Patchouli alcohol alleviates metabolic dysfunction-associated steatohepatitis via inhibiting mitochondria-associated endoplasmic reticulum membrane disruption-induced hepatic steatosis and inflammation in rats.

Metabolic dysfunction-associated steatohepatitis (MASH) is a severe metabolic dysfunction-associated steatotic liver disease (MASLD) characterized by abnormal hepatic steatosis and inflammation. Previous studies have shown that Patchouli alcohol (PA), the primary component of Pogostemonis Herba, can alleviate digestive system diseases. However, its protection against MASH remains unclear. This study explored the protective effects and underlying mechanism of PA against high-fat diet-induced MASH in rats. Results showed that PA considerably reduced body weight, epididymal fat, and liver index and attenuated liver histological injury in MASH rats. PA alleviated hepatic injury by inhibiting steatosis and inflammation. These effects are associated with the improvement of SREBP-1c- and PPARα-mediated lipid metabolism and inhibition of the STING-signaling pathway-mediated inflammatory response. Moreover, PA-inhibited hepatic endoplasmic reticulum (ER) stress and mitochondrial dysfunction, reducing SREBP-1c and STING expressions and enhance PPARα expression. PA treatment had the strongest effect on the regulation of mitogen fusion protein 2 (Mfn2) in inhibiting mitochondrial dysfunction. Mfn2 is an important structural protein for binding ERs and mitochondria to form mitochondria-associated ER membranes (MAMs). MASH-mediated disruption of MAMs was inhibited after PA treatment-induced Mfn2 activation. Therefore, the pharmacological effect of PA on MASH is mainly attributed to the inhibition of MAM disruption-induced hepatic steatosis and inflammation. The findings of this study may have implications for MASH treatment that do not neglect the role of Mfn2-mediated MAMs.

Tetrahydroberberine alleviates high-fat diet-induced hyperlipidemia in mice via augmenting lipoprotein assembly-induced clearance of low-density lipoprotein and intermediate-density lipoprotein.

The promotion of excess low-density lipoprotein (LDL) clearance stands as an effective clinical approach for treating hyperlipidemia. Tetrahydroberberine, a metabolite of berberine, exhibits superior bioavailability compared to berberine and demonstrates a pronounced hypolipidemic effect. Despite these characteristics, the impact of tetrahydroberberine on improving excessive LDL clearance in hyperlipidemia has remained unexplored. Thus, this study investigates the potential effects of tetrahydroberberine on high-fat diet-induced hyperlipidemia in mice. The findings reveal that tetrahydroberberine exerts a more potent lipid-lowering effect than berberine, particularly concerning LDL-cholesterol in hyperlipidemic mice. Notably, tetrahydroberberine significantly reduces serum levels of upstream lipoproteins, including intermediate-density lipoprotein (IDL) and very low-density lipoprotein, by promoting their conversion to LDL. This reduction is further facilitated by the upregulation of hepatic LDL receptor expression induced by tetrahydroberberine. Intriguingly, tetrahydroberberine enhances the apolipoprotein E (ApoE)/apolipoprotein B100 (ApoB100) ratio, influencing lipoprotein assembly in the serum. This effect is achieved through the activation of the efflux of ApoE-containing cholesterol in the liver. The ApoE/ApoB100 ratio exhibits a robust negative correlation with serum levels of LDL and IDL, indicating its potential as a diagnostic indicator for hyperlipidemia. Moreover, tetrahydroberberine enhances hepatic lipid clearance without inducing lipid accumulation in the liver and alleviates existing liver lipid content. Importantly, no apparent hepatorenal toxicity is observed following tetrahydroberberine treatment for hyperlipidemia. In summary, tetrahydroberberine demonstrates a positive impact against hyperlipidemia by modulating lipoprotein assembly-induced clearance of LDL and IDL. The ApoE/ApoB100 ratio emerges as a promising diagnostic indicator for hyperlipidemia, showcasing the potential clinical significance of tetrahydroberberine in lipid management.

Curcumin Alleviates High-fat Diet-induced Nonalcoholic Steatohepatitis via Improving Hepatic Endothelial Function with Microbial Biotransformation in Rats.

Hepatic endothelial function is central to the development of nonalcoholic steatohepatitis (NASH). Curcumin (Cur) is reportedly hepatoprotective, however, it remains unknown whether Cur improves hepatic endothelial function in NASH. Additionally, the poor bioavailability of Cur renders it difficult to elucidate its hepatoprotective effect, hence, its biotransformation should be considered. Herein, we investigated the effects and mechanisms of Cur and its bioconversion on hepatic endothelial function against high-fat diet-induced NASH in rats. The results revealed that Cur improved hepatic lipid accumulation, inflammation, and endothelial dysfunction by inhibiting NF-κB and PI3K/Akt/HIF-1α pathways, however, these effects were weakened via antibiotic addition, which was closely related to reduced tetrahydrocurcumin (THC) produce in the liver and intestinal content. Moreover, THC exerted a better effect than Cur on restoring liver sinusoidal endothelial cells function to attenuate steatosis and injury in L02 cells. Thus, these findings indicate that the effect of Cur on NASH is closely related to hepatic endothelial function improvement with intestinal microbial biotransformation.

Andrographolide sodium bisulfite ameliorates dextran sulfate sodium-induced colitis and liver injury in mice via inhibiting macrophage proinflammatory polarization from the gut-liver axis.

Ulcerative colitis (UC), an inflammatory disease, is widely thought to be associated with colonic barrier damage and inflammatory response. With the destruction of the colonic barrier, lipopolysaccharide (LPS) enters the liver through the portal vein and causes liver injury. Liver injury in turn exacerbates UC to form a vicious cycle, so the treatment of liver injury cannot be ignored. Andrographolide (Andro) has a protective effect against colitis and liver injury, but with low bioavailability. Andrographolide sodium bisulfite (ASB), a water-soluble sulfonate of Andro, has better bioavailability, whether it has a better curative effect against UC and liver injury is rarely reported. Hence, we investigated the protective effect and potential mechanism of ASB against dextran sulfate sodium (DSS)-induced UC and liver injury in mice. The results showed that treatment with ASB significantly relieved the clinical symptoms of UC and liver injury by reducing disease activity index, inhibiting gut-derived LPS leakage, and improving colonic and hepatic injury, and its curative effect was better than Andro. Moreover, ASB effectively decreased the YAP-mediated colonic inflammation and TLR4/MyD88/NF-κB-mediated pro-inflammatory factor release in the liver. Both colonic and hepatic inflammation were associated with macrophage proinflammatory polarization, but they were significantly inhibited by ASB. ASB showed good safety in the treatment of UC and liver injury and has no nephrotoxicity as previously described. In conclusion, ASB has an effective protective effect on DSS-induced UC and liver injury, mainly by suppressing macrophage proinflammatory polarization from the gut-liver axis.