Abstract: Objective To observe and compare the antihypertensive effects of Hanjingtang and its disassembled prescriptions on hypertensive rats with cold coagulation syndrome and the influence on serum inflammatory factors, vascular endothelial function and vascular collagen fiber, so that to explore the antihypertensive mechanism. Methods A total of 40 male SD rats aged 6 to 8 weeks were randomly divided into control group, model group, Hanjingtang group, Tongyang group and Tongluo group, with 8 rats in each group. The control group was fed with ordinary diet, and the other groups were given diet with 8% sodium chloride and high salt, and placed in a freezer at(-15±2)℃ for 3 hours every day for 6 weeks, followed by intragastric administration for 2 weeks. The control group and model group were given equal volume of normal saline. The blood pressure was measured twice a week with the rat noninvasive blood pressure analysis system, and the average value was taken. The changes of aortic pathological morphology and collagen deposition were observed with HE and Masson staining. The IL-1β, TNF- α and ET-1 were detected with ELISA, and NO was detected with colorimetry. The expressions of eNOS, type I collagen(ColI)and TGF-β1 in aortic tissue were detected with IHC. Results (1) Compared with the control group, the model group had raised blood pressure(P<0.01); incomplete aortic intima; thicker intima-media; disordered cell arranging; increased serum TNF-α, IL-1β, IL-6 and ET-1; decreased NO; increased collagen fibers. Meanwhile, IHC showed that eNOS expression decreased, but ColI and TGF-β1 expressions increased in aorta(P<0.01). (2) Compared with the model group, the Hanjingtang, Tongyang and Tongluo groups had decreased blood pressure(P<0.01, P<0.05); improved aortic structure at different levels; increased serum NO(P<0.05); Hanjingtang group had decreased TNF-α, IL-1β, ET-1 and IL-6(P<0.01, P<0.05); Tongyang group had decreased TNF-α, IL-1β and IL-6(P<0.05); Tongluo group had decreased ET-1 and TNF-α(P<0.05). IHC showed that the expression of ColI in aorta decreased but eNOS increased in the three treatment groups(P<0.05). The expression of TGF-β1 decreased in Hanjingtang and Tongyang groups(P<0.01, P<0.05); aortic collagen fibers decreased in the three treatment groups(P<0.01). (3) The antihypertensive effects and improvement of aortic collagen deposition were better in the Tongyang and Tongluo groups than those in the Hanjingtang group(P<0.05, P<0.01). Conclusion Hanjingtang can significantly reduce the serum inflammatory factors of IL-1β, TNF-α and IL-6, improve endothelial function, reduce collagen deposition in blood vessels, improve aortic fibrosis, partially explaining the antihypertensive mechanism of Hanjingtang. The Tongyang ingredients can mainly reduce inflammatory factors, while Tongluo ingredients can regulate NO / ET-1 levels to play a synergistic role.

Key words: Hanjingtang, Hypertension with cold syndrome, Aortic fibrosis, Inflammation factors, Endothelial dysfunction