The function of omega-3 polyunsaturated fatty acids in response to cadmium exposure

Abstract

Throughout history, pollution has become a part of our daily life with the improvement of life quality and the advancement of industry and heavy industry. In recent years, the adverse effects of heavy metals, such as cadmium (Cd), on human health have been widely discussed, particularly on the immune system. Here, this review summarizes the available evidence on how Cd exposure may affect health. By analyzing the general manifestations of inflammation caused by Cd exposure, we find that the role of omega-3 (n-3) polyunsaturated fatty acids (PUFAs) in vivo can counteract Cd-induced harm. Additionally, we elucidate the effects of n-3 PUFAs on the immune system, and analyze their prophylactic and therapeutic effects on Cd exposure. Overall, this review highlights the role of n-3 PUFAs in the pathological changes induced by Cd exposure. Although n-3 PUFAs remain to be verified whether they can be used as therapeutic agents, as rehabilitation therapy, supplementation with n-3 PUFAs is reliable and effective.

Keywords: cadmium; health; immune system; omega-3 PUFAs; oxidative stress.

Figure 1

Omega-3 PUFAs and their main sources. N-3 PUFAs mainly consist ALA, EPA, DHA and intermediate derivatives, among which only SDA and DPA are listed in the table, but other derivatives, such as eicosatetraenoic acid (ETA), are not included, which means there is a lack of clarity regarding these derivatives currently.

Figure 2

The mechanism of action of n-3 in cells when subjected to external inflammatory stimuli. When cells encounter external inflammatory stimuli, n-3 PUFAs will be activated. On the one hand, more extracellular n-3 PUFAs enter the cell by changing the fluidity of the cell membrane. On the other hand, free intracellular n-3 PUFAs inhibit the expression of intracellular inflammatory factors by combing with other factors. Among them, GPR120: free fatty acid receptor 4 (FFA4). In the figure, the red line indicates the inhibitory effect.

Figure 3

Hazards from Cd exposure. Cd can enter the body through air, tobacco, seafood, grain, water, vegetable, and damage different organs.

Figure 4

The mechanism of Cd exposure on cells. Cd exposure damages most of the immune cells in the immune system, including decreased vitality and increased apoptosis rate. Oxidative stress in cells occurs mainly through damage to the endoplasmic reticulum and mitochondria.

Figure 5

What n-3 PUFAs can do when Cd exposure harms bodies. In this figure, the red line represents the damage to various organs of the body caused by Cd exposure. The solid blue line represents the organ that has been studied so far with n-3 PUFAs that can resist damage from Cd exposure. The blue dashed line indicates that n-3 PUFAs are known to have a positive effect on the organ’s immune system.