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.