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1 Faculty of Health Studies, Charles Sturt University & Therapeutic Research, TTD International Pty Ltd, GPO Box 4792, Sydney 2001 (Australia) 3 Research Institute of Medicinal Plants, 61-707 Poznan, 27 Libelta St. (Poland)
Correspondence to: Tomohiro Nakayama MD, Division of Receptor Biology, Advanced Medical Research Center, Nihon University School of Medicine, Ooyaguchi-kamimachi, 30-1 Itabashi-ku, Tokyo 173-8610, Japan. Tel: +81 3-3972-8111(ext.2751) Fax: +81 3-5375-8076 E-mail: tnakayam@med.nihon-u.ac.jp
Short title – page header: Effect of Maca (Lepidium peruvianum) in Rats
The mailing address of principal author: Dr Henry O Meissner, GPO Box 4792, Sydney 2001, Australia Tel: + (61) 414 836 159; Tel/Fax: + (61 2) 9906 1580; E-Mail: hmeissner@ttdintnl.com.au| |
ABSTRACT |
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INTRODUCTION |
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MATERIAL AND METHODS |
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RESULTS |
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DISSCUSSION |
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ACKNOWLEDGMENTS |
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DISCLAIMER |
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REFERENCES |
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ABSTRACT
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Objective: The aim of this study is to identify physiological responses of male and female rats to either a short- or long-term administration of two doses of Maca (Lepidium peruvianum) and observe relationships which may exist between groups of hormones and effects mediated by them.
Design: The effect of pre-gelatinized (extruded) organic Maca powder (Maca-GO) was studied on Sprague-Dowley male and female rats (1:1 ratio) receiving two dietary levels of Maca-GO (0.75g/kg and 7.5g/kg body weight) and assessed against control during 28 and 90 day laboratory trials on 30 and 60 rats respectively. Blood morphology, biochemistry (hormones, lipids and minerals) and histology of internal organs were determined. Homogenates of skeletal muscles and bones of rats were also analyzed.
Results: Maca-GO has low toxicity (LD=7.5g/kg) and appears to be safe for short-term and extended use as dietary supplement or as a component of functional dietary and therapeutic preparations. There were different responses of male and female rats to different levels of Maca-GO administered during a short- and a longer-term periodl. When administered at higher dose for extended period of time (90 days), Maca-GO acted as a toner of hormonal processes in adult female rats at increased progesterone and a steady estradiol level, without affecting levels of blood FSH, LH and TSH.
Conclusions: Obtained results justify further clinical research on use of Maca-GO in sportsmen, physically-active people of both sexes and peri-menopausal women to clarify mechanisms underlaying physiological mode of action of Maca-GO validaet in clinical study on humans.
Substantial decrease in blood cortisol levels in a short- and longer-term trial and simultaneous tendency to lower blood ACTH, may indicate antidepressive effect of Maca-GO, which together with reduction in body weight, lowering triglycerides in blood plasma and increasing calcium and phosphorus deposition in bone and muscle tissues is worthy consideration in potential application to women at both, pre- and postmenopausal stage.
KEY WORDS: Maca (Lepidium peruvianum) – toxicity – hormones – male-female rats - pharmacology
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INTRODUCTION |
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Maca (Lepidium peruvianum Chacon), which grows in the high Andean
plateaus of Peru and was described in more details previously (1, 2), has been
traditionally used by native Peruvians as both food and medicine. In recent
years, variety of commercial preparations based on Maca have been introduced on
markets around the world, classified as over the counter (OTC) dietary
supplements or as dietetic food supplements for special medicinal applications
to enhance physical, physiological and psychological performance. Many aspects
of traditionally-recognised biological activity of Maca are not well documented
(3, 4, 5) and most of them are based on testimonials and anecdotal evidence,
which, although supported by authentic and reputable reference source, lacks
scientifically-accepted credibility.
Some of traditional applications of Maca have been in recent years
experimentally proven (1, 6, 7, 8, 9), mainly in regards to fertility and energy
enhancing properties in humans, improving libido and sexual functioning, hormone
balancing and alleviating menopausal discomfort. Results of studies conducted so
far, may suggest that action of Maca relies on plant sterols, which act as
chemical triggers to help the body itself produce a higher level of hormones
appropriate to the age and gender of person taking it (10), the fact already
established by Chacon (11) in her pioneer study on Maca back in early 1960s.
Chacon concluded that there are four alkaloids in the Maca root, responsible for
fertility effects on the ovaries and testes of the rats, which were measurable
within 72 hours of administration to the animals. She has concluded that since
Maca contains no plant hormones, therefore the alkaloids were acting on the
hypothalamus-pituitary gland axis, which may explain why both male and female
rats were afflicted in a gender-appropriate manner. This may also explain why
the effects of Maca in humans are not limited to ovaries and testes, but through
acting on the adrenals, gives a feeling of greater energy and vitality and
through this possibly affecting the pancreas and thyroid as well.
Current commercial interest in Maca turned into its energizing and revitalizing
properties and its successful use in alleviating menopausal symptoms. In a pilot
clinical study on early-postmenopausal women volunteers (1) it has been shown
that Maca can be of value in the treatment of menopausal syndrome. However,
although hormonal profiles and standardised subjective assessment of symptoms
experienced by participants (Greene’s Menopausal Index) were presented, it was
not possible to assess a mode of action and a role of Maca in balancing hormones
along the hypothalamo-pituitary-ovarian axis. In the same study, noticeable
differences were observed in results obtained during shorter (two months) and a
longer-term (eight months) administration of Maca preparation. Also, Muller (4,
5) noted that the response of menopausal women to Maca is dose-dependent and
should be taken into consideration in determining the level of daily dose,
either for hormone-balancing effect at lower Maca doses, or as opposed to
stimulating Maca mode of action, which may be achieved at high levels of
administration.
In this study, using a model laboratory experimental design, an attempt has been
made to demonstrate the effect of a short- (28 days) and a longer-term effect
(90 days) of administration of two levels of Maca (0.75g/kg and 7.5g/kg body
weight respectively) on blood morphology, biochemistry, histo-pathology of
internal organs and chemical analyses of muscle and bone tissues in male and
female rats. Simultaneously, a toxicity (LD50) of Maca-GO preparation as used in
this study was determined.
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MATERIAL AND METHODS |
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Maca (Lepidium peruvianum Chacon):
The plant species was described in details in monographs by Chacon (11) and
Obregon (12) as well as in the catalogue of the flowering plants and gymnosperms
of Peru (13). The depositions of Maca plant identified as Lepidium peruvianum
Chacon, after formal authentication by San Marcos Herbarium in Lima have been
deposited in Herbarium of Medicinal Plants in Australia (Lismore) and in Poland
(Poznan) for reference purpose and to verify authentcity of the material used in
internationally-coordinated laboratory and clinical study and, if required, to
authenticate analytically commercial preparations marketed under the name of
Maca.
Maca roots, used in the present study were harvested in Junin area (Central
Andean Region of Peru between 4200m and 4500m altitude) and represented typical
distribution of three main ecotypes (out of 13 known): black, yellow and
purple/red roots observed in this cultivation area – averaging to approximately
16%, 48% and 9% respectively. After some three month drying at high altitude (on
the plantation site), according to traditionally used system of dehydration,
considered superior to oven dried method currently used in commercial “modern”
operations in Peru (Obregon, 2001 and Chacon 2003 – personal communications),
dried Maca roots selected for this study were transported to a processing plant
at the National Institute of Agricultural Research (NIAR), National Agricultural
University La Molina in Lima (Peru) after previous attestation of its organic
status, and its authentication by Dr Gloria Chacon as cultivated Maca Lepidium
peruvianum Chacon which represent the same plant species, which she used in her
pioneering work on Maca published back in 1961 (10).
After cleaning (washing under pressure) and cutting into pieces, dried
hypocotyls of Maca were re-hydrated prior to being exposed to a gelatinization
process comprising of exposure to a short-term elevated pressure under moist
conditions (a proprietary extrusion process), followed by drying and
pulverizing. Such treatment of Maca, without any chemicals used in the process,
resulted in the final powdered product (Maca-GO) achieving increased density and
through pre-gelatinization of a starch component in the product (not less than
98% according to BRI Laboratory assay, Sydney, Australia), expected to promote
its easier digestion and bio-availability.
Composition of the pre-gelatinized Maca-GO powder (batch TTD-ZMP-20100351) as
per analyses conducted in NIAR in Lima, Peru and in Analytical Laboratory of the
Research Institute of Medicinal Plants in Poznan is given in Table 1.
Animals and treatment:
The study was carried out at the Research Institute of Medicinal Plants in
Poznan between December 2003 and June 2004. The studies were performed on 90
Sprague-Dowley rats sourced from the Toxicology Department, Medical University
in Poznan: 45, nine week old females weighing 240g to 250 g and 45, twelve weeks
males weighting 340 to 350g at the beginning of the experiment. Males and
females were kept separately (5 rats per cage), under standard animal laboratory
conditions at temperature 22oC (+/-2oC) and relative humidity 55% (+/-5%). The
animals had free access to standard laboratory diet (pellets-Muligran) and to
tap water in their cages. All the experiments were conducted in compliance with
relevant OECD standards (Recommendation No. 408) regarding procedures for
testing toxicity of unknown toxic substances on rodents (14) and conforming to
the relevant Polish Law (35/03)
Experiment was conducted under a standard laboratory model approved by a
Bioethics Committee for Animal Experimentation of the Research Institute of
Medicinal Plants (RIMP) in Poznan. Applied in this study experimental protocol
was adopted from a standard OECD method used in determination of toxicity of
unknown products (14). Maca-GO was administered to restrained rats (positioned
in a vertical position) by intubation of 0.75g/kg or 7.5g/kg suspended in 15ml
water. Control group was intubated with corresponding volume of water.
Intubations were carried out for 5 days each week during either 28 or 90 days
trial.
Short-term study (28 days): In this Trial (I) - animals were randomly assigned
to three groups, each of 10 animals (50% male and 50% female), two groups
receiving Maca-GO at the level of 0.75g/kg and 7.5g/kg respectively and the
third being a control group.
Sub-chronic study protocol (90 days): In this Trial (II) animals were randomly
assigned to three groups of 20 animals each (50% male and 50% female), two
groups receiving Maca-GO at the level of 0.75g/kg and 7.5g/kg respectively and
the third being a control group. On completion of the each Trial, all rats were
weighed and blood samples were taken for analyses under thiopental narcosis. In
trial II, after blood sampling, the following internal organs were dissected:
liver, pancreas, spleen, kidneys and gonads for histo-pathological examination
of internal organs. Also, both legs were dissected for analysis of homogenates
of skeletal muscles and bones for proximate analyses extended for calcium and
phosphorus determination.
Toxicity (LD50) was determined according to Litchfield-Wilcoxon method
modified according to Roth (1961). Blood which was collected at the end of each
Trial (between 09:00hr and 11:00hr from male and female rats; sampling by
decapitation under thiopental narcosis after 12 hr starvation period), was used
for morphology study by conventional clinical diagnostic techniques at the
Clinical Diagnostic Laboratory LABO-MED in Poznan. Biochemical blood analyses
were conducted in the same laboratory using officially accepted standard
clinical methods (chemiluminescence procedure on Immulite – DPC equipment).
Precision of this technique is monitored by National Center of Quality of
Diagnostic Medical Laboratories in Poland and the Laboratory is a participant of
the International Quality Control RIQAS maintained by Randox Company.
Histopathology of internal organs was determined at Pathomorphology Department,
Medical University, Poznan and proximate analyses of skeletal muscles and bones
were conducted at the Animal Feed and Nutrition Laboratory, Agricultural
University, Poznan according to the standard AOAC procedure.
Statistical analyses:
Data were expressed as mean (±SEM) where applicable. Statistical analysis was
performed by the Student’s t-test with the difference considered significant at
P<0.05 and highly significant at P<0.01 and P<0.001).
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RESULTS |
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Short-term study protocol (28 days)
Body Weight: The effect of administration of Maca-GO at levels 0.75g and 7.5g
per kg body weight to male and female rats during the 28 day experimental period
on the growth of animals is summarized in Table 2. Maca-GO reduced body weight
(P<0.001) in male rats by 8.6% and 14.3% respectively in relation to their
initial weight at the start of the Trial and as compared to the control group,
which slightly gained weight during the same time period. No weight gains were
recorded in all the female groups (control and Maca-GO).
Blood Morphology: Due to observed similar pattern of recorded blood constituents
in male and female rats, their individual morphology results were presented in
Table 3 as combined male and female groups of rats receiving two doses of Maca-GO.
During the 28 days of administration of the 0.75g/kg Maca-GO dose resulted in
statistically high significant increase (P<0.001) in white blood cell and
lymphocyte counts as compared to control animals. There were no statistically
significant (P.0.05) differences observed between groups in other morphological
characteristics of blood. Similarly, Maca-GO applied at the 10 times higher dose
(7.5g/kg) resulted in a significant increase (P<0.05) in lymphocytes count,
relative red cell decomposition index as well as in an average volume of red
blood cells. There were no differences in other indices of morphological blood
characteristics.
Biochemical analyses of blood serum: Results of biochemical analyses of blood
serum in rats administered Maca-GO at levels 0.75g/kg and 7.5g/kg during 28 days
experimental period is given in Table 4. Maca-GO at level 0.75g/kg resulted in
statistically high significant decrease in serum cortisol level (P<0.001) and a
noticeable (although statistically-not confirmed) increase in blood glucose
level (from 83 do 111 mg/dl). The remaining blood indices in Maca-GO group did
not showed statistically-significant differences in recorded values as compared
to the control group.
Administration of 7.5g Maca-GO to rats resulted in statistically significant
decrease in serum cortisol (P<0.01) and triglycerides (P<0.05) levels, while
estradiol concentration significantly increased (P<0.01). Also, noticeable (50%)
but statistically not significant (P>0.05) increase in glucose level was
observed, with a simultaneous 12% decrease in progesterone level. There were no
significant differences between groups in the remaining blood indices.
Histopathology: After 28 days oral administration of the 0.75g of Maca-GO to
both groups of rats there were no changes recorded which could be attributed to
Maca-GO treatment. All rats in both groups had histological characteristics of
assessed internal organs within the picture considered as normal for animals at
their stage of growth (Table 5).
Similarly as at the lower level (0.75g/kg) of Maca-GO inclusion during 28 days
trial, rats receiving a 7.5g/kg dose of Maca GO showed no visible effect in
histopathology of internal organs as compared to animals in corresponding
control groups. In both, control and Maca-GO groups of male rats there were
slight enlargement of cells in prostate, and in female group of control rats
uterus showed enlargement in diameter of ducts and thinning of endometrium of
uterus, the changes, which were not observed in female rats in the Maca-GO
group. Histo-pathologic examination of the remaining organs in male rats (liver,
spleen, pancreas, kidneys, seminal vessel urinary tract and testes) and female
rats (liver, pancreas, spleen and kidneys), showed no visible changes which
could be attributed to administered Maca-GO at the 7.5g/kg level. The remaining
internal organs of male and female rats in both groups exhibited histological
characteristic considered normal for animals of the appropriate gender and at
the stage of their physiological development.
Sub-chronic study protocol (90 days)
Body Weight: – In all four groups of both, male and female rats used in this
Trial (II), there were statistically-significant (P<0.01) differences in weight
gains recorded (Table 6) as a result of 90 day administration of Maca-GO at both
levels 0.75g/kg and 7.5g/kg, with female gaining much less than male rats.
Administering Maca-GO to female rats at both doses, lowered their weight gains
in relation to the female control (8% gain against the 25% gain in the control
group), while male group had also lower gains but the difference between the
test and control groups was much lower (14%-17% against 20% respectively).
Blood Morphology: There were no statistically significant (P>0.05) differences
in morphological characteristics of blood of rats receiving for 90 days Maca-GO
at both, 0.75g/kg and 7.5g/kg levels (Table 7).
Biochemical analyses of blood serum: Similarly to the short-term trial, a
long-term administration of Maca-GO at 0.75g/kg level resulted in a significant
decrease in serum cortisol (P<0.05) only (Table 8). There was a noticeable, but
statistically not significant, increase (P> 0.05) in glucose and progesterone
levels, and a decrease in triglycerides and ACTH levels (P>0.05). There were no
significant differences (P> 0.05) detected between the groups in the remaining
biochemical blood plasma characteristics.
Long-term (90 days) administration of Maca-GO (7.5g/kg) to female rats, resulted
in statistically high significant increase in blood glucose concentration
(P<0.01) and significant increase in progesterone level (P<0.05), with
statistically not significant but noticeable decrease in both Cortisol and ACTH
levels as compared to the control group
Histopathology of internal organs: Administering rats with a 7.5g/kg dose of Maca GO for the extended period of time had no effect on histopathology of
internal organs as compared to animals in a control group. All the assessed
samples, exhibited histological characteristic considered normal for animals at
their stage of physiological development and gender (Table 9).
Chemical composition of muscle and bone tissues: Results of chemical analyses
from pooled homogenates of skeletal muscles and bones obtained from dissected
hind legs of rats exposed for 90 days to two levels of Maca-GO (0.75g/kg and
7.5g/kg) are summarised in Table 10. Irrespective of the level of Maca-GO
administered to male rats, there was a substantial reduction (17% to 19%) in
total lipid contents determined in homogenates of muscle and bones. However,
there was a reverse effect observed in female rats showing an increase in tissue
fat content by 27% to 30% in comparison to control female rats. While there were
no distinctive differences in dry matter and protein contents in homogenates,
there was an increase in ash level determined in male rats receiving Maca-GO at
the 0.75g/kg level only and this was accompanied by an increase in both Calcium
and Phosphorus contents (11% and 19% respectively). There was a lesser increase
in Calcium and Phosphorus concentrations in tissue homogenates observed in
female groups of rats, however, all the recorded values at both levels of
Maca-GO administration were above the corresponding levels determined in
corresponding control groups of female rats.
TOXICITY (LD50) for Maca-GO:
All animals survived the test without any adverse effects noticed on the basis
of abnormal behavior and histopathology of internal organs (liver, spleen,
pancreas, testis and ovaries). On the basis of the obtained results, adopting
recommendations by Hodge & Sterner, the 7.5 g Maca-GO per kg body weight (the
highest dose applied in this study) was determined as LD50 for Maca-GO,
established in a standard bioassay to have no toxic effects on test animals and
upto this level considered to be safe for oral administration in therapeutic and
dietary preparations. The above dose is considerably higher than the 2g/kg limit
determined by the OECD (14) as non toxic and safe for use as dietary
supplements.
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Table 1 shows the clinical features for the EH patients and the NT
controls. The SBP and DBP were significantly higher in the EH group as
compared to that seen in the NT group. Age, body mass index (BMI), pulse
rate, serum concentrations of creatinine and uric acid, and plasma
concentrations of total cholesterol did not significantly differ between
the two groups.
We performed an association study using 4 SNPs. Table 2 shows the genotype
distributions of the 4 SNP variants and allelic frequencies. The overall
distribution of the genotypes did not significantly differ between the
EH and NT groups. However, there was a difference noted for the allelic
frequency of the SNP rs2290105 between women in the EH and NT groups (p
value = 0.0409), with the allelic frequency of the minor allele in the
EH group higher than that seen for the NT group.
The haplotype-based case-control study also documented significant
differences between the women of the EH and NT groups (Table 3). There
were significant differences for the results of the A-T-A-C haplotype,
with this haplotype higher in the EH (42.6%) than in the NT group
(28.8%).
| DISCUSSIONS
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It has been generally-accepted, that Maca exhibits specific – yet unresolved
to the present days - endocrine effect, which, has been demonstrated in diverse
areas of its biological action from being an energizing plant (11), stimulating
reproductive functions (7, 8, 9) and balancing hormones (11, 12) as well as
alleviating physical, physiological and psychological discomfort associated with
menopause in women (1, 5, 6). However, until convincing proof is found as to the
individual active compound, biochemically-identified as a key active Maca root
component, or specific group of them, responsible for therapeutic functionality
of Maca root, the authors decided to use in their study and recommend to use
further in therapeutic practice, the entire root in its entity with its cohesive
complexity considered as compositionally-unaltered herb with its
historically-acknowledged and traditionally-unquestioned medicinal properties.
The complexity of components present in Maca root powder such as sterols (campesterol,
stigmasterol and beta-sitosterol), polyunsaturated acids and their amides,
called “macaenes” and “macamides” (9, 11), aromatic glucosinolates (16) and
several alkaloids – yet to be characterized , through their complex synergistic
and/or interactive action amongst them, will eventually provide an answer to
physiological action of specific doses of standardized Maca preparations
recommended for prophylactic and/or specific therapeutic effect for men and
women.
Since the first report of Chacon on medicinal properties of Maca root (10), it
has been generally accepted and confirmed that this plant doesn’t contain plant
estrogens or any other phyto-hormones (15, 17, 18, 19), but through plant
sterols, stimulate endocrine system helping to maintain hormonal balance (10) in
a way that is not yet well understood (6, 13). According to Muller (5), these
sterols are used by the body with the help of the pituitary to improve adrenal
function, ovarian and testicular function, as well as the functioning of the
thyroid and the pancreas, and the pineal gland. Multi-functional effect of Maca
on endocrine relationships may also explain reported in the literature, its
positive influence on stimulation of endocrine glands in regulation of hormonal
balances in the body (3, 20).
Present study were conducted on growing male and female rats, which, in addition
to blood morphology, biochemistry and hormonal changes, allowed for an
observation of growth patterns during short-term and longer-period of Maca-GO
administration at two application levels. It appears that Maca applied to male
rats at high dose (7.5g/kg) during a short-term trial, significantly reduced
body weights, while female rats have maintained their weight unchanged. However,
when Maca was applied during longer period of time (90 days), female rats showed
lesser body weight gains in relation to control female rats and as compared to
male rats. The results indicate that Maca-GO administration induces body weight
reducing action, howver, affecting male and female rats in a different way, and
again differently in a short- and a longer-term study. This positive effect of
Maca-GO on reduction of body weight in male and female rats could not be
explained by lowering in TSH content in the blood, which usually leads to
slowing down body metabolism, hence reducing the weight gains of rats.
In the Trial I, where a slight increase in white cell and lymphocyte counts and
lowering hemoglobin content was recorded, may indicate an overall defensive
blood morphology status in animals due to some factors other than Maca, such as
may be observed when animals are fighting some mild infection. Signs of mild
changes observed in histopathology of internal organs dissected from rats after
a short-term trial, at lower (0.75g/kg) Maca-GO administration level may support
this assumption. Longer-term Maca-Go use, have not produced any significant
changes in morphology nor in histopathology picture of rats.
Observed in the Trial I effect of 7.5g/kg level of Maca-GO on an increased
Estradiol level was accompanied by lowering in progesterone level which may
indicate that blood sampling for analyses was done after the ovulation. In this
trial, due to difficulties in precise detection of a menstrual cycle stage at
the time of blood sampling from female rats (mainly due to their peculiar
ability to spontaneous ovulations), the status of ovulation cycle was not
determined. On the other hand, in a longer term trial, the level of Maca-GO
application had no effect on estradiol level but simultaneous increase of
progesterone contents could keep estradiol at uniformly moderate level at both
Maca-GO application doses. The observed relationship between progesterone and
estradiol are in accord with observations made by Lucille (21) in clinical
practice, emphasizing the balance between progesterone, estradiol and thyroid
function as one of the key factors in female maintaining hormonal balance during
the reproduction years and in menopause. It is a function of progesterone to
control estradiol and negative effects of its dominance as well as to support
thyroid function in maintaining growth, healthy bone metabolism and balancing
psychological equilibrium in females during and after their reproductive stage.
It was an interesting to observe a positive significant effect of Maca-GO on
blood cortisol reduction in both short-and long-term trial, with more pronounced
effect visible in Trial I (28 days). This may indicate positive effect of Maca-GO
on lowering susceptibility of rats to stress factors and its sedative effect on
laboratory animals, the properties also reported by Lopez Fondo et al. (22).
Observed in Trial II, a long-term effect of both, low and high doses of Maca-GO
administration on maintaining, or slightly reducing Estradiol level, at
simultaneous increase in Progesterone in rats, opens a new important avenue for
application of Maca-GO during perimenopausal phase in women, since at this stage
of women life, there is a tendency to gradually increase Estradiol level due to
decline in secretion of Progesterone (23). Gradually increasing blood estradiol
level in perimenopausal stage leads to development of depression (24) in females
at the perimenopause stage. It appears that an extended application of low doses
of Maca-GO may slow down, delay or even prevent depression and other unpleasant
symptoms which are manifested prior to and/or during the menopause (1, 5, and
6). In a preliminary study on ovariectomised rats (25) it has been suggested
that Maca-GO posessess anti-depressant-like and sedative, but not anxiolytic
effects as measured in locomotor activity test, Porsolt and anxiolytic activity
tests which corresponded with significant lowering in Cortisol and ACTH
concentrations, leading to conclusion that Maca-GO could have value in treatment
of some depressive symptoms during perimenopausal period. The follow-up study
(26) on the same samples of Maca-GO as used in this study, when tested against
Fluoxentine, a known antidepressant agent, confirmed the above assumptions
showing that Maca-GO possesses typical antidepressant–like characteristics.
After Maca-GO administration to ovariectomised rats, both blood Cortisol and
ACTH as well as spontaneous activity and immobility time (Porsolt test) were
significantly (P<0.05) reduced, while Fluoxetine induced anti-depressive effect
in control, non-ovariectomised animals only, without affecting ovariectomised
rats, with one exception, that, Fluoxetine increased the blood Cortisol only in
non-ovariectomised rats without significantly affecting ACTH and spontaneous
activity test values. This led to conclusion that antidepressive action of Maca-GO
is based on different mode of action in non- and ovariectomised rats as compared
to the antidepressive effect of Fluoxentine on both groups of female rats. The
above results from a model laboratory tests (25, 26) in conjunction with the
results recorded in this study on male and non-ovariectomised female rats
suggest that active phyto components present in Maca-GO act in a specific way on
release of body steroids or affecting the hypothalamo-pituitary-ovarian axis in
female rats (or -testes in males) resulting in triggering similar, but other
than serotoninergic response mechanisms as observed in anti-depressive action of
Fluoxentine on rats. This assumption however, needs to be tested clinically.
Maca-GO had positive effect on increased level of glucose in the blood of rats
at both levels of application, however only in long-term Trial II, the high dose
of Maca-GO administered to rats resulted in statistically significant rise in
blood glucose level. This may explain reported energizing effect of Maca and its
use as an energizing dietary supplement for sport people and those whose
lifestyle requires energy reserves for intensive physical activity (3, 24, 27,
28). Obsrved in this study (Tables 4 and 7) increased glucose level in groups of
rats receiving Maca-GO contradicts results reported by Lopez-Fernando (22) who
observed hypoglycemic effect of methanolic extract of maca on stressed animals.
Possible explanation of the discrepancy in results obtained in these two
studies, may be due to response of non-stressed animals used in the present
study, as opposed to stressed one in Lopez-Fernando’s experiment and/or due to
carbohydrate fraction presence in Maca-GO, while this particular fraction, as
insoluble in methanol, was not present in the extract administered to stressed
animals.
There was a trend observed in this study across the all groups receiving Maca-GO
that red blood cells, haematocrit, haemoglobin and other red cell
characteristics were lower in recorded values as compared to the corresponding
control groups of rats. This was associated with lowering in blood iron
concentration at lower doses of Maca-GO, while at higher doses in short-term
Trial and during an extended period had no such visible effect. This may
indicate Maca-Go playing a role in modulating availability of dietary iron, the
fact which could be explained by alteration in absorption of iron from the
intestines (29), or by possible chelating effect of Maca-GO on dietary iron,
without discounting the fact of lesser diet being consumed by rats after forced
feeding them with Maca-GO. Overall haematology indices were within the norms
considered as normal for rats (30).
This study to certain degree confirmed observation of Muller (6) that Maca,
depending on the level and the length of its intake may act either as an
adaptogenic herb displaying "stimulating" or "balancing" effect. However, higher
doses during extended period of administration were not necessary more effective
in inducing changes in blood indices and other tissue measurements taken in this
study.
Observations made in this laboratory study justify further clinical research on
use of Maca in peri-menopausal women and on physically-active people and
sportsmen, this in order to assess effectiveness of Maca-GO as an energizing,
non-hormonal, therapeutic supplement and as a potential substitute to HRT
programs. Result obtained in earlier pilot study on use of pre-gelatinised Maca
in early postmenopausal women (31), confirmed that through balancing hormones in
the body, Maca-GO helped women to reduce discomfort which they experienced in
post-menopausal stage. On the basis of results obtained in this laboratory study
on rats, it is reasonable to suppose that Maca-GO may help women to reduce
discomfort experienced not only in post-menopause, but also well before onset of
menopause and during entering menopausal stage, which may simultaneously assist
in restricting weight increase, lowering triglycerides in blood plasma and an
increase in calcium and phosphorus deposition in bone and muscle tissues.
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ACKNOWLEDGMENTS |
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Participation of NatureCorp Pty Ltd, Australia in costs related to securing
commercial batch of standardized Maca-GO used in this study is gratefully
acknowledged. Some results from 90 days trial period, in a preliminary form,
were published (in Polish) in Advances of Physiotherapy. 2005; 1-2: 11.
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DISCLAIMER |
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Reference to a company and/or product named in this paper is only for purpose of information and does not imply approval or recommendation of the product to the exclusion of others which may also be suitable.
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REFERENCES
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