Saw palmetto Prostate & Bladder Health Support

saw palmetto botanical

Other common names: Sabal palm
Latin name: Serenoa repens (W. Bartram) Small [Arecaceae]
Latin synonyms: Sabal serrulata (Michx.) Nutt. ex Schult. &
Schult. f.; Serenoa serrulata (Michx.) G. Nichols.
Plant part: Fruit



Saw palmetto is native to North America and grows wild in Texas,
Louisiana, South Carolina, and Florida. Traditionally, Native Americans
in this region used the berries for food and as a tonic (USP,
2000). In addition, the berries have been used for more than 100 years
to treat benign prostatic hyperplasia. Modern saw palmetto preparations
contain lipids extracted from the powdered berries. The primary
ingredients include saturated and unsaturated fatty acids (mostly free
fatty acids), as well as free and conjugated plant sterols (Schulz,
Hänsel, and Tyler, 2001).

saw palmetto tree

Saw palmetto preparations have been assessed in clinical studies
for the treatment of symptomatic benign prostatic hyperplasia (BPH),
also known as benign prostatic hypertrophy and prostatic adenoma.
BPH is a nonmalignant enlargement of the prostate that is common in
men over 40 years of age. Symptoms include increased urinary urgency
and frequency (diuresis: increased formation and release of
urine; and nocturia: frequent and/or excessive urination at night), urinary
hesitancy, intermittency, sensation of incomplete voiding, and
decreased force of the urine stream. BPH is linked with a normal
change in hormone levels that occurs with aging. Testosterone levels
decrease while estrogen levels remain constant. This change is implicated
in BPH since estrogens induce hyperplasia (cell growth) in laboratory
experiments. Further, BPH is associated with an increase in
the activity of 5-alpha-reductase, the enzyme that converts testosterone
to dihydrotesterone (DHT). The levels of DHT are not increased,
but the number of androgen receptors seem to be. DHT has a greater
affinity for androgen receptors than testosterone and is thought to
stimulate prostatic growth. However, the pathology of BPH is not
completely understood. Although BPH is associated with prostate
enlargement, the size of the gland is not necessarily indicative of the
degree of obstruction of the urethra and the extent of symptoms
(Schulz, Hänsel, and Tyler, 2001; Barrett, 1999).

Several different rating systems have been developed to characterize
the symptoms of BPH: the International Prostate Symptom Score
(IPSS), the American Urological Association (AUA) symptom score,
the Vahlensieck classification, and the Alken classification.
The IPSS is derived from a questionnaire regarding urinary urgency,
frequency, hesitancy, intermittency, sensation of incomplete
voiding, and force of urine stream (Schulz, Hänsel, and Tyler, 2001).
The AUA symptom score is also a composite score obtained from
seven questions covering frequency, nocturia, weak urinary stream,
hesitancy, intermittence, incomplete emptying, and urgency (Barry et
al., 1992).



The Vahlensieck classification has four stages based upon symptoms:
Stage I is characterized by no voiding difficulties, no residual
urine, and a urine flow of more than 15 ml per second; Stage II is
characterized by transient voiding difficulties and urine flow between
10 and 15 ml per second; Stage III is characterized by constant voiding
dysfunction, urine flow less than 10 ml per second, residual urine
greater than 50 ml, and a trabeculated (ridged) bladder; and Stage IV
is characterized by residual urine volume of more than 100 ml and
bladder dilatation (Schulz, Hänsel, and Tyler, 2001).

The Alken classification has three stages. Stages I to III are similar
to Vahlensieck Stages II through IV. Stage I is the irritative stage,
characterized by an increase in the frequency of urination, pollakiuria
(abnormally frequent urination), nocturia, delayed onset of urination,
and weak urinary stream. Stage II is the residual urine stage, characterized
 by the beginning of the decomposition of the bladder function
accompanied by formation of residual urine and the urge to urinate.
Stage III is the regressive-obstructive stage, characterized by decomposition
of the bladder, vesicular overflowing, continuous drip incontinence,
and damage to the urinary system and kidneys due to
regressive obstruction (Löbelenz, 1992).

Predominant pharmaceutical treatments of BPH include alphareceptor
blockers and 5-alpha-reductase inhibitors. Alpha-adrenergic
receptor blockers (e.g., prozosin, terazosin) are thought to relax
smooth muscles in the bladder neck and within the prostate and thus
reduce symptoms. Five-alpha-reductase inhibitors (e.g., finasteride)
prevent the transformation of testosterone to DHT, thus increasing
levels of testosterone and reducing levels of DHT (Barrett, 1999).

Suggested pharmacological actions for saw palmetto include antiandrogenic,
anti-inflammatory, antiproliferative, and smooth muscle
relaxation. Saw palmetto preparations have been shown to inhibit 5-
alpha reductase, as well as the binding of DHT to androgen receptors.
However, questions remain as to whether these actions, demonstrated
in vitro, are clinically relevant (Barrett, 1999).