Experts caution on anti-fertility effects of sweet basil

For men that take extracts of Ocinum gratissimum for various medical conditions, this new finding should not make you cringe but rather caution you against
indiscriminate and long time use of herbs.
If the finding of this new study that
investigated the effects of aqueous leaf
extracts of Ocinum gratissimum (OG) on
hormonal and semen parameters of mice is
translatable to humans, drinking solely
water extracts of OG could pose a grave
danger to men’s health because of its toxic
effects on the testis.
The study found that the aqueous leaf
extract of O.gratissimum (nchuanwu in
Ibo, efinrin in Yoruba and daidoya in
Hausa) has anti-fertility property when
administered alone and that the toxic
effects of the plant on the testis may be due
to its deleterious effects on the
seminiferous tubules, which are important
testicular structures involved in sperm
formation.
Normal male reproductive function is
dependent on the normal functioning of the
male reproductive organ and other
accessory organs/structures. The male
reproductive organ is the testis, which is
primarily responsible for the production of
spermatozoa. Sperm production occurs in
the seminiferous tubules of the testis, which
is controlled by testosterone, produced by
the Leydig (interstitial) cells of the testis. The
quality and quantity of spermatozoa
produced will therefore depend on normal
functioning of the testicular structures and
reproductive hormones.
Ocimum gratissimum (also known as
African basil) is a medicinal plant which is a
native of Africa and Asia. In Nigeria, African
basil is described by different local names,
but it is popularly known as “scent leaf” in
most parts of the country. The plant is used
as a condiment and spice in most parts of
the world, including Nigeria, in the
preparation of different dishes.
It is also used widely in folk medicine for
the treatment of several ailments including
fever, cough and respiratory disorders, sore
throat, kidney stones, epilepsy, dermatitis,
headache, stress and mental diseases. In
addition to its many health benefits, African
basil is used widely as a condiment or spice
and as a source of flavour and which may
be used in soup preparation.
For the study, the researchers had three
groups of animals and orally gave water
extracts of dried sweet basil leaves daily for
one, two and four weeks, respectively,
while a fourth (control) group received only
distilled water. They were sacrificed at the
end of each treatment period and blood
sample was analysed for their levels of
testosterone, follicle stimulating hormone
(FSH) and leutinizing hormone (LH).
In addition, semen was collected and
analysed for semen parameters, while the
testis was evaluated for histological
changes.
The 2010 study published in the Journal of
Medicinal Plants Research was entitled
“Antifertility effects of aqueous crude
extract of Ocimum gratissimum L. leaves in
male mice’’. It was carried out by
Atuboyedia Wolfe Obianime, Chinagoro T. O.
Esomonu and Jonah Sydney Aprioku from
the College of Health Sciences, University of
Port-Harcourt, Rivers State.
The researchers found that while daily
administering African basil for a week
caused significant decrease in testosterone
at some doses, it failed to cause clear dose-
dependent effects.
In addition, they found that African basil
caused significant dose dependent
decreases in sperm count and motility over
one week. Dose-dependently increase in the
percentages of abnormal sperm cells,
primordial sperm cells and sperm debris
were discovered.
Similarly, one week’s administration of
African basil caused significant dose-
dependent decreases in testicular weight.
However, there were no significant changes
in testicular weight in animals that received
African basil for two and four weeks,
compared to the control animals.
Furthermore, a week’s exposure to African
basil caused damages to the seminiferous
epithelium, characterised by varying
degrees of swelling or oedema within the
tubules and the interstitial cells and reduced
rate at which mature sperms are formed
(spermatogenesis) compared to normal
testicular structures in the control animals.
They remarked that the effects of aqueous
leaf extract of African basil on the
reproductive hormones and semen
parameters were consistent with previous
findings on the anti-fertility effects of
Ocimum sanctum.
Since African basil had no significant effects
on the reproductive hormonal profile but
adversely affected semen parameters and
testicular histology, they suggested that the
deleterious effects of African basil may
mainly be due to direct deleterious effects
on the seminiferous tubules as well as the
Leydig and Sertoli cells, which are directly
involved in the production of spermatozoa.
They wrote:”The present study in mice
however has shown that four weeks
administration of the plant is toxic on
testicular structures/function. The different
actions of African basil may be attributed to
the effects of different components of the
plant under the different conditions. African
basil contains several pharmacologically
active components. The spermicidal effect
of African basil in this study may be due to
the effects of triterpenes and saponnins
components in the plant which are
deleterious to sperm cells. The toxicity of
the saponnins may be related to their
astringent actions on the cell surfaces of
sperm cells, causing a disruption of the cell
membrane, which could result in the
reduction in sperm motility, as well as the
inhibition of specific enzymes (e.g.
hyaluronidase and acrosin) necessary for
sperm synthesis.
Although African basil had been reported in
previous studies to cause congestion and
oedema in seminiferous tubules, with
increase in abnormal sperm cells, the study
failed to show any dose- and time related
effects because only two doses were used
and harvesting was done once.
In addition, previous studies on the toxic
effects of the extract of Sweet basil on the
blood production in the body found that it
also caused a reduction in the Packed Cell
Volume (PCV) and hemoglobin (Hb) values,
with proliferation of white blood cells
(leucocytes)
Furthermore, Ocimum sanctum which is in
the same genus with African basil had been
reported to have anti-fertility effects in
male albino rats. However, not much was
known about the reproductive effects of
African basil prior to this study.