Table 3.
Chemical obesogens and their effects on thermogenic fat and adipose tissue.
| Chemical | Source/Use | Proposed Mechanism | Effects | References |
|---|---|---|---|---|
| Bisphenols (A, F, S) | Chemical used to make polycarbonate plastics and epoxy resins. Found in the lining of food packaging. | Acts as an estrogen receptor agonist androgen, receptor antagonist | Shifts mesenchymal stem cell commitment and differentiation towards adipogenesis | (111, 112) |
| Dichlorodiphenyltrichloroethane (DDT) & dichlorodiphenyldichloroethylene (DDE) | Found in pesticides. DDE is a metabolite of DDT. | Acts as an estrogen receptor agonist, androgen receptor antagonist. | Induces a loss of BAT thermogenesis and affects the SNS that innervates BAT and WAT. | (77, 111, 113) |
| Silver nanoparticles (AgNPs) | Bactericides, found in fabric of athletic clothing to reduce odor. | Elevates the reactive oxidative species (ROS) levels within beige adipocytes and activates the MAPK-ERK signaling pathway. | Inhibits beige adipocyte differentiation, adipocyte thermogenesis, and mitochondrial functioning. | (114) |
| Arsenic | Polluted ground water | Lowers the expression of PPARγ, UCP1 and PGC1. Activates Estrogen Receptor | Inhibits the differentiation of BAT. | (115, 116) |
| Arsenite | A form of arsenic found in polluted water | Reduces UCP1 expression, accumulates in BAT, and suppresses Sestrin2 phosphorylation by ULK1. Activates Estrogen Receptor | Reduces BAT differentiation, decrease mitochondrial functioning, and lowers thermogenesis in BAT | (116–118) |
| Cadmium (Cd) | Released through the burning of fossil fuels. Used in electroplating, battery production, fertilizers. | Alters the gene expression of MCP-1 in WAT. Acts as an estrogen receptor agonist. |
Elicits pro-inflammatory and carcinogenic effects. Causes damage to the kidneys, liver, lung, pancreas, testis, placenta, and bone. Causes metabolic disease including obesity and diabetes. | (119, 120) |
| Dechlorane Plus (DP) | Flame retardant | Downregulates UCP1 expression in BAT. Activates PPARγ pathway as an agonist. |
Shifts BAT functioning towards that of WAT in a process termed “whitening” of brown adipocytes. Causes cells to be more prone to death, disrupts mitochondrial functioning, activates an inflammatory response by the accumulating macrophages around dead cells within WAT. | (121, 122) |
| Tetrabromobisphenol A (TBBPA) and analogs (TBBPA-MAE, TBBPA-MDBPE, TBBPA-BAE, AND TBBPA-BDBPE) | Flame retardant; found in plastic, and electrical equipment. | PPARγ and glucocorticoid receptor (GR) agonist | Causes adipogenesis. Increases lipid droplets in in hMSCs that differentiate into osteoblasts. | (123–125) |
| Dibutyl phthalate (DBP) | Found in plastic products including toothbrushes and food wrappers. Found in common household items are scented. | Estrogen receptor and PPARγ activator Activates CAR, PXR, PPARα, -β, and -γ). |
Causes insulin resistance, increase in WAT, and endoplasmic reticulum stress. | (5, 126) |
| β-Cypermethrin (βCYP) | Used in insecticides | Promotes adipogenesis in stem cells. Increases ROS within cells by binding to the mitochondrial respiration chain complex 1. | (127) |