Iota-Carrageenan from Marine Alga Solieria filiformis Prevents Naproxen-Induced Gastrointestinal Injury via Its Antioxidant and Anti-Inflammatory Activities

Background: Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used in therapy due to their anti-inflammatory and analgesic properties. However, their clinical use is often associated with gastrointestinal complications. Thus, this study aimed to investigate the protective effect of a sulfated iota-carrageenan isolated from the marine alga Solieria filiformis (IC-Sf) against naproxen-induced gastrointestinal injury. Methods: Parameters of gastrointestinal injury, secretory and motor functions, and toxicity were evaluated. Results: The results demonstrated that IC-Sf significantly reduced naproxen-induced gastrointestinal macroscopic injury, with a maximum effect observed at 30 mg/kg. IC-Sf also preserved gastrointestinal antioxidant defense and prevented lipid peroxidation, with a reduction in the non-protein sulfhydryl group (NP-SH) and malondialdehyde (MDA) concentrations induced by naproxen. Additionally, IC-Sf mitigated naproxen-induced gastrointestinal inflammation, as evidenced by reduced myeloperoxidase (MPO) activity, tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β). IC-Sf did not alter gastric secretion or gastrointestinal motility. In addition, the animals treated with IC-Sf did not present toxic effects. Conclusions: In conclusion, IC-Sf protected the gastrointestinal tract against the harmful effects of naproxen by inhibiting the inflammatory response and lipid peroxidation, suggesting its potential as a new therapeutic agent or food additive.