of ligustrum fruit extract on reproduction in experimental diabetic rats
FENG, Shu-Hua LI1, Yan WANG2, Chang-Chun CHEN1,
Provincial Diabetes Treatment Center, Shenyang 110015 , China
Asian J Androl 2001 Mar; 3: 71-73
Aim: To study the effect of ligustrum fruit on spermatogenesis and blood gonadal hormones in diabetic rats. Methods: Experimental diabetes was induced in male Wistar rats with streptozotocin. Ligustrum fruit extract was given by gastric gavage at a dose of crude drug 30 gkg-1d-1 for 110 days. The serum gonadadotropic hormones and testosterone were determined on d 60 and testicular histology examined on d 110. Results: In the control diabetic rats, the seminiferous tubules were dilated and the spermatogenic cells irregularly arranged. Spermatogenesis was arrested with the number of spermatids highly reduced and spermatozoa not observed. In the treated rats, all types of spermatogenic cells were practically normal. The serum luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone levels were higher in the treated than in the control rats, but the difference was insignificant. Conclusion: In experimental diabetic rats, ligustrum fruit extract protects the damaging effect of experimental diabetes on spermatogenesis.
1 IntroductionAbout 90% of diabetic patients have disturbances in sexual function, including a decrease in libido, impotence and infertility. Due attention has been paid to the search of effective drugs in the field of traditional Chinese medicine (TCM). The glossy privet fruit is a kind of herb known to nourish the Liver and Kidney. In TCM, the so called Kidney is supposed to be related to reproduction. Experimental studies have shown that the fruit alleviates hyperlipidemia and hyperglycemia, and may mitigate atherosclerosis[2,3], however, its effect on reproduction has not been experimentally clarified. The present investigation was designed to study the effect of ligustrum fruit on spermatogenesis and serum FSH, LH and testosterone levels in experimental diabetic rats.
2 Materials and methods
Ligustrum fruit preparation
fruit we used were cultivated in Henan and bought from the Haozhou Drug
Company. First soak 1 kg of the fruit in 2000 mL of tap water for one
hour, then boil for 30 minutes. Add more water to supplement the water
loss and boil for another 30 minutes. Finally, condense the decoction
to a concentration of 4 g crude drug per mL. The principal active constituent
in the preparation is oleanolic acid and the content is 2.93%.
Animals and treatments
Wistar rats (body weight 24020 g) were supplied by the Laboratory Animal
Centre of the China Medical University. The animals were separated at
random into two groups, 10 normal controls and 20 experimental diabetic
rats. To the latter, streptozotocin (Sigma, USA) 60 mg/kg was injected
intraperitoneally. Seven days later, blood was sampled from the orbital
vein and the glucose concentration was determined by the glucose-oxidase
method following the procedures described in the kit (Exquisite Chemical
Industry Co., Beijing). Animals with blood glucose higher than 16.7 mmol/L
were used for the experiment and divided at random into the Diabetic Treated
and Diabetic Control groups of 5 animals each. Rats of the Diabetic Treated
group were gavaged ligustrum fruit preparation (4.5 mLkg-1d-1,
equivalent to crude drug 30 gkg-1d-1) for 110
days and the two Control groups, the same quantity of water. On day 60
of treatment, the serum levels of FSH, LH and testosterone were determined
by radioimmuno-method according to the procedures provided in the kit
(North Biochemistry Kit Center, Beijing). On day 110, rats were sacrificed
and the testes routinely fixed, sectioned into discontinuous slices (8
m) and stained with hematoxylin/eosin for morphological examination
under light microscope.
60 days of treatment the changes in the serum hormone levels were shown
in Table 1. It can
be seen that: the hormonal levels in the Diabetic Control rats were lower
than those of the Normal controls; the LH, FSH and T levels were higher
in the Diabetic Treated rats than in the Diabetic Control rats; and the
LH and FSH levels were even higher in the Diabetic Treated rats than in
the Normal Control rats. The difference between any of the two groups
was statistically insignificant.
1. Ligustrum effect on serum hormones in normal and experimental diabetic
Diabetic Treated group and Normal Control group
110 days of treatment, all kinds of spermatogenic cells were practically
normal. Cells were arranged regularly in 8-9 layers. There were numerous
spermatids and grown-up spermatozoa could be seen scattered here and there
(Figures 1, 2). The morphology of the Normal Control rats was more or
less the same.
Diabetic Control group
this group the spermatogenesis was noticeably disturbed. The seminiferous
tubules were dilated and the spermatogenic cells were irregularly arranged
in 3-5 layers. The number of spermatogonium, primary spermatocyte, secondary
spermatocyte and spermatids were markedly decreased and grown-up spermatozoa
were not found (Figures 3, 4).
tubules of rat in the control group: the spermatogenic cell are sparsely
separated, spermatids unnoticed, no sperm present (200) HE stain.
fruit is a kind of herb possessing nourishing effects on the Liver
and Kidney. According to the TCM theory, Kidney is the origin
of the innate constitution storing vital essence and in charge of growth,
development and reproduction. The Kidney also strengthens the bone
and helps producing the marrow. Li indicated that herbal
drugs nourishing the Kidney could regulate female reproductive function.
In the present study we observed that in rats ligustrum fruit counteracted
the damaging effect of experimental diabetes on spermatogenesis. Data
also suggested that the fruit might also revert the inhibitory effect
of experimental diabetes on serum FSH, LH and testosterone levels, however,
it is not conclusive. It is a pity that we did not assay the hormonal
profiles on d 110 of treatment, which have been scheduled in a future
study. The toxicity of the glossy privet fruit was very low. Rabbit taking
orally fresh fruit 75 g did not show any toxic manifestation.
The LD50 of liguustrum in mice is 600 mg/kg (Liu HS, restricted publication,
Jiang GY. Practical Diabetes. 1st Edition. Beijing: People's Health Publishing
House; 1996. p 295.
Shi-Liang FENG, Liaoning Provincial Diabetes Treatment Center, 48 First
Quanyuan Road, Shenyang, China.