Osteoarthritis (OA) is the most common joint disorder and is classically defined as a progressively degenerative disease of articular cartilage. It manifests as
joint pain and disability and currently has no comprehensive treatments. The primary purpose of the present study was to test the effects of probiotics, Streptococcus thermophilus (TCI633), on anterior cruciate ligament transection (ACLT)-induced experimental
osteoarthritis (OA) in rats. In the current study, the experimental groups were given TCI633 (5x109, 5x1010 and 5x1011 CFU/kg/day) and
glucosamine sulfate (250 mg/kg) between week 8 and 20 following ACLT. The results showed that
oral administration of TCI633 and
glucosamine had significant
therapeutic effects on
pain behaviors and knee swelling. Dose-dependent effects of TCI633 were also observed in ACLT-treated rats. Histopathological analysis demonstrated that ACLT+TCI633 (5x109, 5x1010 and 5x1011 CFU/kg/day) improved the synovial
inflammation and cartilage damage of ACLT rats. Histology evaluation using the
Osteoarthritis Research Society International system and synovial inflammatory score analysis showed the dose-dependent inhibition of TCI633 on synovial
inflammation and cartilage damage. Immunohistochemical staining and TUNEL apoptosis staining showed that TCI633 could effectively increase the expression of
type II collagen and reduce the amount of chondrocyte apoptosis in cartilage. Therefore, the present study demonstrated that oral intake of TCI633 could significantly suppressing
pain behavior, reduce joint swelling and synovial tissue
inflammation and increase
type II collagen expression in cartilage. There was also a reduction in chondrocyte apoptosis and decreased progression of OA in ACLT-treated rats.