The effect of quercetin on plasma oxidative status, c‑reactive protein and blood pressure in women with rheumatoid arthritis
Background:Considering the increased production of free radicals and inflammatory factors in rheumatoid arthritis (RA) and the effects of bioflavonoid quercetin on reducing oxidative stress, inflammation and blood pressure, the present study examined the effects of bioflavonoid quercetin on total antioxidant capacity (TAC) of plasma, lipid peroxidation and blood pressure in women with RA. Methods: The current study was a randomized doubleblind clinical trial in which 51 women with RA aged 1970 years, were participated. Patients were assigned into quercetin (500 mg/day) or placebo groups for 8 weeks. Dietary intake was recorded using 24h dietary recall questionnaire and the physical activity was assessed through an international short questionnaire of physical activity at the beginning and end of the study. Plasma TAC and malondialdehyde (MDA) using colorimetric method, oxidized low density lipoprotein (ox- LDL) and high sensitivity creactive protein (hsCRP) using enzymelinked immunosorbent assay method and also blood pressure were measured at the beginning and end of intervention. Results: After 8 weeks there were no significant differences in TAC of plasma, oxLDL, MDA, hsCRP, systolic and diastolic blood pressure between quercetin and placebo groups and in each group comparing before and after. Conclusion:In this study, quercetin had no effect on oxidative and inflammatory status of plasma and blood pressure in patients with RA. Further studies are needed to ensure the effect of quercetin on oxidative stress and inflammation in human.