Objective To study the protective effect of Huangqi Guizhi Wuwu Decoction （ Astragalus and Cinnamon Twig Five Agents Decoction ） on chemotherapy-induced peripheral never injury in rats.Methods Fifty-five adult female Wistar rats were randomized into five groups

i.e.blank group

model group

mecobalamin （ 104 μ g / kg ） group

Huangqi Guizhi Wuwu Decoction small-dose （ 4.85g / kg · d ） group and Huangqi Guizhi Wuwu Decoction large-dose （ 19.40g / kg · d ） group

with 11in each.Rat models with blood arthralgia syndrome were established with repeated intraperitoneal injection of oxaliplatin.The rats in Huangqi Guizhi Wuwu Decoction groups and mecobalamin group were preventively administered from 7days before modeling and lasted for 50days.The rat mechanical paw withdrawal threshold and rat tail thermal hyperalgesia latency were recorded on the 1st

10th

13th

20th

27th

34th

42nd

and 48th day during the administration.The rats were sacrificed after administration and the L4-6lumbar spinal segments and L5dorsal root ganglion （ DRG ） were resected.The level of NR2B mRNA in L4-6lumbar spinal segments was detected with the real-time quantitative reverse transcriptase polymerase chain reaction （ qRT-PCR ） method.The expression of pNF-H in L5DRG was detected with immunohistochemistry assay.Results Comparing with the blank group

rat mechanical paw withdrawal threshold decreased obviously in the model group after the 13th day of experiment （ P<0.05 ） .Rat mechanical paw withdrawal threshold increased obviously in Huangqi Guizhi Wuwu Decoction groups and mecobalamin group as compared with the model group （ P<0.05 ） .There was a significant difference between Huangqi Guizhi Wuwu Decoction groups and mecobalamin group in rat mechanical paw withdrawal threshold after the 42nd day of experiment （ P<0.05 ） .There was no significant difference in tail thermal pain incubation period between groups （ P>0.05 ） .The level of NR2BmRNA in the model group was significantly higher than that in the blank group （ P<0.05 ） . The levels of NR2BmRNA significantly decreased in Huangqi Guizhi Wuwu Decoction groups （ P<0.05 ）

but the decrement in the mecobalamin group was not significant （ P>0.05 ） .A large number of pNF-H positive cells and deeply stained cell body could be seen in the normal group.A small number of pNF-H positive cells could be seen in the model group.A large number of pNF-H positive cells

cell hypertrophy and deeply stained cell body could be seen in Huangqi Guizhi Wuwu Decoction groups.Conclusion Huangqi Guizhi Wuwu Decoction could relieve pain of the blood arthralgia syndrome induced by chemo-therapy and its mechanism may be relevant to down-regulating the expression of NR2Bin the L4-6lumbar spinal segments and up-regulating the level of pNF-H protein in DRG.