# Effects of cerium oxide nanoparticle on liver oxidative stress and morphological changes in opium withdrawal rats

## TL;DR

This study shows that cerium oxide nanoparticles reduce liver damage and oxidative stress in rats undergoing opium withdrawal.

## Contribution

The study demonstrates the hepatoprotective effects of cerium oxide nanoparticles during opium withdrawal for the first time.

## Key findings

- CeONP normalized oxidative stress markers like MDA, TOS, GSH, and TAC in withdrawal rats.
- CeONP restored liver enzyme activity and histological changes in the liver.
- CeONP increased the expression and activity of antioxidant enzymes in withdrawal rats.

## Abstract

Since oxidative stress increased during opioid withdrawal, this study aimed to evaluate the effects of cerium oxide nanoparticles (CeONP) on oxidative stress markers in rat livers. Male Wistar rats were randomly divided into 3 groups, including 1: control rats, 2: withdrawal group, and 3: withdrawal rats received CeONP. Opium administration was administered for 30 days. Then the withdrawal period started and CeONP (0.1 mg/kg) was administrated intravenously for 14 days. After that, the liver was removed, and serum was prepared. The expression of superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were measured by Real-time PCR. The amount of malondialdehyde (MDA), total oxidant status (TOS), total antioxidant capacity (TAC), and glutathione levels were determined by the available kit. Blood glucose levels and liver enzymes were measured by using the colorimetric method. A light microscope evaluated liver morphological changes. The liver biomarkers (ALT and AST) and glucose levels significantly increased in the withdrawal group (P < 0.05). Furthermore, the MDA and TOS increased dramatically in the withdrawal group (P < 0.001). However, the levels of GSH and TAC were reduced in the withdrawal group(P < 0.05). The gene expressions and activities of SOD, CAT, and GPx were reduced in the withdrawal group (P < 0.05). However, treatment of withdrawal rats with CeONP normalized all these factors(P < 0.05). CeONP restored histological alterations in the liver. Administration of opium causes an increase in oxidative stress and the activity of liver enzymes. However, treatment of withdrawal rats with CeONP showed potential hepatoprotective effects.

•The activity and expression of superoxide dismutase, glutathione peroxidase, and catalase increased in withdrawal rats.•The MDA and TOS significantly were increased and GSH and TAC were reduced in the withdrawal group.•CeONP normalized oxidative stress markers in withdrawal rats.•CeONP restored histological alterations of the liver.

The activity and expression of superoxide dismutase, glutathione peroxidase, and catalase increased in withdrawal rats.

The MDA and TOS significantly were increased and GSH and TAC were reduced in the withdrawal group.

CeONP normalized oxidative stress markers in withdrawal rats.

CeONP restored histological alterations of the liver.