Abstract:

Objective: To investigate the effect of high dose of royal jelly on the growth and development of female rats.
Methods: The rats were given by gavage fresh royal jelly in the experimental group at a dose of 3 g/(200 g·d) body weight
(BW), while the rats in the control group was administered by gavage with normal saline at a dose of 3 mL/(200 g·d)
BW. After 4 weeks of administration, the rats were continuously fed for additional 2 weeks. Eight rats from each group
were anatomized every two weeks. The visceral indexes of heart, liver, spleen, lung, kidney and adrenal grand were
examined. Serum estradiol (estradiol, E2), follicle stimulating hormone (FSH), luteinizing hormone (LH) and progesterone
(progesterone, P) was detected with radioimmunoassay. Real-time PCR was used to detect the expression levels of estrogen
receptor alpha (ERα), estrogen receptor beta (ERβ), follicle stimulating hormone receptor (FSHR), luteinizing hormone
receptor (LHR) and progesterone receptor (PR). The results showed that there was no significant difference between the
experiment and control groups after 2 weeks of administration, but a significant difference was found after 4 weeks. Body
weight in the experiment group was significantly lower than in the control group, E2 level was significantly higher than in
the control group, and the mRNA expression level of ovarian PR was higher than in the control group. The expression levels
of ERα, ERβ and PR in uterus were significantly higher than in the control group. At 2 weeks after administration, there
was no significant difference in body weight, organ coefficients or serum sex hormone levels between both groups. But the
mRNA expression level of FSHR, ERβ and PR in the ovary were significantly higher than those in the control group, and
the expression levels of ERα, ERβ, FSHR and PR in the uterus were significantly higher than those in the control group. In all, the
growth and development of female rats were influenced by the gavage administration of high-dose royal jelly to some extent.

Key words: royal jelly, organ coefficient, hormone, hormone receptor