Re: Berberine

The first, second and 4th study all deal with the effects of berberine on rat, not human tissues.  Animal studies do not automatically align with human studies.  For example, humans can eat chocolate, which can be deadly to dogs.  Sheep can consume arsenic in levels that would kill a human.

In addition, the 4th study was a Petri dish study, which again does not correlate to what happens in the body.  For example, look at oleander for cancer.  Petri dish studies showed some effect against some cancers.  But when oleander extract was actually tested for cancer on humans it found to ineffective.   Petri dish studies tell us no more than animal studies.  There was a study that came out years ago claiming that St. Johnswort was found to cause infertility and it was all over the news.  If the media would have bothered to look at the actual study though the study actually showed no evidence of this.  What they did in the study was poured a St. Johnswort extract directly on to semen in a Petri dish, which lead to deformation and death of the semen.  Does this mean that the same thing would happen in the body?  Of course not.  In fact, if you put vitamin C directly on semen this will also kill the semen.  Yet it clearly does not do this in the body or none of us would have been born.  So in short Petri dish studies are not evidence of anything.

As for the third study the big problem I see is that there is no information on method of administration.  Again how something is administered can greatly change a substances effects.  If plant saponins are taken orally for example they are not absorbed, but still provide various benefits to the body such as inflammation reduction, immune support, lowering cholesterol, etc.  If injected though saponins would hemolyze red blood cells, which could lead to a number of problems from hemolytic anemia and gout to blood clots and death.  Therefore we have a problem with the study not detailing the administration method.  Was the berberine administered orally or injected?  Because berberine is so poorly absorbed from the gut this makes an extremely big difference.  If injected in the study we could conclude that the effects were from direct contact of high levels of berberine.  Of course this would not happen with oral ingestion due to the poor absorption of berberine.  On the other hand, if the berberine was taken orally there is another explanation of how the berberine could have lead to the lowering of blood pressure.  Around 80% of the body's serotonin is produced by the intestinal flora.  Serotonin actually plays a number of roles in the human body other than mood regulation.  In fact, there are 18 different serotonin receptors in the body.  One of those roles is blood pressure regulation.  As serotonin goes up so dies blood pressure and vice versa.  Since berberine kills the intestinal flora this would lead to reduced blood serotonin and thus a drop in blood pressure if the berberine induced loss of potassium if offset by dietary or supplemental potassium.

Regardless, there are numerous, safer herbs and supplements that can relax vascular muscle without the dangers of berberine.  Magnesium salts for example act as natural calcium channel blockers, which relax blood vessels reducing blood pressure and preventing damage to blood vessels from strong vasoconstrictors such as cocaine and insulin.  Sterol sources such as jiaogulan (Gynostemma) or yucca root also work great.  Or weak cardiac glycoside sources, such as cactus grandiflorus (night blooming cereus) or lily of the valley also relax blood vessels by acting as calcium antagonists.