Content uploaded by Gustavo Francisco Gonzales
Author content
All content in this area was uploaded by Gustavo Francisco Gonzales
Content may be subject to copyright.
Original Article · Originalarbeit
Forsch Komplementmed 2010;17:137–143 Published online: June 16, 2010
DOI: 10.1159/000315214
Carla Gonzales
Biological and Physiological Science Department, Faculty of Science and Philosophy
Universidad Peruana Cayetano Heredia
Av. Honorio Delgado 430, Lima 31, Peru
Tel. +511 3190000, ext. 2515
carla.gonzalez@upch.pe
© 2010 S. Karger GmbH, Freiburg
Accessible online at:
www.karger.com/fok
Fax +49 761 4 52 07 14
Information@Karger.de
www.karger.com
Effects of Different Varieties of Maca (Lepidium meyenii)
on Bone Structure in Ovariectomized Rats
Carla Gonzalesa, b Isaias Cárdenas-Valenciaa Johanna Leiva-Revillaa Cecilia Anza-Ramireza
Julio Rubioa, b Gustavo F. Gonzalesa, b
a Biological and Physiological Science Department, Faculty of Science and Philosophy, Universidad Peruana Cayetano Heredia,
b Instituto de Investigaciones de la Altura, Universidad Peruana Cayetano Heredia, Lima, Peru
Key Words
Lepidium meyenii · Black maca · Red maca ·
Bone structure · Ovariectomy
Summary
Objective: This study was designed to determine the ef-
fect of different varieties of maca (Lepidium meyenii) on
bone structure in ovariectomized (OVX) rats. Materials
and Methods: 36 female rats were randomly divided into
6 groups: sham and OVX rats treated with vehicle, estra-
diol (40 mg/kg), black, yellow or red maca (63 mg/ml) for
4 weeks. At the end of the treatment, uterine weight,
femoral bone and lumbar vertebra histomorphology
were assessed. Results: Ovariectomy reduced weight, di-
ameter and width of the femoral bone. Estradiol, black
and red maca treatment reduced the effect of ovariec-
tomy on these variables. Histological analyses revealed
that estradiol, black and red maca treatments reversed
the effect of ovariectomy by increasing the trabecular
bone area in the second lumbar vertebra. Uterine weight
was reduced in OVX rats, and estradiol but neither black
nor red maca increased uterine weight. Conclusion: Red
and black maca have protective effects on bone architec-
ture in OVX rats without showing estrogenic effects on
uterine weight.
Schlüsselwörter
Lepidium meyenii · Schwarzes Maca · Rotes Maca ·
Knochenstruktur · Ovariektomie
Zusammenfassung
Ziel: Diese Studie wurde entwickelt, um die Wirkung
verschiedener Arten von Maca (Lepidium meyenii) auf
die Knochenstruktur von Ratten nach Ovariektomie
(OVX) zu untersuchen. Material und Methoden: 36 weib-
liche Ratten wurden zufällig 6 Gruppen zugeteilt: eine
scheinoperierte Gruppe sowie Ratten, die nach einer
OVX 4 Wochen lang mit destilliertem Wasser, Estradiol
(40 mg/kg), schwarzem, rotem oder gelbem Maca (63
mg/ml) behandelt wurden. Am Ende der Behandlung
wurden das uterine Gewicht sowie die Histomorphologie
des Femurknochens und der Lumbalwirbel erhoben. Er-
gebnisse: Die Ovariektomie reduzierte Gewicht, Durch-
messer und Breite des Femurknochens. Behandlungen
mit Estradiol, schwarzem oder rotem Maca reduzierten
die Effekte der OVX auf diese Variablen. Histologische
Analysen zeigten, dass Behandlungen mit Estradiol,
schwarzem und rotem Maca den Effekt der Ovariekto-
mie umkehrten, indem sie die Trabekelzone des zweiten
Lumbalwirbels vergrößerten. Das uterine Gewicht war
bei den OVX-Ratten reduziert und wurde durch Estra-
diol, aber weder durch schwarzes noch rotes Maca er-
höht. Schlussfolgerung: Rotes und schwarzes Maca
haben protektive Effekte auf die Knochenstruktur von
OVX-Ratten ohne östrogene Auswirkungen auf das ute-
rine Gewicht.
© Free Display Copy – for personal use only
ANY DISTRIBUTION OF THIS ARTICLE WITHOUT WRITTEN CONSENT FROM
S. KARGER GmbH, FREIBURG, IS A VIOLATION OF THE COPYRIGHT.
Written Permission to distribute the PDF will be granted against payment of a
permission fee, which is based on the number of accesses required.
Please contact e.traenkle@karger.de
138 Forsch Komplementmed 2010;17:137–143 Gonzales/Cárdenas-Valencia/Leiva-Revilla/
Anza-Ramirez/Rubio/Gonzales
4–6 per cage at environmental temperature (24 ± 1 °C) with a 12:12 h
light/dark cycle. Also, rats were fed with laboratory chow and water ad
libitum.
Ovariectomy
Naive rats were anesthetized with 40 mg/kg of pentobarbital (ip). Bilat-
eral ovariectomies were performed using a dorso-lateral approach. Ova-
ries and surrounding fat tissue were removed and the incision was closed
by suturing muscles and skin. Similar surgical procedures were carried out
for the sham-operated animals except that their ovaries were not re-
moved. Experiments were performed 4 weeks after surgery.
Design
The present experimental study evaluated the effect of black, yellow and
red varieties of Lepidium meyenii (maca) on bone structure in OVX rats.
Rats were divided at random into 6 groups (n = 6): sham rats were treated
with vehicle (distilled water) and OVX rats treated with vehicle, estradiol
valerate (Sigma Chemical Co., St Louis, MO), or hydroalcoholic extracts
of black, yellow or red maca. Vehicle and each variety of maca were
orally administered for 4 weeks. Also, estradiol was administered daily,
by intramuscular route, for 4 weeks. The dosage of estradiol (40 mg/kg)
used in the present study was chosen from a previous study [20]. All ani-
mal experiments were performed in compliance with the ‘Guide of care
and use of laboratory animals’ [21].
At the end of each treatment, animals were sacrificed by decapitation.
The uterus, both femoral bones and the second lumbar vertebra body
were carefully dissected, cleaned of adhering connective tissues and ac-
curately weighed and stored for further analyses.
Preparation of Hydroalcoholic Extracts of Maca
The dried hypocotyls of black, yellow and red maca were obtained from
Ninacaca, Pasco at 4,100 m altitude. A botanist of the Department of
Pharmaceutical Science, Universidad Peruana Cayetano Heredia, au-
thenticated the identity of the plant. The voucher number IFV 1885 was
deposited at the Department of Pharmaceutical Science. The biological
activity of maca is located in its hypocotyl, the edible part of the plant,
which is consumed by natives after being naturally dried. All three varie-
ties of maca grow in the same field and are differentiated by their color.
Nutritional compounds differ between these three varieties as described
previously [4].
A standardized hydroalcoholic extract of black, yellow or red maca
was prepared from the pulverized hypocotyls of each color. The extract
was spray-dried before being used. The dose of maca chosen for the
present study was equivalent to 4.3 mg of polyphenols / kilogram body
weight.
Physical Parameters of Femoral Bone
Fresh isolated right femoral bones were weighed using an analytic scale.
Both the length and external diameter of the femoral bone were meas-
ured using calipers. The length was measured from the proximal tip of the
femoral head to the distal tip of the medial condyle. The width was deter-
mined by measuring the distance between periosteum and endosteum. In
addition, the external diameter was measured at the midshaft femoral
bone using a caliper. Thereafter, femoral bones were dried at 110 ºC for
12 h, and their weight measured again using an analytical scale.
Hystomorphometric Evaluation
The lumbar vertebrae (LV2) body was fixed in formaldehyde-0.1 M phos-
phate buffer for 24 h. Then, the samples were decalcified in acetone for
36 h following a xylen immersion for 24 h, and embedded into paraffin.
Introduction
Osteoporosis, described as a reduction of bone mass and an
alteration in bone micro-structure, is a result of decreased
serum estrogen levels during and after menopause. In post-
menopausal women, loss of estrogen is associated with an
elaboration of cytokines that not only increase the formation
of precursors of osteoclasts and their differentiation into os-
teoclasts but also decrease the development and function of
osteoblasts [1]. This results in an increase of bone fragility and
fractures [1]. In fact, the high incidence of fractures by post-
menopausal osteoporosis is an important public health prob-
lem, resulting in increased financial charges for health serv-
ices. It is well known that antioxidants have a beneficial effect
on this altered cytokine balance [2].
Hormone replacement therapy (HRT) has been used to
treat post-menopausal bone loss. However, HRT has several
secondary effects including breast cancer, heart and brain vas-
cular failures and blood clots [3]. For these reasons, alterna-
tive treatments without secondary adverse effect are needed.
Maca (Lepidium meyenii) is a Peruvian plant that belongs
to the Brassicaceae family. The edible part of the plant is a
radish-like tuber that constitutes the hypocotyl and the root of
the plant [4]. Previous studies focused on proving the tradi-
tional fertility-enhancing properties of the hypocotyls of maca
regarding sperm production [5–8], sexual behavior [9–11], and
female fertility [12]. Up to 13 varieties of maca have been de-
scribed according to the color of its hypocotyls [4, 13] that
showed different biological effects [14–16]. Black maca, for
example, presented the greatest effect on sperm production in
rats [15] and on latent learning in ovariectomized (OVX)
mice [16] and red maca significantly reduced prostate size in
rats [14]. Furthermore, we have demonstrated that maca can
enhance sperm count and sperm motility in normal men with-
out altering serum testosterone, luteinizing hormone (LH) or
follicle stimulating hormone (FSH) levels [4].
Recent studies have also shown that extracts of Lepidium
meyenii (Maca) (3.5 g/d) can reduce psychological symptoms,
including anxiety and depression, and lower measures of sex-
ual dysfunction in post-menopausal women independently of
any estrogenic and androgenic activity [17]. In addition, maca
improves bone mass and restores bone trabecular area of lum-
bar vertebrae in OVX rat [18, 19]. Yet, the authors did not
mention the variety of maca they used in their studies.
The present study aims to evaluate the effect of three dif-
ferent maca varieties (black, yellow and red) on bone struc-
ture in OVX female rats, using standardized extracts based on
polyphenols content.
Methods
Animals
36 female rats (3-months old) were obtained from the animal house at
the Universidad Peruana Cayetano Heredia. The rats were maintained
Forsch Komplementmed 2010;17:137–143
Black and Red Maca for Bone Loss 139
homogeneous, differences between groups were assessed by analysis of
variance (ANOVA). If the F value in the ANOVA test was significant,
the differences between a pair of means were assessed by Scheffé tests.
P < 0.05 was considered as statistically significant.
Results
Content of Polyphenols
The content of polyphenols was higher in the spray-dried ex-
tract of maca than in the pulverized powder. The highest
amount of polyphenols was observed in red maca, followed by
yellow maca. Black maca had the lowest polyphenols content
(table 1).
The block was then cut into 5-mm slices. The sections were stained with
hematoxylin and eosin (HE) and examined for morphology under a light
microscope (40´) with Leica Application Suite for Windows program, and
the intra-trabecular bone areas were measured.
Total Polyphenol Assay
Content of phenols was measured as described previously [22]. Results
are expressed as grams of total polyphenols per 100 grams of maca ex-
tract. For comparisons, content of phenols in pulverized maca (raw mate-
rial) was also measured.
Statistical Analysis
Data were analyzed using the statistical package STATA version 8.0 for
personal computer (Stata Corporation, College Station, TX, USA). Data
are presented as mean ± standard error of the mean (SEM). Homogene-
ity of variances was assessed by the Bartlett test. When variances were
Red maca Black maca Yellow maca
Pulverized dried hypocotyls 0.84 0.55 0.78
Spray dried hydroalcoholic extract 5.81 1.76 6.5
Table 1.
Phenols content (g pyrogallol / 100 g
maca) in varieties of Lepidium meyenii (maca)
8
Fig. 1. Absolute (A) and dried (B) femoral weights (g) in ovariectomized (OVX) rats treated with yellow, black and red maca
(OVX + YY, OVX + BM, OVX + RM) or estradiol (OVX + E2). Data are expressed as mean ± SEM. ap < 0.05 (vs. sham); bp <
0.05 (vs. OVX); cp < 0.05 (vs. OVX + E2); dp < 0.05 (vs. OVX + YM); fp < 0.05 (vs. OVX + RM). ((bitte auf 88 mm Breite, s/w,
o.R.))
Fig. 1.
Absolute (
A
) and dried (
B
) femoral weights (g) in ovariect-
omized (OVX) rats treated with yellow, black and red maca (OVX + YM,
OVX + BM, OVX + RM) or estradiol (OVX + E2). Data are expressed
as mean ± SEM. ap < 0.05 (vs. sham); bp < 0.05 (vs. OVX); cp < 0.05 (vs.
OVX + E2); dp < 0.05 (vs. OVX + YM); fp < 0.05 (vs. OVX + RM).
9
Fig. 2. Femoral bone diameter (A) and width (B) in OVX rats treated with yellow, black and red maca (OVX +YM, OVX + BM,
OVX + RM) or estradiol (OVX + E2). Data are expressed as mean ± SEM. ap < 0.05 (vs. sham); bp < 0.05 (vs. OVX); cp < 0.05 (vs.
OVX + E2). ((bitte auf 88 mm Breite, s/w, o.R.))
Fig. 2.
Femoral bone diameter (
A
) and width (
B
) in OVX rats treated
with yellow, black and red maca (OVX +YM, OVX + BM, OVX + RM)
or estradiol (OVX + E2). Data are expressed as mean ± SEM. ap < 0.05
(vs. sham); bp < 0.05 (vs. OVX); cp < 0.05 (vs. OVX + E2).
140 Forsch Komplementmed 2010;17:137–143 Gonzales/Cárdenas-Valencia/Leiva-Revilla/
Anza-Ramirez/Rubio/Gonzales
10
Fig. 3. Trabecular bone area (µm2) in the second lumbar vertebral body of OVX rats treated with yellow, black and red maca (YM,
BM, RM) or estradiol (E2). Data are expressed as mean ± SEM. ap <0.05 (vs. sham group); bp < 0.05 (vs. OVX group); cp < 0.05
(vs. OVX + YM group). ((A: bitte auf 88 mm Breite, s/w, o.R.; B bitte auf 149,6 mm Breite, s/w, o.R.)) .
B
Figure 2 depicts the effects of black, yellow or red maca on
femur diameter (A) and femur width (B) of OVX rats. The
femur diameter was reduced in OVX rats as compared to the
sham group (p = 0.002). In OVX rats treated with estradiol,
yellow, black or red maca the effect of ovariectomy on femur
diameter was reversed (p = 0.005, p = 0.043, p = 0.009, p =
0.002, respectively). No difference was observed in OVX rats
treated with estradiol, yellow, black or red maca (p > 0.05).
In OVX rats, femur width was lower than in sham rats
(p = 0.04). Again, estradiol, black or red maca increased
femur width in OVX rats (p = 0.009, p = 0.001; p = 0.001, re-
spectively) as compared to sham rats. Black and red maca
showed higher values than those obtained with yellow maca
(p = 0.018 and p = 0.023, respectively) without showing dif-
ferences between both groups (p > 0.05).
Histomorphometric Determination
Figure 3 depicts the histology of the lumbar vertebra of sham
rats and OVX rats treated with estradiol and yellow, black or
red maca. Ovariectomy reduced the trabecular bone area in the
second lumbar vertebra as compared to sham rats (p = 0.0001;
fig. 3A). In OVX rats, spacing-enlarged and area-diminished
trabecular bone was observed (fig. 3B). In addition, the admin-
istration of estradiol, black or red maca resulted in a protective
effect in the vertebra by increasing trabecular bone area (p =
0.001, p = 0.003 and p = 0.0001, respectively; fig. 3A) and reduc-
ing intra-trabecular space (fig. 3B) as compared to OVX rats.
Treatments with black or red maca yielded higher effects than
treatment with yellow maca (p = 0.019 and p = 0.0001, respec-
tively). No difference was observed between the groups treated
with estradiol, black or red maca (p > 0.05).
Differential Effect of Maca Varieties on Physical Parameters
of the Femur
Ovariectomy reduced the absolute weight of the femoral
bone (fig. 1a) compared to sham rats (p = 0.0036). OVX rats
treated with estradiol and sham rats had similar femur
weights (p > 0.05). Black and red maca reversed the effect of
ovariectomy on the absolute weight of the femur (p = 0.0018
and p = 0.006; respectively) reaching values similar to those
in sham rats. No effect was observed if OVX rats had been
treated with yellow maca (p > 0.05). Regarding the weight of
dried femur (fig. 1b), ovariectomy reduced the weight of fem-
oral ashes as compared to sham rats (p = 0.0001). No weight
difference was observed between OVX rats treated with
estradiol, yellow or black maca and sham rats (p > 0.05). An
increased weight of dried femur was observed in OVX rats
treated with red maca as compared to the values in OVX rats
(p = 0.0001). No difference was observed in femur length
between groups (data not shown).
A
10
Fig. 3. Trabecular bone area (µm2) in the second lumbar vertebral body of OVX rats treated with yellow, black and red maca (YM,
BM, RM) or estradiol (E2). Data are expressed as mean ± SEM. ap <0.05 (vs. sham group); bp < 0.05 (vs. OVX group); cp < 0.05
(vs. OVX + YM group). ((A: bitte auf 88 mm Breite, s/w, o.R.; B bitte auf 149,6 mm Breite, s/w, o.R.)) .
B
Fig. 3.
Trabecular
bone area (mm2) in the
second lumbar verte-
bral body of OVX rats
treated with yellow,
black and red maca
(YM, BM, RM) or es-
tradiol (E2). Data are
expressed as mean ±
SEM. ap <0.05
(vs. sham group);
bp < 0.05 (vs. OVX
group); cp < 0.05 (vs.
OVX + YM group).
B
Forsch Komplementmed 2010;17:137–143
Black and Red Maca for Bone Loss 141
ously [19]. In fact, black and red maca reduced qualitatively
and quantitatively the effect of ovariectomy on the trabecular
bone area after only 4 weeks of treatment. A discrepancy was
observed for black maca when the weight of fresh femur was
compared to that of dried femur. In fact, the weights of fresh
femur in animals treated with maca were higher than in the
OVX animals, but when the dried weights were compared, no
difference was observed. We do not fully understand how to
explain this difference but in any case, dried weight better rep-
resents the bone mass than fresh weight.
The outcomes observed in the present study demonstrate
that black and red maca have reversed the deleterious effects of
ovariectomy on bone loss. In addition, the results reported in
this study show that black and red maca have similarly benefi-
cial effects on bone mass as estradiol but do not affect uterine
weight. Although estrogenic regulation can be necessary for
bone remodeling [24], our results support the assumption that
maca acts without any estrogenic effect, as suggested by others
[15]. One possibility is that maca acts through hypothalamus/
hypophysis levels. For instance, FSH has been demonstrated to
have effects on male and female fertility. A similar effect is ob-
served with maca [25]. Moreover, a recent study has shown that
FSH stimulates TNF production from immune cells to enhance
osteoblast and osteoclast formation [26]. However, maca did
not affect serum estradiol, LH or FSH levels [17, 27], which sug-
gests that it did not act at pituitary or hypothalamus levels.
Maca contains polyphenols, but amounts differ between
varieties with the highest content found in red maca and a
lower content in black maca. Naturally occurring polyphe-
nolic constituents are potential antioxidants [28, 29]. In fact,
maca contains flavonoids, such as flavonols and quercetin, as
well as anthocyanines [4]. These compounds have been shown
to have antioxidant properties in many systems [28, 29] and
could explain the effects of maca.
Post-menopausal osteoporosis is a metabolic bone disease
characterized by a decrease of bone mass after cessation of
the ovarian function [30]. Many factors are associated with
the development and maintenance of skeletal mass before
and after menopause [31, 32]. In fact, bone mass is regulated
by a dynamic and complex process called remodeling, charac-
terized by a balance between osteoclastic bone resorption and
osteoblastic bone formation [33]. Polyphenolic compounds
play a bone-protective role by both reducing osteoclastic
resorption and increasing osteoblastic activity [34–37]. This
action can be related to the antioxidant capacity of polyphe-
nols [38]. Dietary quercetin, a polyphenolic flavonoid that is
also present in maca [4], inhibits bone loss without effects on
the uterus in OVX mice and does not act as a potent inhibitor
of osteoclastogenesis or as a selective estrogen receptor mod-
ulator (SERM) in vivo [39]. We have observed that red and
black maca inhibits bone loss without affecting uterine weight.
Thus, it is probable that maca acts as SERM.
Polyunsaturated fatty acids that have also been described
in maca [40] may also affect bone structure [41, 42]. Maca
Uterine Weight
OVX rats showed lower uterine weights than sham rats (p =
0.0001). Estradiol administration increased uterine weight in
OVX rats (p = 0.0001). Yellow, black or red maca did not
modify uterine weight after being administered to OVX rats
(fig. 4).
Discussion
Maca exists in different varieties which are characterized by
the external color of their hypocotyl: red, black and yellow
[4]. The present study aimed to evaluate the effect of hydroal-
coholic extracts of these three varieties of maca on bone struc-
ture using as a model an animal to produce osteoporosis.
Previous studies have demonstrated different biological
effects of yellow, red or black maca. For instance, black maca
demonstrated the highest effect on sperm production in rats
[15] and the highest effect on memory and learning [16],
whereas red maca was able to reduce prostate size in rats with
benign prostatic hyperplasia induced by external androgen
administration [14, 22].
Ovariectomy is a well-known procedure used to mimic
changes in bone parameters related to menopause [23]. The
present study shows that after 4 weeks, ovariectomy produced
a significant loss of trabecular bone area in the second lumbar
vertebrae. In addition, OVX rats also showed effects on dif-
ferent femur parameters studied.
Zhang et al. [19] and Wang et al. [18] presented the first evi-
dence regarding beneficial effects of maca on bone loss. How-
ever, they did not specify the type of maca used. After 28 weeks
of treatment, maca qualitatively ameliorates the effect of ova-
riectomy on the trabecular area. Regarding the histomorpho-
metric analyses, our results are similar to those observed previ-
11
Fig. 4. Uterine weight (g) in ovariectomized (OVX) rats treated with yellow, black or red maca (YM, BM, RM) or estradiol (E2).
Data are expressed as mean ± SEM. ap < 0.05 (vs. sham); bp < 0.05 (vs. OVX); cp < 0.05 (vs. OVX + E2); dp < 0.05 (vs. OVX +
YM). ((bitte auf 88 mm Breite, s/w, o.R.))
Table 1. Phenols content (g pyrogallol / 100 g maca) in varieties of Lepidium meyenii (maca)
Red maca Black maca Yellow maca
Pulverized dried hypocotyls 0.84 0.55 0.78
Spray dried hydroalcoholic extract 5.81 1.76 6.5
Fig. 4.
Uterine weight (g) in ovariectomized (OVX) rats treated with
yellow, black or red maca (YM, BM, RM) or estradiol (E2). Data are
expressed as mean ± SEM. ap < 0.05 (vs. sham); bp < 0.05 (vs. OVX);
cp < 0.05 (vs. OVX + E2); dp < 0.05 (vs. OVX + YM).
142 Forsch Komplementmed 2010;17:137–143 Gonzales/Cárdenas-Valencia/Leiva-Revilla/
Anza-Ramirez/Rubio/Gonzales
In conclusion, black and red maca can be an alternative
treatment for osteoporosis without affecting other estrogen-
dependent organs such as the uterus, thus avoiding undesir-
able secondary effects.
Acknowledgment
It is acknowledged the financial support from the Peruvian National
Council of Science, Technology and Innovation (CONCYTEC) through
the grant PROCYT 2007.
Conflicts of Interest
The authors declare that they do not have any conflict of interest related
to this study.
contains a considerable amount of glucosinolates, particularly
benzyl glucosinolate [4, 43] which increases serum levels of
non-esterified fatty acids (NEFA) [44]. These fatty acids may
in turn affect bone structure.
It is well known [47] that post-menopausal women are at
high risk of osteoporosis and coronary heart disease (CHD).
Maca contains phytosterols, such as campesterol, stigmasterol
and b-sitosterol [9] which play a role in the expression of sex
hormones [45] and gonadal steroidogenic acute regulatory
protein (StAR) [46]. Phytosterol intake and increased plasma
levels, however, have also been associated with a low inci-
dence of CHD.
Results from the present study can be relevant to replace
HRT protocols which can induce negative secondary effects [55,
56]. Further studies are required to elucidate the mechanism re-
lated to the effect of black and red maca on bone metabolism.
References
1 Syed F, Khosla S: Mechanisms of sex steroid effects
on bone. Biochem Biophys Res Commun 2005;328:
688–696.
2 Lean JM, Davies JT, Fuller K, Jagger CJ, Kirstein
B, Partington GA, Urry ZL, Chambers TJ: A cru-
cial role for thiol antioxidants in estrogen-deficien-
cy bone loss. J Clin Invest 2003;112:915–923.
3 Moskowitz D: A comprehensive review of the
safety and efficacy of bioidentical hormones for
the management of menopause and related health
risks. Altern Med Rev 2006;11:208–223.
4 Valerio LG, Gonzales GF: Toxicological aspects
of the South American herbs Cat’s Claw (Uncaria
tomentosa) and Maca (Lepidium meyenii). Toxicol
Rev 2005;24:11–35.
5 Gonzales GF, Ruiz A, Gonzales C, Villegas L, Cor-
dova A: Effect of Lepidium meyenii (Maca) roots
on spermatogenesis of male rats. Asian J Androl
2001;3:231–233.
6 Gonzales GF, Gasco M, Cordova A, Chung A,
Rubio J, Villegas L: Effect of Lepidium meyenii
(Maca) on spermatogenesis in male rats acutely ex-
posed to high altitude (4340 m). J Endocrinol 2004;
180:87–95.
7 Chung F, Rubio J, Gonzales C, Gasco M, Gonzales
GF: Dose-response effects of Lepidium meyenii
(Maca) aqueous extract on testicular function and
weight of different organs in adult rats. J Ethno-
pharmacol 2005;98:143–147.
8 Rubio J, Riqueros MI, Gasco M, Yucra S, Miranda
S, Gonzales GF: Lepidium meyenii (Maca) reversed
the lead acetate induced-damage on reproductive
function in male rats. Food Chem Toxicol 2006;
44:1114–1122.
9 Zheng BL, He K, Kim CH, Rogers L, Shao Y,
Huang ZY, Lu Y, Yan SJ, Qien LC, Zheng QY:
Effect of a lipidic extract from Lepidium meyenii
on sexual behavior in mice and rats. Urology 2000;
55:598–602.
10 Cicero AF, Bandieri E, Arletti R: Lepidium mey-
enii Walp. improves sexual behaviour in male rats
independently from its action on spontaneous loco-
motor activity. J Ethnopharmacol 2001;75:225–229.
11 Cicero AF, Piacente S, Plaza A, Sala E, Arletti R,
Pizza C: Hexanic Maca extract improves rat sexual
performance more effectively than methanolic and
chloroformic maca extracts. Andrologia 2002;34:
177–179.
12 Ruiz-Luna AC, Salazar S, Aspajo NJ, Rubio J,
Gasco M, Gonzales GF: Lepidium meyenii (Maca)
increases litter size in normal adult female mice.
Reprod Biol Endocrinol 2005;3:17.
13
Tello J, Hermann M, Calderon A: La Maca (Lepid-
ium meyenii Walp.) cultivo alimenticio potencial para
las zonas altoandinas. Boletin de Lima 1992;14:59–66.
14 Gonzales GF, Miranda S, Nieto J, Fernandez G,
Yucra S, Rubio J, Yi P, Gasco M: Red Maca (Le-
pidium meyenii) reduced prostate size in rats. Re-
prod Biol Endocrinol 2005;3:5.
15 Gonzales C, Rubio J, Gasco M, Nieto J, Yucra S,
Gonzales GF: Effect of short-term and long-term
treatments with three ecotypes of Lepidium mey-
enii (MACA) on spermatogenesis in rats. J Ethno-
pharmacol 2006;103:448–454.
16 Rubio J, Caldas M, Dávila S, Gasco M, Gonzales
GF: Effect of three different cultivars of Lepidium
meyenii (Maca) on learning and depression in ova-
riectomized mice. BMC Complement Altern Med
2006;6:23.
17 Brooks NA, Wilcox G, Walker KZ, Ashton JF,
Cox MB, Stojanovska L: Beneficial effects of Le-
pidium meyenii (Maca) on psychological symptoms
and measures of sexual dysfunction in postmeno-
pausal women are not related to estrogen or andro-
gen content. Menopause 2008;15:1157–1162.
18 Wang Z, Yang J, Wang G, Bian L: Influence of
Lepidium meyemii walp on lipid and bone mass in
ovariectomized rats. Wei Sheng Yan Jiu 2009;38:
420–2, 425.
19 Zhang Y, Yu L, Ao M, Jin W: Effect of ethanol
extract of Lepidium meyenii Walp on osteoporosis
in ovariectomized rat. J Ethnopharmacol 2005;105:
274–279.
20 Hertrampf T, Gruca MJ, Seibel J, Laudenbach U,
Fritzemeier KH, Diel P: The boneprotective ef-
fect of the phytoestrogen genistein is mediated
via ER alpha-dependent mechanisms and strongly
enhanced by physical activity. Bone 2007;40:1529–
1535.
21 National Research Council: Guide of the care and
use of laboratory animals. Washington, DC, Na-
tional Academy Press, 1996, p 125.
22 Gonzales GF, Gasco M, Malheiros-Pereira A,
Gonzales-Castañeda C: Antagonistic effect of
Lepidium meyenii (red maca) on prostatic hyper-
plasia in adult mice. Andrologia 2008;40:179–185.
23 Zhang Y, Lai WP, Leung PC, Wu CF, Wong MS:
Short- to mid-term effects of ovariectomy on bone
turnover, bone mass and bone strength in rats. Biol
Pharm Bull 2007;30:898–903.
24 Riggs BL, Khosla S, Melton LJ 3rd: Sex steroids
and the construction and conservation of the adult
skeleton. Endocr Rev 2002;23:279–302.
25 Gonzales GF, Gonzales C, Gonzales-Castañeda C:
Lepidium meyenii (Maca): A plant from the high-
lands of peru – from tradition to science. Forsch
Komplementmed 2009;16:373–380.
26 Iqbal J, Sun L, Kumar TR, Blair HC, Zaidi M:
Follicle-stimulating hormone stimulates TNF pro-
duction from immune cells to enhance osteoblast
and osteoclast formation. Proc Natl Acad Sci U S
A 2006;103:14925–30.
27
Gonzales GF, Córdova A, Vega K, Chung A, Ville-
na A, Góñez C: Effect of Lepidium meyenii (Maca)
a root with aphrodisiac and fertility-enhancing
properties on serum reproductive hormone levels in
adult healthy men. J Endocrinol 2003;176:163–168.
28
Scalbert A, Manach C, Morand C, Rémésy C,
Jiménez L: Dietary polyphenols and the prevention
of diseases. Crit Rev Food Sci Nutr 2005;45:287–306.
29
Weaver CM, Barnes S, Wyss JM, Kim H, Morré
DM, Morré DJ, Simon JE, Lila MA, Janle EM, Fer-
ruzzi MG: Botanicals for age-related diseases: from
field to practice. Am J Clin Nutr 2008;87:493S–497S.
30 Lerner UH: Bone remodeling in post-menopausal
osteoporosis. J Dent Res 2006;85:584–595.
31 Weitzmann MN, Pacifici R: Estrogen deficiency and
bone loss: an inflammatory tale. J Clin Invest 2006;
116:1186–1194.
32 Kim JG, Ku SY, Lim KS, Jee BC, Kim CS, Choi
YM, Moon SY: Cytokine production by whole
blood cells: relationship to interleukin gene poly-
morphism and bone mass. J Korean Med Sci 2005;
20:1017–1022.
Forsch Komplementmed 2010;17:137–143
Black and Red Maca for Bone Loss 143
33 Ono Y, Fukaya Y, Imai S, Yamakuni T: Beneficial
effects of Ajuga decumbens on osteoporosis and
arthritis. Biol Pharm Bull 2008;31:1199–1204.
34 Do SH, Lee JW, Jeong WI, Chung JY, Park SJ,
Hong IH, Jeon SK, Lee IS, Jeong KS: Bone-pro-
tecting effect of Rubus coreanus by dual regulation
of osteoblasts and osteoclasts. Menopause 2008;15:
676–683.
35 Wattel A, Kamel S, Prouillet C, Petit JP, Lorget F,
Offord E, Brazier M: Flavonoid quercetin decreas-
es osteoclastic differentiation induced by RANKL
via a mechanism involving NF kappa B and AP-1. J
Cell Biochem 2004;92:285–295.
36 Prouillet C, Mazière JC, Mazière C, Wattel A,
Brazier M, Kamel S: Stimulatory effect of natu-
rally occurring flavonols quercetin and kaempferol
on alkaline phosphatase activity in MG-63 human
osteoblasts through ERK and estrogen receptor
pathway. Biochem Pharmacol 2004;67:1307–1313.
37 Horcajada-Molteni MN, Crespy V, Coxam V, Dav-
icco MJ, Rémésy C, Barlet JP: Rutin inhibits ova-
riectomy-induced osteopenia in rats. J Bone Miner
Res 2000;15:2251–2258.
38 Shen CL, Wang P, Guerrieri J, Yeh JK, Wang JS:
Protective effect of green tea polyphenols on bone
loss in middle-aged female rats. Osteoporos Int
2008;19:979–990.
39 Tsuji M, Yamamoto H, Sato T, Mizuha Y, Kawai
Y, Taketani Y, Kato S, Terao J, Inakuma T, Take-
da E: Dietary quercetin inhibits bone loss without
effect on the uterus in ovariectomized mice. J Bone
Miner Metab 2009;27:673–681.
40 Ganzera M, Zhao J, Muhammad I, Khan IA:
Chemical profiling and standardization of Lepid-
ium meyenii (Maca) by reversed phase high per-
formance liquid chromatography. Chem Pharm
Bull 2002;50:988–999.
41 Shomali T, Rezaian M, Rassouli A, Asadi F: Effect
of eicosapentaenoic acid on bone changes due to
methylprednisolone in rats. Basic Clin Pharmacol
Toxicol 2009;105:46–50.
42 Eriksson S, Mellström D, Strandvik B: Fatty acid
pattern in serum is associated with bone miner-
alisation in healthy 8-year-old children. Br J Nutr
2009;102:407–12.
43 Li G, Ammermann U, Quiros CF: Glucosinolate
contents on maca (Lepidium meyenii Chacon)
seeds, sprouts, mature plants and several derived
commercial products. Econ Bot 2001;55:255–262.
44 Ikeuchi M, Koyama T, Takei S, Kino T, Yazawa
K. Effects of benzyl glucosinolate on endurance
capacity in mice. J Health Sci 2009;55:178–182.
45 Oshima M, Gu Y. Pfaffia paniculata-induced
changes in plasma estradiol-17beta, progesterone
and testosterone levels in mice. J Reprod Dev 2003;
49:175–80.
46 Sharpe RL, Woodhouse A, Moon TW, Trudeau
VL, MacLatchy DL: Beta-sitosterol and 17beta-
estradiol alter gonadal steroidogenic acute regula-
tory protein (StAR) expression in goldfish, Carassi-
us auratus. Gen Comp Endocrinol 2007;151:34–41.
47 Escurriol V, Cofan M, Moreno-Iribas C, Larranaga
N, Martinez C, Navarro C, Rodriguez L, Gonzalez
CA, Corella D, Ros E: Phytosterol plasma concen-
trations and coronary heart disease in the prospec-
tive Spanish EPIC cohort. J Lipid Res 2010;51:618–
624.
48 Rachoƒ D, Teede H: Postmenopausal hormone
therapy and the risk of venous thromboembolism.
Climacteric 2008;11:273–279.
49 Writing Group for the Women’s Health Initia-
tive Investigators: Risks and benefits of estrogen
plus progestin in healthy postmenopausal women.
JAMA 2002;288:321–333.
