BOLDO LEAVES
Source: Peumus boldus Molina (syn.
Boldu boldus (Mol.) Lyons) (Family
Monimiaceae).
Common/vernacular names: Boldo, boldo
leaves, boldus.
GENERAL DESCRIPTION
Dioecious evergreen shrub or small tree, up to
about 6 m high; native to mountainous regions
of Chile and naturalized in Europe (Mediter-
ranean region). Parts used are the dried leaves.
CHEMICAL COMPOSITION
The dried leaves contain0.25–0.5%aporphine
alkaloids, including laurotetanine,N-methyl-
laurotetanine, boldine (0.06%), isoboldine,
laurolitsine, norisocorydine, isocorydine, iso-
corydine-N-oxide, and reticuline;1–5approxi-
mately 2.5% volatile oil composed mainly of
ascaridole (45%),^1 p-cymene (28.6%), ascar-
idole (16.1%), 1,8-cineole (16.0%), and
linalool (9.1%), among 38 identified com-
pounds;5,6flavonol glycosides (e.g., isorham-
netin-3-a-L-arabinopyranoside-7-a-L-rham-
nopyranoside,^7 boldoside, fragroside, and
pneumoside),^1 resin, and tannins.
PHARMACOLOGY AND BIOLOGICAL
ACTIVITIES
The leaves have shown choleretic, diuretic,
stomachic, cholagogic, and other activities.5,7
One study indicated that in rats, the total
alcoholic extract of the leaves, as opposed to
partial extracts, had the highest choleretic
activity.^8 Boldine has shown anti-inflamma-
tory activity in guinea pigs in the carrageenan-
induced paw edema test (ED 50 , 34 mg/kg
p.o.), and in rabbits (60 mg/kg p.o.) reduced
hyperthermia induced by bacterial pyrogen.
In vitro tests showed that boldine inhibits
prostaglandin biosynthesis.^9 In streptozoto-
cin-induced diabetic rats, the addition of bol-
dine in the drinking water resulted in less
weight loss and hyperglycemia, restoration of
aberrant enzyme activities in the pancreas
and liver, and attenuation of various oxidative
processes.^10
Ethanolic and ether extracts of the leaves
exhibitstrongin vitroantioxidantactivity,^11 as
does boldine in a variety of assays.1,12In vitro
free radical scavenging activity of extracts of
the dried leaves is mainly attributable to cate-
chin.^13 Boldine has also shownin vitroche-
moprotectant activity, in part by decreasing
metabolic activation of chemical mutagens
and stimulating glutathioneS-transferase.^14
Antihilminthic activity of the leaves is attrib-
uted to ascaridole.^1
In a placebo-controlled study, volunteers
administered a powder extract of the leaves
(2.5 g p.o.) showed a significant increase in
oro-cecal transit time, thereby confirming re-
sults found in animal studies, which showed
that boldo could prolong the intestinal transit
time and relax smooth muscles.^15TOXICOLOGYNo toxicity was observed in rats that adminis-
tered a hydro-alcoholic extract of the leaves
containing boldine at doses of up to 3 g/kg
p.o., which was three times the lethal oral dose
of boldine in mice. Boldine is nonmutagenic
and showed no genotoxicity in the mouse
micronucleus test following oral doses of up
to 900 mg/kg.16,17In chronic toxicity tests in
rats, both a hydro-alcoholic extract of the
dried leaves and boldine produced a low level
of fetal toxicity from oral doses of 800 mg/kg
and none from 500 mg/kg p.o. Similarly, al-
terations in cholesterol, bilirubin, urea, AST,
and ALTwere found from the 800 mg doses of
the extract or boldine over 90 days, whereas
the 500 mg dose was without significant ef-
fects. The authors of the study advised that
boldo should not be used during pregnancy.^18
The German Commission E advises againstBoldo leaves 107