Effects of Tenghuang Jiangu Capsule on Bone Metabolism and PI3K/Akt/Nrf2/HO-1 Signaling Pathway in Rats with Knee Osteoarthritis
Objective To investigate the effects of Tenghuang Jiangu Capsule on bone metabolism and PI3K/Akt/Nrf2/HO-1 signaling pathway in rats with knee osteoarthritis(KOA).Methods A rat model of KOA was construc-ted with papain,and 40 successfully modeled rats were randomly divided into model group,positive drug group,Tenghuang Jiangu Capsule low-dose group and high-dose group according to random number table method,with 10 rats in each group.At the same time,10 untreated rats were as assigned to control group.After 4 weeks of modeling,the rats in positive drug group,Tenghuang Jiangu Capsule low-dose group and high-dose group were treated with meloxicam aqueous solu-tion,0.09 g/kg and 0.36 g/kg Tenghuang Jiangu Capsule,respectively,and the rats in model group and control group were administrated with the same amount of normal saline once a day.After 4 weeks of administration,Mankin scores and joint swelling were compared among all groups.Enzyme-linked immunosorbent assay(ELISA)was used to measure the levels of interleukin1β(IL-1β),tumor necrosis factor α(TNF-α),metallomatrix proteinase 3(MMP3),tissue metallo-proteinase inhibitor 1(TIMP-1),osteocalcin(BGP),tartrate-resistant acid phosphatase(TRACP)and C-terminal te-lopeptide of type Ⅰ collagen(CTX)in the five groups.The protein expression of PI3K/Akt/Nrf2/HO-1 signaling pathway in cartilage tissues was detected by Western blot.Results HE staining showed that the articular surface,articular cartilage and chondrocytes were normal in the control group.In the model group,the articular surface was irregular,with a small a-mount of chondrocytes or chondrocyte necrosis,and the articular cartilage was replaced by fiber tissue.The articular surface was irregular and the number of chondrocytes was reduced in the positive drug group and the Tenghuang Jiangu Capsule high-dose group,while the Tenghuang Jiangu Capsule low-dose group showed moderate chondrocyte necrosis.Compared with control group,Mankin score and joint swelling degree were significantly increased in model group(P<0.05).Com-pared with model group,Mankin score and joint swelling degree were significantly decreased in positive drug group,Teng-huang Jiangu Capsule low-dose group and high-dose group(P<0.05).The comparison of Mankin score and joint swell-ing degree among different drug treatment groups showed the positive drug grouP<Tenghuang Jiangu Capsule high-dose grouP<Tenghuang Jiangu Capsule low-dose group,and the difference was statistically significant(P<0.05).Compared with control group,the levels of IL-1β,TNF-α,MMP-3 and TIMP-1 in model group were significantly increased(P<0.05).Compared with model group,the levels of IL-1β,TNF-α,MMP-3 and TIMP-1 in positive drug group,Teng-huang Jiangu Capsule high-dose group and low-dose group were significantly decreased(P<0.05).The comparison of levels of IL-1β,TNF-α,MMP-3 and TIMP-1 among all drug treatment groups showed the positive drug grouP<Ten-ghuang Jiangu Capsule high-dose grouP<Tenghuang Jiangu Capsule low-dose group,and the difference was statistically significant(P<0.05).Compared with control group,TRACP and CTX levels in model group were significantly increased,while BGP levels were significantly decreased(P<0.05).Compared with model group,TRACP and CTX levels in positive drug group,Tenghuang Jiangu Capsule high-dose group and low-dose group were significantly decreased,while BGP lev-els were significantly increased(P<0.05).The comparison of TRACP and CTX levels among all drug treatment groups showed positive drug grouP<Tenghuang Jiangu Capsule high-dose grouP<Tenghuang Jiangu Capsule low-dose group.The comparison of BGP level showed positive drug group>Tenghuang Jiangu Capsule high-dose group>Tenghuang Jian-gu Capsule low-dose group,and the difference was statistically significant(P<0.05).Compared with control group,the protein levels of PI3K,Akt,Nrf2 and HO-1 in model group were significantly decreased(P<0.05).Compared with mod-el group,the protein levels of PI3K,Akt,Nrf2 and HO-1 in positive drug group,Tenghuang Jiangu Capsule high-dose group and low-dose group were significantly increased(P<0.05).Moreover,the protein levels of PI3K,Akt,Nrf2 and HO-1 among all drug treatment groups were compared,and the protein levels were higher in positive drug group than those in Tenghuang Jiangu Capsule high-dose group,which were higher than those in Tenghuang Jiangu Capsule low-dose group,with statistical significant difference(P<0.05).Conclusion Tenghuang Jiangu Capsule can significantly im-prove bone metabolism and alleviate the symptoms of KOA in rats,which may be related to the activation of PI3 K/Akt/Nrf2/HO-1 signaling pathway.