Coenzyme Q and its Medical Implications Coenzyme Q (CoQ), a lipophilic substituted benzoquinone, is present in all animal and plant cells. It is endogenously synthesised in tissues and involved in a variety of cellular processes. It is well documented that CoQ is an obligatory component of the respiratory chain in the inner mitochondrial membrane coupled to ATP synthesis. However, its additional localisation in different subcellular fractions is probably associated with its multiple functions in the cell (as a part of extramitochondrial electron transport chains, a powerful antioxidant agent or a membrane stabiliser). The actions outlined for CoQ can explain its broad range of therapeutic effects. This presentation is a brief review of recent knowledge concerning medical aspects of CoQ in mammals. The energetic role seems sufficient to explain at least some of the clinical effects (heart failure, neurodegenerative diseases) but in other cases the antioxidant function may be a more convenient explanation. Nevertheless, a better knowledge of CoQ functions at the molecular level and additional well-designed studies are required to provide specific recommendation and definitive evidence of its therapeutic effects.

        Key words: coenzyme Q – energetic role – antioxidant function – therapeutical effects