Lepidium meyenii Walp. improves sexual behaviour in male rats independently from its action on spontaneous locomotor activity
Introduction
The incidence of sexual inadequancy in human males, including sexual impotence, and the concern that it causes in the affected subjects, are indirectly indicated by the great number of available treatments (drugs or combination of drugs for systemic administration, topical application or intracavernous injection) (Montorsi et al., 1995). The increasing number of men seeking help for impotence has expanded basic physiological and pharmacological research on sexual performance.
Many plants extracts are traditionally employed among different cultures in order to improve sexual performances (Gay et al., 1975, Hollister, 1975, Kirkorian, 1984, Nishimoto et al., 1984, Popik et al., 1995, Susset et al., 1989, De Smet, 1997a, Arletti et al., 1999); in spite of this, pharmacologists generally disparage this use, and few experimental studies have been performed in order better to define claims of efficacy (Clark et al., 1984, Taha et al., 1995, De Smet, 1997b).
Lepidium meyenii Walpers, well known in South America as ‘Maca’, is an Andean crop which it is found only in a very restricted area of central Peru in the department of Jinin and Pasco, in the agro-ecological zone above 4000 m where low temperature and strong winds limit other crops, but it can be successfully cultivated outside its current ‘natural’ habitat. Maca is a biennial herbaceous plant, whose subterraneous part (hypocotyl) is edible and highly valued for its nutritional value (especially proteins and minerals). The rural community is firmly convinced that eating Maca enables couples who think they are infertile to have children (Quiros et al., 1996, Toledo et al., 1998). Moreover, recently, athletes are finding Maca to be an excellent alternative to anabolic steroids (but the real efficacy in this field has still to be totally proved) (Grunewald and Bailey, 1993).
The aim of the present study is to determine the effect of acute and chronic oral administration of a purified extract from L. meyenii root on male rats sexual performances and spontaneous locomotion.
Section snippets
Animals
A total of 110 Sprague–Dawley rats of either sex (90 males and 20 females) were obtained from Charles River (Calco, Como, Italy). They were housed in groups of three, males and females separately, in Plexiglas cages (40×25×15 cm), in climatized colony rooms (21±1°C; 60% humidity) on a 12 h light/dark cycle, with lights off at 07:00 h. The rats were 3 months old on arrival, and weighed 240–260 g (males) and 180–200 g (females). Food in pellets (MIL, Morini, S. Polo d'Enza, Reggio nell'Emilia,
Sexual performances
As shown in Table 1, both lower and higher acutely administered Maca doses significantly decreased ML, IL and ICI (P<0.05), while only the 75 mg kg−1 dose decreased the PEL (T=29, P<0.05). This effect was more evident with the higher dose (m vs. M: T=25, P<0.05). After 15 days of treatment, both doses are able to decrease ML, IL, EL and PEL in a statistically significant way (Table 2), while only the 75 mg kg−1 dose reduced ICI (T=40, P<0.05). IL, EL and PEL variations after chronic treatment
Discussion
Clinical plant-based research has made particularly rewarding progress in many important fields like that of anticancer drugs (taxoids and comptothecins). In addition to fluid plant-derived drugs there is an enormous market for crude herbal medicines. Natural product research can often be guided by ethnopharmacological knowledge, and it can give substantial contribution to drug innovation by providing novel chemical structures and/or mechanisms of actions (Harvey, 1999).
Sexual incompetence,
References (24)
Male rat sexual behaviour
Brain Research Protocols
(1997)Chemical composition of Lepidium meyenii
Food Chemistry
(1994)Medicines from nature: are natural products still relevant to drug discovery
Trends in Pharmacological Science
(1999)- et al.
Pfaffosides and nortriterpenoid saponins from Pfaffia paniculata
Phytochemistry
(1984) - et al.
Effect of yohimbine hydrochloride on erectile impotence: a double blind study
Journal of Urology
(1989) - et al.
Effect of (−)cathinone, a psycho-active alkaloid from khat (Catha edulis Forsk.) and caffeine on sexual behavior in rats
Pharmacological Research
(1995) - et al.
Genetic variability of Lepidium meyenii and to other Andean Lepidium species (Brassicaceae) assessed by molecular markers
Annals of Botany
(1998) - et al.
Effect of a lipidic extract from Lepidium meyenii on sexual behavior in mice and rats
Urology
(2000) - et al.
Stimulating property of Turnera diffusa and Pfaffia paniculata extracts on the sexual behavior of male rats
Psychopharmacology
(1999) Characteristic of masculine ‘sex drive’
Enhancement of sexual motivation in male rats by yohimbine
Science
Cited by (136)
<sup>1</sup>H qNMR-based quantitative analysis of total macamides in five maca (Lepidium meyenii Walp.) dried naturally
2021, Journal of Food Composition and AnalysisHerbal medicine used to treat andrological problems: Americas
2021, Herbal Medicine in AndrologyLepidium meyenii (Maca) in male reproduction
2021, Natural Product ResearchChemical composition and health effects of maca (Lepidium meyenii)
2019, Food ChemistryAcridocarpus Smeathmannii (DC.) Guill. & Perr. Root enhanced reproductive behavior and sexual function in male wistar rats: Biochemical and pharmacological mechanisms
2019, Journal of EthnopharmacologyCitation Excerpt :Studies have shown an association between reproductive and social behavior, we assessed exploratory behavior in the treated rats. In the studies of Cicero et al. (2001) and Carro-Juarez et al. (2004), sexual behavior in male rats was independent of spontaneous locomotor activity in rats. Here, locomotion activity improved irrespective of whether divided doses of HEASR, clinical agents or both were administered to animals.