A Preliminary Study On The Effect Of HPβCD On Rabbit Osteoarthritis

In recent years,As the risk factors for osteoarthritis(OA)(such as eating habits,lack of exercise,and joint damage)increase,the prevalence of OA is increasing year by year.The formation of OA is abnormal lipid metabolism,such as a high cholesterol.For this reason,scientists are paying more and more attention to the diagnosis(such as marker testing)and treatment(such as related drug development)of osteoarthritis caused by high cholesterol.Cyclodextrin(CD)is a cyclic polysaccharide structure composed of multiple(6-9)glucose residues.In a shape of a tuncated cone.It has internally hydrophobic and externally hydrophilic characteristics,which can reduce the hydrophobicity.Molecules(such as lipids,etc.)can be entrapped in the cavity and carried away,thus having a good lipid-removing effect.We speculate that CD may be able to achieve an inhibitory effect on OA through its lipid-removing ability(e.g:lowering cholesterol content).In order to verify the hypothesis,this study uses hydroxypropyl-β-cyclodextrin(HPβCD)as a representative of cyclodextrin,uses primary chondrocytes for in vitro cell experiments,and high-fat diet or collagenase injury for the development of rabbit OA models in vivo experiments.The primary chondrocytes extracted by enzymatic digestion from the articular cartilage of rabbit knees were used for in vitro cell experiments.First,the MTT method was used to detect the effect of HPβCD on the proliferation of chondrocytes.The results showed that ≧20 m M HPβCD had a significant cytotoxic effect on chondrocytes whereas 5 m M and 10 m M HPβCD(within 3 days)promoted cell proliferation.Therefore,5 m M was used as the working concentration of HPβCD in subsequent cell experiments.Second,the toluidine blue staining method was used to detect the loss of interleukin-1β(IL-1β)and cholesterol-mediated glycosaminoglycan(GAG)in chondrocytes.The results showed that 5 m M and 10 m M HPβCD could inhibit the GAG loss of cells.The cholesterol content in chondrocytes was detected by a microplate reader,and the results showed that IL-1β induced the increase in intracellular,extracellular,and total cholesterol of chondrocytes,which could be reversed effectively by HPβCD.In the in vivo experiment,the unstable OA rabbit model fad a high-fat diet(HFD)was treated with HPb CD.The results showed that 0.74g/kg HPβCD inhibited the HFD-induced increase of the lipid levels in blood and of the cholesterol level in synovial fluid.The morphological data via Safranin O fast green staining showed that HPβCD could well inhibit the development of OA.Subsequently,another rabbit OA model was constructed by the collagenase injury method.The results showed that a certain concentration of HPβCD(such as 23.27 mg/kg)reduced the cholesterol content in the synovial fluid.The morphological changes were observed by safranin O fast green staining,showing that HPβCD could inhibit the development of OA.The above-mentioned in vitro and in vivo experimental results show that HPβCD has a certain recovery effect on chondrocytes and cartilage tissue,thereby inhibiting the development of OA,which verified our initial speculation.This study is of great significance to the understanding and prevention of bone and joint diseases caused by high-fat diet and implies the possibility of utilizing HPb CD as a novel drug for OA treatment.