Effect of N-acetylcysteine administration on homocysteine level, oxidative damage to proteins, and levels of iron (Fe) and Fe-related proteins in lead-exposed workers

Abstract

N-Acetylcysteine (NAC) could be included in protocols designed for the treatment of lead toxicity. Therefore, in this study, we decided to investigate the influence of NAC administration on homocysteine (Hcy) levels, oxidative damage to proteins, and the levels of iron (Fe), transferrin (TRF), and haptoglobin (HPG) in lead (Pb)-exposed workers. The examined population (n = 171) was composed of male employees who worked with Pb. They were randomized into four groups. Workers who were not administered any antioxidants, drugs, vitamins, or dietary supplements were classified as the reference group (n = 49). The remaining three groups consisted of workers who were treated orally with NAC at three different doses (1 × 200, 2 × 200, or 2 × 400 mg) for 12 weeks. After the treatment, blood Pb levels significantly decreased in the groups receiving NAC compared with the reference group. The protein concentration was not affected by NAC administration. In contrast, Hcy levels significantly decreased or showed a strong tendency toward lower values depending on the NAC dose. Levels of the protein carbonyl groups were significantly decreased in all of the groups receiving NAC. Conversely, glutamate dehydrogenase activity was significantly elevated in all of the groups receiving NAC, while the level of protein thiol groups was significantly elevated only in the group receiving 200 mg of NAC. Treatment with NAC did not significantly affect Fe and TRF levels, whereas HPG levels showed a tendency toward lower values. Treatment with NAC normalized the level of Hcy and decreased oxidative stress as measured by the protein carbonyl content; this effect occurred in a dose-dependent manner. Moreover, small doses of NAC elevated the levels of protein thiol groups. Therefore, NAC could be introduced as an alternative therapy for chronic Pb toxicity in humans.

Exposure to Toxic Heavy Metals Can Influence Homocysteine Metabolism?

“…All studies of this review support that Pb concentrations are correlated with high levels of Hc [9,[21][22][23][24][25][26][27][28][29][30].…”

“…In studies describing workers exposed to Pb [9,24,26], the levels of Hc were slightly higher than in the general population and confirmed that Pb blood levels were associated with high Hc levels. Kasperczyk et al [24] reported that Pb decreases levels of GSH and protein thiol groups. Pb-induced oxidative stress contributes to the increase in protein carbonyl groups.…”

“…Twelve were ruled out a subsequent review of title and abstract, and 26 studies were disqualified after review of the manuscript. In conclusion, 16 studies satisfied the inclusion criteria and were included in the systematic review [6,[21][22][23][24][25][26][27][28][29][30][31][32]. A flowchart depicting the choice of studies is revealed in Figure 1.…”

“…Aside from this, Pb poisoning seems to be associated with hHc, which may promote the development of atherosclerosis. Kasperczyk et al [24], moreover, promoted the N-Acetylcysteine (NAC) administration in Pb-exposed workers and observed that treatment with NAC normalized the level of Hc and decreased oxidative stress, as measured by the protein carbonyl content [24].…”

“…However, regardless of the route of entry into the organism, its distribution and accumulation always show a similar pattern [24]. Pb is not easily eliminated from the body and can reside in the body (liver, spleen, kidneys, and especially bones) for years [9].…”