Melanophryniscus admirabilis (admirable red-belly toad) is a microendemic and critically endangered species found exclusively along 700 meters of the Forqueta River, in a fragment of Atlantic Forest in southern Brazil. One of the greatest concerns regarding the conservation of this species is the extensive use of pesticides in areas near their natural habitat. In recent years, the adaptation and persistence of animal species in impacted environments have been associated with microbiota. Therefore, the current study aimed to characterize the oral bacterial community of wild M. admirabilis and to address the question of how this community might contribute to toad’s adaptation in the anthropogenic environment and its general metabolic capabilities. In the present study, 11 oral samples collected from wild M. admirabilis were characterized and analyzed via high-throughput sequencing. A total of 181,350 sequences were obtained, resulting in 16 phyla, 34 classes, 39 orders, and 77 families. Proteobacteria dominated (53%) the oral microbiota of toads followed by Firmicutes (18%), Bacteroidetes (17%), and Actinobacteria (5%). No significant differences in microbial community profile from among the samples were reported, suggesting that the dietary restriction may directly influence the bacterial composition. Functional inference of microbiome was performed using PICRUSt2 and important pathways, such as xenobiotic degradation pathways to pesticides and aromatic phenolic compounds were detected, suggesting that the bacterial communities may have important roles in M. admirabilis health and survival in the anthropogenic environment. Overall, our results have important implications for the conservation and management of this microendemic and critically endangered species.

The proportion of human cells to the microbial cell is 1:1. These procaryotes use efflux pumps and enzymes to prevent cellular intoxication of ions and compounds respectively. There is promising evidence on the role of the gut microbiome and its enzymes in metabolizing xenobiotics. The genetic potential of oral bacteria in drug and xenobiotic metabolism is yet to be unveiled. This study aimed to characterize the bacteriome associated with oral fibroepithelial polyps (FEP) and to predict the genetic potential. A representative sub-sample of 22 clinically diagnosed oral FEP (the control group) was selected from a main case-control study. Amplification of nucleotides of extracted DNA from frozen tissues was performed for the V1 to V3 region and sequencing of the amplicon with Illumina’s 2 X 300–bp chemistry. Classification of high-quality nonchimeric merged reads was done to the species level with a prioritized BLASTN-based algorithm. Downstream compositional analysis was performed with QIIME (Quantitative Insights into Microbial Ecology). Functional prediction of bacteriome was obtained by PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States). Rothia mucilaginosa, Streptococcus mitis, Gamella haemolysans, Streptococcus sp. oral taxon 431, and Rothia dentocariosa accounted for the top five taxa among 810 bacterial species according to the percentage of average relative abundance. Rothia mucilaginosa was elevated statistically significantly (p< 0.05). The genetic potential of xenobiotics and drug metabolism catalyzed by the P450 enzymes was observed for the first time as an attribute of bacteriome associated with oral FEP tissues dominated by R. mucilaginosa. This finding needs further investigation.

The molecular interaction between the nematode and the host plant cells is complex and sophisticated. Initial contact with the plant parasitic nematodes (PPNs) triggers immune response in the host plant system which includes the release of toxic molecules. To put a bridle on this immune response, PPNs trigger pivotal cytoprotective mechanisms, such as antioxidant and detoxification pathways. Mechanisms of these pathways have been studied in PPNs and the specific genes involved have been targeted for gene silencing research in view of developing novel control measures. However, one of the important group of proteins involved in detoxification pathways known as ABC-transporters are not being studied until recently in PPNs. This opinion article focusses on the current knowledge and future prospects of ABC transporters in PPNs.

Molecular hydrogen (H2) has been shown to have antioxidant and anti-inflammatory activities that may reduce the development and progression of many diseases. In this study, Hydrogen-rich water (HRW) was obtained by reacting hybrid magnesium-carbon hydrogen storage materials with water. Then the effects of intake of HRW on the activities of xenobiotic-metabolizing enzymes, membrane transporters, and oxidative stress in rats were investigated. Rats were given HRW ad libitum for 4 weeks. Results showed that intake of HRW had no significant effect on the activities of various cytochrome P450 (CYP) enzymes (CYP1A1, 1A2, 2B, 2C, 2D, 2E1, 3A, 4A), glutathione-S-transferase and UDP-glucuronosyltransferase. Except for a slight lower plasma glucose concentration, intake of HRW had no effect on other plasma biochemical parameters in rats. P-Glycoprotein and multidrug resistance-associated protein (Mrp)2 protein expressions in liver were elevated after intake of HRW. However, HRW had no significant effects on glutathione, glutathione peroxidase, or lipid peroxidation in liver. Results from this study suggest that consumption of HRW may not affect xenobiotic metabolism or oxidative stress in liver. However, intake of HRW may increase the efflux of xenobiotics or toxic substances from the liver into bile by enhancing the expression of p-glycoprotein and Mrp2 protein.

Smoking has been established as a major risk factor for developing oral squamous cell carcinoma (OSCC), but less attention has been paid to the effects of smokeless tobacco products. Our objective is to identify potential biomarkers to distinguish the biological effects of combustible tobacco products from those of non-combustible using oral cell lines. Normal human gingival epithelial cells (HGEC), non-metastatic (101A) and metastatic (101B) OSCC cell lines were exposed to different tobacco product preparations (TPPs) including cigarette smoke total particulate matter (TPM), whole-smoke conditioned media (WS-CM), smokeless tobacco extract in complete artificial saliva (STE), or nicotine (NIC) alone. We performed microarray-based gene expression profiling and found 3456 probe sets from 101A, 1432 probe sets from 101B, and 2717 probe sets from HGEC to be differentially expressed. Gene Set Enrichment Analysis (GSEA) revealed xenobiotic metabolism and steroid biosynthesis were the top two pathways that were upregulated by combustible but not by non-combustible TPPs. Notably, aldo-keto reductase genes, AKR1C1 and AKR1C2, were the core genes in the top enriched pathways and were statistically upregulated more than 8 fold by combustible TPPs. Our qRT-PCR results statistically support AKR1C1 as a potential biomarker for differentiating the biological effects of combustible from non-combustible tobacco products.

The New Zealand brushtail possum (Trichosurus vulpecula), introduced from Australia in the 1850s, is an invasive species that is widespread throughout New Zealand and forms the largest self-sustained reservoir of bovine tuberculosis (Mycobacterium bovis) in the wild. Conservation and agricultural authorities regularly apply a series of population control measures to suppress brushtail possum populations. The evolutionary consequence of more than half a century of intensive population control operations on the species genomic diversity and population structure is hindered by a paucity of available genomic resources for the species. This study is the first to characterise the functional content and diversity of brushtail possum liver and brain cerebral cortex transcriptomes. Raw sequences from hepatic cells and cerebral cortex were assembled into 58,001 and 64,735 transcripts in hepatic cells and cerebral cortex, respectively. Functional annotation and polymorphism assignment of the assembled transcripts demonstrated a considerable level of variation in the core metabolic pathways that represent potential targets for selection pressure exerted by chemical toxicants. This study suggests that the brushtail possum population in New Zealand harbours considerable levels of variation in metabolic pathways that could potentially promote the development of tolerance against chemical toxicants.

Diffuse type of gastric cancer (GC) has an increasing prevalence worldwide, especially in Western countries, is usually diagnosed at advanced stages, and has no efficacious treatment options. Epidemiological studies have reported an increased mortality from GC after occupational exposure to well-studied pro-carcinogen that are metabolically activated by Cyp P450 enzymes through aryl hydrocarbon receptor (AhR). Substantial studies support the involvement of AhR in gastric carcinogenesis. However, little is known about the role of AhR in diffuse GC, as compared to intestinal GC. In a cohort of 29 gastric tumors, we described a significantly increased AhR protein and mRNA expression levels in GCs, independently of subtypes and clinical parameters. AhR and RhoA mRNA expression were correlated in diffuse GC. Further, our study characterized how AhR affects gene expression in diffuse GC. Using qRT-PCR, we compared the expression levels of AhR, Cyp1A1 and Cyp1B1 to the expression of genes in a panel previously described. In diffuse GC, Cyp1A1 expression correlated with genes involved in IGF signalling, EMT (VIM), migration (MMP2). In an in vitro assay using the poorly differentiated KATOIII epithelial cell line, two well-known ligands for AhR (TCDD and BaP) induced mRNA expression of CYP1A1, IL1b, as well as UGT1, NQO1 and AhRR to a lower extent. We also observed a strong increase in Cyp1B1 expression in diffuse GC, along with a lower TCDD-increased Cyp1B1 expression as compared to Cyp1A1 in KATOIII cells, and immunostaining in stromal cells. In intestinal GC, Cyp1B1 inversely correlated with several genes including IDO1 (generating endogenous kynurenin-e AhR ligand). Our data provide evidence for a major role of AhR in GC, as an environmental xenobiotics receptor, through different mechanisms and pathways in diffuse and intestinal GC. Our results support continued efforts to clarify the identities of exogenous AhR ligands in diffuse GC in order to define new therapeutic strategies.