Objective: Tartrazine (TZ) is an anionic azo dye widely used to color food products, pharmaceuticals, and cosmetics; however, its harmful effects on the kidneys are still unclear and need to be confirmed. Meanwhile, taurine (TA) is a natural antioxidant amino acid that can provide protection against various forms of glomerulonephritis. Our aim was to study the structural, and biochemical effects of TZ on the kidney and evaluate the potential protection provided by taurine.

Material and Methods: We used 28 adult male albino rats equally divided into 4 groups. The control group did not receive TZ or TA. The TA group received 100 mg/kg/day of TA. The TZ group received 100 mg/kg/day of TZ dissolved in distilled water. The TZ/TA group received both TZ and TA. Animal blood samples were obtained to estimate blood urea, creatinine, and random glucose levels. Kidneys samples were examined for structure as well as oxidative enzymes and kidney injury molecule 1 (KIM-1).

Results: Compared to the control group, the TZ group showed hyperglycemia, increased markers of oxidative stress, and shrunken, lobulated glomeruli with mesangial expansion, pyknosis, and vacuolation in the tubular lining. There was also strong immunoreactivity for PCNA and caspase-3, a thickened glomerular capillary basement membrane lacking fenestrations, swollen mitochondria with destructed cristae, and increased expression of the KIM-1. In the TZ/TA group, the convoluted tubules mostly retained the normal histological structure, but some tubules still showed a wide lumen and nuclear pyknosis of lining cells. Oxidative markers and random blood glucose levels were significantly reduced.

Conclusion: TZ is suggested to cause adverse kidney effects in rats, including kidney injury and structural changes, which can be mitigated by co-administration with TA.