Mitochondrial Biogenesis

 Small amounts of Nitric Oxide stimulate mitochondrial biogenesis and boost the supply of oxygen and respiratory substrates to mitochondria.  In contrast, high amounts of Nitric Oxide produced by iNOS block mitochondrial respiration, and can be cytotoxic.

"Basal nitric oxide (NO) release, such as provided through moderate exercise, seems to be the most potent guardian..." - from Aging and the Endothelium, Experimental Gerontology, vol.39, no.2.

Nitric Oxide can be obtained from arginine via the action of the body's nitric oxide synthases. 

Pomegranate improves Nitric Oxide synthesis, as does genistein. Nitric Oxide produces peroxynitrites that peroxidize lipid membranes to some degree, so the peroxynitrites should probably be neutralized with gamma tocopherol ( high-gamma vitamin E ).

CoQ10 improves the density of mitochondria in mammalian cells.