Coenzyme Q10 and its putative role in the ageing process

Summary A phenomenon associated with the aging process is a general age-dependent decline in cellular bioenergetic capacity that varies from tissue to tissue and even from cell to cell within the same tissue. This variation eventually forms a tissue bioenergy mosaic. Recent evidence by our group suggests that the accumulation of mitochondrial DNA mutations, in conjunction with a concurrent decrease in full-length mtDNA in tissues such as skeletal and cardiac muscle, strongly correlates with decreased mitochondrial function and accounts for the bioenergy mosaic. Evidence is also presented suggesting that amelioration with coenzyme Q₁₀ may restore some of the age-associated decline in bioenergy function, in effect providing the potential for a “redox therapy”. Coenzyme Q is a naturally occurring material that is present in the membranes of all animal cells. Its primary function is to act as an electron carrier in the mitochondrial electron transport chain enabling the energy from substrates such as fats and sugars (in the form of reducing equivalents) to be ultimately captured in the form of ATP, which in turn may be utilised as a source of cellular bioenergy. Coenzyme Q₁₀ has no known toxic effects and has been used in a limited number of animal studies and human clinical trials; however, the mechanism of action of coenzyme Q₁₀ remains unclear. A series of experiments by this group aimed at determining the efficacy of coenzyme Q₁₀ treatment on ameliorating the bioenergy capacity at the organ and cellular level will also be reviewed.