Home  |  Archive  |  AJA @ Nature  |  Online Submission  |  News & Events  |  Subscribe  |  APFA  |  Society  |  Links  |  Contact Us  |  中文版

Effects of flavonoids from Semen Cuscutae on the reproductive system in male rats

Da-Nian QIN, Bai-Rong SHE, Yun-Chu SHE1, Jian-Hong WANG1

Department of Physiology, Shantou University School of Medicine, Shantou 515031, China
1Jiangxi College of Traditional Chinese Medicine, Nanchang 330006, China

Asian J Androl  2000 Jun; 2: 99-102

Keywords: Cuscuta sinensis; Leydig cell; testosterone; LH; estradiol; pituitary gland
Aim: To evaluate the effects of the flavonoids extracted from the Semen Cuscutae (FSC) on the reproductive and endocrine functions in male rats. Methods: (1) FSC were obtained from the semen of Cuscuta sinensis Lam through solvent extraction and polyamide columnar chromatography; (2) Effect of FSC on the reproductive organs was assessed in immature rats. Rats were administered FSC through gastric gavage at a dose of 300 mg/kg per day for 7 days and the weights of testis, epididymis, seminal vesicle and pituitary gland were then observed; (3) To observe the effect of FSC on the reproductive endocrine function: same dose level of FSC was given to male rats of different age groups for 7 days; on day 8, the plasma testosterone (T), estradiol (E2) and LH were determined by RIA, the specific binding of LH was estimated and the testes were weighed. (4) Effect of FSC on LH secretion was assessed in vitro on cultured adenohypophysis. (5) Effect of FSC on T secretion was assessed in vitro on Leydig cell culture. Results: FSC increased the weights of testis, epididymis and pituitary gland, and stimulated T and LH secretion both in vitro and in immature rats. Conclusion: FSC invigorates the reproductive system and reproductive endocrine function in male rats.

1 Introduction

The semen of Cuscuta sinensis Lam (SCS) is a classical kidney invigorating drug[1]. In Chinese Traditional Medicine (TCM), the kidney is considered to be closely related to reproduction. The reproductive and endocrine effects of kidney invigorating drugs, including SCS, have been studied to some extents in the humans and animals[2-5]. It has been shown that the principal components of SCS are flavonoids[6]. The drug is widely used in the treatment of reproductive endocrine diseases both in men and women[7,8]. The aim of the present study was to evaluate the effects of the flavonoids extracted from the semen of Cuscuta sinensis Lam (FSC) on the reproductive-endocrine system of male rats.

2 Materials and methods

2.1 Drug preparation

The mature seeds of Cuscuta sinensis Lam were dried and powdered, and were then extracted with 75% alcohol under reflux. The extract was concentrated and subjected to columnar chromatography on polyamide, which was eluted successively with alcohol and petroleum ether to yield the total flavonoids, the retrieval rate being 0.5%. Thin layer chromatography showed that the extract mainly contained four components: quercetin, astragalin, hyperoside and quercetin-3-o-glucose, which were identical with those reported in the literature[6]. In the present study, FSC was prepared at a concentration of 10 g/L. Rats were treated with FSC at a dose of 150 mg/kg body weight through gastric gavage bid.   

2.2  Animals

Healthy SD rats of different age groups were obtained from the Experimental Animal Centre of our Medical School. They were housed under standard conditions in a controlled environment with a 12-h photoperiod and had free access to food and water.

2.3  Hormone determination

Testosterone (T) and estradiol (E2) were determined by RIA, and LH by radio-receptor assay (RRA)[9]. The RIA kits and 125I-hCG were provided by the Shanghai Institute of Biological Products.

2.4 Assessment of effect of FSC on reproductive organs

Sixty immature male SD rats, 50-60 days old (60-80 g), were divided randomly into 3 groups of 20 rats each. To the first group, FSC was administered through gastric gavage at a dose of 300 mg/kg per day. To the second group, hCG was administered im at a dose of 5 IU/rat per day. To the third group (control) a similar volume of physiological saline was given orally. The drugs were administered consecutively for 7 days and on the 8th day, the animals were sacrificed and the weights of the testis, epididymis, seminal vesicles and pituitary gland were observed.

2.5  Assessment of effect of FSC on reproductive endocrine function

Male SD rats at the age of 2 months (75-85 g), 10 months (200-250 g), 18 months (250-350 g) and 24 months (250-350 g) were used in this experiment. The rats from each age group were randomly divided into 2 groups: treatment and control. To the treatment group FSC was administered at a dose similar as in the above experiment and to the control group equal volume of physiological saline was administered. On the 8th day, the animals were sacrificed and blood was obtained from the abdominal aorta. Plasma samples were prepared for T, E2 and LH determination. Testes were weighed and the specific binding of hCG to testis (in pg hCG/10 mg testis) was determined according to the method of Frowein and Engel[11].

2.6  Effect of FSC on LH production in vitro

The experiment was performed according to the method of Lee et al[12] fly, 30 pituitary glands were obtained from adult male SD rats and were immediately preserved in frozen PBS. The adenohypophyses were then divided into two parts along the midline and were grouped by pair-matched design. One part was used as the control and the other treated as follows: (1) FSC group: 200 g FSC and 1 mL M199 (Sigma, USA) were added; (2) GnRH group: 1 g of GnRH (Shanghai Institute of Biochemistry, The Chinese Academy of Science ) and 1 mL M199 were added; (3) GnRH+FSC group: both reagents and 1 mL M199 were added; to the 3 control groups, only M199 was added. These groups were then cultured at 37 for 4 hours in an atmosphere of 95% O2 and 5% CO2. Thereafter LH concentrations were assayed in the media.

2.7   Effect of FSC on T production in vitro

Leydig cell suspension was prepared from SD rats according to the method of Kinefelter[13] with a final concentration of 1106 cells/mL M199. Four groups were constituted: (1) FSC group: to this group 200 g FSC and 1 mL M199 were added; (2) hCG group: 5 IU hCG (Calbiochem-Behring Grop, USA) and 1 mL M199 were added; (3) FSC+hCG group: both reagents and 1 mL M199 were added; (4) Control: 1 mL M199 was added. These groups were then cultured at 37 for 3 hours in an atmosphere of 95% O2 and 5% CO2 shaking at 90 times/min. Thereafer T concentrations were assayed in the media.

2.8 Statistical analysis

All two-group comparisons were made with the Student's t test. All multiple comparisons were made by a one-way analysis of variance (ANOVA) followed by the Student-Newman Keuls test.

3 Results

3.1  Effect of FSC on reproductive organs

As can be seen from Table 1, FSC stimulated the development of reproductive organs in immature male rats. The weights of the pituitary gland, testis and epididymis were significantly increased upon FSC administration. hCG increased the weights of testis, epididymis and seminal vesicles, but not the pituitary glands.

Table 1. Effect of FSC on reproductive organs. bP<0.05, cP<0.01, vs control. n=20. means.


Organ weights (mg/100 g body weight)




Seminal vesicle
















3.2 Effect of FSC on reproductive endocrine function

Table 2 indicates that in the 2-month-old male rats, FSC increased the plasma levels of LH and T and the specific binding capacity of testis to hCG. In the 10-month-old male rats, FSC did not increase plasma LH and T levels, but enhanced the binding capacity of testis to hCG. In the 18-month-old rats (when aging began), both the plasma T and the testicular binding capacity were significantly decreased in the control rats, but FSC significantly elevated both parameters. In the aged rats (24-month-old), the plasma T and testicular binding capacity were further decreased with significant elevation of plasma E2 and LH in the control rats, while FSC still significantly increased plasma T and testicular binding capacity with a significant suppression of plasma LH elevation. 

Table 2. Effect of FSC on reproductive endocrine function. bP<0.05, cP<0.01 vs the control, eP<0.05, fP<0.01 vs the 10 months group. n=20. means.



Hormone concentration in plasma

Binding capacity of testis
to hCG (pg/10 mg of testis)

Ts (ng/dL)

E2 (pg/mL)

LH (pg/mL)













































3.3  Effect of FSC on LH and T production in vitro

As can be seen from Tables 3 and 4, FSC significantly stimulated LH production by  adenohypophysis and T production by Leydig cells in vitro.

Table 3. Effect of FSC on LH production in vitro. bP<0.05, cP<0.01 vs the control. I vs II: P<0.05. n=10 samples, means.



(ng/mg adenophypophsis)

with control






















Table 4. FSC effect on T production in vitro. bP<0.05, cP<0.01 vs the control. eP<0.05 vs the hCG group. n=10 samples, means.


Ts (ng/mL)









4 Discussion

The present work indicates that FSC, a kidney invigorating drug, exerts an all-round effect on the reproduction-endocrine system in male rats. It enhanced the growth of reproductive organs and pituitary gland, and increased the blood levels of T in immature and aged male rats; it also stimulated the production of LH by the adenophypophysis and T by Leydig cells in vitro. In aged rats, the FSC-induced LH suppression may be the result of a negative feedback action of elevated T level. It seems that FSC possesses both GnRH- and LH-like activities. However, its effect appears to differ from that of hCG, as FSC increases the weight of pituitary, while hCG does not (Table 1). Although FSC increased T levels both in immature and aged rats, it did not affect the T level in adult rats, suggesting the presence of a stimulatory effect only when T production is below normal levels.

The results may indicate that the effects of FSC on the reproduction-endocrine system are multifactorial with more than one site of action. The participation of a multifactorial network in the regulation of physiological functions and the pathogenesis of diseases has attracted increasing attention[14-16]. This may be an effective approach to study the mysteries of Traditional Chinese Medicine.

5 Acknowledgements

The study was supported by Grant 97255 of the Guangdong Bureau of Traditional Medicine Administration.


[1] Guo GH. Dictionary of Clinical Chinese Traditional Drugs. Zhengzhou: Henan Science and Technology Publisher; 1994. p 451.
[2] Li BR, She YC. The effects of kidney invigorating Chinese Traditional drugs on the functions of the hypothalamus-pituitary-gonads axis. J Tradit Chin Med (China) 1985; 5: 119-21.
[3] Wang XM, Xie ZF, Liu GX. Effect of Wuzi Yanzong Liquid (prepared from Semen Cuscutae, Fructus Lycii, Fructus Schisandrae, Semen Plantaginis, and Fructus Rubi) on the hypothalamus, monoamines, sexual hormones and reproductivity in male rats. Chin J Integr Tradit West Med 1993; 13: 349-51.
[4] Xiong YB, Zhou CH. The effect of extracts from Herba Epimedii and Semen Cuscutae on the function of male reproduction. Chin Pharm J 1994; 29: 89-91.
[5] Yue GP, Chen Q, Dai N. Experimental study on effect of Bushen Shengjing Decoction (prepared from Semen Cuscutae, Herba Epimedii, Rhizoma Curculiginis, Fructus Mori, Fructus Lycii, Placenta Hominis, Fructus Schisandrae, Fructus Rubi, Cortex Cinnamomi, and Herba Cistanches) on kidney Yang and testicular dysfunction in rats. Chin J Integr Tradit West Med 1997; 17: 289-91.
[6] Jin X, Li JS, Yan MW. Studies on flavonoids in the seed of Cuscuta Chinensis Lam. China J Chin Mat Med 1992; 17: 292-4.
[7] Yu J, Chen HY, Mao QN. Experimental studies on the relationship between kidney and reproduction. Chin J Integr Tradit West Med 1989; 9: 548-55.
[8] Zhao RH, Liu YM, Yang L. Clinical research of the Bushen Tiaojing Decoction (prepared from Semen Cuscutae, Radix Morindae Officinalis, Fructus Ligustri Lucidi, Herba Cistanches, and Fructus Lycii) in promoting ovulation. Chin J Integr Tradit West Med 1996; 16: 264-6.
[9] She YC. Establishment of hCG/LH radio-receptor assay. Reprod Contracep (China) 1982; 2 (1): 48-50.
[10] Fujotas S, Chiba M, Ohta M, Kitani K, Suzuki T. Alteration of plasma sex hormone levels associated with old age and its effects on hepatic drug metablism in rats. J Pharmacol Exp Ther 1990; 253: 360-74.
[11] Forwein J, Exgel W. Binding of human chorionic gonadotropin by rat testis: effect of sexual maturation, cryptorchidism and hypophysectomy. J Endocrinol 1975; 64: 59-66.
[12] Lee VWK, de Krester DM, Hudson B, Wang C. Variation in serum FSH, LH and testosterone levels in male rats from birth to sexual maturity. J Reprod Fertil 1975; 42:121-6.
[13] Kilinefelter GR, Hall PF, Ewing LL. Effect of Luteiuizing hormone deprivation in situ on steroidogenesis of rat Leydig cells purified by a multistep procedure. Reprod Biol 1987; 36: 769-83
[14] Komessaroff PA, Funder JM, Fuller PJ. Hormone-nuclear receptor interactions in health and disease. Baillieres Clin Endocrinol Metab 1994; 8: 333-55.
[15] Draca SR. Endocrine-immunological homeostasis: the interrelationship between the immune system and sex steroid involves the hypothalamo-pituitary-gonadal axis. Panminerva Med 1995; 37: 71-6.

[16] Wilder RL. Neuroendocrine-immune system interactions and autoimmunity. Ann Rev. Immunol 1995; 13: 307-38.


Correspondence to Dr Da-Nian QIN, Shantou University School of Medicine, Shantou 515031, China.  
Tel: +86-754-856 6776  Fax: +86-754-855 7562
E-mail: lqchen@mailserv.stu.edu.cn
Received 2000-02-02   Accepted 2000-03-31