Oxidative stress is involved in the pathophysiology of nonalcoholic fatty liver disease (NAFLD). However, reliable biomarkers of NAFLD in relation to oxidative stress are not available. While paraoxonase 1 (PON1) is an antioxidant biomarker, there appears to be mixed data on PON-1 in patients with NAFLD. The aim of this meta-analysis was to assess the current data on PON1 activity (i.e., paraoxonase and arylesterase) in patients with NAFLD. A PubMed, CENTRAL, and Embase search identified 12 eligible articles. In the meta-analysis, the paraoxonase activity was low in patients with NAFLD (mean difference (MD) -27.17 U/L; 95% confidence interval (CI) -37.31 to -17.03). No difference was noted in the arylesterase activity (MD 2.45 U/L; 95% CI -39.83 to 44.74). In a subgroup analysis, the paraoxonase activity was low in biopsy-proven nonalcoholic steatohepatitis (MD -92.11 U/L; 95% CI -115.11 to -69.11), while the activity in NAFLD as diagnosed by ultrasonography or laboratory data was similar (MD -2.91 U/L; 95% CI -11.63 to 5.80) to that of non-NAFLD. In summary, the PON1, especially paraoxonase, activity could be a useful biomarker of NAFLD. Further studies are warranted to ascertain the relevance of PON1 measurements in patients with NAFLD.

Previous studies reported that Angiotensin converting enzyme 2 (ACE2) is the main cell receptor of SARS-CoV and SARS-CoV-2. It plays a key role in the access of the virus into the cell to produce the final infection. In the present study we investigated in silico the basic mechanism of ACE2 in the lung and provided evidences for new potentially effective drugs for Covid-19. Specifically, we used the gene expression profiles from public datasets including The Cancer Genome Atlas, Gene Expression Omnibus and Genotype-Tissue Expression, Gene Ontology and pathway enrichment analysis to investigate the main functions of ACE2-correlated genes. We constructed a protein-protein interaction network containing the genes co-expressed with ACE2. Finally, we focused on the genes in the network that are already associated with known drugs and evaluated their role for a potential treatment of Covid-19. Our results demonstrate that the genes correlated with ACE2 are mainly enriched in the sterol biosynthetic process, Aryldialkylphosphatase activity, adenosylhomocysteinase activity, trialkylsulfonium hydrolase activity, acetate-CoA and CoA ligase activity. We identified a network of 193 genes, 222 interactions and 36 potential drugs that could have a crucial role. Among possible interesting drugs for Covid-19 treatment, we found Nimesulide, Fluticasone Propionate, Thiabendazole, Photofrin, Didanosine and Flutamide.