Effect Of Huangqiguizhiwuwu Decoction On Voltage-sodium Channels In A Rat Model Of Oxaliplatin Induced Neuropathic Pain

Objective The experiment by observing changes in the behavior and body weight of chemotherapy-induced neuropathic pain model of rats, observing dorsal root ganglion cells in pathological changes and the expression changes of Nav1.7protein and voltage-sodium channels (Nav1.7、Nav1.8、Nav1.9) mRNA to explore decoction HuangQiGuiZhi Tang on oxaliplatin-induced peripheral neuropathic pain and the possible mechanisms.Methods After adaptiving feed seven days45adult Wistar male rats weighing200-250g were used for the oxaliplatin-induced neuropathy model. They were randomly divided into three groups:blank group, model group, and high dose group of Huangqiguizhiwuwu decoction decoction(n=15).blank group was injected5%glucose2ml/kg intraperitoneal, the other two groups were injected oxaliplatin2ml/kg intraperitoneally twice a week for4weeks. The blank group, model group were received by gastric lavage with2ml of0.9%NS daily from dl to d28; and Huangqiguizhiwuwu group were received by gastric lavage with high doses of Huangqiguizhiwuwu decoction at the dosage ofl Oml/kg body weight daily; the decoction was given one hour before oxaliplatin on the day when it need to inject oxaliplatin. Observe changes in the behavior and Cold acetone experimental pain before oxaliplatin and repeat Cold acetone experimental pain on the second day after injecting oxaliplatin.The rats were weighed once a week, observed the changes of reactions, stool daily and diet. On26day,bilateral sciatic nerve and L4-5bilateral dorsal root ganglia were harvested from rats.1、By Nissl staining,Observe the change of the size of the nucleolus of dorsal root ganglion by electron microscope.2、 Immunohistochemistry was used to detect the expression of Nav1.7cell membrane protein.3、 Western-blot was used to observe the change of the expression of Navl.7.4、Detect the expression changes of voltage-sodium channels (Nav1.7、Nav1.8、Nav1.9) mRNA in the dorsal root ganglion by qRT-PCR.Results The behavior measure、Cold acetone experimental pain and histological examination can prove the success of the chemotherapy-induced neuropathic pain rat model preparation. Compared with the blank group, model group’s body weight markedly decrease(p<0.01).Compared with the blank group, model group’s mechanical allodynia markedly decrease (p<0.01), and Huangqiguizhiwuwu group can alleviate oxaliplatin induced peripheral neuropathy pain(p<0.01). Compared with the blank group, model group’s Cold acetone experimental pain markedly decrease (p<0.01), and Huangqiguizhiwuwu group can alleviate the change(p>0.05). Compared with the blank group, nucleolar size significantly decrease after the injection of oxaliplatin(p<0.01),and Compared with the model group,Huangqiguizhiwuwu group can alleviate the decrease of nucleolar size(p<0.01). Immunohistochemistry、WB and qPCR shows:Compared with the blank group, oxaliplatin can up-regulate the expression of Navl.7,and Compared with the model group,Huangqiguizhiwuwu group can down-regulating the high expression.qPCR shows:compared with the blank group, oxaliplatin can increase the expression ofNavl.8、Navl.9mRNA significantly in dorsal root ganglion,and Compared with model group, the Chinese medicine can down-regulate the expression ofNavl.9, but the expression of Navl.8was increased.Conclusions Huangqiguizhiwuwu decoction can alleviate oxaliplatin induced neuropathic pain.The possible mechanisms:1、By alleviating the decrease of nucleolar size in dorsal root ganglion neurons after injecting oxaliplatin.2、By down-regulating the high expression of Navl.7in dorsal root ganglion.3, Huangqiguizhiwuwu decoction can block up Nav1.7.