Protective effect of a fermented substance from Saccharomyces cerevisiae on liver injury in mice caused by acetaminophen

Population-Level Configurations of Gut Mycobiome Across 6 Ethnicities in Urban and Rural China

BACKGROUND & AIMS

Beyond bacteria, the human gastrointestinal tract is host to a vast diversity of fungi, collectively known as the gut mycobiome. Little is known of the impact of geography, ethnicity, and urbanization on the gut mycobiome at a large population level. We aim to delineate the variation of human gut mycobiome and its association with host factors, environmental factors, and diets.

METHODS

Using shotgun metagenomic sequencing, we profiled and compared the fecal mycobiome of 942 healthy individuals across different geographic regions in China (Hong Kong and Yunnan), spanning 6 ethnicities: Han, Zang, Bai, Hani, Dai, and Miao (including both urban and rural residents of each ethnicity). In parallel to fecal sampling, we collected participant metadata (environmental exposure, bowel habits, anthropometrics, and medication), diet, and clinical blood measurement results (a total of 118 variables) and investigated their impact on the gut mycobiome variation in humans.

RESULTS

The human gut mycobiome was highly variable across populations. Urbanization-related factors had the strongest impact on gut mycobiome variation, followed by geography, dietary habit, and ethnicity. The Hong Kong population (highly urbanized) had a significantly lower fungal richness compared with Yunnan population. Saccharomyces cerevisiae was highly enriched in urban compared with rural populations and showed significant inverse correlations with liver pathology-associated blood parameters, including aspartate transaminase, alanine transaminase, gamma-glutamyltransferase, and direct bilirubin. Candida dubliniensis, which was decreased in urban relative to rural populations, showed correlations with host metabolism-related parameters in blood, including a positive correlation with fasting high-density lipoprotein cholesterol levels and a negative correlation with fasting glucose levels. The fungal-blood parameter correlations were highly geography- and ethnicity-specific. Food choices had differential influences on gut mycobiome and bacterial microbiome, where taxa from the same genus tended to be coregulated by food and thereby cobloom. Ethnicity-specific fungal signatures were associated with distinct habitual foods in each ethnic group.

CONCLUSIONS

Our data highlight, for the first time to our knowledge, that geography, urbanization, ethnicity, and habitual diet play an important role in shaping the gut mycobiome composition. Gut fungal configurations in combination with population characteristics (such as residing region, ethnicity, diet, lifestyle) influence host metabolism and health.

Nephrotoxicity assessments of acetaminophen during zebrafish embryogenesis

We used a green fluorescent kidney line, Tg(wt1b:GFP), as a model to access the acetaminophen (AAP)-induced nephrotoxicity dynamically. Zebrafish (Danio rerio) embryos at different developmental stages (12-60hpf) were treated with different dosages of AAP (0-45mM) for different time courses (12-60h). Results showed that zebrafish embryos exhibited no evident differences in survival rates and morphological changes between the mock-treated control (0mM) and 2.25mM AAP-exposure (12-72hpf) groups. In contrast, after higher doses (22.5 and 45mM) of exposure, embryos displayed malformed kidney phenotypes, such as curved, cystic pronephric tube, pronephric duct, and a cystic and atrophic glomerulus. The percentages of embryos with malformed kidney phenotypes increased as the exposure dosages of AAP increased. Interestingly, under the same exposure time course (12h) and dose (22.5mM), embryos displayed higher percentages of severe defects at earlier developmental stage of exposure (12-24hpf), whereas embryos displayed higher percentages of mild defects at later exposure (60-72hpf). With an exposure time course less than 24h of 45mM AAP, no embryo survived by the developmental stage of 72hpf. These results indicated that AAP-induced nephrotoxicity depended on the exposure dose, time course and developmental stages. Immunohistochemical experiments showed that the cells' morphologies of the pronephric tube, pronephric duct and glomerulus were disrupted by AAP, and consequently caused cell death. Real-time RT-PCR revealed embryos after AAP treatment decreased the expression of cox2 and bcl2, but increased p53 expression. In conclusion, AAP-induced defects on glomerulus, pronephric tube and pronephric duct could be easily and dynamically observed in vivo during kidney development in this present model.

Protective Effects of the Supernatant of Ethanol Eluate from Artemisia sacrorum Ledeb. against Acetaminophen-Induced Liver Injury in Mice [corrected]

This study was designed to investigate the protective effects of the active part of Artemisia sacrorum Ledeb. Extract (ASE) against acetaminophen (APAP)-induced hepatotoxicity in mice. As a result, pretreated with ASE prior to the administration of APAP significantly prevented the increases of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and tumor necrosis factor-alpha (TNF-alpha) levels in serum, and glutathione (GSH) depletion, malondialdehyde (MDA) accumulation in liver tissue. In addition, ASE prevented APAP-induced apoptosis and necrosis, as indicated by a liver histopathological analysis and DNA laddering. Furthermore, according to the results from Western blot analysis, ASE markedly decreased APAP-induced caspase-3 and -8 protein expressions in mouse livers. All these results suggest that the protective effects of ASE against APAP-induced liver injury may involve mechanisms associated with its inhibitive effects of lipid peroxidation and the down-regulation of TNF-alpha mediated apoptosis.

Gentiana manshurica Kitagawa prevents acetaminophen-induced acute hepatic injury in mice via inhibiting JNK/ERK MAPK pathway

AIM: To investigate the in vivo hepatoprotective effects and mechanisms of Gentiana manshurica Kitagawa (GM) in acetaminophen (APAP)-induced liver injury in mice.

METHODS: GM (200, 150 or 50 mg/kg body weight) or N-acetyl-L-cysteine (NAC; 300 mg/kg body weight) was administrated orally with a single dose 2 h prior to APAP (300 mg/kg body weight) injection in mice.

RESULTS: APAP treatment significantly depleted hepatic glutathione (GSH), increased serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and malonyldialdehyde (MDA) and 4-hydroxynonenal levels, and decreased hepatic activity of glutathione peroxidase (GSH-px) and superoxide dismutase (SOD). However, the pretreatment of GM significantly alleviated APAP-induced oxidative stress by increasing GSH content, decreasing serum ALT, AST and MDA, and retaining the activity of GSH-px and SOD in the liver. Furthermore, GM pretreatment can inhibit caspase-3 activation and phosphorylation of c-Jun-NH2-terminal protein kinase 2 (JNK1/2) and extracellular signal-regulated kinase (ERK). GM also remarkably attenuated hepatocyte apoptosis confirmed by the terminal deoxynucleotidyl transferase mediated dUTP nick end-labeling method.

CONCLUSION: Hepatoprotective effects of GM against APAP-induced acute toxicity are mediated either by preventing the decline of hepatic antioxidant status or its direct anti-apoptosis capacity. These results support that GM is a potent hepatoprotective agent.