Dose-response effects of Lepidium meyenii (Maca) aqueous extract on testicular function and weight of different organs in adult rats

J Ethnopharmacol. 2005 Apr 8;98(1-2):143-7. doi: 10.1016/j.jep.2005.01.028.


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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Animals
  • Dose-Response Relationship, Drug
  • Drug Evaluation, Preclinical / methods
  • Epididymis / cytology
  • Epididymis / drug effects
  • Estradiol / blood
  • Lepidium*
  • Male
  • Organ Size / drug effects*
  • Peru / ethnology
  • Plant Extracts / administration & dosage
  • Plant Extracts / chemistry
  • Plant Extracts / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Seeds / chemistry
  • Seminal Vesicles / drug effects
  • Seminal Vesicles / physiopathology
  • Seminiferous Tubules / drug effects
  • Sperm Count / methods
  • Sperm Motility / drug effects
  • Sperm Motility / physiology
  • Spermatogenesis / drug effects
  • Testis / drug effects*
  • Testis / physiology*
  • Testosterone / blood
  • Time Factors
  • Water


  • Plant Extracts
  • Water
  • Testosterone
  • Estradiol