G. Saw Palmetto
Saw palmetto (Serenoa repens), also known as “Sabal,” is a small fan palm tree that is native to the south-
eastern coastal regions of the United States. The use of this plant by humans dates back to Native Amer-
ican tribes who populated this region, although their use for this this plant was primarily as a food source
[43]. For medicinal purposes, the berries are utilized to produce a phytomedicinal extract that is useful for
the treatment of symptoms associated with noncancerous swelling of the prostate (benign prostatic hy-
perplasia or BPH) [15,42–44]. This phytomedicinal extract is generally produced by extracting the ripe
berries with either hexane or liquid carbon dioxide [12,15,43]. Although most research supporting the
usefulness of saw palmetto as an herbal treatment for benign prostatic hyperplasia was conducted in Eu-
rope starting in the 1960s [12,15,42,44], this use for extracts of the berries was suggested by Felter and
Lloyd in the United States in 1898 [45]. The use of saw palmetto as an alternative herbal treatment for be-
nign prostatic hyperplasia has become popular in the United States because of its low cost and the absence
of many undesirable side effects (e.g., impotence) associated with the types of synthetic pharmaceuticals
utilized in the treatment of this condition [42].
Saw palmetto extracts that are effective for symptomatic treatment of benign prostatic hyperplasia
appear to be a complex mixture of primarily hydrophobic components [12]. However, extensive research
on the chemical composition of saw palmetto extracts has not yet been conducted. Nevertheless, it is
known that the major components present in these extracts are saturated and unsaturated fatty acids, free
and esterified plant sterols (e.g., -sitosterol, campesterol, cycloartenol), polyprenols, and anthranilic acid
[12,15,44]. Nearly 50% of the fatty acids contain 14 or fewer carbons [12].
Although the cause of benign prostatic hyperplasia is not well understood, the most widely favored
hypothesis involves an alteration in steroid hormone metabolism in prostate cells resulting in increased
levels of dihydrotestosterone and an increase in the estrogen/androgen ratio [15,44]. Key enzymes in
prostate cells related to this process include 5-reductase, which converts testosterone to dihydrotes-
terone, and aromatase, which converts testosterone to estrogens [15,44]. In this respect, several labora-
tory studies have shown that extracts of saw palmetto berries are inhibitors of these enzymes [12,44]. In
addition to potential effects in decreasing alterations in prostatic steroid hormone metabolism, saw pal-
metto extracts appear to have anti-inflammatory activity that would also be beneficial for symptoms of
benign prostatic hyperplasia [12,44].
H. Kava-Kava
The use of kava originated in the “Oceania” island communities encompassed by Polynesia, Melanesia,
and Micronesia [46]. In these cultures “kava” (also known as “kava-kava,” “ava,” and “awa”) refers to an
intoxicating beverage used in rituals and ceremonies that is produced from the mashed rhizome and roots
of the woody shrub Piper methysticum. However, the term kava is now used as the common name for P.
methysticumas well as the phytomedicinal produced from root-rhizome extracts. Worldwide, kava is re-
ceiving considerable attention as a phytomedicinal treatment for anxiety, nervous tension, agitation,
and/or insomnia. Clinical studies have shown that the effectiveness of kava is comparable to that of seda-
494 BRISKINFigure 6 Berberine and hydrastine present in the rhizome and roots of goldenseal (Hydrastis canadensis).
(Adapted from Ref. 12.)