Effects of Exposure to Genistein during Pubertal Development on the Reproductive System of Male Mice

Abstract

Abstract. Genistein, a soybean-originated isoflavone, is widely consumed by humans for putative beneficial health effects but its estrogenic activity may affect adversely the development of the male reproductive system. Twenty-one days old ICR mice weaned from dams fed with a casein-based AIN-76A diet during gestation and lactation were exposed to genistein (2.5 and 5.0 mg/kg/day, p.o.) for 5 weeks. 17β-Estradiol (7.5 µg/kg/day) and corn oil were used for the positive and negative vehicle controls, respectively. The animals were fed the casein-based AIN-76A diet throughout the experiment. There were no significant differences in body weights of mice between the genistein groups and the negative control group. No significant differences in relative reproductive organ weights were found among all experimental groups. Sperm counts in epididymis and testes were slightly decreased in the genistein-exposed groups compared with control group. Sperm motile characteristics in genistein-exposed groups were slightly higher than those of the control group. Levels of phospholipid hydroxide glutathione peroxidase mRNA in the testis, epididymis, and prostate of mice exposed to genistein or estradiol were significantly higher than those of the controls (P<0.05). Exposure to genistein caused hyperplasia of Leydig cells in the testis and a slight increase of interstitial fibroblasts in the epididymis, while estradiol treatment caused severe damage to the testis and epididymis. These results suggest that dietary uptake of genistein during the juvenile period may affect male reproductive development, resulting in a slight decrease in sperm count, but with an increase in sperm motion quality.

Licorice Extract Does Not Impair the Male Reproductive Function of Rats

“…Estrogens including phytoestrogens such as genistein were found to impair gonadal development and spermatogenesis [10,14,17,19,20,24,26]. It is well known that licorice possesses estrogenic activity [22,35,36,39,40].…”

“…Moreover, it is well known that testes of young rats under development are much more susceptible to estrogens than those of adults [24]. Also, there are gender and species differences in the susceptibility of reproductive functions to genistein [19,24]. Females and mice are more vulnerable than males and rats.…”

“…In addition, licorice was found to exert estrogen-like activity [22,35,36,39,40]. Like estrogen, phytoestrogens such as genistein have been found to impair spermatogenesis, and thereby induce deficit of sperm [10,14,17,19,20,24,26]. Such observations led us to investigate the effects of licorice on male reproductive function.…”

Case study with natural substances on the various options to identify and categorise endocrine disruptors

“…Additionally, there is a LOAEL of 2.5 mg/(kg bw x d) for Leydig cell hyperplasia and slight decrease in sperm count in a subacute oral toxicity study in male mice [17]. Such an effect may also be due to endocrine disruption (see OECD Guidance document 150 on TG 407) of a substance.…”

Expression pattern of cytosolic glutathione peroxidase (cGPx) mRNA during mouse embryogenesis

“…To determine the expression pattern of cGPx mRNA in mouse embryos, cDNA was amplified by a thermal cycler (MJ Research, USA) using the primers 5¢-tacattgtttgagaagtgcg-3¢ and 5¢-gacagcagggtttctatgtc-3¢ (S 1 -AS 2 :266 bp; Chambers et al1986). Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) primers were used as an internal standard control (Lee et al 2004). Results were analyzed with an AlphaEase version 5.5 analyzer system (Alpha Innotech, USA).…”