Cinnamomum cassia Modulates Key Players of Gut-Liver Axis in Murine Lupus

Background: Systemic lupus erythematosus is a multi-faceted auto-immune disease. Growing evidence points to gut permeability and microbiota as key players in the development of the disease. Cinnamomum cassia is gaining attention as a potential modifier of the gut and liver health. We aim in this study to explore the effect of cinnamon on key elements of the gut-liver axis in imiquimod-induced lupus. Methods: Female C57BL/6J mice were stratified into five experimental groups: sham, sham plus cinnamon, lupus, lupus with cinnamon treatment, and lupus with pre- and post-induction cinnamon treatment. Lupus was induced through application of 1.25 mg of 5% imiquimod cream to the right ear, three times per week over six weeks. Cinnamomum cassia was given orally at 200 mg/kg, five days weekly. High-Throughput Sequencing of Bacterial 16S rRNA Gene was used on fecal samples with subsequent bioinformatic analysis of microbiota. Western blot and antibody array were used to measure E. coli translocation, and hepatic inflammatory, oxidative, and apoptotic markers. Results: Cinnamon treatment mitigated the trend toward a lower Firmicutes/Bacteroidota ratio in the lupus mice. While not statistically significant, cinnamon also led to a decrease in Lachnospiraceae abundance. Interestingly, sham mice given cinnamon had more Lactobacillus and Limosilactobacillus. Furthermore, cinnamon effectively reversed the increase in E. coli protein in the liver and normalized the enhanced expression of TLR-7, p-NFκB/NFκB, SOD1 and SOD2 induced by lupus. Conclusions: Cinnamomum cassia modulates oxidative, inflammatory, and microbial elements of the gut-liver axis in lupus, offering a new perspective on lupus pathogenesis and potential nutritional interventions.