Objective To explore the antioxidation effect of ursolic acid on early silicosis in rats by experiment study.
Methods Totally 60 SPF Wistar rats were randomly divided into six groups:control (NS),model (M),and,low (UA10),medium (UA20),and high ursolic acid (UA40),and solvent control groups (S)(n=10/group).Except the group NS,the rats in other groups were induced by intratracheal instillation of silica in suspension (250 mg/kg) to establish silicosis model.Ursolic acid at 10,20,and 40 mg/kg was then injected by gavage into the rats in the group UA10,UA20,and UA40 respectively.The group S were gavaged daily with 0.6% sodium carboxymethyl cellulose (10 mL/kg) solution,while the group NS was given sodium chloride (10 mL/kg) for 56 consecutive days.Pulmonary organ coefficient on 28 d was calculated for each group.Serum nitric oxide (NO),malondialdehyde (MDA),superoxide dismutase (SOD),glutathione peroxidase (GSH-Px) contents were also measured.The expression of nuclear factor kappa B (NF-κB) protein in lung tissue was evaluated.
Results Compared with the group NS,the pulmonary organ coefficients,serum NO and MDA contents,and NF-κB protein expression were elevated,while the SOD and GSH-Px contents were decreased in the group M and group S (P < 0.05).However,the up-regulation of pulmonary organ coefficients,serum NO and MDA contents,and NF-κB protein expression and the down-regulation of SOD and GSH-Px observed in the group M and group S were significantly reversed by the ursolic acid treatment and showed a dose-dependent effect (P < 0.05).
Conclusion Ursolic acid could slow silicosis fibrosis by correcting the imbalance of antioxidant system and inhibiting NF-κB activation.
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