Protective effects of the ethanolic fenugreek seeds extract and its potentiation with nitric oxide modulators in adjuvant induced changes in arthritic index, proinflammatory/anti-inflammatory cytokines imbalance and oxidative stress markers in rats

Abstract

Objectives: The current study was designed to evaluate protective role of the ethanolic fenugreek seed extract (FSE) and potentiating its effects with nitric oxide (NO) modulators in experimental arthritis and its comparison with the standard drug methotrexate. Materials and Methods: The FSE was prepared using standard procedures. Fifty-four male Wistar rats were equally distributed into nine groups of six animals in each group. Rheumatoid arthritis was induced by administration of complete Freund’s adjuvant (CFA) in sub-plantar region of rt. hind paw. FSE alone and with L-arginine or Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) were administered on day 10 of CFA inoculation, i.p. Animals were evaluated for arthritic parameters, cytokines and oxidative stress markers estimation. Statistics: The data were analysed by two-way ANOVA followed by Newman Keul’s post hoc test for inter group analysis by GraphPad Prism 6.0 and P < 0.05 was taken as significant. Results: Adjuvant inoculated rat shows significant increase in arthritic and inflammatory parameters as well as oxidative stress biomarkers in serum, paw homogenates and joint synovial fluid. CFA inoculation significantly decreased anti-inflammatory cytokine-10 and SOD activity. These adjuvant-induced arthritic changes were significantly attenuated by ethanolic FSE administration from 10 to 28 days. These results are comparable to standard drug methotrexate. NO modulators further potentiated protective effects of FSE when given in combination. These results were more prominent when ethanolic seed extract was given with iNOS inhibitor, L-NAME. Conclusion: These findings suggest that FSE shows protective effects in CFA induced arthritic changes that may be mediated through pro-inflammatory/anti-inflammatory cytokines imbalance and it is associated with modulation of oxidative stress and NO-signalling.