title: Licorice extract does not impair the male reproductive function of rats.
abstract: The effect of water extract of licorice (Glycyrrhiza uralensis), one of the most widely used medicinal plants in Oriental nations and in Europe, on male reproductive function was investigated in rats. Licorice extract was prepared as in Oriental clinics and orally administered at doses of 500, 1,000 or 2,000 mg/kg, the upper-limit dose (2,000 mg/kg) recommended in the Toxicity Test guideline of the Korea Food and Drug Administration, to 6-week-old male rats for 9 weeks. Licorice extract neither induced clinical signs, nor affected the daily feed consumption and body weight gain. There were no significant changes in testicular weights, gross and microscopic findings, and daily sperm production between vehicle- and licorice-treated animals, in spite of slight decreases in prostate weight and daily sperm production at the high dose (2,000 mg/kg). In addition, licorice did not affect the motility and morphology of sperm, although the serum testosterone level tended to decrease without significant difference, showing a 28.6% reduction in the high-dose (2,000 mg/kg) group. The results suggest that the no observed adverse-effect level of licorice extract is higher than 2,000 mg/kg, the upper-limit dose, and that long-term exposure to licorice might not cause profound adverse effects.
authors.affiliation: College of Veterinary Medicine and Research Institute of Veterinary Medicine, Cheongju, Chungbuk, Korea.
authors.forename: Sunhee
authors.initials: S
authors.lastname: Shin
authors.forename: Ja Young
authors.initials: JY
authors.lastname: Jang
authors.forename: Byong-il
authors.initials: BI
authors.lastname: Choi
authors.forename: In-Jeoung
authors.initials: IJ
authors.lastname: Baek
authors.forename: Jung-min
authors.initials: JM
authors.lastname: Yon
authors.forename: Bang Yeon
authors.initials: BY
authors.lastname: Hwang
authors.forename: Dongsun
authors.initials: D
authors.lastname: Park
authors.forename: Jeong Hee
authors.initials: JH
authors.lastname: Jeon
authors.forename: Sang-Yoon
authors.initials: SY
authors.lastname: Nam
authors.forename: Young Won
authors.initials: YW
authors.lastname: Yun
authors.forename: Yun-bae
authors.initials: YB
authors.lastname: Kim
mesh_terms: D000284:Administration, Oral; D000818:Animals; D006035:Glycyrrhiza / Q000009:adverse effects*; D008297:Male; D009929:Organ Size; D010936:Plant Extracts / Q000008:administration & dosage / Q000009:adverse effects; D011467:Prostate / Q000187:drug effects; D051381:Rats / Q000523:psychology*; D017207:Rats, Sprague-Dawley; D012098:Reproduction / Q000187:drug effects* / Q000502:physiology*; D013047:Specific Pathogen-Free Organisms; D013094:Spermatozoa / Q000187:drug effects; D013737:Testis / Q000187:drug effects; D013739:Testosterone / Q000097:blood
chemical_list: D010936:Plant Extracts; D013739:Testosterone