Attenuation of oxidative stress in arthritic rats by ethanolic extract of Albizia procera benth bark through modulation of the expression of inflammatory cytokines.

Abstract

Albizia procera L. (Leguminosae) commonly known as Konda vagai in Tamil, is used for the treatment of stomach and intestinal disorders. A decoction of the bark is prescribed for rheumatism and haemorrhage. Traditionally, literature claims Albizia procera as a drug to have antirheumatic properties and hence used by Tribal for the management of chronic rheumatism. Consequently, the present study has been undertaken to illustrate the beneficial outcome of Albizia procera in adjuvant induced arthritic rat model with respect to its antioxidant and anti-inflammatory activities. The present study is aimed to investigate the oxidative stress and the expression of inflammatory markers in arthritic rats treated with ethanolic bark extract of Albizia procera. Ethanolic bark extract was characterized by HPTLC analysis. Acute oral toxicity study was performed according to the OECD test guideline 423 - Acute toxic class method. The anti-inflammatory effect of ETBE (100, 200mg/kg/day/p.o.) was evaluated in complete Freund's adjuvant induced arthritic rats using diclofenac as positive control (0.3mg/kg/day/p. o.). Plasma levels of interleukins TNF- α, IFN-α, IL-2, IL-6, myeloperoxidase and Cathepsin D levels were measured to assess the inflammatory effect of ETBE extract of Albizia procera. Further, the effect of ETBE on superoxide dismutase (SOD), glutathione peroxidase (GPX), reduced glutathione (GSH) and lipid peroxidation (LPO) were assessed in plasma. HPTLC analysis showed the presence of 0.57% w/w of biochanin-A in ETBE. ETBE did not show any toxic signs up to 2000mg/kg body weight. It exhibited the significant anti-inflammatory and antioxidant potential and did not show mortality up to 2000mg/kg body weight. ETBE treatment significantly reduced the levels of TNF- α, IFN-α, IL-2, IL-6 and myeloperoxidase, and increased cathepsin D levels compared to vehicle treated animals. SOD, GSH and GPX levels were significantly restored to normal levels while LPO was significantly reduced at 200mg/kg b. wt. Treated animals. Histopathological studies showed complete cartilage regeneration and near normal joint in ETBE treated arthritic rats. ETBE demonstrated potent anti-inflammatory activity by modulating the expression of inflammatory cytokines and restoring the antioxidant enzyme levels.