Diospyros kaki fruit extract produces antiarthritic and antinociceptive effects in rats with complete Freund's adjuvant‐induced arthritis

Abstract

Current treatments for rheumatoid arthritis produce untoward effects; thus, considerable effort has been made to recognize effective herbal medicines against the condition. In the present study, the therapeutic effect of Diospyros kaki fruit hydroalcoholic extract (DFHE) on complete Freund's adjuvant (CFA)‐induced arthritis in rats was investigated. The extract was characterized using liquid chromatography–electrospray mass spectrometry (LC‐ESIMS). Male Wistar rats were grouped as follows (eight rats in each): control, CFA, CFA + indomethacin (5 mg/kg), CFA + DFHE (50 mg/kg), and CFA + DFHE (100 mg/kg). Paw volume, mechanical allodynia, thermal hyperalgesia, and arthritis score were evaluated. Serum levels of malondialdehyde (MDA), thiol groups, tumor necrosis factor‐alpha (TNF‐α), as well as glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were evaluated. Carotenoids were found to be the major components of DFHE. Administration of DFHE (100 mg/kg) significantly decreased arthritis score, paw volume, and thermal hyperalgesia, and improved mechanical allodynia. MDA and TNF‐α levels were decreased while thiol levels and SOD and GPx activities were increased in DFHE‐treated groups compared to the CFA group. These results suggest that D. kaki extract caused an improvement in clinical signs of rheumatoid arthritis symptoms possibly through suppression of oxidative stress and inflammation.