Al-Yahya Abdulaziz A, Al-Majed Abdulhakeem A, Al-Bekairi A M, Al-Shabanah O A, Qureshi S
Department of Pharmacology, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh-11451, Saudi Arabia.
J Ethnopharmacol. 2006 Sep 19;107(2):222-8. doi: 10.1016/j.jep.2006.03.014. Epub 2006 Mar 27.
Ginkgo biloba (an herbal product), used as a folkloric medicine in the treatment of dementia, was evaluated for its effects on reproductive, cytological and biochemical toxicity in male Swiss albino mice. The mice were treated with different doses (25, 50 and 100mg/kg/day) of the aqueous suspension of Ginkgo biloba for 90 days by oral gavage. The following parameters were evaluated: (1) reproductive organ weight; (2) motility and content of sperms; (3) spermatozoa morphology; (4) cytology of the testes chromosomes; (5) study on reproduction; (6) biochemical study on proteins, nucleic acids, malondialdehyde (MDA) and nonprotein sulfhydryl (NP-SH). The treatment caused significant changes in the weight of caudae epididymis, prostate, chromosomal aberrations, rate of pregnancy and pre-implantation loss. However, the percent motility, sperm count and morphology of spermatozoa were not affected. Our study on biochemical parameters showed depletion of nucleic acids, NP-SH and increase of MDA, which elucidated the role of free radical species in the induced changes in testis chromosomes and the reproductive function. The exact mechanism is not known, however, the activation of GABA, glycine and glutamate under the influence of Ginkgo biloba and its constituents might have generated free radicals and depleted cellular glutathione by calcium influx and membrane depolarization. The observed toxicity is attributed to the toxic constituents (ginkgolic acids, biflavones, cardanols, cardols, bilobalides and quercetin) of Ginkgo biloba. Our results warrant careful use of Ginkgo biloba as a remedy for impotence and/or erectile dysfunction.
银杏叶（一种草药产品），作为治疗痴呆症的民间药物，对雄性瑞士白化小鼠的生殖、细胞学和生化毒性作用进行了评估。通过口服灌胃法，用不同剂量（25、50和100毫克/千克/天）的银杏叶水悬浮液对小鼠进行处理，持续90天。评估了以下参数：（1）生殖器官重量；（2）精子活力和含量；（3）精子形态；（4）睾丸染色体细胞学；（5）生殖研究；（6）蛋白质、核酸、丙二醛（MDA）和非蛋白巯基（NP-SH）的生化研究。该处理导致附睾尾、前列腺重量、染色体畸变、妊娠率和植入前丢失率发生显著变化。然而，精子活力百分比、精子计数和精子形态未受影响。我们对生化参数的研究表明核酸、NP-SH减少，MDA增加，这阐明了自由基在睾丸染色体和生殖功能诱导变化中的作用。确切机制尚不清楚，然而，在银杏叶及其成分的影响下，γ-氨基丁酸、甘氨酸和谷氨酸的激活可能通过钙内流和膜去极化产生自由基并消耗细胞内谷胱甘肽。观察到的毒性归因于银杏叶的有毒成分（银杏酸、双黄酮、腰果酚、卡多醇、白果内酯和槲皮素）。我们的结果表明应谨慎使用银杏叶作为治疗阳痿和/或勃起功能障碍的药物。
