Comparative Evaluation of White Quinoa and Tri-Color Quinoa on Indomethacin-Induced Gastrointestinal Damage

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as indomethacin, frequently cause gastric injury, often characterized by ulceration. This study investigated the comparative gastroprotective effects of white quinoa and tri-color quinoa (a combination of red, black, and white varieties) in mitigating indomethacin-induced gastric damage in male rats. Thirty-six male rats were divided into dietary groups and administered quinoa-supplemented diets for 21 days before gastric injury was induced using indomethacin. Biochemical markers, including TNF-α and IL-6, were assessed, and molecular docking was employed to examine the interactions of quinoa-derived compounds, such as procyanidin B2 and cinchonain IB, with target proteins Atp4a, COX-2, and NF-κB. Tri-color quinoa demonstrated greater efficacy than white quinoa, reducing mucosal necrosis by 83%, attenuating oxidative stress, and significantly enhancing anti-inflammatory markers (p < 0.05). Furthermore, bioactive compounds showed strong binding affinities (-7.1 to -8.9 kcal/mol) to target proteins through hydrogen and hydrophobic interactions. Histological examination confirmed superior protection for the tri-color group, displaying near-normal mucosa (lesion score 0.4 vs. 2.4) and minimal submucosal edema. In conclusion, tri-color quinoa provides more effective protection against NSAID-induced gastric injury than white quinoa, likely due to its enhanced phytochemical profile and broader range of plant-derived compounds that collectively reduce inflammation and preserve gastric mucosal integrity.