Effects of Tetrahydroxystilbene Glucoside on Liver P450 Enzym e Expressions in Lipopolysaccharide-induced Dopamine Neuronal Dama ge Rats

Background: Tetrahydroxystilbene glucoside (TSG), the main active ingredient derived from the dried tubor root of Polygonum multiflorum, presents different pharmacological activities such as anti-oxidant and anti-inflammation. Recent studies indicated that TSG produced neuroprotection against Parkinson's disease (PD). However, few researches focusing on the effects of TSG on the liver cytochrome P450 (Cyp) enzyme expressions in PD animal model were also shown. Objective: This study aimed to detect the effects of TSG on liver Cyp protein expressions in lipopolysaccharide (LPS)-induced PD rat model. Methods: Male rats were randomly divided into control, model (LPS, 5μg), LPS+TSG (10 mg/kg) and LPS+TSG (50 mg/kg) groups. The dopaminergic neuronal damage rat model was induced by single direct injecting LPS into the brain substantia nigra. After seven daily intraperitoneal injection of TSG, rats were sacrificed and the livers were collected. The protein levels of liver Cyp1a2, Cyp2e1 and Cyp3a and several transcription factors, such as peroxisome proliferator-activated receptor α (PPARα ), aryl hydrocarbon receptor (AhR) and pregnane X receptor (PXR), were detected by western blotting assay. Results and Conclusion: TSG (10 and 50 mg/kg) significantly increased Cyp1a2 protein expression and decreased Cyp2e1 and Cyp3a protein levels in the LPS-induced dopaminergic neuronal damage rats. Moreover, TSG (10 and 50 mg/kg) inhibited LPS-induced increase in the AhR protein level and TSG (50 mg/kg) suppressed LPS-increased PXR and PPARα protein expressions after TSG treatment for 7 days. TSG increased Cyp1a2 and decreased Cyp2e1 and Cyp3a protein expressions through the regulatory effects on AhR, PXR and PPARα activation in the LPS-induced dopaminergic neuronal damage rat liver.