Pomegranate trees are tropical and subtropical shrubs with nutritional benefits and pharmaceutical and therapeutic uses. Antioxidative systems protect the structure and function of cellular membranes. This study demonstrated the connection between oxidative stress generated by excess nanoparticles ZnO (ZnO-NPs) accumulation in pomegranate calli and the involvement of thiol groups and volatile and semi-volatile compounds in alleviating this stress. The effect of the non-enzymatic antioxidant system was studied using callus treated with three levels of ZnO-NPs or bulk particles (ZnO-BPs). With rising ZnO levels in the media, callus growth was gradually decreased by ZnO in both forms (NPs and BPs). Malondialdehyde (MDA) measurements revealed that different concentrations of both forms promoted lipid peroxidation. The supply of both forms had a considerable stimulatory influence on the cysteine (Cys