Objective: To study the impact of the water extract from Codonopsis thalictrifolia Wall (CTW) on the reproductive
Methods: We divided 32 male SD infant rats into four groups of equal number to be treated intragastrical-system of male infant rats. ly with distilled water (control) and CTW at 10 g/kg (low dose) , 20 g/kg (medium dose), and 40 g/kg (high dose), respectively, twice a day for 2 weeks. Then we killed the rats, measured the levels of testosterone (T), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in the serum, obtained the testis weight, body weight, testis visceral coefficient and sperm concentration, and detected sperm viability, sperm motility and the level of cyclic adenosine monophosphate (cAMP) in the Leydig cells, followed by
Results: Compared with the control group, the low-dose, me-analysis of differences among different groups using the SPSS software. Medium-dose and high-dose CTW groups showed significant decreases in the serum T level ([3.09 +/-0.42] vs [1.22 +/-0. 32] , [1.06 +/- 0.29] and [0.57 +/-0.18] nmol/L, P<0.01), testis weight ([1.40 +/-0.16] vs [0.96 +/-0.09], [0.92 +/-0.11] and [0.91 +/- 0.08] g, P <0.01), and sperm concentration ([1.03 +/-0.16] vs [0.19 +/-0.07], [0.17 +/-0.08] and [0.16 +/-0.07] x 10(6)/ml, P <0.01), but a dramatic elevation in the testis visceral coefficient ([42.22 +/- 3.02] vs [51.39 +/- 3.09], [52.28 +/- 4.86] and [54.13 +/-6.06] mg/10 g, P <0.01); the medium- and high-dose CTW groups exhibited remarkable increases in the levels of serum LH ([13.62+/-0.89] vs [14.69 +/-0.12] and [14.93 +/-0.28] ng/L, P<0.01) and FSH ([4.32 +/-0.18] vs [4.77 +/-0.23] and [4.89 +/-0. 38] IU/L, P <0.05); all the three CTW groups showed markedly inhibited serum T secretion ([1.85 +/- 0.18] vs [1.42 +/-0.15], [1.12+/-0.18] and [0.88 +/-0.21] nmol/L, P<0.01) and intracellular cAMP ([5.51 +/-0.12] vs [4.39+/-0.06], [4.28 +/-0.07] and [4.11 +/- 0.10] nmol/L, P <0.01) in the Leydig cells.
Conclusion: The water extract from CTW may reduce the synthesis of testosterone in the serum of male infant rats through the PKA pathway and consequently inhibit their testicular development and sperm production and affect the development of their reproductive system.