The Timing and Effects of Low-Dose Ethanol Treatment on Acetaminophen-Induced Liver Injury

Acetaminophen overdose inhibits steroidogenic acute regulatory protein expression by reducing AKT-mediated SP1 expression in human granulosa-lutein cells

Overdose of acetaminophen (APAP) has been shown to adversely affect the outcome of pregnancy. The steroidogenic acute regulatory protein (StAR) plays a pivotal role in steroidogenesis, but the impact of APAP on StAR expression in adult human ovarian granulosa cells remains elusive. Here, we demonstrate that APAP overdose leads to the downregulation of StAR expression in the human granulosa cell tumor cell line, KGN, and in the primary culture of human granulosa-lutein (hGL) cells. Treatment of overdose APAP inhibits the activation of the AKT signaling pathway and downregulates the expression of transcription factor SP1. Using a small molecule of AKT activator and SP1 overexpression approaches, we show that the suppressive effect of APAP on StAR expression is mediated through the inhibition of AKT-mediated upregulation of SP1 expression. This study contributes to a deeper understanding of the pharmacological actions of APAP and its impacts on female reproductive health.

Pathogenic mechanisms and regulatory factors involved in alcoholic liver disease

Alcoholism is a widespread and damaging behaviour of people throughout the world. Long-term alcohol consumption has resulted in alcoholic liver disease (ALD) being the leading cause of chronic liver disease. Many metabolic enzymes, including alcohol dehydrogenases such as ADH, CYP2E1, and CATacetaldehyde dehydrogenases ALDHsand nonoxidative metabolizing enzymes such as SULT, UGT, and FAEES, are involved in the metabolism of ethanol, the main component in alcoholic beverages. Ethanol consumption changes the functional or expression profiles of various regulatory factors, such as kinases, transcription factors, and microRNAs. Therefore, the underlying mechanisms of ALD are complex, involving inflammation, mitochondrial damage, endoplasmic reticulum stress, nitrification, and oxidative stress. Moreover, recent evidence has demonstrated that the gut-liver axis plays a critical role in ALD pathogenesis. For example, ethanol damages the intestinal barrier, resulting in the release of endotoxins and alterations in intestinal flora content and bile acid metabolism. However, ALD therapies show low effectiveness. Therefore, this review summarizes ethanol metabolism pathways and highly influential pathogenic mechanisms and regulatory factors involved in ALD pathology with the aim of new therapeutic insights.

A New Method for Breath and Blood Alcohol Determination in Rats Using a Breath Alcohol Meter: An Experimental Study

Background

The use of police breath alcohol detectors in rat breath alcohol detection experiments has always been a challenge because of the small lung capacity and inability of rats to actively inhale. However, the method of using gas chromatography to detect blood alcohol concentration is time-consuming, complex, relatively expensive, and cannot achieve on-site detection and multi-point unlimited non-invasive detection.

Objectives

In this study, a laboratory method was validated for rat breath ethanol concentration (BrAC) measurement to estimate blood ethanol concentration (BAC) in rats.

Methods

The rats were placed in a gas collection bottle, the breath sample was drawn out with a syringe, and injected into the mouthpiece of the breath alcohol detector through a rubber tube. The results were immediately detected and automatically converted to BAC. Male rats were randomly divided into three groups. The control group received an intraperitoneal injection of normal saline, the liver injury group received an intraperitoneal injection of 50% Carbon tetrachloride (CCL4 1 mL.kg^-1), and the induction group received an intraperitoneal injection of phenobarbital sodium (75 mg.kg^-1). Western blot analysis was used to detect the protein expression of CYP2E1. Similar grouping and experimental methods were used for female rats.

Results

This method was reproducible. The metabolic activity of CYP2E1 was downregulated in the injury group and upregulated in the induction group, which was consistent with the results obtained for CYP2E1 protein expression.

Conclusions

Our results confirmed that the rat gas cylinder breath alcohol assay can be used for multiple detections with immediate and non-invasive determination of alcohol metabolizing capacity. This is important for studies that require repeated assessment of blood alcohol levels.

Amelioration of Alcoholic Liver Disease by Activating PXR-Cytochrome P450s Axis with Blackberry Extract

Blackberry is widely used in diets for its rich biological phytochemicals and health benefits. However, the relationship between the effect of blackberry extract (BBE) on ameliorating alcoholic liver disease (ALD) and the PXR-Cytochrome P450s axis in vivo and in vitro is unknown. In this study, 50% and 30% ethanol by gavage were used to establish acute and subacute ALD. Male mice were intragastrically administered BBE with 25, 50, and 100 mg/kg BW in the treatment groups. In the experiment, samples were collected, and related indices and histopathological observation were measured. In addition, the potential mechanism was predicted by network and docking studies, which were verified by qRT-PCR analysis, the detection of apoptosis, the measurement of mitochondrial membrane potential, the detection of ROS levels, and Western blotting in liver tissues and HepG2 cells. The acute and subacute ALD experiments indicated BBE ameliorated liver indices, AST, ALT, SOD, and MDA in serum, and the histopathology changed, as observed via H&E, Sirius red, and oil red O staining. The potential mechanism was predicted by network and docking studies, which were verified by experiments. Western blotting suggested BBE reduced the protein expression of NF-κB, TGF-β, IL-6, and α-SMA, and enhanced PXR and CAR in livers. In addition, qRT-PCR showed BBE significantly elevated the mRNA levels of PXR, CAR, CYP3A25, CYP3A11, and CYP2B10. In the experiment of the ethanol-induced apoptosis of HepG2 cells, BBE reduced the apoptosis of HepG2 cells by boosting mitochondrial membrane potential, reducing the apoptotic rate and ROS content, lessening the expression of Bax, and inducing the expression of PXR. For the first time, this study demonstrated BBE’s preventive effects on ALD, which are associated with the antioxidation and stimulation of the PXR-Cytochrome P450s axis. In addition, BBE is available as a nutritional agent.