Alleviative effects of green and black tea aqueous extracts on cellular oxidative stress and anemia in rat adjuvant-induced arthritis

Abstract

The aim of this study was to evaluate and compare the alleviative effects of two doses (0.5 and 1.0 gm/kg body weight) of green and black tea aqueous extracts (GTE and BTE, respectively) on articular/extra-articular complications in rat adjuvant-induced arthritis (AIA). Arthritic rats received distilled water as vehicle, indomethacin (1.0 mg/kg body weight; a non-steroidal/anti-inflammatory drug), or tea aqueous extracts orally/daily for 28 days started from the day of arthritis induction (day 0). Other arthritic rats received tea aqueous extracts orally/daily for 14 days started from the day of arthritis onset (day 15). Both tea aqueous extracts significantly suppressed (but with different degrees) the arthritis severity/complications in AIA rat model especially at the high dose and when the treatment started from day 0. Only the high dose of GTE (from day 0) significantly alleviated, as indomethacin (53.32 ± 15.41 and 48.35 ± 17.09, respectively), all complications shown in arthritic rats including body weight loss, anemia, arthritic score, and synovial/hepatic tissues lipid peroxidation (P<0.05-0.001) through significantly increasing food intake (P<0.001) and cellular antioxidants (P<0.05-0.001): reduced glutathione level and catalase, glutathione peroxidase and superoxide dismutase activities. Therefore, tea (especially green tea) may be useful in the management of rheumatoid arthritis complications.