Effect of glucosamine on the synovial level of soluble RANKL, IL-6 and IL-10. Joint extracts were collected from individual mice treated with PBS (healthy, n = 9), non-arthritic mice treated with glucosamine hydrochloride for 20 days (20 mg/kg/daily; healthy + Glu, n = 10), CIOA mice (n = 15) and CIOA mice treated with glucosamine hydrochloride for 20 days, starting from Day 7 (20 mg/kg/daily; CIOA + Glu1; n = 15). The levels of particular cytokine (MIP-1α, RANTES, soluble RANKL, TNF-α, IL-6, IL-4 and IL-10) on Day 14 (insert) and on Day 30 of CIOA were determined by ELISA and expressed as picograms/ml supernatant. Data represent the mean ± SD of two independent experiments involving from 9 to 15 animals/group; *P < 0.05; ***P < 0.001 CIOA vs CIOA+Glu1; ###P < 0.001 vs healthy. Student's t-test.