Serenoa repens
is the plant commonly referred to as
saw palmetto. It is a member
of the Palmaceae, or Palm family. [1]
The fruit of the saw palmetto is quite unique.
It appears deep
purple to almost black, and is an
ovate (some 3 cm long), 1-seeded berry with a hard but
fragile pericarp that covers a pale
brown, spongy pulp. [2]
These berries are the part of the plant
used for various medicinal
applications. Preparations of saw
palmetto are generally characterized
as tasting
sweet and 'soapy.'
Saw palmetto
is native to the southern United
States, growing from South Carolina
to Florida, and parts of southern
California as well. [3]
It is also cultivated on a mass
scale in Mexico.
The main constituents
in saw palmetto are the
lipid-soluble compounds. The
purified fat-soluble extract is
considered the most medicinally
active component, and contains between 85
and 95% fatty acids and
sterols. The
fruity-smelling oil contains both saturated and unsaturated fatty
acids, and sterols. About 63% of this
oil is composed of free fatty acids
including; capric, caprylic, caproic,
lauric, palmitic, and oleic
acids. Beta-sitosterol and its glucoside
are also important components.
Saw
palmetto contains carotenes, lipase,
tannins, and sugars, as well. [4-6]
Pharmacologic
activity of saw palmetto is
primarily attributed to inhibition
of the intraprostatic conversion of
testosterone to dihydrotestosterone
(DHT); via blocking 5-alpha reductase,
inhibition of its intracellular
binding and transport, and
contraction of epithelial cells. [7,
8] However, more recent research has
suggested additional mechanisms of
action, including
increased
molecular markers involved in the
apoptotic process, i.e. the
Bax-to-Bcl-2 expression ratio and
caspase-3 activity. [9]
A six month study of
treatment with a saw palmetto herbal
blend appeared to alter the DNA
chromatin structure and organization
in prostate epithelial cells,
suggesting a possible molecular
basis for tissue changes and
therapeutic effect of the compound.
[10]
Other mechanisms of
action may include an
anti-inflammatory effect, and an
anti-proliferative influence through
the inhibition of growth factors.
[11]
Medicinal actions
ascribed to saw palmetto
include; anti-androgenic,
anti-exudative, anti-inflammatory,
endocrine agent, and spasmolytic. [5,
12]
Traditionally, it has been
used for respiratory
complaints (especially if
accompanied by chronic catarrh),
genitourinary complaints (such as to
reduce irritation), prostatic and
uterine hypertrophy, atrophy of the
breasts, inflammation or atrophy of
the ovaries and testes, and as an
aphrodisiac. Saw palmetto was
considered to be a tissue building
plant.
[13,
14]
The main application
of saw palmetto is for the
treatment of lower urinary tracts
symptoms (LUTS) associated with
benign prostatic hyperplasia (BPH), a common disorder in elderly
men. Over the years, there have been
numerous trials with conflicting
results; some showing no effect and
some showing profound effects. [15-18]
A review of clinical trials
published in 2004 focused on trials that examined the benefit to risk
ratio of lipido- sterolic extracts
of S. repens in the treatment
of BPH. [19]
Researchers found that S. repens
extract significantly reduces the
symptoms of BPH, increases urinary
flow, improves the quality of life,
and is generally well
tolerated.
A
meta-analysis conducted of 14
randomized clinical trials and three
open-label trials involving the saw palmetto extract, Permixon,
for treating men with BPH also showed a
significant improvement in peak flow
rate and reduction in nocturia above
placebo; a 5-point reduction in
the International Prostate Symptom
Score (IPSS) was also noted. [20]
Furthermore, a review published in
American Family Physician in 2003
summarized that saw palmetto was
comparable in efficacy to
finasteride, the conventional
therapy for BPH,
but it is better
tolerated and far less expensive. [21]
An updated Cochrane review in 2002
had a similar conclusion stating
that S. repens provides mild
to moderate improvement in urinary
symptoms and flow measures, produces
similar improvement compared to
finasteride, and is associated with
fewer adverse treatment events. [22]
Saw palmetto
may also be of benefit in the
treatment of patients undergoing
transurethral resection of prostate
(TURP). A study of
lipo-sterolic extract
of Serenoa repens (Permixon)
was conducted by Italian researchers
in 2004 to determine whether
pre-treatments would significantly
reduce bleeding that occurs with
this surgical procedure. [23]
108 patients were randomized into
the experimental group or the
control.
The pretreatment consisted
of 320 milligrams per day of Permixon for 8
weeks prior to the TURP
procedure. The results showed that
perioperative bleeding was
significantly lower in the
experimental group than individuals
in the control category (respectively 124 vs 287
milliliters); paralleled with a
remarkable decrease for need of transfusion.
The
researchers also discovered that the duration
of postoperative catheterization and
hematological parameters in
the experimental group (red cells
4.5 vs 4 million, hemoglobin 13.4 vs
11.9 g, hematocrit 40% vs 35%) were
significantly lower when compared to
control.
Saw palmetto
has also demonstrated effectiveness in
treating androgenetic alopecia (AGA).
AGA has been shown to
be responsive to drugs and agents
used to treat BPH; the authors
theorized that botanicals used to
treat BPH may also address this
disorder. A double-blind, placebo-controlled pilot study of men with
mild to moderate AGA showed that 60%
of the study subjects dosed with a
lipo-sterolic S. repens
extract and beta-sitosterol were
rated as improved at the final
visit.
[24]
Finally, Saw
palmetto may be useful for
patients with non-infectious
prostatitis, edema, and inflammatory
disorders. [5]
A lipo-sterolic
saw palmetto extract at a
dose of 160mg twice daily is the
dose most commonly employed in
study. The extract Permixon
received the greatest attention;
this particular extract is an 8:1 -
10:1
concentrate of dried, saw palmetto
berries. A
high ethanolic tincture of a
strength consisting of 1:2, could also provide
an effective dose if given in
amounts ranging from 2 to 4ml daily.
[5]
A
six month
double-blind, randomized,
parallel-group study compared two
dose regimens of Libeprosta, the
lipidosterolic extract of Serenoa
repens, in 100 male outpatients
with lower urinary tract symptoms
suggestive of BPH. [25]
The results showed that both doses
(80 mg twice daily and 80 mg three
times daily) resulted in no
significant differences in efficacy,
showing improvements of statistical
significance after 3 months. As
well, no treatment-related
complications or clinical adverse
events occurred in either dose
regimen.
A study in 2004
examined the variation in 14
different commercial brands
of Serenoa repens extracts
currently available. [26]
The researchers discovered
significantly
different proportional content of
free fatty acids, methyl and ethyl
esters, long-chain esters, and
glycerides; this finding suggests
that the inconsistencies in nutrient
content may impact the clinical efficacy and
safety of such products.
Additionally, researchers also suggested that only
extracts with demonstrable
pharmacological activity and
proven clinical efficacy should be
considered for the treatment of
patients with benign prostatic
hypertrophy.
|
Saw Palmetto Toxicities and
Contraindications |
There are no known
drug interactions with saw
palmetto, and reported side
effects are quite rare.
[21]
High
concentrations of S. repens
have shown inhibition of sperm
motility in vitro, at
periods of 24 and 48 hours. [27]
However, specific cases of gastrointestinal
problems have been reported,
including symptoms of nausea. [12]
Saw palmetto is contraindicated in
pregnancy. [1]
The following table lists various
products that contain a safe and
reliable source of Saw Palmetto:
|
Manufacturer |
Ingredient |
Amount |
US RDA |
Learn More |
|
NSI |
Saw Palmetto Extract |
160mg |
--
|
Click Here
 |
|
Nature's Way |
Saw Palmetto Berries |
-- |
-- |
Click Here
 |
|
GNC |
Saw Palmetto Berries Extract
|
160mg |
-- |
Click Here
 |
