Mechanism of Ethanol Extracts from Sophorae Tonkinensis Radix et Rhizoma on Hypertrophic Scars of Rabbit Ears Through TGF-β1/Smad Pathway / 中国实验方剂学杂志

ABSTRACT

Objective:To investigate that the effect of ethanol extracts from Sophorae Tonkinensis Radix et Rhizoma on the expression of transforming growth factor-β1 (TGF-β1)and Smad3 in the hypertrophic scars of rabbit ears and elucidate its mechanism to improve hypertrophic scars. Method:The model of hypertrophic ear scar model was established by damaging the inner skin of ears in New Zealand white rabbits.The 49 rabbits were randomly divided into control group, model group, low, medium and high-dose ethanol extracts groups from Sophorae Tonkinensis Radix et Rhizoma (0.4，1.0，2.0 g·kg-1), asiaticoside ointment group(5 mg·kg-1) and compound heparin sodium allantoin gel group(20 mg·kg-1), 7 rabbits per group. Except control group, the different drug about 0.5 mL had been applied the hypertrophic scar of rabbit ears once a day. After 42 days, the tissues of hypertrophic scar were obtained. Hematoxylin-eosin（HE）staining was used to observe the pathological changes of rabbit ear scar tissue and determine the scar hyperplasia index. The expression of TGF-β1 and Smad3 in scar tissue of rabbit ears were detected by immunohistochemistry, Western blot and reverse transcription PCR（RT-PCR）. Result:Compared with control group, the pathological changes of the ear scars in the model group showed obvious hyperplasia and higher hyperplasia index (P<0.01). Meanwhile, the expressions of TGF-β1 and Smad3 in scar tissue of rabbit ears were significantly increased (P<0.01). Compared with model group, the pathological structures of the ear scar tissue were significantly improved and the hyperplasia index of ear scar tissue was clearly reduced in medium and high-dose groups of ethanol extracts from Sophorae Tonkinensis Radix et Rhizoma(P<0.05，P<0.01). The protein and mRNA expression of TGF-β1 and Smad3 in scar tissue were also decreased in different group of ethanol extracts from Sophorae Tonkinensis Radix et Rhizoma compared with the model group (P<0.05，P<0.01). Conclusions:Ethanol extracts from Sophorae Tonkinensis Radix et Rhizoma may play a curative role in inhibiting hypertrophic scars by reducing the expression of TGF-β1 and Smad3 in scar tissue and inhibiting the TGF-β1/Smads signal transduction pathway. These provides the experimental basis for the clinical application of Sophorae Tonkinensis Radix et Rhizoma in the treatment of hypertrophic scars.