Bletilla striata polysaccharides alleviate metabolic dysfunctionassociatedsteatotic liver disease through enhancing hepatocyteRelA/HNF1αsignal

BACKGROUND Bletilla striata polysaccharides(BSP)have antioxidant,immune regulation,and anti-fibrotic activities.However,the therapeutic effect and mechanisms underlying the action of BSP in metabolic dysfunction-associated steatotic liver disease(MASLD)have not been fully understood.AIMTo investigate the therapeutic effects and mechanisms of BSP on MASLD by centering on the hepatocyte nuclearfactor kappa B p65(RelA)/hepatocyte nuclear factor-1 alpha(HNF1α)signaling.METHODSA mouse model of MASLD was induced by feeding with a high-fat-diet(HFD)and a hepatocyte model of steatosiswas induced by treatment with sodium oleate(SO)and sodium palmitate(SP).The therapeutic effects of BSP onMASLD were examined in vivo and in vitro.The mechanisms underlying the action of BSP were analyzed for theireffect on lipid metabolism disorder,endoplasmic reticulum(ER)stress,and the RelA/HNF1αsignaling.RESULTSHFD feeding reduced hepatocyte RelA and HNF1αexpression,induced ER stress,lipid metabolism disorder,andnecroptosis in mice,which were significantly mitigated by treatment with BSP.Furthermore,treatment with BSP orBSP-containing conditional rat serum significantly attenuated the sodium oleate/sodium palmitate(SO/SP)-induced hepatocyte steatosis by decreasing lipid accumulation,and lipid peroxidation,and enhancing theexpression of RelA,and HNF1α.The therapeutic effects of BSP on MASLD were partially abrogated by RELAsilencing in mice and RELA knockout in hepatocytes.RELA silencing or knockout significantly down-regulatedHNF1αexpression,and remodeled ER stress and oxidative stress responses during hepatic steatosis.CONCLUSIONTreatment with BSP ameliorates MASLD,associated with enhancing the RelA/HNF1αsignaling,remodeling ERstress and oxidative stress responses in hepatocytes.

Targeting TLR4 and regulating the Keap1/Nrf2 pathway with andrographolide to suppress inflammation and ferroptosis in LPS-induced acute lung injury

Acute lung injury(ALI)is a severe inflammatory condition with a high mortality rate,often precipitated by sepsis.The pathophysiology of ALI involves complex mechanisms,including inflammation,oxidative stress,and ferroptosis,a novel form of regulated cell death.This study explores the therapeutic potential of andrographolide(AG),a bioactive compound derived from Andrographis,in mitigating Lipopolysaccharide(LPS)-induced inflammation and ferroptosis.Our research employed in vitro experiments with RAW264.7 macrophage cells and in vivo studies using a murine model of LPS-induced ALI.The results indicate that AG significantly suppresses the production of pro-inflammatory cytokines and inhibits ferroptosis in LPS-stimulated RAW264.7 cells.In vivo,AG treatment markedly reduces lung edema,decreases inflammatory cell infiltration,and mitigates ferroptosis in lung tissues of LPS-induced ALI mice.These protective effects are mediated via the modulation of the Toll-like receptor 4(TLR4)/Kelch-like ECH-associated protein 1(Keap1)/Nuclear factor erythroid 2-related factor 2(Nrf2)signaling pathway.Molecular docking simulations identified the binding sites of AG on the TLR4 protein(Kd value:-33.5 kcal·mol^(-1)),and these interactions were further corroborated by Cellular Thermal Shift Assay(CETSA)and SPR assays.Collectively,our findings demonstrate that AG exerts potent anti-inflammatory and anti-ferroptosis effects in LPS-induced ALI by targeting TLR4 and modulating the Keap1/Nrf2 pathway.This study underscores AG's potential as a therapeutic agent for ALI and provides new insights into its underlying mechanisms of action.