This fundamentally important area of human life is not only an expression
of mystery and miracle, but impacts directly on the future of life on this
planet under the pressure of the population explosion. Before exploring
some of the ways in which Phytotherapy may contribute, let's focus on research
into potential herbal tools for population control.
Great attention is being given to plants with anti-fertility properties.
These may act through effects upon sperm motility and viability, implantation
of the fertilized egg or a rejection effect within the uterus. The biochemistry
of these different pathways is complex, and the study of plants having such
effects is revealing new mechanisms all the time. I must point out, however,
that I am not aware of any plant presently available in North America or
Europe that is a safe or effective contraceptive.
Zoapatle
The planetary crisis that is upon us has the population explosion as a major
component, and the W.H.O. has put great attention on the search for a safe,
cheap and socially acceptable form of contraception. Part of this vital
work has focused upon folk use of anti-fertility herbs. Very recent published
work has highlighted the Mexican plants known as Zoapatle.1 All
the work referred to in this section has been published since 1981.
Zoapatle is a decoction made from Montanoa tomentosa which has been
used as an oral contraceptive in traditional Mexican medicine for centuries.
Records of the use of this fascinating herb go back to Spanish reports of
1529, though of course its use goes back a lot further. Many historical,
biological, ethnobotanical, agricultural, clinical and chemical studies
have been done, mostly by Mexican scientists. It is perhaps because this
excellent Mexican research was published in Spanish it was largely ignored
in Europe and America until recently.2
Attempts to identify the nature of the plants activity have
shown a great variation of effects on the uterus among wild plants.
This should remind the us that there is great ecological variation
in all plant's biological activity. Nature is diverse and variable, not
a standardized factory any more than people are! Much of the research has
focussed upon establishing standards for optimum environmental conditions
and effectiveness of different varieties. After some confusion about different
species it has been established that both Montanoa tormentosa and
M. frutescens and should be the primary focus of research.
Zoapatle has been used in Mexico for the last 5 centuries for
the induction of labor, treatment of post-partum bleeding problems, and
as a menses inducer. Today, it is sold in street markets, and its long documented
history of use could be taken as indirect evidence of a lack of toxicity.
This assumption that the herbalist often makes, has for once been confirmed
by rigorous pharmacological and clinical studies. The empirical observations
of the therapist and the witness of history are augmented by the toxicologists
findings that Montanoa is completely safe.3
Its antifertility characteristics are being explored as the possible starting
point development of a new oral contraceptive agent which works by stimulating
an evacuation of the implanted egg in the uterus. A confusingly ambivalent
uterine response to Zoapatle leaves aqueous extract was found, the plant
stimulating different responses at different times. This is due to different
activity depending upon the phase of oestrous cycle or stage of pregnancy,
the hall mark of a primary normalizing remedy.4
Research into the chemistry and physiology of the herbs activity
indicate it does not work in the oestrogenic way that formulations such
as the birth control `pill' do. Zoapatle seems possess a quite unique antifertility
activity.5
In laboratory tests the species usually described, Montanoa
tomentosa, did not influence sperm motility or viability, but Montanoa
frutescens had immediate and constant inhibitory effect upon motility
and decreased cell viability.6 When administered intra-uterinly
in laboratory rats, markedly different results were obtained depending which
species was used. Montanoa frutescens produced an almost total inhibition
of implantation sites, whilst Montanoa tomentosa prepared and administered
in the same fashion, did not inhibit the number of implants at all.7
When the Zoapatle was prepared from Montanoa tomentosa
it did not alter the normal structures changes of the uterine by days 5
and 8 of pregnancy in the rat. On the other hand, Zoapatle made from Montanoa
frutescens caused profound alterations on those structures. These included
loss of epithelial lining, thickened blood vessels and alterations in endometrial
stroma cells. These morphological changes fit in with the anti-implantation
effect found with experimental administration of Zoapatle.8
The chemical basis of this activity is starting to be found. A number of
unique biochemicals are being found, such as Kaurenoic acid, Kauradienoic
acid (its mixture), Zoapatanol and Montanol. Kaurene compounds appear to
be several times more potent than Montanol and Zoapatanol in their activity
on the uterus.9
A review of recent published material reveals many patents dealing
with the isolation, characterization and total synthesis of some of Zoapatle's
constituents. It is clear that this Mexican herb is being seen by both scientists
and the drug industry as a new, safe, reliable, inexpensive and, potentially,
a widely used contraceptive agent.
Chinese research
The People's Republic of China is at the forefront of this research. Chinese
scientists have capitalized on the rich flora and the ethnomedical experience
in China, in their pursuit of fertility regulating agents from natural products.
Discoveries range from anti-implantation agents to abortifacient and pregnancy-terminating
compounds, as well as a male contraceptive. Much of the excellent research
is filled with a quality of social concern and relevance that western institutions
could benefit from. It is to be hoped that further research and collaboration
of this quality will take place to help solve the problem of the population
explosion.10
Indian research
Ayurvedic medicine from the Indian sub-continent is suggesting important
leads for researchers in this field. Ancient Indian literature abounds with
information on large numbers of plants reputed to have sterilizing, contraceptive
and abortifacient properties. Scholars of Ayurveda have also mentioned several
plants in their Ayurvedic treatises. A number of these preparations are
still being used by Ayurvedic physicians all over India, who claim their
effectiveness but are unable or unwilling to produce data.
The traditional remedy .Avrodhak (Lawsonia inermis) appears
to have some contraceptive value under laboratory conditions, preventing
pregnancy in 60% of the animals tested. None of the treated animals showed
loss in body weight or abnormal estrus cycles. However, rats administered
a high dose of Avrodhak failed to regain fertility up to 2 months after
drug withdrawal.11
Hibiscus rosa sinensis
An herbal remedy with an ancient history is currently receiving attention
as a potential tool in population control. Hibiscus rosa sinensis
is a common ornamental plant cultivated widely throughout India and Burma.
Flowers of this plant are said to possess anti-fertility property by ancient
Ayurvedic texts. Traditional use of the flowers in Kerala (Southern India)
is for its emmenagogue and contraceptive action.
A problem common to pharmacological studies of plant remedies is the proper
identification of most therapeutically active part of the plant, the best
ecological conditions to grow or collect it from and the season variations.
The Indian research team have found that only the flowers showed significant
activity. This anti-fertility action was maximum during winter followed
by spring then rainy and minimum in summer season.12
Much modern research has shown the flowers to have a post-coital
anti-fertility activity. An example is a study undertaken in 1976 that indicated
that the H. rosa sinensis flowers possess significant antifertility
activity with the effects dependant upon the dose, duration of the treatment
and the stage of the pregnancy. The presence of potent anti-estrogenic activity
in the flower portion may be the responsible factor in terminating pregnancy.
An antifertility agent can work by any one or combination of factors. These
can include, rapid expulsion of the fertilized ova from the fallopian tube
or by the tube locking mechanism; as a blastocyst-toxic agent; by the inhibition
of implantation due to a disturbance in estrogen-progesterone balance; or
through foetal absorption or abortion, perhaps due to lack of supply of
nutrients to the uterus and thus to the embryo.
In the light of above observations, it seems probable that the maximum anti-fertility
activity occurs via inhibition of implantation. A restriction of oestrogen
levels, which is indispensable for implantation, is considered a probable
cause in termination of pregnancy. The researchers demonstrated that the
herbal extract possesses potent anti-estrogenic property. On the basis of
present evidences it seems probable that, the treatment alters, in one way
or other, the delicate estrogen-progesterone balance, resulting in termination
of pregnancy.13
Not only does H. rosa sinensis have an impact on female
reproduction but also on that of males. Extracts of the flowers also affect
the generation of sperm as well as the endocrine function of the testes
themselves. The herbs' effect upon the male reproductive system has been
studied in rats by observation of changes in weight, histology and endocrine
functions.
In trying to find how the herb works, the researchers have suggested that
it may be due to the inhibition of synthesis or the release of gonadotropins
from the pituitary gland, a direct inhibitory effect of tested or hormonal
activity. The extract given to young male rats caused a reduction in the
weights of the testes, accessory reproductive organs and pituitary gland.
There was a marked decrease in levels of the gonadotrophin hormones. After
stopping the administration of the herb, spermatogenesis and secretory activity
of accessory sex organs started again, thus indicating that the plants effects
are transient.
Hormonal activity is a totally integrated process, so it is important to
look at any possible wider endocrine impact. The thyroid and adrenal are
apparently unaffected. This suggests that the inhibitory effects of H. rosa
sinensis on spermatogenesis are selective, mediated via the pituitary
gland, without affecting pituitary-adrenal and pituitary-thyroid function.
Though effective in affecting spermatogenesis the use of H. rosa sinensis
as a male contraceptive is unlikely due to probable reduction of libido
because it suppresses endocrine activity of the testis. Although, the effects
are reversible, persistent daily therapy would be needed because of the
rapidity by which pituitary function could recover.14 Such a
herbal remedy having a potent antifertility activity in women and reversible
anti-spermatogenic effect in men offers the potential of a safe and acceptable
aid in the drive to controlling population growth.
The Malvacaea family contains other potential anti-fertility plants. Malvaviscus
conzattii is another Indian ornamental plant whose flower closely resembles
that of Hibiscus rosa sinensis..
There is a marked anti-spermatogenic activity in the flowers of Malvaviscus
conzattii. In more animal experiments the testes were damaged and a
reduction in male sex hormones production was reflected by the atrophy of
the accessory organs. Along with atrophy of the gonadal glands, a significant
reduction in levels of protein and sialic acid of testes, epididymis and
seminal vesicles was also recorded, since protein anabolism is dependent
on androgenic production and also sialic acid and protein contents of the
sex accessories reflect changes in testicular androgen production. The genital
degenerative changes were found to be more pronounced when the results were
observed after oral administration of 50 doses. The drug administration
resulted in mass atrophy of the spermatogenic elements and the testicular
stages were left with only 1-2 cell layers.
Changes in testicular cholesterol level are physiologically important as
cholesterol is involved in spermatogenesis and is responsible for androgen
synthesis. In the study of the herbs impact on the treated animals, tissue
changes paralleled increased cholesterol level in the testes.15
Dried berries of another Indian herb, Embelia ribes, have a tradition
reputation for an anti-fertility activity. One of its active components,
embelin has been documented to possess significant anti-implantation activity
in rats but its hormonal activity is still controversial. Studies show that
embelin is a potent oral contraceptive of plant origin which possesses 85.71%
anti-implantation activity in rats when administered at 50 mg/kg for 7 days
and also inhibits pregnancy at single dose regimen. Embelin is also known
as embelic acid or to be chemically accurate 2, 5-dihydroxy-3-undecyl-2, 5-cyclohexadiene-1, 4-benzoquinone.
The ammonium salt is used in medicine as an anthelmintic.16 Embelin
inhibited pregnancy and also possesses anti-estrogenic and weak progestational
activity. From this it is possible that administration of embelin may cause
a disturbance in the hormonal levels and thus prevent implantation, since
specific hormonal equilibrium of estrogen and progesterone is required for
egg implantation. Another suggestion is that it produces a change in the
uterine environment which inhibits or interferes in the process of implantation.
It may also have a direct action on the hypothalamus and releasing factors,
interfering thereby with the secretion of gonadotropins.17
We are re-discovering the profound relationship that exists between plants
and humanity. As the old rapport is renewed in a new context, many insoluble
human problems will resolve. Inviting Gaia to point the way will open many
doors. Wether it be auto-immune disease, stress, arthritis or even population
explosion, the future looks bright indeed.
References mentioned in the section on Herbs, Fertility and Contraception.
1. Levine: The Mexican plant zoapatle (Montanoa tomentosa) in reproductive
medicine. Past, present and future.
J REPROD MED (1981 Oct) 26(10):524-8
2. Gallegos AJ et. al.: The zoapatle I -- A traditional remedy from Mexico
emerges to modern times.
CONTRACEPTION 1983 Mar; 27(3):211-25
3. Southam L et.al.: The zoapatle IV--toxicological and clinical studies.
CONTRACEPTION 1983 Mar; 27(3):255-65
4. Bejar E Enriquez R Lozoya X: The in vitro effect of grandiflorenic acid
and zoapatle aqueous crude extract upon spontaneous contractility of the
rat uterus during oestrus cycle. J ETHNOPHARMACOL 1984 Jun; 11(1):87-97
5. Hahn DW Ericson EW Lai MT Probst A: Antifertility activity of Montanoa
tomentosa
CONTRACEPTION 1981 Feb; 23(2):133-40
6. Ponce-Monter H et. al.: The zoapatle. X. The in vitro effect of zoapatle
aqueous crude extract (ZACE) and histamine upon rat and guinea pig uterine
strips. CONTRACEPTION 1985 May; 31(5):533-41
7. Pedron N: The zoapatle. VII. Antiimplantation effect in the rat of zoapatle
aqueous crude extract (ZACE) from Montanoa tomentosa and Montanoa
frutescens. CONTRACEPTION 1985 May; 31(5):499-507
8. Gonzalez et. al. : The zoapatle. VIII. Ultrastructural changes in endometrium
of rats.
CONTRACEPTION 1985 May; 31(5):509-21
9. Gallegos AJ et. al.: The zoapatle. VI. Revisited. CONTRACEPTION 1985
May; 31(5):487-97
10. Kong et.al.: Fertility regulating agents from traditional Chinese medicines.
J ETHNOPHARMACOL 1986 Jan; 15(1):1-44
11. Munshi, Shetye & Nair: Antifertility activity of three indigenous
plant preparations.
PLANT MEDICA 1977 Vol. 31: 73-75
12. Kholkute et.al.: Studies on the Anti-fertility uses of Hibiscus rosa
sinensis. PLANTA MEDICA 1977 Vol. 31 : 35-39
13. Kholkute and Udupa: Effects of Hibiscus rosa sinensis on fertility
of rats. PLANTA MEDICA, 1976 Vol. 29 : 321-329
14. Kholkute et.al.: Effects of Hibiscus rosa sinensis on spermatogenesis
in rats. PLANTA MEDICA 1977 Vol.31 : 127-135
15. Joshi: Antifertility effects of chronically administered Malvaviscus
conzattii. PLANTA MEDICA 1981Vol. 41 : 274-280
16. Merck Index : 10th edition, pg.513
17. Prakash: Anti-fertility investigations on Embellin. PLANTA MEDICA 1981Vol
41 : 259-266