Effects of Hyaluronic Acid and Chitosan Microspheres on Inducible Oxide Synthase Activity and Expression in Osteoarthritis Chondrocytes

Objective:To investigate the effecs of hyaluronic acid(HA)and chitosan(CS)microspheres on inducible oxide synthase activity and expression in chondrocytes exposured to rrIL-1β in vitro.Methods:HA(microspheres),CS(microspheres)and HA/CS(microspheres)were added to culture medium for 24 hours,respectively,after 10ng/ml IL-1β were added to the culture medium of rat chondrocytes and co-cultured for 1 hours.Then,we examined the expressions of inducible nitric oxide synthase(iNOS)mRNA and activity of iNOS by RT-PCR.The concentration of nitric oxide(NO)in the supernatants were measured by Griess reaction.Results:HA and CS(microspheres)could inhibit the up-regulated iNOS activity and NO production induced by IL-1β effectively.RT-PCR results showed that the expression of iNOS mRNA was inhibited by HA and CS(microspheres).Conclusion:HA and CS(microspheres)could decrease the NO production in osteoarthritis chondrocytes by inhibiting the activity and mRNA expression of iNOS.