Background: Humulus lupulus (Hops) is well-known throughout the world as the raw material in the brewing industry. In addition, hops have been found to have estrogenic and antioxidant properties. The object of this study aimed to examine the effects of hops during gestation and lactation on the onset of puberty, estrus cycle, reproductive organ weights and fertility index in female mice.
Methods: 10 pregnant mice were exposed to hops at doses of 0 (control), 50, 100 and 150 mg/kg/ day, by gavage, from gestational days 7 to postnatal day 7. Female offspring (n=10) were analyzed for vaginal opening day, estrus cycle regularity, weights of the uterus and ovaries, and fertility index. Statistical analysis was carried out using one-way ANOVA and post-hoc Tukey tests (p<0.05).
Results: Vaginal opening day was significantly advanced by 100 (p<0.01) and 150 (p<0.001) hops. Duration mean of estrus cycle increased in 50 (p<0.05), 100 (p<0.001) and 150 (p<0.001) hops and diestrus index increased in 100 (p<0.001) and 150 (p<0.001). Decreased ovary weight in 100 (p<0.01) and 150 (p<0.01) hops and increased uterus weight in 50 (p<0.05), 100 (p<0.01) and 150 (p<0.01) hops were observed. In addition, fertility index in 100 (p<0.05) and 150 (p<0.01) hops decreased compared with control.
Conclusion: The present study results showed that perinatal exposure to hops advanced the puberty, disrupted estrus cycle and decreased fertility in female offspring.