Background Tartrazine (Tz) is one of the most commonly used colorants incorporated in the food manufacturing. Its toxicity is derived from metabolic byproducts representing health hazards to consumers. Gallic acid (GA) is known for its redox stabilizing, anti-apoptotic, and cytoprotective characteristics. Therefore, the aim of this study is to explore the possible defensive efect of GA against Tz-induced testicular dysfunction. To achieve this objective, 18 male Wistar adult rats were randomly and equally categorized into three groups for 30 days. The control group received no treatment. Tz at a dose of 30 mg/kg BW was administered to the Tz group. The Tz+GA group received GA at a dose of 200 mg/kg BW in concurrent with the previously described Tz dosage. Both Tz and GA were supplemented orally once daily by a stomach tube. Results The marked decline in luteinizing hormone, follicle stimulating hormone, testosterone, and estradiol 17beta confrmed deviation in pituitary–gonadal axis of Tz-exposed rats. Imbalances in plasma redox equilibrium were evi‑ dent, characterized by a notable increase in malondialdehyde and nitric oxide levels, along with a decrease in reduced glutathione and total antioxidant capacity. Deteriorations in histopathological features, fbrosis in testicular tissue, abnormalities in Sertoli cell, and up-regulation in caspase-3 were observed. Conversely, GA administration successfully reversed these issues. Conclusion The ability of GA to counteract toxicological molecular targets in Tz-exposed testes is believed to be achieved through the restoration of oxidant/antioxidant balance and the prevention of the apoptotic cascade. Keywords Tartrazine, Gallic acid, Testis, Sexual hormones, Redox balance, Apoptosis

This study evaluated oxidative stress (OS) in human testicular tissue in obstructive (OA) and nonobstructive azoospermia (NOA) before and after cryopreservation. Azoospermic patients were subjected to surgical sperm retrieval (SSR) and cryopreservation. Assay of catalase activity (CAT) and malondialdehyde level (MDA) using colorimetric methods was done. The number of retrieved spermatozoa and the Johnson score were assessed in fresh testicular samples. The study included 21 OA (group A) and 16 positive sperm retrieval (group B, positive NOA). The basal CAT activity in the positive NOA group was significantly higher than that in the OA group. Basal MDA level was also significantly higher in NOA than in OA group. CAT activity and MDA level correlated negatively with the mean number of retrieved spermatozoa. After cryopreservation, there was a significant increase in CAT activity in OA, while there was no significant difference in MDA level in both OA and positive NOA. We concluded that patients with NOA seem to have increased testicular OS compared to OA. The extent of OS correlated negatively with spermatogenesis grade. Testicular tissue of patients with OA seems to withstand OS induced by cryopreservation more than NOA.