Acknowledgements We thank all members of the Department of Rheumatology at Tongji Hospital for their help
The mechanism likely involves coordinated mTOR activation and nitric oxide upregulationtwo pathways that prime the body's repair machinery
Studies have demonstrated that 4% niacinamide can significantly reduce melasma severity ( Navarrete-Sols et al., Dermatology Research and Practice, 2011 ), improve moisture retention, and enhance overall texture ( Boo, 2021 )
Nutrient and cofactor depletion: B12 and folate deficiency impairs methylation (reduced SAM-e) R Glutathione depletion (from chronic oxidative stress, acetaminophen overuse, mycotoxin exposure) impairs GST conjugation R Glycine deficiency impairs both amino acid conjugation and glutathione synthesis R Magnesium deficiency impairs UGT activity (magnesium is required for UDPGA synthesis) R Molybdenum deficiency impairs sulfite oxidase, causing sulfite accumulation and sulfation pathway dysfunction R Sulfate and cysteine depletion impairs sulfation (reduced PAPS) R Vitamin B5 deficiency impairs CoA synthesis, affecting acetylation and amino acid conjugation R Toxic overload and substrate competition: Alcohol depletes glutathione, NAD+, and SAM-e simultaneously, impairing GST conjugation, methylation, and driving acetaldehyde accumulation R High-dose acetaminophen saturates both sulfation and glucuronidation, forcing CYP2E1 to generate the hepatotoxic metabolite NAPQI, which then depletes glutathione catastrophically R Multiple toxin exposures create competition for conjugation enzymes, creating a bottleneck where no single toxin is cleared efficiently Oral contraceptives induce certain UGTs while depleting B vitamins, folate, and magnesium, creating mixed effects on conjugation capacity R Gut dysfunction: Dysbiosis elevates beta-glucuronidase, deconjugating glucuronidated toxins and estrogens in the gut R Leaky gut increases systemic toxin entry, overwhelming conjugation capacity Small intestinal bacterial overgrowth (SIBO) impairs taurine and glycine availability through bacterial deconjugation of bile acids R Liver and mitochondrial dysfunction: Chronic liver inflammation reduces UGT, GST, and SULT expression R Biotoxin accumulation damages hepatocyte mitochondria, impairing energy-dependent conjugation (acetylation, amino acid conjugation) Non-alcoholic fatty liver disease (NAFLD) downregulates multiple Phase II enzymes R Medications and environmental factors: Glyphosate depletes glycine by substituting for it in protein synthesis, and chelates manganese and other minerals needed for conjugation enzymes R NSAIDs compete for glucuronidation and amino acid conjugation R Proton pump inhibitors reduce magnesium absorption, indirectly impairing glucuronidation R Valproic acid depletes carnitine and CoA, impairing acetylation and amino acid conjugation How Conjugation Overlaps With Other Conditions Phase II conjugation dysfunction is a thread running through many chronic conditions
It has been also reported that selenium supplementation promotes differentiation of CD4+ T cells into T-helper-1 (Th1) rather than T-helper-2 (Th2) effector
10.1111/jcmm.14254 250 YeleswaramK.McLaughlinL
