Effects of several cerebroprotective drugs on NMDA channel function: evaluation using Xenopus oocytes and [3H]MK-801 binding.
Kaneko S, Sugimura M, Inoue T, Satoh M.

Department of Pharmacology, Faculty of Pharmaceutical Sciences, Kyoto University, Japan.

The effects of several cerebroprotective and nootropic drugs on the function of excitatory amino acid (EAA) receptor subtypes expressed in Xenopus oocytes after injection of rodent brain poly(A)+ mRNA were investigated. The oocyte response to N-methyl-D-aspartate (NMDA) in the presence of glycine (Gly) was inhibited dose-dependently by bifemelane, indeloxazine, vinpocetine and vincamine while no effect was observed by idebenone, Ca hopantenate, aniracetam or piracetam. Bifemelane, indeloxazine and vinpocetine suppressed the maximum response of NMDA and Gly without affecting their EC50 values. Unlike Mg2+, they did not affect the current-voltage relationship of the NMDA response below 0 mV. On the non-NMDA-type responses of the injected oocytes to kainate (KA), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) and quisqualate (QA), no significant effects were observed by these drugs at 100 microM. On the binding of [3H](+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imi ne (MK-801) to brain membranes, the estimated IC50 values were 88 microM for bifemelane, 102 microM for indeloxazine, and 115 microM for vinpocetine. The dissociation rate of [3H]MK-801 was significantly slowed by Zn2+ and vinpocetine, but not affected by bifemelane or indeloxazine. The Kd value for [3H]MK-801 binding was increased by bifemelane and indeloxazine while Bmax was unchanged. These results suggest that the inhibition of NMDA channels by vinpocetine shows a similarity to the action of Zn2+ which closes the gate of the NMDA channel. In contrast, bifemelane and indeloxazine may affect the phencyclidine (PCP)-site in the open channels and inhibit NMDA function.

PMID: 1652446 [PubMed - indexed for MEDLINE]

Vinpocetine preferentially antagonizes quisqualate/AMPA receptor responses: evidence from release and ligand binding studies.
Kiss B, Cai NS, Erdö SL.

Pharmacological Research Centre, Gedeon Richter Ltd., Budapest, Hungary.

The effect of vinpocetine on excitatory amino acid receptors was examined in the rat brain by two different biochemical approaches. In release experiments with striatal slices, vinpocetine reduced the efflux of dopamine and acetylcholine evoked by glutamate, quisqualate and N-methyl-D-aspartate (NMDA), but not that evoked by kainate. In binding experiments with cortical membranes, vinpocetine reduced the binding of [3H]2-amino-3-3-hydroxy-s-methylisoxasole-4-yl-propionic acid ([3H]AMPA), a quisqualate partial agonist, in an incomplete manner, but failed to influence the binding of [3H]kainate and [3H]3-(2-carboxypyperazine-4-yl)-propyl-1-phosphonic acid ([3H]CPP), an NMDA agonist. These findings suggest that vinpocetine is a quisqualate/AMPA antagonist of some specificity and selectivity.

PMID: 1687679 [PubMed - indexed for MEDLINE]

It's my view that a healthy balanced diet gives all the necessaries and probably much more than a mediocre diet with supplements of whatever fashionable tablets are currently considered necessary by some (which may not be all of the ones our bodies really need anyway).

Think about it. Our bodies are "designed" to get these things out of our food, like our ancestors did. Who's to say the body likes getting it concentrated and in the chemical forms that they come as in tablets? Who's to say people aren't overdosing when they eat these tablets? Who's to say that having too much of one thing in one go inhibits normal absorption of another necessary thing? Etc. What happens after a lifetime of supplements? Not worth the risk in my opinion, I'd only take supplements when a doctor told me I needed to for a medical condition that was making my life miserable.

Ecologically, why go to all that effort refining chemicals into little pills when they're in our food already? And what a waste of money to be buying a load of supplements all the time!

I have heard of how giving prison inmates vitamins makes them behave better. However, feeding them a proper diet would I'm sure do many more wonders.

A healthy diet should take into consideration a proper mix of food, like our ancestors evolved to accept. Not just meat and two veg (some may argue the necessity of meat but I have found it necessary for myself). Nuts, berries, polyunsaturated fats, beans, wholegrains, omega 6 from oily fish (or flaxseed etc if you're veggie), little to no refined sugar, some but little salt (<6g a day), unprocessed food cooked from fresh. Watch out for processed food, it's full of sugar, salt and other crap, especially if you're in the USA. The Okinawan Japanese people are the longest lived in the world ahead of the Mediterraneans, and they eat 15 different types of fruit and veg a day, not just 5. Wishing you all a long healthy life

i take aniracetam too, and come to think of it, I never took it with vinpocetine (have taken vinpo with piracetam, no noticable side effects, aside from a mild headache)...

i smell an experiment (taking both now).