Effects of simulated digests of Biota orientalis and a dietary nutraceutical on interleukin-1– induced inflammatory responses in cartilage explants

Abstract

To test the hypothesis that simulated digests of Biota orientalis (BO) and a dietary nutraceutical (DN; composed of mussel, shark cartilage, abalone, and BO seed lipid extract) inhibit prostaglandin E2 (PGE2), nitric oxide (NO), and glycosaminoglycan (GAG) production in interleukin (IL)-1-stimulated cartilage explants. Cartilage tissue from 12 pigs. Articular cartilage explants were conditioned with a simulated digest of BO (BOsim) or DN (DNsim) at concentrations of 0, 0.06, or 0.18 mg/mL or indomethacin (INDOsim; 0 or 0.02 mg/mL) for 72 hours. Control explants received digest vehicle only. Explants were or were not stimulated with recombinant human-IL-1beta (10 or 0 ng/mL) during the final 48 hours of culture. Concentrations of PGE2, GAG, and NO in media samples (mPGE2,mGAG, and mNO concentrations, respectively) were analyzed, and explant tissue was stained fluorochromatically to determine chondrocyte viability. Treatment effects during the final 48-hour culture period were analyzed. IL-1 increased mPGE2, mGAG, and mNO concentrations in control explants without adversely affecting cell viability. Treatment with INDOsim blocked PGE2 production and increased mNO concentration in IL-1-stimulated and unstimulated explants and increased mGAG concentration in unstimulated explants. Treatment with DNsim (0.06 and 0.18 mg/mL) reduced mPGE2 concentration in IL-1-stimulated and unstimulated explants, reduced mNO concentration in IL-1-stimulated explants, and increased mNO concentration in unstimulated explants. Treatment with 0.18 mg of DNsim/mL increased cell viability in the presence of IL-1. In IL-1-stimulated explants, BOsim (0.06 and 0.18 mg/mL) reduced mPGE2 concentration, but 0.18 mg of BOsim/mL increased cell viability. Effects of IL-1 on cartilage explants in vitro were modulated by DNsim and BOsim.