Exposure to Toxic Heavy Metals Can Influence Homocysteine Metabolism?

Abstract

Background: Homocysteine is a sulfur amino acid whose metabolism is activated in two pathways: remethylation to methionine, which requires folate and vitamin B 12 , and transsulfuration to cystathionine, which needs pyridoxal-5'-phosphate. High homocysteine level increases the risk of developing heart disease, stroke, peripheral vascular diseases, and cognitive impairment. Some evidence showed that exposure to these metals increased plasma homocysteine levels. Methods: A systematic review was carried out to clarify the relationship between homocysteine blood levels and exposure to toxic heavy metals (Lead, Cadmium, Mercury, and Chromium). Results: The results of this systematic review indicate that exposure to Pb, Cr, Cd, and Hg is connected with nonphysiological homocysteine levels or vitamin B 12 and folate serum concentrations. Conclusions: These findings reinforce the importance of involvement in exposure to heavy metals in homocysteine metabolism. This supports the role of blood metals as potential upstream modifiable risk factors to prevent the development of other established risk factors as hyperhomocysteinemia.

Serum cardiovascular-related metabolites disturbance exposed to different heavy metal exposure scenarios

“…Heavy metal exposures pose a significant threat to human health ( Wang et al, 2020 ), which has been identified as risk factor for cancer and non-cancerous disease (e.g., cardiovascular, metabolic disease) ( Choi et al, 2020 , Ledda et al, 2020 , Domingo-Relloso et al, 2019 ). Particularly, some heavy metals (e.g., Ni, Cd) have been classified as Class I carcinogen to humans ( IARC (International Agency for Research on Cancer), 2011 ).…”

Detrimental Health Relationship Between Blood Cadmium and the Red Blood Cell Folate Level

“…As we have known, lots of researches had illustrated that homocysteine levels are inversely related to serum folate [15][16][17]. In one systemic study, Ledda et al had the similar result that exposure to heavy metal, including cadmium, is correlated with homocysteine levels or folate serum concentrations [9]. Besides, the role of red cell folate in presenting the individual's folate status is well demonstrated [8].…”

“…A rising number of researches disclose the robust relationship between toxic heavy metal and homocysteine metabolism [9]. Homocysteine is an intermediate amino acid in conversion of methionine and cysteine, and the accumulation of it will cause adverse heathy effects.…”

Relative Telomere Length in Peripheral Blood Cells and Hypertension Risk among Mine Workers: A Case-Control Study in Chinese Coal Miners

“…Increasing evidence also indicated that toxic and harmful particles enter the body and produce an inflammatory response, which releases reactive oxygen species, leading to an imbalance between oxidation and antioxidant effects in the body, followed by oxidative stress [ 25 ]. Exposure to toxic heavy metals, which usually occurs in workers, increases the risk of cardiovascular disease by increasing homocysteine levels, the underlying mechanism may be that high homocysteine leads to changes in the elasticity of the vascular wall, the inhibition of nitric oxide synthesis, and the increase of oxidative stress [ 26 ]. A study in mouse models provided evidence that chronic inflammation causes telomere dysfunction and premature ageing [ 27 ].…”