Unraveling the Protective Effect of Hesperetin In Experimentally Induced Colitis: Inhibition of NF-κB and NLRP3 Inflammasome Activation

Abstract

This study aimed to investigate the protective effects of hesperetin (HES) against acetic acid (AA)-induced colitis (AAC) in rats through suppression of nuclear factor kappa B (NF-κB) and modulation of the NOD-like receptor pyrin-containing protein 3 (NLRP3) inflammasome. Forty-eight rats were allocated into four groups: control, AAC, HES-treated, and HES pre-treatment followed by AAC. Disease activity index (DAI), macroscopic and histological colonic changes were assessed. Moreover, inflammatory markers, and signaling pathways were evaluated through qRT-PCR, Western blot analysis, ELISA, and immunohistochemistry.

HES pre-treatment significantly decreased the DAI by 61.31%, macroscopic colonic damage by 61.25% and the histological score by 41.86% compared to the AAC group. HES also reduced the expression of miR-155 by 73.79%, NLRP3 by 66.07%, Apoptosis-associated speck-like protein containing CARD (ASC) by 66.09%, cleaved caspase-1 by 63.86%, and the pyroptosis marker gasdermin-N (GSDMD-N) by 61.29%. Concurrently, HES attenuated the NF-κB pathway, reducing NF-κB-positive cells by 74.47% and p-inhibitory κB kinaseα (IκBα)/IκBα and p-Inhibitor of nuclear factor kappa-B kinase subunit alpha (IKKα/β)/IKKα/β levels by 43.77% and 38.68%, respectively. Inflammatory cytokines IL-1β and IL-18 were diminished by 73.41% and 71.88%, respectively. HES pre-treatment increased peroxisome proliferator-activated receptors-γ (PPAR-γ) expression by 259.97%, while reducing CD68+ macrophage infiltration by 72.72%.

In conclusion, HES alleviated AAC in rats by targeting the NF-κB and NLRP3 inflammasome signaling pathways. This protective effect was mediated through the downregulation of miR-155 expression and the concurrent enhancement of PPAR-γ expression, resulting in reduced inflammation and pyroptosis. These findings highlight HES as a potential therapeutic protective agent for colitis.