Biological
effects
A 2010
ethnopharmacological
inventory
study on
Eurycoma
longifolia
stated:
"The
plant
parts
have
been
traditionally
used for
its
antimalarial,
aphrodisiac,
anti-diabetic,
antimicrobial
and
antipyretic
activities…"[6]
Even
though
there
are many
other
legitimate
medical
areas of
interest
in
Eurycoma
longifolia
(as
evident
from the
quote
included
above),
most
Southeast
Asians
consume
it for
the
plant's
impact
on
sexual
conduct.
Already
in 2001,
Malaysian
scientific
researchers
opened
their
peer-reviewed,
Medline-archived
report
on
Eurycoma
longifolia's
effect
on lab
rats
with the
statement
"that
Eurycoma
longifolia
Jack
commonly
known as
Tongkat
Ali has
gained
notoriety
as a
symbol
of man's
ego and
strength
by the
Malaysian
men
because
it
increases
male
virility
and
sexual
prowess
during
sexual
activities."[7]
An
article
on the
website
of the
scientific
journal
Nature
referred
to
Eurycoma
longifolia
as
Malaysia's
home-grown
Viagra
and
cited
"increased
sexual
desire,
enhanced
performance
and
general
well-being".[8]
This
journal
article
is also
indexed
on
Medline,
but
without
abstract.[8]
Some
scientific
studies
found
that it
enhances
sexual
characteristics
and
performance
in
rodents.[9][10][11]
Other
laboratory
animal
tests
have
produced
positive
indications,
with one
extract
having
been
observed
to
increase
sexual
activity
in
mature
rats,
including
arousal,
sniffing,
and
mounting
behavior.
In an
experiment
conducted
on male
rats, it
was
found
that
eurycoma
longifolia
increases
sperm
count.
The
authors
also
reported
that the
plasma
testosterone
level of
Eurycoma
longifolia
extract
treated
rats
"was
significantly
increased
when
compared
with
that of
the
control
and
infertile
animals."[12]
Another
group of
scientists
confirmed
that
Eurycoma
longifolia
has the
capacity
to
"reverse
the
inhibitory
effects
of
estrogen
on
testosterone
production
and
spermatogenesis."[13]
One
Medline-indexed
journal
article
cited as
result
that
Eurycoma
longifalia
had an
effect
similar
to
testosterone
replacement
therapy
in
counteracting
osteoporosis.[14]
An
Italian
study on
Eurycoma
longifolia
noted
improved
sexual
performance
in lab
animals
and
concluded
that the
"effect
could be
mainly
ascribed
to
increased
testosterone
levels."[15]
After
scientists
investigating
Eurycoma
longifolia's
effect
on
sexual
parameters
had
established
that
sexualizing
effects
went
hand-in-hand
with
increased
testoterone
tone,
researchers
in the
field of
sports
medicine
started
to look
into the
anabolic
potential
of the
plant.
In a
placebo-controlled
human
study
with
healthy
young
men in a
weight-training
program,
it was
found
that
"the
lean
body
mass of
the
treatment
group
showed a
significant
increment,
from
52.26
(7.18)
kg to
54.39
(7.43)
kg (p =
0.012)."
Furthermore,
"the
increase
in
strength
in the
treatment
group
was
larger
than in
the
placebo
group
(6.78%
and
2.77%
respectively)…
The mean
arm
circumference
of the
treatment
group
increased
significantly
by 1.8
cm after
the
supplementation…
but
there
was no
significant
increase
in the
placebo
group."
The
results
of the
study
were
published
in the
peer-reviewed
British
Journal
of
Sports
Medicine.[16]
The
anabolic
impact
of
Eurycoma
longifolia
has been
confirmed
in the
animal
model,
when the
size and
weight
of just
one
muscle
was
measured
in
treated
and
untreated
rats of
equal
size.
"Results
showed
that 800
mg/kg of
butanol,
methanol,
water
and
chloroform
fractions
of E.
longifolia
Jack
significantly
increased
(p<0.05)
the
levator
ani
muscle…"[7]
Because
of
Eurycoma
longifolia's
testosterone-enhancing
capacity,
it has
been
included,
at least
by name,
in
numerous
supplements,
marketed
primarily
to
bodybuilding
men. One
such
product
lists
Eurycoma
longifolia
as one
of more
than 30
unquantified
ingredients.[17]
In such
formulas,
the
minimal
Eurycoma
longifolia
part
isn't a
therapeutic
dose by
any
standard,
as the
quassinoids
of
Eurycoma
longifolia
are
characterized
by poor
oral
bioavailability.
A study
into
this
aspect
concluded:
"The
results
indicate
that
eurycomanone
is
poorly
bioavailable
when
given
orally…
the
absolute
bioavailability
of the
compound
was low
with
10.5%…
its poor
oral
bioavailability
may be
due to
poor
membrane
permeability
in view
of its
low
P value
and/or
high
first-pass
metabolism."[18]
In vivo
studies
with lab
animals
used
root
powder
of 250,
500, or
1000 mg
per kg
of body
weight,[15]
or 200
to 800
mg/kg
twice
daily,[11][19]
or 50,
100, and
200 mg
of
Eurycoma
longifolia
extract
per kg
of body
weight.[12]
At the
higher
dosages
(800 mg
of the
water,
chloroform,
methanol,
or
butanol
extracted
fraction
of
Eurycoma
longifolia
per kg
of body
weight),
the
effects
were
more
pronounced
for both
sexual
motivation[20][21]
and
levator
ani size
increase.[7]
Apart
from the
testosterone-related
effects,
the
antimalarial,[22]
antibacterial,[23]
antipyretic,
antiulcer,
antitumor,[24]
and
cytotoxic
properties
are well
documented.
Taiwanese
scientists
isolated
65
biochemical
compounds
from the
roots of
Eurycoma
longifolia,
of which
ten
exhibited
"strong
cytotoxicity"
towards
human
lung and
breast
cancer
cell
lines.[25]
Apart
from the
better-known
quassinoids,
the same
group of
scientist
also
isolated
beta-carboline
alkaloids,
several
of which
were
active
against
lung and
breast
cancer
cell
lines.[26]
Investigating
the
activity
of 24
Eurycoma
longifolia
quassinoids
against
cancer
cell
lines,
including
lung
cancer
cells,
medical
researchers
in Japan
found
that
eurycomalactone
was as
effective
against
cancer
cells as
the
established
anti-cancer
drug
doxorubicin.[27]
The same
group of
researchers
also
discovered
several
new
biochemical
compounds
in
Eurycoma
longifolia
and
screened
them for
cytotoxic
properties.
They
concluded
that
different
fractions
were
effective
against
different
cancers.[28][29]
Another
study
confirmed
that
fractions
of
Eurycoma
longifolia
extract
induced
apoptosis
in
breast-cancer
cells.[30]
One
extract
has
since
been
co-patented
by the
government
of
Malaysia
and the
Massachusetts
Institute
of
Technology.[31]
However,
the idea
that
products
of
nature
on which
there
exists a
large
body of
knowledge
among
indigenous
peoples
can be
the
subject
of
intellectual
property
rights,
even of
national
governments,
has long
been
challenged
in
peer-reviewed
law
journals.[32]
