8 replies to this topic

[9H}@}C\%kmFHOB#?X]

FYI:

Neurochem Res. 2011 Jun;36(6):1062-72. Epub 2011 Mar 30.
Oxidative stress in a model of toxic demyelination in rat brain: the effect of piracetam and vinpocetine.
Abdel-Salam OM, Khadrawy YA, Salem NA, Sleem AA.
Source
Department of Toxicology and Narcotics, National Research Centre, Tahrir St, Dokki, Cairo, Egypt. omasalam@hotmail.com
Abstract

We studied the role of oxidative stress and the effect of vinpocetine (1.5, 3 or 6 mg/kg) and piracetam (150 or 300 mg/kg) in acute demyelination of the rat brain following intracerebral injection of ethidium bromide (10 μl of 0.1%). Results: ethidium bromide caused (1) increased malondialdehyde (MDA) in cortex, hippocampus and striatum; (2) decreased total antioxidant capacity (TAC) in cortex, hippocampus and striatum; (3) decreased reduced glutathione (GSH) in cortex and hippocampus (4); increased serum nitric oxide and (5) increased striatal (but not cortical or hippocampal) acetylcholinesterase (AChE) activity. MDA decreased in striatum and cortex by the lower doses of vinpocetine or piracetam but increased in cortex and hippocampus and in cortex, hypothalamus and striatum by the higher dose of vinpocetine or piracetam, respectively along with decreased TAC. GSH increased by the higher dose of piracetam and by vinpocetine which also decreased serum nitric oxide. Vinpocetine and piracetam displayed variable effects on regional AChE activity.

PMID: 21448596 [PubMed - in process]


Full paper: http://www.springerl...50745333h85131/

These findings are likely to suggest a pro-oxidant effect as well for vinpocetine at 6 mg/kg
and explaining the less marked increase in GSH compared
with the lower dose of the drug. In case of piracetam, the
highest dose of the drug increased lipid peroxidation in
brain, whilst eliciting increased brain GSH. An intriguing
explanation for these observations is that at their high
concentration, these drugs exhibit pro-oxidant properties
and increase free radical production or act as a free radical
and in this latter case, it is possible that either piratcetam or
vinpocetine react with other free radicals or antioxidant
systems other than glutathione, which is spared in this
condition.

Edited by Watson, 17 July 2011 - 10:54 AM.

[jven014]

This is somewhat alarming for piracetam users. I thought that piracetam was well studied and the safety was well understood. Now there is a study showing that piracetam causes oxidative damage to cell membranes?

[TheFountain]

This is somewhat alarming for piracetam users. I thought that piracetam was well studied and the safety was well understood. Now there is a study showing that piracetam causes oxidative damage to cell membranes?

In rats.

[jven014]

This is somewhat alarming for piracetam users. I thought that piracetam was well studied and the safety was well understood. Now there is a study showing that piracetam causes oxidative damage to cell membranes?

In rats.

Haha a lot of the studies on nootropics show positive results IN RATS and a lot of people take that as promising so then they start taking said nootropic. So why can't we look at the flip-side of that coin?

[nezxon]

This is somewhat alarming for piracetam users. I thought that piracetam was well studied and the safety was well understood. Now there is a study showing that piracetam causes oxidative damage to cell membranes?

I think the information highlights the importance of supplementing with potent antioxidants, perhaps even more so for nootropic users.

[TheFountain]

This is somewhat alarming for piracetam users. I thought that piracetam was well studied and the safety was well understood. Now there is a study showing that piracetam causes oxidative damage to cell membranes?

In rats.

Haha a lot of the studies on nootropics show positive results IN RATS and a lot of people take that as promising so then they start taking said nootropic. So why can't we look at the flip-side of that coin?

Looking at it is perfectly fine. Subscribing to it is another thing. Personally I am more concerned with the potential for anxiogenesis on nootropics than anything else.

[Sovr'gnChancellor£]

Why hasn't more been said on this?

[knutsayang]

why not indeed? anyone care to comment on piracetam and potential for oxidative stress?

[Algernoot]

We studied the role of oxidative stress and the effect of vinpocetine (1.5, 3 or 6 mg/kg) and piracetam (150 or 300 mg/kg) in acute demyelination

These findings are likely to suggest a pro-oxidant effect as well for vinpocetine at 6 mg/kg
and explaining the less marked increase in GSH compared
with the lower dose of the drug. In case of piracetam, the
highest dose of the drug increased lipid peroxidation in
brain, whilst eliciting increased brain GSH. An intriguing
explanation for these observations is that at their high
concentration, these drugs exhibit pro-oxidant properties
and increase free radical production or act as a free radical
and in this latter case, it is possible that either piratcetam or
vinpocetine react with other free radicals or antioxidant
systems other than glutathione, which is spared in this
condition.

why not indeed? anyone care to comment on piracetam and potential for oxidative stress?

300mg/kg is a fairly large dose of piracetam. For a human, if you weigh 100kg (~220 lbs), that would be a 30g dose of piracetam, which is far more than most of us take.

The dose of vinpocetine seems a bit more insane. Wouldn't 6mg/kg be a huge megadose, even for a human? Isn't it common to take 5 or 10mg per dose 3x/day? (For a 100kg human, 600mg of vinpocetine is 20 times more than a typical daily dose!)

Dosages with rats and humans are not the same. There are different methods to convert them - perhaps someone can do that.

Also, there may be protective factors not explored by the study, for example, the fact that a cholinergic is typically taken with piracetam. That, and the seemingly insane doses used make me skeptical of any real-world implication of this.