Abstract: Objective: To study the preventive and therapeutic effects of safflower water extract on systemic scleroderma (SSc) in mice and its mechanism.Methods: Sixty BALB/C mice were randomly divided into the control group, model group, prednisone group and safflower low, middle, high dose groups, 10 mice in each group.The control group was injected with normal saline, and the other five groups were subcutaneously injected with bleomycin hydrochloride with 100 μl at the concentration of 200 μg /ml on the back, once a day for 28 days to establish the SSc models.At the same time, the control group and model group were treated with normal saline (10 ml/kg), the prednisone group was treated with prednisone 4.5 mg/kg (10 ml/kg), and the low, middle, and high dose safflower groups were treated with safflower at the doses of 1.5, 3, 6 g/kg (10 ml/kg), and all groups were treated for 28 days.After 28 days, all mice were decapitated. The blood samples and back skin of the BLM injection part were collected.After that, all the tissue slices were taken to measure the dermal thickness, and the content of hydroxyproline (HYP) in the skin tissues was detected by hydrolysis method.The contents of tissue growth factor (CTGF) and transforming growth factor-β (TGF-β ) in the skin tissues and the levels of interleukin-6 (IL-6) and interleukin-17 (IL-17) in serum were determined by ELISA.Results: Compared with the control group, the dermal thickness of the model group was increased(P＜0.05), the contents of CTGF, TGF-β and HYP in the skin tissues and the levels of IL-6 and IL-17 in the serum of the model group were increased(P＜0.05); compared with the model group, the dermal thickness in the prednisone group and safflower groups was decreased (P＜0.05), the levels of CTGF, TGF-β and HYP in the skin tissues and the serum levels of IL-6 and IL-17 in the prednisone group and safflower groups were decreased (P＜0.05).Conclusion: Safflower water extract can improve skin condition (or dermal thickness) in SSc mice, and its mechanism may be related to reducing immune inflammatory response.

Key words: systemic scleroderma, bleomycin, CTGF, TGF-β, hydroxyproline, mouse