Abstract
Background:
Carbon nanoparticles (CNPs) are extremely small particles composed mainly of carbon atoms, typically ranging from 1 to 100 nanometers in size. Although CNPs have promising applications in various fields, they can damage cell membranes, cause toxicity, and potentially induce mutations that may lead to cancer.

Aim:
This study aimed to investigate the dose-dependent effects of carbon nanomaterials on liver function and structure in albino rats.

Methods:
Twenty-five male Sprague-Dawley rats (weighing 100–130 g) were acclimated and randomly divided into five groups. Groups I, II, and III received intraperitoneal injections of CNPs at doses of 19.5, 58.5, and 97.5 mg/kg of body weight, respectively, for 28 consecutive days. A saline control group received 0.5 ml of normal saline. Liver samples were collected for biochemical testing and histological analysis.

Results:
Rats exposed to higher doses of CNPs showed significant weight loss. Serum levels of ALT, AST, ALP, and bilirubin increased markedly, especially in the high-dose group. Lipid metabolism was also disrupted. Histological studies revealed hepatocellular degeneration, inflammatory infiltration, and sinusoidal dilation at higher concentrations of CNPs.

Conclusion:
The results suggest that exposure to CNPs, particularly at higher doses, may lead to liver toxicity and pose health risks. As CNP use becomes more widespread, understanding their biological effects is essential to ensure the safe and responsible development of nanotechnology.

Key words: Carbon nanoparticles (CNPs); Toxicity assessment; Hepatotoxicity; Histological analysis; Biochemical markers.