Canagliflozin-loaded chitosan-hyaluronic acid microspheres modulate AMPK/NF-κB/NLRP3 axis: A new paradigm in the rectal therapy of ulcerative colitis

Ulcerative colitis is an idiopathic disease that is widely incident worldwide. Canagliflozin, antidiabetic agent, exhibited significant anti-inflammatory effects in a variety of animal models. Additionally, hyaluronic acid is considered one of the key players in the tissue regeneration process. It has been proven to modulate inflammation and cellular migration, which are the main phases of wound healing. The combination of hyaluronic acid with chitosan in microsphere fabrication was anticipated to reveal a synergistic muco-adhesiveness potential with additional advantage of the chitosan penetration enhancing effect. The current study aimed to explore the potential of canagliflozin-loaded chitosan-hyaluronic acid microspheres intrarectal administration to mitigate acetic acid-induced colitis in rats. Colon tissues were examined for macroscopic and microscopic pathological changes. ELISA and qRT-PCR techniques were applied for the detection of cytokines involved in the AMPK/NF-κB/NLRP3 axis. Intrarectal administration of this formula alleviated colitis severity, which was reflected by the reduced DAI, MES, colonic weight/length ratio and histopathological scoring values. Interestingly, canagliflozin-loaded chitosan-hyaluronic acid microspheres significantly enhanced AMPK phosphorylation and depressed NF-κB and NLRP3 expression leading to a subsequent reduction in caspase-1 cleavage and the inhibition of several inflammatory cytokines, including IL-1β, and IL-18. Overall, the current study revealed that the protective effects of the formula against acetic acid-induced colitis are primarily mediated via augmenting AMPK phosphorylation and its consequences of NF-κB inactivation. Since canagliflozin is not associated with hypoglycemic effects, clinical application of canagliflozin-loaded chitosan-hyaluronic acid microspheres represent a novel therapeutic option for the treatment of patients with ulcerative colitis.