Effects of alpha-phenyl-N-tert-butyl nitrone and N-acetylcysteine on hydroxyl radical formation and dopamine depletion in the rat striatum produced by d-amphetamine.

Previous studies have shown that treatment with free radical scavengers attenuated the D-amphetamine (AMPH) neurotoxicity. But several of these agents also prevent AMPH-induced elevation of body temperature in the rat. Thus, further studies are needed to determine if blockade of the production of free radical or hypothermia are related to the neuroprotective mechanism of the free radical scavengers for AMPH neurotoxicity. In the present study, we examined the effects of the free radical scavengers alpha-phenyl-N-tert-butyl nitrone (PBN) and N-acetylcysteine (NAC) on long-term depletion of striatal dopamine (DA) and lipid peroxidation formation and on hyperthermia induced by AMPH. We also determined their effects on acute hydroxyl radical formation after direct intrastriatal infusion of AMPH. The results showed that both significantly attenuated long-term DA depletion and lipid peroxidation formation in the rat striatum at the dose range that did not block hyperthermia induced by AMPH. These agents also completely inhibited the production of hydroxyl radical after AMPH infusion into the striatum. Our results suggest that free radical scavengers such as PBN and NAC could protect against AMPH-induced oxidative stress and DAergic terminal toxicity via their free radical removing property independent of lowering the core body temperature of rats, and imply that supplement with antioxidants is a potential strategy in the treatment of AMPH neurotoxicity.

Effect of valproate on plasma levels of interleukin-6 in healthy male humans.

Valproate exerts many biochemical and physiological effects and may have a modulating effect on the immune system. The present study aimed to determine whether there is a treatment effect of valproate on plasma levels of the pro-inflammatory cytokine, interleukin (IL)-6, in healthy male humans. Plasma levels of IL-6 were measured in 10 healthy male humans before and after 7 days of treatment with 1000 mg per day of valproate (i.e. 500 mg in the morning and 500 mg in the evening). All the healthy subjects had no past or current psychiatric disorder. They reported to the outpatient clinic at 09.00 h for baseline sampling. Subsequently, they were commenced on valproate 1000 mg per day for 7 days. They took the last dose of valproate at 22.00 h on the day 7, and post-treatment blood sampling for plasma levels of IL-6 was carried out on day 8. An additional blood sample was also taken from each subject at the same time to measure plasma levels of valproic acid for drug compliance. We found a significant increase in plasma levels of IL-6 after the 7 days of valproate treatment in healthy male subjects. Furthermore, there was a significant positive correlation between the changes in plasma IL-6 and blood levels of valproic acid. The findings of this study are consistent with previous studies on subjects with epilepsy, suggesting a modulating effect of valproate on the pro-inflammatory cytokine IL-6 in humans. However, studies with a larger number of participants and employing a double-blind, placebo-control group are required to confirm the findings, and also the levels of other cytokines should be measured to generalize the effect to the immune system.

Acute psychosis following sustained release bupropion overdose.

Bupropion is an antidepressant that is structurally related to amphetamines and enhances dopamine neurotransmission through inhibiting neuronal dopamine re-uptake. Bupropion-related psychosis has been recognized in several papers, but these reports of bupropion-related psychosis almost all involve immediate release (IR) formulation. We present a case of acute psychosis following sustained release bupropion (SR) overdose. A 23-year-old male was admitted because of major depression and a suicidal attempt by ingesting 28 tablets of 150 mg bupropion SR and 14 tablets of 7.5 mg midazolam. He developed paranoid delusions 12 h after the bupropion SR overdose. The paranoid symptoms remitted on the third day of his admission. Our case of acute psychosis following bupropion SR overdose indicates the importance of being aware of the rare complication in patients receiving bupropion SR treatment.