Anti-ulcerogenic and pro-ulcerogenic responses to dietary turmeric rhizome powder in wistar rats

Purpose This study explored the effects of turmeric rhizome powder (TRP) on indomethacin-induced gastric ulcers in wistar rats. With debates surrounding turmeric’s safety at high doses, the research aimed to clarify its anti-ulcer, antioxidative and inflammatory responses. The purpose of this study is to identify both protective and harmful thresholds of dietary turmeric consumption. Design/methodology/approach Thirty-five male wistar rats were randomly assigned to seven groups. Rats received diets supplemented with 1%, 2%, 5% and 10% TRP, a basal diet with omeprazole and control diets. After 28 days, indomethacin was administered to induce ulcers in all the groups except the normal control group (CTL). Gastric lesions, ulcer index (UI), lipid peroxidation(malondialdehyde), gastric mucosal architecture and gene expression of TNF-α and inducible nitric oxide synthase (iNOS) were evaluated, supported by histopathological analysis. Findings TRP at 1%, 2% and 5% significantly reduced UI (7.0 + 1.41b, 2.5 + 0.71 cd and 5.5 + 0.71bc respectively), had high percentage of ulcer inhibition (39.1, 78.3 and 52.2, respectively), preserved gastric mucosa, lowered oxidative stress (p = 0.84, 0.39 and 0.75, respectively) and downregulated gastric TNF-a (p <0.001, 0.001 and 0.001, respectively) and iNOS expression (p < 0.001, 0.001 and 0.001, respectively) when compared with the control group, thereby demonstrating potent gastroprotective effects comparable to that of omeprazole. In contrast, 10% TRP worsened ulceration (p < 0.001), heightened oxidative damage and upregulated inflammatory markers, indicating pro-ulcerogenic action. Histology also confirmed these dose-dependent outcomes. Originality/value This work uniquely demonstrates turmeric’s double-edged nature: protective at 1%, 2% and 5% but ulcer-promoting at 10%. Unlike earlier studies focusing only on benefits, this study reveals the risks of excessive intake and provides molecular evidence of turmeric’s role in modulating inflammation and oxidative stress. The findings redefine turmeric’s therapeutic window, cautioning against high-dose consumption and emphasizing dosage as the key determinant of its safety and efficacy.