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.
The current study was a randomized double-blind clinical trial in which 51 women with RA aged 19-70 years, were participated. Patients were assigned into quercetin (500 mg/day) or placebo groups for 8 weeks. Dietary intake was recorded using 24-h 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 C-reactive protein (hs-CRP) using enzyme-linked immunosorbent assay method and also blood pressure were measured at the beginning and end of intervention.
After 8 weeks there were no significant differences in TAC of plasma, ox-LDL, MDA, hs-CRP, systolic and diastolic blood pressure between quercetin and placebo groups and in each group comparing before and after.