Exploring the Molecular Mechanism of Hepatic Dysfunction Among Workers Exposed to Nickel and Chromium in...

Exposure to nickel (Ni) and chromium (Cr) in environmental and occupational settings appears to be inevitable and significantly affects the liver, the principal organ responsible for their metabolic processes. This research aimed to assess the functional integrity of the liver and the molecular mechanisms underlying hepatic damage in employees exposed to Ni and Cr at work. A cross-sectional investigation was implemented with 86 non-smoking male employees working in a metallurgical factory. Serum Cr, Ni, liver function tests, oxidative and inflammatory indicators, and Keap-1, Nrf2, and miR-223 expression were assessed. In electroplating workers, serum Cr (2.47 ± 2 µg/L), Ni (1.39 ± 0.79 µg/L), liver transaminases, total bilirubin, and NF-κB were all statistically significantly greater than in the referent group. Electroplaters' serum albumin levels were significantly lower than those of controls. Furthermore, oxidative stress was observed in electroplaters, characterized by lower levels of superoxide dismutase (SOD) and glutathione peroxidase (GPx) and greater levels of malondialdehyde (MDA) with respect to controls (p < 0.05). Additionally, compared to controls, gene expressions in electroplaters showed that Keap-1 was upregulated, while Nrf2/Ho-1 and miR-223 were downregulated. In conclusion, occupational exposure to Ni and Cr was associated with hepatic impairment through downregulation of the antioxidant Nrf2 pathway, oxidative stress, and inflammation.