title: Dose-response effects of Lepidium meyenii (Maca) aqueous extract on testicular function and weight of different organs in adult rats.
abstract: Lepidium meyenii (Brassicaceae) known as Maca grows exclusively between 4000 and 4500 m over the sea level in the Peruvian central Andes. The dried hypocotyls of Maca are traditionally used as food and for its supposed fertility-enhancing properties. A dose-response study was performed to determine the effect of 7 days oral administration of an aqueous lyophilized extract of Maca at 0.01-5 g/kg (corresponding to 0.022-11 g dry hypocotyls of Maca/kg) on body and different organ weights, stages of the seminiferous tubules, epididymal sperm count and motility, and serum testosterone and estradiol levels in rats. In doses up to 5 g extract/kg, no toxicity was observed. Almost all organ weights were similar in controls and in the Maca extract-treated groups. Seminal vesicles weight was significantly reduced at 0.01 and 0.10 g extract/kg. Maca increased in length of stages VII-VIII of the seminiferous tubules in a dose-response fashion, with highest response at 1.0 g/kg, while caput/corpus epididymal sperm count increased at the 1.0 g dose. Cauda epididymal sperm count, sperm motility, and serum estradiol level were not affected at any of the doses studied. Serum testosterone was lower at 0.10 g extract/kg. Low-seminal vesicle weights correlated with low-serum testosterone levels (R2=0.33; P<0.0001) and low-testosterone/estradiol ratio (R2=0.35; P<0.0001). Increase in epididymal sperm count was related to lengths of stages VII-VIII. Highest effect on stages VII-VIII of the seminiferous tubules was observed at 1.0 g Maca aqueous extract/kg. The present study demonstrated that Maca extract in doses up to 5 g/kg (equivalent to the intake of 770 g hypocotyls in a man of 70 kg) was safe and that higher effect on reproductive parameters was elicited with a dose of 1 g extract/kg corresponding to 2.2 g dry Maca hypocotyls/kg.
authors.affiliation: Department of Biological and Physiological Sciences and Instituto de Investigaciones de la Altura, Universidad Peruana Cayetano Heredia, Postal Office 1843, Lima, Peru.
authors.forename: Francisco
authors.initials: F
authors.lastname: Chung
authors.forename: Julio
authors.initials: J
authors.lastname: Rubio
authors.forename: Carla
authors.initials: C
authors.lastname: Gonzales
authors.forename: Manuel
authors.initials: M
authors.lastname: Gasco
authors.forename: Gustavo F
authors.initials: GF
authors.lastname: Gonzales
mesh_terms: D000284:Administration, Oral; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical / Q000379:methods; D004822:Epididymis / Q000166:cytology / Q000187:drug effects; D004958:Estradiol / Q000097:blood; D029686:Lepidium; D008297:Male; D009929:Organ Size / Q000187:drug effects*; D010568:Peru / Q000208:ethnology; D010936:Plant Extracts / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012639:Seeds / Q000737:chemistry; D012669:Seminal Vesicles / Q000187:drug effects / Q000503:physiopathology; D012671:Seminiferous Tubules / Q000187:drug effects; D013076:Sperm Count / Q000379:methods; D013081:Sperm Motility / Q000187:drug effects / Q000502:physiology; D013091:Spermatogenesis / Q000187:drug effects; D013737:Testis / Q000187:drug effects* / Q000502:physiology*; D013739:Testosterone / Q000097:blood; D013997:Time Factors; D014867:Water
chemical_list: D010936:Plant Extracts; D014867:Water; D013739:Testosterone; D004958:Estradiol