Examination of some toxicological parameters of dimethylamylamine when consumed alone or with caffeine

Abstract

Dimethylamylamine (DMAA) is a bodybuilding supplement with fat-burner or performance-enhancing properties. DMAA is often combined with caffeine to enhance its effectiveness and this can have serious adverse effects on health. In this study, we examined for the first time the cytotoxic, oxidative and genotoxic effects of DMAA in the presence or absence of caffeine in lymphocytes cultured from human blood, and its vascular irritant effects in a hen's chorioallantoic membrane egg test. Cytotoxic effects were observed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), lactate dehydrogenase release (LDH), which serves as a measure of cell membrane damage, changes in the mitotic index (MI) and proliferative rate index (PRI) assays. Oxidative changes were evaluated by the total antioxidant activity and the total oxidative status assay. Genotoxic damage was analyzed by chromosomal aberration and micronucleus assays. DMAA and its combination with caffeine (cDMAA) had no genotoxic effects. DMAA (1000 mg/L) and cDMAA (500 and 1000 mg/L) decreased cell viability while significantly increasing LDH activity, MI and the oxidative level. DMAA and cDMAA caused weak and moderate vascular irritant effects, respectively. In conclusion, DMAA exhibits cytotoxic effects via membrane dysfunction and mitotic disturbance following increased oxidative stress in a dose- and caffeine-dependent manner.