Pharmacological Potential of Arthrospira platensis in Mitigating Sub-Chronic Colitis: Redox Homeostasis and Gut Microbiota Modulation.

Inflammatory bowel diseases (IBDs) are complex disorders involving interconnected immune, oxidative, and microbial dysregulations. Arthrospira platensis (Spirulina) is a rich source of bioactive compounds with antioxidant, anti-inflammatory, and immunomodulatory properties. This study investigates the pharmacological efficacy of its aqueous extract (APA) in mitigating 2,4-Dinitrobenzene Sulfonic Acid (DNBS)-induced sub-chronic colitis with a focus on restoring redox balance and modulating gut microbiota composition. APA's antioxidant capacity was assessed in vitro by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic) acid (ABTS) radical scavenging, and metal chelation assays. In vivo, BALB/c mice received two DNBS inductions to establish sub-chronic colitis and were treated with APA (50, 100, and 200 mg/kg). Therapeutic efficacy was assessed through clinical scoring, histopathological assessment, biochemical analysis, and gut microbiota profiling based on 16S rRNA gene sequencing. APA exhibited strong antioxidant activity and significantly attenuated colitis severity, as evidenced by reduced Disease Activity Index (DAI) scores, decreased colon inflammation, suppression of Myeloperoxidase (MPO)-mediated neutrophil infiltration, and modulation of redox biomarkers. Moreover, metagenomic profiling revealed APA-induced modulation of the gut microbiota, mainly through a decreased abundance of pathogenic genera such as Staphylococcus and Enterobacteriaceae. APA demonstrates potent antioxidant, anti-inflammatory, and microbiota-modulating activities, supporting its potential as a complementary therapy for IBDs and encouraging further clinical studies.