Niosomal curcumin enhances semen quality in older breeder roosters by regulating steroidogenic and apoptotic genes, as well as serum metabolites

As roosters age, testicular antioxidant efficiency declines, causing reproductive issues from apoptosis and serum biochemistry changes. Niosomal nanocarriers of curcumin (NNCUR) may enhance testicular antioxidant capacity in this context. This study evaluated NNCUR's impact on sperm variables, testis apoptotic gene expression, and blood lipids in senescent roosters. The thin-film hydration method was applied to prepare NNCUR, followed by the characterization of the nanoparticles in terms of particle size, zeta potential, polydispersity index, encapsulation and loading efficiencies, transmission electron microscopy, and Fourier-transform infrared spectroscopy. For the purpose of in vivo assessment, thirty 54-week-old Ross 308 breeder roosters were housed individually in cages and randomly allocated to five distinct treatment groups: a control group, and groups receiving diets supplemented with either 15 or 30 mg/kg of curcumin (CUR) or NNCUR, over duration of nine weeks. All roosters were subjected to semen collection every third week, and blood and internal organs were sampled at the end of the study. Results indicated that feeding 30 mg of NNCUR contributed to a ∼19 % increase in sperm motility, viability, and membrane integrity (P < 0.05). Semen volume significantly increased in CUR-fed birds than in control birds. The highest semen concentration was obtained in NNCUR (15 and 30 mg/Kg) and CUR (30 mg/Kg) groups compared to other treated groups (P < 0.05). The histological features of the testis improved following NNCur30 treatment. Birds that received NNCUR30 demonstrated significantly higher StAR, P450scc and BCL-2 transcripts compared to the control birds. Considering blood parameters, CUR or NNCUR at 30 mg/Kg significantly increased the testosterone and HDL-chol concentrations, but recorded the lowest triglyceride, cholesterol, VLDL-chol, and LDL-chol concentrations. The relative weights of the right and left testis, like their total weight, exhibited a significant increase by feeding NNCUR30 in comparison to the control group (P < 0.05). In summary, dietary supplementation of 30 mg/kg of NNCUR improved the semen quality and blood variables of aged roosters, probably because of boosting the steroidogenic and antioxidant pathways.