NOS2 and rheumatoid arthritis: Furthermore, 50 mg/kg Clitoria ternatea L. flower petals and 2.5 mg/kg of its major compound, which is quercetin-3ß-D-glucoside, showed the ability to reduce MPO activity and lower pro-inflammatory cytokines, chemokines, reactive oxygen and nitrogen species, and TNFR1, TLR2, iNOS, COX-2, and MMP-2 expression levels in rats with RA [346].