Gluten-Free White Quinoa Flour Exhibits Antioxidant and Anti-Inflammatory Activity

Gluten-free foods may help address oxidative stress and inflammation linked to gluten-related disorders. This study characterized the phytochemical profile of a 70% ethanolic extract from commercial white quinoa (<i>Chenopodium quinoa</i> Willd.) flour (Peru) and evaluated its antioxidant and anti-inflammatory activity in vitro and in vivo in a rat model of acute inflammation. Total polyphenols and flavonoids were quantified spectrophotometrically, while individual phenolics were profiled by HPLC-DAD-ESI-MS. Antioxidant capacity was assessed in vitro using DPPH, FRAP, H₂O₂, and nitric oxide (NO) scavenging assays. For in vivo testing, male Wistar rats received for 10 days quinoa extract (100%-1 g/mL, 50-0.5 g/mL, or 25-0.25 g/mL) either therapeutically (after turpentine-induced inflammation) or prophylactically (before induction), with diclofenac and Trolox as reference controls; systemic oxidative stress (TOS, TAC, OSI, AOPP, MDA, NO, 3-NT, total thiols) and inflammatory mediators (NF-κB p65, IL-1β, IL-18, caspase-1, IL-10) were measured by spectrophotometry/ELISA and explored multivariately by PCA. Quinoa extract contained measurable phenolic and flavonoid levels (TPC 1.25 mg GAE/g d.w.; TFC 68.5 mg QE/100 g d.w.) and was dominated by flavonoid glycosides and hydroxybenzoic acids. It showed strong radical-scavenging/reducing activity in vitro. In vivo, the extract dose-dependently attenuated turpentine-induced nitro-oxidative stress and reduced key pro-inflammatory markers (notably NF-κB, IL-1β, IL-18, and caspase-1), in several endpoints matching or exceeding diclofenac/Trolox effects, while IL-10 was largely unchanged. These findings support white quinoa flour extract as a phytochemical-rich, gluten-free ingredient with promising antioxidant and anti-inflammatory potential, warranting further translational investigation.