Vinpocetine is considered as
neuroprotectant drug and used for treatment of
brain ischemia and cognitive deficiencies for decades. A number of
enzymes, channels and receptors can bind
vinpocetine, however the mechanisms of many effects' are still not clear. The present study investigated the effects of
vinpocetine from the mitochondrial bioenergetic aspects. In primary brain capillary endothelial cells the
purinergic receptor-stimulated mitochondrial Ca2+ uptake and efflux were studied.
Vinpocetine exerted a partial inhibition on the mitochondrial
calcium efflux. In rodent brain synaptosomes
vinpocetine (30 μM) inhibited respiration in uncoupler stimulated synaptosomes and decreased H2O2 release from the nerve terminals in resting and in complex I inhibited conditions, respectively. In isolated rat brain mitochondria using either complex I or complex II substrates leak respiration was stimulated, but
ADP-induced respiration was inhibited by
vinpocetine. The stimulation of oxidation was associated with a small extent of membrane depolarization. Mitochondrial H2O2 production was inhibited by
vinpocetine under all conditions investigated. The most pronounced effects were detected with the complex II substrate
succinate.
Vinpocetine also mitigated both Ca2+-induced mitochondrial Ca2+-release and Ca2+-induced mitochondrial swelling. It lowered the rate of mitochondrial
ATP synthesis, while increasing
ATPase activity. These results indicate more than a single mitochondrial target of this vinca
alkaloid. The relevance of the affected mitochondrial mechanisms in the anti ischemic effect of
vinpocetine is discussed.