I agree with beverly. My understanding of SP is that it has the effect of lowering the effects of testosterone generally throughout the body, but specifically in prostate tissue. I think what they are saying is factually correct but doesn't go far enough in explaining why some of the reported effects are important, since one of the hallmarks of medical treatment for benign prostate hyperplasia (BPH or enlarged prostate) and prostate cancer is reducing the effects of testosterone. Apparently whether you reduce the absolute levels of testosterone in the blood (by taking estrogen as some men with prostate cancer do) or you inhibit the conversion of testosterone into dihydrotestosterone (DHT), it has a beneficial effect on prostate hyperplasia.
Here is a link that describes SP in more clinical detail than most people want to know:
http://www.drugs.com/npp/saw-palmetto.html
If you scroll down towards the bottom of the page there is a section "Saw Palmetto Uses and Pharmacology". The following quote is from the beginning of that section:
Quote:Benign prostatic hyperplasia
Saw palmetto's mechanism of action in suppressing the symptoms of BPH is poorly understood. Animal and human in vitro studies have led to several different hypotheses.
Animal data
The leading hypothesis involves the inhibition of testosterone 5-alpha reductase, an enzyme that converts testosterone to 5-alpha-dihydrotestosterone in the prostate. Hexane extracts of saw palmetto inhibited the enzyme from human foreskin fibroblasts, while they had no direct effect on androgen receptor binding.
This article cites conflicting studies that say SP inhibits alpha-reductase and thus the production of DHT and others that say it only has a weak effect or none at all. Still other studies show a decrease in DHT concentrations in biopsy samples of BPH tissue with a corresponding increase in testosterone. The link between testosterone, DHT and prostate cancer is not conclusive, at least from a research perspective.
What does all this mean: if SP inhibits alpha reductase and thus the conversion of testosterone into the more bioactive DHT, then one would expect to see higher serum levels of testosterone, since less is being converted into DHT. So yes the net effect may be that testosterone levels increase, but that it ultimately has less effect since SP inhibits the conversion to DHT.
This is a long way of saying SP seems to help with BPH but they don't really know why. I have read that many men resist taking female hormones even though they are known to shrink prostatic hyperplasia because of the side effects of lowering testosterone and libido, and promoting breast growth. Seemingly, they would rather take their chances with prostate CA than experience lower T and grow boobs (what fools, eh?! LOL). So, if you can technically say SP "increases" testosterone you may get more compliance with the prescribed treatment. Just guessing of course.
Hope this helps.
