Inhibitory effects of a traditional Chinese herbal formula TBL-II on type II collagen-induced arthritis in mice

Abstract

TBL-II is the water extract of an anti-arthritic Chinese herbal formula Tongbiling (TBL), which has been used to treat rheumatoid arthritis (RA) for many years. We herein aimed to confirm its anti-arthritic effect and explore the potential mechanism of action on collagen-induced arthritis (CIA) in mice. Four weeks after the first collagen immunization, mice were treated with TBL-II orally at a lower dose of 100mg/kg/d and higher dose of 300 mg/kg/d for 2 or 8 weeks. The severity of arthritis was evaluated by symptoms, radiological scores and histological assessment. Levels of IL-1β, IL-6, TNFα and IgG2a type anti-collagen II (CII) antibody in serum were measured by ELISA. Competitive RT-PCR and immunohistochemical analysis were used to investigate MMP-2, -3, -9 mRNA and protein expression. Our results revealed treatment with higher dose of TBL-II for 2 weeks attenuated significantly acute inflammation, and decreased the amounts of IL-1β and TNFα in serum; treatment for 8 weeks could obviously suppress chronic inflammation, ameliorate cartilage and bone destruction, and reduce the levels of matrix metalloproteinase (MMP)-2, -3, -9 mRNA and protein expression in joints. The levels of IgG2a type anti-CII antibody in serum were significantly reduced by treatment with higher dose of TBL-II for either 2 or 8 weeks. In contrast, treatment with lower dose of TBL-II for 8 weeks had no effect on articular destruction. Our results suggested that TBL-II at higher dose not only ameliorated symptoms but also modified disease of CIA. TBL-II would be a potent candidate as a novel botanical drug for further investigation.