Natural Products for Acetaminophen-Induced Acute Liver Injury: A Review

Isolation and characterization of a hepatoprotective polysaccharide from Lonicera caerulea L. var. edulis Turcz. ex Herd. fruit against APAP-induced acute liver injury mice

The structure and bioactivities of a novel polysaccharide from Lonicera caerulea L. var. edulis Turcz. ex Herd. fruit (THP-3) were investigated. The crude polysaccharides of Turcz. ex Herd. (THP) were extracted by hot water extraction. After purification, the chemical structure of polysaccharides was identified. Then, a mouse model of acute drug-induced liver injury was constructed using 4-acetamidophenol (APAP) and pretreated with THP. The number-average molecular weight of THP-3 was 48.89 kDa and the mass average molar mass was 97.87 kDa. THP-3 was mainly composed of arabinose (42.54 %), glucose (27.62 %), galacturonic acid and galactose (29.84 %). The main linkage types of THP-3 were 1-linked Araf, 1,4-linked Glcp, and 1,3,6-linked Galp. In addition, after THP treatment, serum Alanine aminotransferase (ALT), Aspartate aminotransferase (AST) and γ-glutamyl transpeptidase (γGT) in AILI mice were successfully down-regulated. The results showed that THP could prevent the characteristic morphological changes of hepatic lobular injury and lipid depletion caused by APAP, reduced the level of oxidative damage in mice, increased the expression of APAP-induced hypolipidemia and related inflammatory indicators, and improved the detoxification function of liver. In general, the newly extracted THP polysaccharide has a good liver protection effect and is an ideal natural medicine for the treatment of liver diseases.

Multi-omics reveals that 5-O-methylvisammioside prevention acute liver injury in mice by regulating the TNF/MAPK/NF-κB/arachidonic acid pathway

BACKGROUND

The pathogenesis of acute liver injury (ALI) has been a pressing issue in the medical scientific community. We previously found that 5-O-methylvisammioside (MeV) from Saposhnikovia divaricata (Turcz.) Schischk has excellent anti-inflammatory properties. However, the mechanism by which MeV protects against ALI still needs to be deeply investigated.

PURPOSE

In the present study, we established an acetaminophen (APAP) -induced ALI mouse model and pre-protected the mice with MeV.

METHODS & RESULTS

Our findings indicate that MeV (5 and 10 mg/kg) lowered the blood levels of alanine aminotransferase and aspartate aminotransferase and reduced the infiltration of inflammatory cells in the liver. MeV initially showed an inhibitory effect on ALI. We then analyzed the molecular mechanisms underlying the effects of MeV by transcriptomic and metabolomic analyzes. Through transcriptomic analysis, we identified 4675 differentially expressed genes between the APAP+MeV group and the APAP-induced ALI group, which were mainly enriched in the MAPK pathway, the TNF pathway, and the NF-κB pathway. Through metabolomic analysis, we found that 249 metabolites in the liver were differentially regulated between the APAP+MeV group and the APAP- induced ALI group, which were mainly enriched in the arachidonic acid pathway. The mRNA expression levels of key genes (encoding TNF-α, p38, AP-1, RelB, IL-1β, and Ptges), as determined by RT-PCR analysis, were consistent with the RNA-seq data. The ELISA results indicate that MeV markedly decreased the serum levels of TNF-α and IL-1β in mice. Finally, the key proteins in the NF-κB and MAPK pathways were examined using immunoblotting. The results showed that MeV decreased IκB-α phosphorylation and inhibited the nuclear translocation of NF-κB. In addition, MeV reduced the hepatic inflammatory burst mainly by inhibiting the phosphorylation of p38 and JNK in the MAPK pathway.

CONCLUSION

The present study demonstrated (i) that MeV could ameliorate APAP-induced ALI by inhibiting arachidonic acid metabolism and the TNF, MAPK, and NF-κB pathways, and (ii) that MeV is a promising drug candidate for the prevention of ALI.

Salvianolic Acid B Alleviates Liver Injury by Regulating Lactate-Mediated Histone Lactylation in Macrophages

Salvianolic acid B (Sal B) is the primary water-soluble bioactive constituent derived from the roots of Salvia miltiorrhiza Bunge. This research was designed to reveal the potential mechanism of Sal B anti-liver injury from the perspective of macrophages. In our lipopolysaccharide-induced M1 macrophage model, Sal B showed a clear dose-dependent gradient of inhibition of the macrophage trend of the M1 type. Moreover, Sal B downregulated the expression of lactate dehydrogenase A (LDHA), while the overexpression of LDHA impaired Sal B's effect of inhibiting the trend of macrophage M1 polarization. Additionally, this study revealed that Sal B exhibited inhibitory effects on the lactylation process of histone H3 lysine 18 (H3K18la). In a ChIP-qPCR analysis, Sal B was observed to drive a reduction in H3K18la levels in the promoter region of the LDHA, NLRP3, and IL-1β genes. Furthermore, our in vivo experiments showed that Sal B has a good effect on alleviating CCl4-induced liver injury. An examination of liver tissues and the Kupffer cells isolated from those tissues proved that Sal B affects the M1 polarization of macrophages and the level of histone lactylation. Together, our data reveal that Sal B has a potential mechanism of inhibiting the histone lactylation of macrophages by downregulating the level of LDHA in the treatment of liver injury.