Main neurotropic and psychotropic effects of methylxanthines (caffeine, theophylline, theobromine, paraxanthine)

Caffeine, the main alkaloid in coffee, corresponds to the 1-3-7 trimethylxanthine. Its concentration is lower in tea and chocolate, where it is associated with theophylline, 1-3 dimethylxanthine, in tea and with theobromine, 3-7 dimethylxanthine, in chocolate. Paraxanthine, 1-7dimethylxanthine, for its part, is produced by the hepatic metabolism of caffeine operated by a cytochrome of 1A2 type. The effects of these methylxanthines on awaking, anxiety, neuroprotection in Alzheimer's and Parkinson's diseases, mood, schizophrenia and nociception are briefly considered. This review is concluded by indicating that these effects of methylxanthines may be modified by various associated substances, such as polyphenols displaying antioxydant properties.