No abstract

Incidence and mortality rates of alcoholic liver disease (ALD) is one of the highest in the world. In the present study, we found that the genetic knockout nuclear receptor the peroxisome proliferator-activated receptor α (PPARα) exacerbated ALD. Lipidomics of the liver revealed changed levels of lipid species encompassing phospholipids, ceramides (CM), and long-chain fatty acids in Ppara-null mice induced by ethanol. Moreover, 4-hydroxyphenylacetic acid (4-HPA) was changed as induced by ethanol in the metabolome of urine. Moreover, the phylum level analysis showed a decrease in the level of Bacteroidetes and an increase in the level of Firmicutes after alcohol feeding in Ppara-null mice, while there was no change in wild-type mice. In Ppara-null mice, the level of Clostridium_sensu_stricto_1 and Romboutsia were upregulated after alcohol feeding. These data revealed that PPARα deficiency potentiated alcohol-induced liver injury through promotion of lipid accumulation, changing the metabolome of urine, and increasing the level of Clostridium_sensu_stricto_1 and Romboutsia. 4-HPA could improve ALD in mice by regulating inflammation and lipid metabolism. Therefore, our findings suggest a novel approach to the treatment of ALD: focusing on the gut microbiota and its metabolites. Data are available via ProteomeXchange (PXD 041465).

No abstract

More than one hundred cannabinoids have been found in cannabis. Δ9-Tetrahydrocannabinol (THC) is the recognized addictive constituent in cannabis; however, the mechanisms underlying THC-induced toxicity remain elusive. To better understand cannabis-induced toxicity, the present study compared the metabolic pathways of THC and its isomer cannabidiol (CBD) in human and mouse liver microsomes using the metabolomic approach. Thirty-two metabolites of THC were identified, including nine undescribed metabolites. Of note, two glutathione (GSH) and two cysteine (Cys) adducts were found in THC’s metabolism. Molecular docking revealed that THC conjugates have a higher affinity with GSH and Cys than with the parent compound, THC. Human recombinant cytochrome P450 enzymes, and their corresponding chemical inhibitors, demonstrated that CYP3A4 and CYP1B1 were the primary enzymes responsible for the formation of THC-GSH and THC-Cys, thus enabling conjugation to occur. Collectively, this study systematically compared the metabolism of THC with the metabolism of CBD using the metabolomic approach, which thus highlights the critical role of metabolomics in identifying novel drug metabolites. Moreover, this study also facilitates mechanistic speculation in order to expand the knowledge of drug metabolism and safety.