Objective To observe the effect of electroacupuncture(EA) on food intake

body weight

number of taste bud cells and the expression of lipid taste bud receptor(CD36)

Gα-gustducin

post-synaptic density protein 95(PSD95) and neurofilament light chain(NFL) proteins in the tongue or hippocampus in obese rats

so as to explore its mechanism underlying reducing body weight. Methods A total of 30 male SD rats were randomly divided into control

model and EA groups(n=10 in each group

5 rats for H.E. staining and immunohistochemistry

and 5 for Western blot). The obesity model was established by feeding the rats with high fat diet for 11 weeks. Following successful modeling

EA(2 Hz/15 Hz

1.0—1.2 mA) was applied to "Tianshu"(ST25) for 30 min

once a day

5 times/week for 5 weeks. The body length

body weight and maximum daily food consumption were recorded every day

followed by calculating the lee's index. Histopathological changes of the circumvallate papillae(CVP) and number of taste bud cells and CD36 were detected by HE staining and immunohistochemistry(IHC)

separately. The expression levels of CD36

PSD95 and NFL proteins in the hippocampus were detected by Western blot. Results The body weight

Lee's index and daily food consumption were significantly higher in the model group than in the control group(P<0.01)

and were significantly lowered after EA intervention in comparison with the model group(P<0.01)

suggesting an improvement of obesity. H.E. staining displayed that the CVP area and the number of taste bud cells were obviously decreased in the model group in contrast to the control group(P<0.01)

and were notably increased in the EA group in contrast to the model group(P<0.05

P<0.01). IHC and Western blot showed that the expression levels of CD36 in the tongue and hippocampus were obviously up-regulated in the model group relevant to the control group(P<0.01

P<0.05)

and considerably down-regulated in the EA group relevant to the model group(P<0.05

P<0.01). The expression levels of Gα-gustducin in the tongue

and PSD95 and NFL in the hippocampus were remarkably decreased in the model group relevant to the control group(P<0.01

P<0.05)

and significantly increased in the EA group relevant to the model group(P<0.01

P<0.05).Conclusion EA can reduce daily food consumption and body weight in obese rats

which is associated with its effects in down-regulating the expression of CD36 in taste buds and hippocampus

and up-regulating the expression of Gα-gustducin in the tongue

and PSD95 and NFL proteins in the hippocampus. It suggests that EA may regulate the feeding behavior of obese rats by influencing the cognitive memory mechanism involved in CD36 in hippocampus.