-κB expression in OA group was similar to model group, but significantly decreased compared with control group at each time point.CONCLUSION: OA inhibits the ex-pression of TNF-αand collagen and attenuates the silicosis fibrosis, which may be related to the NF-κB pathway.