Lipidosterolic Extract of Serenoa repens (Saw Palmetto) in the Treatment of Lower Urinary Tract Symptoms Due to Benign Prostatic Hyperplasia - Episode 2

Saw Palmetto Extract in BPH and LUTS: Mechanism of Action and Efficacy

Bilal Chughtai, MD, shares insight on the use of saw palmetto extracts in benign prostatic hyperplasia and lower urinary tract symptoms.


Bilal Chughtai, MD: When it comes to prostate health, urinary tract symptoms, one of the best-studied supplements is probably saw palmetto. Now, saw palmetto has been used since the early 1800s. This supplement has been studied extensively in rat liver models, mouse models, and human prostate cells. Ultimately, saw palmetto has a very compelling mechanism of action in a couple of different ways. The first is that it can help modulate the androgen receptor signaling, helping to reduce the conversion of testosterone to dihydrotestosterone, which is a much more potent form of testosterone. The second mechanism that we’re seeing from saw palmetto is that it may help with the inflammatory signal pathway. As we know, as prostates enlarge, there’s definitely an inflammatory component to it. This inflammatory component can come from a multitude of reasons, whether it’s subclinical infections, natural parts of aging, or the fact that you have this imbalance of apoptosis and proliferation. This leads to free radicals that can attract different lymphocytes. When you have these lymphocytes present, this may lead to more inflammation. Saw palmetto may actually help with reducing this inflammatory pathway as well.

Saw palmetto has multiple components to it. I think one of the very interesting parts is that it almost has a signature of the fatty acids that go with it. When you have the appropriate fatty acid signature with saw palmetto, that can be found within the cell membranes of prostatic tissue. That’s what may lead to it working on its mechanism of action, both in the androgen receptor signaling pathway as well as in the inflammatory pathway. When it comes to this specific supplement, it does require the appropriate fatty acid signature to go with it as well.

When it comes specifically to the saw palmetto berry, there’s a multitude of ways to extract saw palmetto and the active components. The European guidelines suggests using a compound known as Permixon. Permixon is derived through the use of hexane. Unfortunately, hexane has been linked, especially in high doses, with a possible carcinogenic effect. Therefore, hexane-derived saw palmetto is not really available in the United States, although the amount of hexane in any of these supplements is minuscule. The other ways that it can be extracted are through a supercritical carbon dioxide extraction method, or an ethanol extraction.

When it comes to saw palmetto products that are available, especially in the United States, one thing we have to keep in mind is that these supplements are not regulated in this market. As a result, it’s sometimes very hard to tell from the bottle exactly how the saw palmetto was extracted, through what mechanism, how ripe the berries were, and if there is a batch-to-batch variation. Sometimes it leads to a wide variation of the type of saw palmetto and its efficacy that you can get from this compound.

Transcript edited for clarity.