Serum Basal Paraoxonase 1 Activity as an Additional Liver Function Test for the Evaluation of Patients with Chronic Hepatitis

The Activity and Polymorphism of the PON1 in Patients with Chronic Liver Disease: a Systematic Review and Meta-analysis

BACKGROUND

Liver diseases are among the ten deadliest diseases in the world. Measuring PON1 is a test to assess the degree of liver disorder. There are several preliminary studies on the rate of PON1 activity in people with liver disease, and there are differences between the results of these studies; therefore, the aim of this research work is to determine the level of PON1 activity in people with liver disease using meta-analysis.

METHOD

The study searched to select articles that were published electronically from 2002 to 2020, in national and international databases of SID, MagIran, Embase, ScienceDirect, Scopus, PubMed, and Web of Science (WoS).

RESULTS

Among the articles included in the meta-analysis, the samples in the case (patients) and control groups were 807 and 2276, respectively. The mean activity of PON1 in individuals with liver disease in the case and control groups were 142.06 ± 7.7 and 272.19 ± 39.6, respectively, and this was statistically significant (P < 0.05). The mean difference analysis highlights a difference of - 2.75 ± 0.48 between the patient and control groups, indicating that liver disease significantly reduces PON1 activity.

CONCLUSION

The results of this study demonstrate that the polynomorphism of the PON1 is associated with an increased risk of liver disease, with lower levels of PON1 activity in people with liver disease than in healthy patients and this decrease was more in patients with liver cirrhosis than in other liver diseases. Given the importance of this gene's activity, studies such as this could provide a promising path for better drug design and treatment in future.

Physiologically based kinetic modelling based prediction of in vivo rat and human acetylcholinesterase (AChE) inhibition upon exposure to diazinon

The present study predicts in vivo human and rat red blood cell (RBC) acetylcholinesterase (AChE) inhibition upon diazinon (DZN) exposure using physiological based kinetic (PBK) modelling-facilitated reverse dosimetry. Due to the fact that both DZN and its oxon metabolite diazoxon (DZO) can inhibit AChE, a toxic equivalency factor (TEF) was included in the PBK model to combine the effect of DZN and DZO when predicting in vivo AChE inhibition. The PBK models were defined based on kinetic constants derived from in vitro incubations with liver fractions or plasma of rat and human, and were used to translate in vitro concentration-response curves for AChE inhibition obtained in the current study to predicted in vivo dose-response curves. The predicted dose-response curves for rat matched available in vivo data on AChE inhibition, and the benchmark dose lower confidence limits for 10% inhibition (BMDL10 values) were in line with the reported BMDL10 values. Humans were predicted to be 6-fold more sensitive than rats in terms of AChE inhibition, mainly because of inter-species differences in toxicokinetics. It is concluded that the TEF-coded DZN PBK model combined with quantitative in vitro to in vivo extrapolation (QIVIVE) provides an adequate approach to predict RBC AChE inhibition upon acute oral DZN exposure, and can provide an alternative testing strategy for derivation of a point of departure (POD) in risk assessment.

Paraoxonase-1 Serum Concentration and PON1 Gene Polymorphisms: Relationship with Non-Alcoholic Fatty Liver Disease

Background: Non-alcoholic fatty liver disease (NAFLD) is an important cause of chronic liver diseases around the world. Paraoxonase-1 (PON1) is an enzyme produced by the liver with an important antioxidant role. The aim of this study was to evaluate PON1 serum concentration and PON1 gene polymorphisms in patients with NAFLD. Materials and methods: We studied a group of 81 patients with NAFLD with persistently elevated aminotransferases and a control group of 81 patients without liver diseases. We collected clinical information and performed routine blood tests. We also measured the serum concentration of PON1 and evaluated the PON1 gene polymorphisms L55M, Q192R, and C-108T. Results: There was a significant difference (p < 0.001) in serum PON1 concentrations among the two groups. The heterozygous and the mutated homozygous variants (LM + MM) of the L55M polymorphism were more frequent in the NAFLD group (p < 0.001). These genotypes were found in a multivariate binary logistic regression to be independently linked to NAFLD (Odds ratio = 3.4; p = 0.04). In a multivariate linear regression model, the presence of NAFLD was associated with low PON1 concentration (p < 0.001). Conclusions: PON1 serum concentrations were diminished in patients with NAFLD, and the presence of NAFLD was linked with low PON1 concentration. The LM + MM genotypes of the PON1 L55M polymorphism were an independent predictor for NAFLD with persistently elevated aminotransferases.

Arylesterase activity of Paraoxonase 1 - prognostic factor for one-year survival in patients with acute myocardial infarction

Introduction: Reduced serum levels of paraoxonase 1 (PON1) activities are associated with diseases involving increased oxidative stress, such as acute coronary syndrome. We aimed to determine whether serum PON1 activities are a prognostic factor for one-year survival following ST-elevation myocardial infarction (STEMI).

Material and methods: We prospectively followed for one-year 75 patients diagnosed and treated for STEMI. Clinical, laboratory and imagistic data were gathered after coronary angiography. PON1 activities (paraoxonase, arylesterase, and lactonase) were assayed spectophotometrically on samples of heparinized plasma taken from the patients in a timeframe of maximum 20 minutes after coronary angiography.

Results: Increased mortality was linked to age (patients over 68 years), permanent atrial fibrillation or left ventricular ejection fraction (LVEF) <40% (associated with global hypokinesia, apical or septal akinesia), trivascular disease atherosclerosis, reduced PON1 activities (paraoxonase <18.4 IU/mL, arylesterase <12.6 IU/mL, lactonase <27.6 IU/mL), and glomerular filtration rate levels <54 mL/min/1.73m2. Multivariate survival analysis showed the independent prognostic role of age (HR 3.92; 95%CI 1.08-14.16; p=0.03), LVEF (HR 9.93; 95%CI 2.20-44.86; p=0.003) and arylesterase (HR 4.25; 95%CI 0.94-19.18; p=0.05) for one-year mortality.

Conclusion: Reduced arylesterase activity of PON1 is an independent predictor of one-year survival after acute myocardial infarction.