Evaluation of the protective effects of icariin on nicotine-induced reproductive toxicity in male mouse -a pilot study

Abstract

Background: Nicotine, a pharmacologically active component of tobacco adversely affects the male reproductive system and fertility whereas icariin (ICA), the main active ingredient in Epimedium herba has been used in the treatment of several male reproductive problems. This study aimed at evaluating the protective or ameliorative effect of ICA against reproductive toxicity induced by intraperitoneal injection of nicotine in mice.

Methods: Using simple random allocation, forty male mice were randomly divided into 4 groups: control (received 0.35 mL physiological saline via gastric gavage), nicotine (0.75 mg/kg BW/day intraperitoneally), ICA (75 mg/kg BW/day gastric gavage), and nicotine plus ICA (nicotine, 0.75 mg/kg BW/day intraperitoneally + ICA, 75 mg/kg BW/day gastric gavage) group. After 35 days of treatment, the mice were weighed, sacrificed, and their reproductive organs (testis and epididymis) were collected and examined for further studies.

Results: The nicotine-treated group showed significantly decreased epididymal sperm density and serum testosterone concentration relative to the control group. Nicotine also caused oxidative damage shown by significant reduction in the activities of antioxidant enzymes and elevation in Malondialdehyde (MDA) levels. ICA on the other hand, improved the reduction in sperm density, hormone levels, and activities of antioxidant enzymes altered in the nicotine treated mice.

Conclusions: These findings indicate that nicotine-induced reproductive toxicity and oxidative damage on male reproductive tissues could be attenuated by ICA.

Keywords: Antioxidant enzyme; Icariin; Male mice; Nicotine; Sperm density; Testosterone.

Fig. 1

Haematoxylin and eosin stained sections of testes in different groups (× 200). a Control, (b) 0.75 mg/kg BW Nicotine, (c) 75 mg/kg BW Icariin, (d) 0.75 mg/kg BW Nicotine plus 75 mg/kg BW Icariin. Lu, lumen; Sc, Sertoli cells; Lc, Leydig cells; PS, primary spermatocyte; ES, early spermatid; BW, body weight

Fig. 2

Expressions of 3β-HSD, 17β-HSD, and StAR mRNA in the testes of control, nicotine, icariin, and nicotine plus icariin groups. The mRNA levels were normalized using β-actin mRNA as internal control. The mRNA levels of the control group were set as 1. #P < 0.05 compared with the control group, *P < 0.05 compared to the nicotine-treated group. (n = 10). 3β-HSD, 3β-Hydroxysteroid dehydrogenase; 17β-HSD, 17β-Hydroxysteroid dehydrogenase; StAR, steroidogenic acute regulatory protein

Fig. 3

Expressions of SOD1, SOD2, SOD3, and GPx1 mRNA in the testes of control, nicotine, icariin, and nicotine plus icariin groups. The mRNA levels were normalized using β-actin mRNA as internal control. The mRNA levels of the control group were set as 1. #P < 0.05 compared to the control group, *P < 0.05 compared to the nicotine-treated group. (n = 10). SOD1, cytoplasmic superoxide dismutase 1; SOD2, mitochondrial superoxide dismutase 2; SOD3, extracellular superoxide dismutase 3; GPx1, Glutathione peroxidase 1