4-chloro-1,2-phenylenediamine induces apoptosis in Mardin-Darby canine kidney cells via activation of caspases

Hepatocellular carcinoma antibodies preferably identify nitro-oxidative-DNA lesions induced by 4-Chloro-orthophenylenediamine and DEANO

The widespread use of oxidative hair colouring cosmetics threatens public health. Phenylenediamine derivatives serve as the main pigment in permanent hair colours. They interact with biological macromolecules, altering their functional and structural physiology. The study aimed to investigate the effect of a typical synthetic hair dye pigment, 4-Chloro-orthophenylenediamine (4-Cl-OPD), under a nitrating environment of DEANO on the calf thymus DNA molecule. The results showed single-stranded regions, base/sugar-phosphate backbone alterations, molecular changes, and nitro-oxidative lesions. These modifications are referred to as neo-epitopes on the DNA molecule. IgGs from cancer patients with a history of permanent hair dye use were screened for the recognition of neo-epitopes on DNA molecules. Hepatocellular carcinoma IgG showed the highest binding with 56% inhibition in the competition ELISA. The immune complex formation was observed through electrophoretic mobility shift assay. In conclusion, synthetic hair dye users are likely to present with heightened immunological triggers under elevated nitric oxide levels. The study reports chronic hair dye exposure as one of the factors responsible for altering the intricacies of the DNA's microarchitectural structure and inducing neo-epitopes on the molecule. The physiological status of NO may define the susceptibility towards 4-Cl-OPD and humoral response in hair dye users. Persistent nitro-oxidative stress due to 4-Cl-OPD and NO may induce a heightened immune response against neoepitopes in the nitro-oxidatively modified DNA. Therefore, chronic hair dye exposure may be identified as a risk to human health. These findings may contribute to a better understanding and reinforcement of hair dye as one of the modifiable risk factors responsible for the pro-inflammatory carcinogenic environment.