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Effect
of Lepidium meyenii
(maca) roots on spermatogenesis of male rats
Gustavo
F. Gonzales, Ana Ruiz, Carla Gonzales, Len Villegas, Amanda Cordova
Department
of Physiological Sciences, Faculty of Sciences and Philosophy and Instituto
de Investigaciones de la Altura. Universidad Peruana Cayetano Heredia.
Postal Office 1843 . Lima, Peru
Asian J Androl 2001 Sep; 3: 231-233
Keywords:
spermatogenesis;
Lepidium meyenii; maca; transillumination
Abstract
Aim: To determine the effect of oral administration of an aqueous extract from the roots of Lepidium meyenii (maca) on spermatogenesis in adult male rats. Methods: Male rats received an aqueous extract of the root (66.7 mg in one mL) twice a day for 14 consecutive days. Results: Treatment with Lepidium meyenii resulted in an increase in the weights of testis and epididymis but not the seminal vesicle weight. The length and frequency of stages IX-XIV seminiferous tubules, where mitosis occurred, were increased and stages I-VI were reduced in rats treated with Lepidium meyenii. Conclusion: The Lepidium meyenii root invigorates spermatogenesis in male rats by acting on its initial stages (IX-XIV).
1
Introduction
Lepidium
meyenii or
maca is a plant of the Brassicaceae family growing in the Andean region
of Peru over 3000 meters altitude. From the time of the Spaniard conquest
it has been recognized by its function to improve fertility[1].
It is named Andean Ginseng due to its supposed activity to provoke sexuality[2].
This activity has been scientifically documented in the literature in
male mice and rats[3].
It is suggested that the plant also act on spermatogenesis[1],
however no experimental evidence so far exists.
In
the seminiferous epithelium, germ cells are arranged in distinct associations
or stages. In the rat, Leblond & Clermont have defined 14 stages[4].
The wave of the seminiferous epithelium can be visualized by transillumination
in freshly isolated unstained seminiferous tubules[5]. This
technique allows the examination of a large amount of fresh seminiferous
tubules after different treatments[6,7].
2 Materials and methods
2.1 Animals
Three-month-old male Holtzman rats from the animal house of the Universidad Peruana Cayetano Heredia were used. Animals were housed under standardized conditions. Rats were divided at random into 2 groups of 10 animals each, the control and the Lepidium meyenii treated. Control rats weighed 246.4 g and treated rats weighed 274.8 g on the average.2.2 Preparation of aqueous extract of Lepidium meyenii
The root of Lepidium meyenii was obtained from Carhuamayo at 4000 m altitude. The identity of the plant was authenticated by Irma Fernndez, a Botanist of the Department of Physiological Sciences, Universidad Peruana Cayetano Heredia. An aqueous extract of the root was prepared according to a traditional method. In brief, 500 g of the root were placed in a container with 750 mL of water and boiled for 30 min. The preparation was left standing to cool and was then filtered. The filtrate, containing 66.7 mg root in 1 mL, was placed in small vials and kept in 4 refrigerator until use.2.3 Treatment of animals
The extract of Lepidium meyenii was orally administered at a dose of 1 mL/rat, twice a day for 14 days. A similar volume of the vehicle was given to the control rats. Rats were sacrificed one day after the last dosing. The testes, epididymides and seminal vesicles were removed and weighed. After that the seminiferous tubules were prepared for transillumination assessment.2.4 Assessment of stages of rat seminiferous cycle
Assessment of the length and the frequency of stage was made by transillumination under an inverted stereomicroscope at 40magnification as previously described[6,7]. For each rat, a total length of 1000 mm seminiferous tubules was assessed. The frequency of each stage in the 1000-mm tubules was recorded and calculated as percentage. The frequency of seminiferous tubules obtained from control rats were considered as 1 in each of the stages and the seminiferous tubules of treated rats were assessed relatively to the control group as previously described[7,8].
2.5 Statistical analysis
Data were presented as meanSD and analyzed using Student's t-test and analysis of variance (one-way) when more than two groups were compared. Parametric statistics was used since data were normally distributed. P<0.05 was considered significant. The relative frequency in each specific stage represents the mean value of 10 rats.3
Results
The testicular weight (1.520.06 g in the control and 1.590.06 in the treated group, P<0.05) and the epididymal weight (0.400.03 g in the control and 0.460.03 in the treated rats, P<0.05) were significantly higher in the treated rats. No significant difference was found between the seminal vesicle weights of the 2 groups.The length (mm) of stage(s) per 1000 mm of seminiferous tubules of the two groups were: stage II (199.321.3 vs 64.7514.48 mm; P<0.01), II-III (103.510.8 vs 23.46.1 mm; P<0.01), IV-V (62.711.9 vs 22.77.9; P<0.05) and VI (73.220.9 vs 23.312.9 mm; P<0.05). All these values were significantly higher in the control rats, whereas with stages IX-XI (349.261.0 vs 583.550.2 mm; P<0.05) and XII (36.59.3 vs 40.99.6; P<0.05), the values were significantly higher in the treated rats.
Treatment with Lepidium meyenii also resulted in increased frequency of stages IX-XI, XII and XIII-XIV, and a relative reduction in stages II-III, IV-V, VI, and I. Figure 1 shows the relative frequency of stages of the cycle in the rats.
Figure 1. Relative frequency of each stage of the seminiferous epithelium cycle. To each stage of the seminiferous cycle, the control group was assigned a relative frequency of 1.4
Discussion
Father
Cobo in the History of the New World in 1653 believed that the root of
Lepidium meyenii
or maca in the Andean region could improve fertility in animals
and humans[1].
Our
results demonstrated that extract of Lepidium meyenii prepared
as used by the natives
of the Andean region had a beneficial effect on spermatogenesis. Testicular
weight was significantly higher in the rats treated with Lepidium meyenii and
the pattern of stages of the seminiferous epithelium was modified with increased
stages IX-XII and ensuing reduction in stages I-VI. In stages IX and XII
spermatogonial mitosis are located[5]. Therefore, in
the present experimental setting, Lepidium meyenii is considered
to act on the initial stages of spermatogenesis.
Our
data suggest that Lepidium meyenii may improve spermatogenesis
in the spermatogonial mitosis. A high testicular weight and an increase
in the frequencies and lengths of stages IX-XII support this hypothesis.
It
was interesting to find that the epididymal weight increased significantly
in the animals treated with Lepidium meyenii. Epididymis is a target
for androgen action.
It is not due to a possible androgenic action of the plant as the weight
of the seminal vesicles, another androgen-dependant organ, was not affected.
In addition, stage VII which will be increased after testosterone administration[6]
is not affected as well. The increase in epididymal weight might be due
to an increase in the sperm number. Further investigations are required
to clarify this point.
References
[1]
Obregn LE. Maca. Lima: Instituto de Fitoterapia Americana; 1998. p 19-63.
[2] Kim C, Choi H, Kim CC, Kim JK, Kim MS. Influence of ginseng on mating
behavior of male rats. Am J Chin Med 1976; 4: 163-8.
[3] Zheng BL, He K, Kim CH, Rogers L, Shao Y, Huang ZY, et al.
Effect of lipidic extract from Lepidium meyenii on sexual behavior in
mice and rats. Urology 2000;55: 598-602.
[4] Le Blond CP, Clermont Y. Definition of the stages of the cycle of
the seminiferous epithelium in the rat. Ann NY Acad Sci 1952; 55: 548-73.
[5] Parvinen M. Regulation of the seminiferous epithelium. Endocrinol
Rev 1982; 3: 404-17.
[6] Almenara A, Escalante G, Gazzo E, Gonzales GF. Transillumination to
evaluate spermatogenesis: Effect of testosterone enanthate in adult male
rats. Arch Androl 2001; 46: 21-7.
[7] Gonzales GF, Del Valle L. Adult rat seminiferous tubules secretes
a fraction greater than 30 Kda to regulate spermatogenesis. Hum Reprod
1995; 10: 1435-43.
[8] Van Beek ME, Meistrich ML. A method for quantifying synchrony
in testes of rats
treated with vitamin A deprivation and readministration. Biol Reprod 1990;
42:
424-31.
Correspondence
to: Dr.
Gustavo F. Gonzales. Instituto de Investigaciones de la Altura,
Universidad Peruana Cayetano Heredia, P.O. 1843, Lima, Peru.
Tel:
+51-1-4821195
E-mail: iiad@upch.edu.pe
Received 2001-04-25 Accepted
2001-08-19
