Okra polysaccharide activates PPAR-γ signaling to attenuate metabolic-associated fatty liver disease in mice

Okra (Abelmoschus esculentus (L.) Moench) serves as a botanical resource extensively utilized in ethnomedicine. Prior investigations revealed that okra polysaccharide (OP) ameliorated hepatocellular lipotoxicity in vitro context. Nonetheless, the curative efficacy and the precise molecular mechanisms implicated in metabolic-associated fatty liver disease (MAFLD) warrant further elucidation. To address this gap, two murine models of MAFLD, namely obese Ob/Ob mice and high fat/cholesterol/fructose (HFCF) fed mice, were employed. The therapeutic implications of OP supplementation were assessed through quantification of lipid specific biomarkers and hepatic histopathological examination. Complementary transcriptomic, phosphoproteomic, and in vitro analyses were conducted to decipher the molecular underpinnings. In the Ob/Ob mouse model, OP substantively mitigated both circulating and hepatic lipid concentrations, concurrently ameliorating hepatic steatosis. In the context of HFCF-induced MAFLD, OP not only attenuated hepatic lipidic sequestration but also abrogated concomitant inflammation and fibrosis. Subsequent RNA-sequencing analyses on hepatic tissues derived from HFCF-diet mice delineated that OP modulated MAFLD-associated transcriptional signatures. A synergistic assessment of transcriptomics and phosphoproteomics disclosed a salient effect of OP on the Peroxisome Proliferator-Activated Receptor (PPAR) pathway, particularly manifested by the upregulation of PPAR-γ signaling. In murine hepatocytes, OP counteracted steatosis and inflammation via the activation of PPAR-γ signaling. The effects induced by OP were nullified upon administration of the PPAR-γ-specific antagonist GW9662. Collectively, our empirical evidence furnishes the inaugural demonstration that OP mitigates MAFLD pathology through the activation of PPAR-γ signaling, thereby presenting a novel therapeutic avenue for MAFLD intervention.