Objective: To investigate the effect of electroacupuncture (EA) on intestinal Toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB) in obese rats, so as to explore the mechanism of action of acupuncture in losing weight.
Methods: A total of 50 male Wistar rats were randomly divided into control and model groups. High-fat feed was used to establish a rat model of obesity, and after modeling, the 24 rats were randomly divided into model group, TLR4 inhibitor group, and EA group, with 8 rats in each group. The rats in the EA group were given EA at "Guanyuan" (CV4), "Zhongwan "(CV12), "Zusanli" (ST36), and" Fenglong" (ST40), 10 minutes each time, 3 times a week, and those in the TLR4 inhibitor group were given intraperitoneal injection of TAK-242 three times a week; the course of treatment was 8 weeks for both groups. Body weight and blood glucose were measured every two weeks. Co-immunoprecipitation was used to observe the interaction between TLR4 and NF-κB p65 in the intestinal tissue; electrophoretic mobility shift assay was used to measure the activity of NF-κB p65; Western blot was used to measure the protein expression of TLR4, phosphorylated nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor alpha (p-IκBα), and NF-κB p65; quantitative real-time PCR was used to measure the mRNA expression of TLR4, NF-κB p65, and IκBα.
Results: Compared with the control group, the model group had significant increases in body weight, blood glucose, and protein and mRNA expression of TLR4 and NF-κB p65 (P<0.01, P<0.05), as well as significant enhancement in the interaction between TLR4 and NF-κB p65 and activity of NF-κB p65 (P<0.05，P<0.01). Compared with the model group, the EA group had a significant reduction in body weight (P<0.05), both of the EA group and the TLR4 inhibitor group had significant reductions in blood glucose, and protein and mRNA expression of TLR4, p-IκBα， and NF-κB p65 (P<0.05，P<0.01), as well as significant reductions in the activity of NF-κB p65 (P<0.01).
Conclusion: EA can effectively regulate intestinal TLR4, inhibit the interaction between TLR4 and NF-κB p65, and reduce the activity of NF-κB p65, which may be a potential mechanism of EA in reducing body weight and blood glucose in obese rats.
Keywords: Electroacupuncture; Intestinal tract; Nuclear factor-kappa B; Obesity; Toll-like receptor 4.