The neurotoxicity is caused by dopamine being taken up by the serotonin reuptake channel, where it is oxidized to compounds which are or creates free radicals, which causes the damage. Serotonin reuptake blockers (SSRI's like Prozac) taken a few hours into the MDMA "trip" prevents the dopamine being taken up by this channel, thus preventing neurotoxicity. A reuptake enhancer would cause more dopamine entering, and potentially causing more damage.
Yes, large doses of antioxidants may very well prevent this, but I wouldn't take the chance myself though, that that would be enough. YMMV.