IL-10 and TGF-β: Roles in chondroprotective effects of Glucosamine in experimental Osteoarthritis?

Osteoarthritis (OA) is a complex disease of the whole joint. Glucosamine (GlcN) treatment may have a chondroprotective effect on OA. We investigated the mechanism of action of glucosamine treatment through interleukin-10 (Il-10) and transforming growth factor β-1 (TGF β-1).

Thirty male albino rats were used. A single intraarticular (i.a.) injection of 2mg of Monosodium Iodoacetate (MIA) was injected into the knee joint of anesthetized rats. GlcN (50 or 100mg/kg/day, p.o. for 2 month) was administered orally. Serum levels of Il-10 and TGF-β1 were determined by ELISA. Histopathological changes in treated and control joints were examined using hematoxylin-eosin (H & E) staining.

The mean serum level of IL-10 significantly decreased in the OA group compared to control group (P value<0.0001). On the other hand, mean serum level of IL-10 significantly increased in GlcN treated groups when compared to the OA group (P value<0.0001). Serum level of TGF β-1 was significantly elevated in OA group compared to control group (P value<0.0001). On the other hand, the mean serum level of TGF β-1 was significantly decreased in the GlcN treated groups when compared to the OA group (P value<0.0001). Histopathological evaluation of GlcN treated groups showed different grades of healing, according to Osteoarthritis Research Society International (OARSI) grading system.

Our results showed that IL-10 and TGF-β1 possibly mediate GlcN chondroprotective effects in OA. Both serum biomarkers can be useful in the follow-up of articular cartilage damage in clinical settings.