Abstract
Background:
Naringenin, a bioflavonoid present in various species of citrus fruit, tomatoes and grapes, has been shown to have various pharmacological effects. We evaluated the anti-arthritic potential of naringenin in formaldehyde-induced inflammation and complete Freund's adjuvant (CFA)-induced arthritis.
Methods:
For both evaluations, rats were divided into groups of six. Different doses of naringenin (5, 10 and 20mg/kg) were used in the models. Body weight and the arthritic index were assessed. Biochemical and antioxidant parameters were determined. Naringenin dose-dependently reduced joint inflammation, decreasing the joint diameter and inflammatory cell infiltration.
Results:
Naringenin-treated rats showed an improvement in the synovium redox status (down-regulation of malondialdehyde and glutathione and up-regulation of Catalase (CAT) and superoxide dismutase levels). Naringenin significantly reduced the level of the inflammatory marker TNF-α. Naringenin increased Nrf-2/HO-1 and reduced NF-κB mRNA levels in CFA-treated animal joints. Additionally, naringenin treatment decreased the expression of extracellular matrix degrading enzymes, such as matrix metalloproteinase (MMP-3 and MMP-9), in CFA-induced arthritic rats.
Conclusions:
We conclude that naringenin exerts anti-arthritic effects by downregulating NF-κB and activating the Nrf-2/HO-1 pathway.
