Mijung Yeom1, Jinhee Park2, Bombi Lee1, Hyang Sook Lee2, Hi-Joon Park2, Ran Won3, Hyejung Lee2, Dae-Hyun Hahm4. 1. Acupuncture and Meridian Science Research Center, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea. 2. Acupuncture and Meridian Science Research Center, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea; Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea. 3. Department of Biomedical Laboratory Science, Division of Health Sciences, Dongseo University, Busan 47011, Republic of Korea. 4. Acupuncture and Meridian Science Research Center, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea; Department of Physiology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea. Electronic address: dhhahm@khu.ac.kr.
Abstract
AIMS: Acupuncture, particularly electroacupuncture (EA) has been shown to have the lipid-lowering effects, but not completely investigated. The present study was aimed to examine whether EA could attenuate poloxamer-407 (P-407)-induced hyperlipidemia in the rats and to investigate its potential mechanisms. MAIN METHODS: Rats received P-407 (0.4 g/kg, i.p.) to induce hyperlipidemia. EA was performed at ST36 and ST40 acupoints a total of three times with 12 h-interval starting 1 h before the P-407 injection at 0.6 mA intensity and 2 Hz frequency for 10 min. KEY FINDINGS: In P-407-induced hyperlipidemic rats, EA stimulation at ST36 and ST40 acupoints significantly lowered the serum levels of triglycerides, total cholesterol, LDL-cholesterol and atherogenic index, while markedly increasing the serum HDL-cholesterol levels. Meanwhile, hyperlipidemic rats had significantly higher expression of sterol regulatory element-binding protein (SREBP)-2, without any difference in SREBP-1 expression in the liver, as compared with normal ones. EA significantly attenuated the expression of SREBP-2 with a subsequent decrease in 3-hydroxy-3-methylglutaryl coenzyme A reductase and an increase in low-density lipoprotein receptor at both mRNA and protein levels in the liver of hyperlipidemic rats. These changes did not occur after electrical stimulation at a non-acupoint. SIGNIFICANCE: Taken together, our findings indicate that EA stimulation to P-407-induced hyperlipidemic rats improves the lipid abnormalities, which may be associated with regulation of the expression of key enzymes of cholesterol synthesis in the liver through modulation of SREBP-2.
AIMS: Acupuncture, particularly electroacupuncture (EA) has been shown to have the lipid-lowering effects, but not completely investigated. The present study was aimed to examine whether EA could attenuate poloxamer-407 (P-407)-induced hyperlipidemia in the rats and to investigate its potential mechanisms. MAIN METHODS:Rats received P-407 (0.4 g/kg, i.p.) to induce hyperlipidemia. EA was performed at ST36 and ST40 acupoints a total of three times with 12 h-interval starting 1 h before the P-407 injection at 0.6 mA intensity and 2 Hz frequency for 10 min. KEY FINDINGS: In P-407-induced hyperlipidemic rats, EA stimulation at ST36 and ST40 acupoints significantly lowered the serum levels of triglycerides, total cholesterol, LDL-cholesterol and atherogenic index, while markedly increasing the serum HDL-cholesterol levels. Meanwhile, hyperlipidemic rats had significantly higher expression of sterol regulatory element-binding protein (SREBP)-2, without any difference in SREBP-1 expression in the liver, as compared with normal ones. EA significantly attenuated the expression of SREBP-2 with a subsequent decrease in 3-hydroxy-3-methylglutaryl coenzyme A reductase and an increase in low-density lipoprotein receptor at both mRNA and protein levels in the liver of hyperlipidemic rats. These changes did not occur after electrical stimulation at a non-acupoint. SIGNIFICANCE: Taken together, our findings indicate that EA stimulation to P-407-induced hyperlipidemic rats improves the lipid abnormalities, which may be associated with regulation of the expression of key enzymes of cholesterol synthesis in the liver through modulation of SREBP-2.