[Moxibustion of 45 ℃ at "Zusanli" (ST36) improves vascular endothelial oxidative stress in hyperlipidemia rats].

Objective: To explore the antioxidant effect of moxibustion on vascular endothelial function and the under-lying mechanism.

Methods: Forty male SD rats were randomly divided into blank, model, moxibustion and endothelial nitric oxide synthase (eNOS) inhibitor groups, with 10 rats in each group. Hyperlipidemia rat model was established by high fat diet for 8 weeks. Rats in the moxibustion group received 45 ℃ moxibustion at "Zusanli" (ST36) for 10 min once daily for consecutive 4 weeks. Rats in the eNOS inhibitor group received intraperitoneal injection of eNOS inhibitor L-NAME (1 mg/100 g) at the same time of moxibustion intervention. The morphology of abdominal aorta endothelium was observed by HE staining. Lipid deposition in abdominal aorta was observed by oil red O staining. The contents of total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) in serum and reactive oxygen species (ROS), nitric oxide (NO), superoxide dismutase (SOD), oxidized LDL lipoprotein (ox-LDL), endothelin-1 (ET-1), eNOS, malondialdehyde (MDA) in serum and abdominal aorta were determined by ELISA. The expression of eNOS in abdominal aorta was detected by immunofluorescence.

Results: HE staining of the abdominal aorta showed no significant pathological abnormality in the blank group; the endovascular cortex was rough, and the inner, media and outer membrane were rough in the model group; the nucleus and surrounding tissue structure were clear and the vascular wall was smooth in the moxibustion group; abdominal aorta texture was rough in the eNOS inhibitor group. Compared with the blank group, the area of oil red O staining in abdominal aorta increased (P<0.05); the contents of serum TC, TG and LDL-C increased (P<0.01, P<0.05) while HDL-C decreased (P<0.05); the contents of ET-1 in serum and abdominal aorta were increased (P<0.01, P<0.05) while the contents of NO and eNOS were decreased (P<0.05, P<0.001); the contents of ROS, ox-LDL and MDA in serum and abdominal aorta were increased (P<0.001, P<0.01, P<0.000 1) while the content of SOD in abdominal aorta was decreased (P<0.000 1); the expression level of eNOS in abdominal aorta was decreased (P<0.05) in the model group. Compared with the model group, the area of oil red O staining in abdominal aorta decreased (P<0.05); the contents of TC, TG and LDL-C in serum decreased (P<0.05) while HDL-C increased (P<0.05); the contents of ET-1 in serum and abdominal aorta were decreased (P<0.01, P<0.05) while the contents of NO and eNOS in abdominal aorta were increased (P<0.001, P<0.01); the contents of ROS and MDA in serum and abdominal aorta were decreased (P<0.001, P<0.01, P<0.05), the content of ox-LDL was decreased (P<0.01) and the content of SOD was increased (P<0.000 1) in abdominal aorta; the expression level of eNOS in abdominal aorta was increased (P<0.05) in the moxibustion group. Compared with the moxibustion group, the contents of serum TC, LDL-C and MDA in the eNOS inhibitor group were increased (P<0.05); the contents of ET-1, ROS, ox-LDL and MDA in abdominal aorta were increased (P<0.05), the contents of NO, eNOS and SOD were decreased (P<0.05); the expression level of eNOS in abdominal aorta was decreased (P<0.05).

Conclusion: 45 ℃ moxibustion at ST36 can protect and repair vascular endothelial injury in abdominal aorta of hyperlipidemia rats and improve the oxidative stress of vascular endothelium.