Objective: To evaluate the effect of different antioxidant agents during in vitro establishment of allspice (Pimenta dioica L. Merrill).Design/methodology/approach: The effect of different antioxidant agents (Methylene blue, L-cysteine, and silver nanoparticles [AgNPs]) added to Murashige and Skoog culture medium at different concentrations were studied during axenic establishment of P. dioica. A completely randomized experimental design was used. All trials were performed in triplicate. The percentage of survival, oxidation, contamination was determined, the phenols content, antioxidant capacity and lipid peroxidation. Results: The highest survival occurred with the addition of L-cysteine. The lowest percentage oxidation were observed in explants treated with L-cysteine. Treatments with 100 and 200 mg L1 AgNPs had the lowest contamination values. L-cysteine and 50 and 100 mg L1 AgNPs resulted in an increase in the content of soluble phenols.The highest contents of cell wall-linked phenols were obtained in treatments with 200 mg L1 methylene blue, L-cysteine, and 200 mg L1 AgNPs. In this study, all treatments had a reaction of scavenging/reduction mechanisms free radicals. The highest content of malondialdehydes was observed in the control treatment and 200 mg L1 methylene blue. The highest content of malondialdehydes was observed in the control treatment and 200 mg L1 methylene blue.Limitations on study/implications: The highest percentage of oxidation was observed in the control treatments, 100 and 200 mg L1 methylene blue, causing cell death.Findings/conclusions: The addition of L-cysteine to the culture medium is alternative to reduce oxidation during in vitro introduction of P. dioica
