Abstract: Objective To study the effect of myricetin on spermatogenesis impairment in male mice exposed to lead
and discuss its mechanism. Methods Sixty Kunming mice were randomly divided into control group, lead group,
methyltestosterone group, myricetin (low, medium and high doses) groups, 10 mice in each group. The spermatogenic
disorder model was established by intraperitoneal injection of lead acetate (20 mg/kg, 7 d). From the second day of modeling, different doses of myricetin (100, 200 and 400 mg/kg, for 42 d) were given to low, medium and high dose myricetin groups. The sperm density, the testis index and changes of sperm aberration rate were observed in mouse groups. The serum levels of  testosterone (T), follicle-stimulating hormone (FSH), luteinizing hormone (LH), sorbitol dehydrogenase (SDH) and
malondialdehyde (MDA) in the testis tissue were detected. The pathological changes of testicular tissues were observed by
HE staining. Results Compared with lead exposed group, the sperm density increased, the testis index increased and the
distortion rate of sperm reduced in myricetin groups. The serum levels of LH and FSH decreased and T increased, the
content of MDA in testis decreased and the activity of SDH increased in myricetin groups (P＜0.05). Pathological results
showed that there were decline of spermatogenic cells, and few spermiogenesis in most of seminiferous tubule in lead
exposed group. No above changes were found in high dose myricetin group. Conclusion Myricetin can improve
spermatogenesis, reduce the oxidative stress damage of testicular tissue caused by lead acetate and promote testosterone
secretion, increase testicular and sperm activity, thereby improving the spermatogenic function of testes.

Key words: testosterone, luteinizing hormone, follicle-stimulating hormone, myrica flavonoids, lead acetate poisoning,
spermia