This study aimed to investigate the synergistic effects of
resveratrol and
sulfamethoxazole-
trimethoprim (ST) on the treatment of mice experimentally infected by Toxoplasma gondii during the chronic phase of the disease considering
infection, behavior, and oxidative/
antioxidants profile aspects. For the study, 60 mice were initially divided into two groups: uninfected (n = 24) and infected by T. gondii (n = 36). These two groups were later subdivided into other groups and treated with
resveratrol (free and inclusion complex containing
resveratrol) alone and co-administered with ST: groups A to D were composed by healthy mice and groups E to J were consisted of animals infected by T. gondii (VEG strain). Treatments began 20 days post-
infection for 10 consecutive days with oral doses of 0.5 mg kg(-1) of ST (groups B and F), 100 mg kg(-1) of free
resveratrol (groups C and G) and inclusion complex of
resveratrol (nanoparticles containing
resveratrol) (groups D and H), and lastly an co-administration of both drugs (groups I and J). Behavioral tests (memory, anxiety and locomotion) were performed
after treatment. Liver and brain fragments were collected to evaluate pathological changes, brain
cysts counts, as well as
oxidant and
antioxidant levels. A reduction on the number of
cysts in the brain of animals treated with both drugs combined was observed; there was also reduced number of lesions on both organs. This drug combined effect was also able to reduce oxidative and increase
antioxidant levels in infected mice, which might be interpreted as a
resveratrol protective effect. In addition, the combination of ST and
resveratrol was able to prevent behavioral changes in infected mice. Therefore, the use of co-administration drugs enhances the
therapeutic effect acting on a synergic way, reducing the oxidizing effects of the chemical treatment for
toxoplasmosis. In addition,
resveratrol in inclusion complex when co-administered with ST showed an improved
therapeutic effect of ST reducing oxidative damage, liver damage and the number of
cysts in the brain of T. gondii infected mice.