EFFECTS OF 1, 4-NAPHTHOQUINONE ON MALE REPRODUCTIVE FUNCTIONS IN MICE

Abstract

The derivative of naphthoquinone, 1, 4-naphthtoquinone, has been extensively shown to be cytotoxic, with significant antibacterial, antifungal, antiviral, insecticidal, anti-inflammatory and antipyretic properties. Many cytotoxic and antibacterial agents have been implicated in male reproductive disorders. However, information on the effects of 1, 4-naphthoquinone on male reproductive functions is scanty. This study was carried out to assess the effects and probable mechanisms of action of 1, 4-naphthoquinone on male reproductive functions in mice. Swiss albino male mice (18-22 g, 20 per group) were treated with either Tween 20 (vehicle, control) or 1, 4-naphthoquinone (0.1, 0.5, 1 and 2 mg/kg) intraperitoneally (i.p) for 5 days/week for 2 weeks. Another set of male mice (10 per group) were treated with chloroquine (5, 10, 15 and 20 mg/kg, i.p) to serve as standard drug. At the end of the experimental period, epididymal sperm motility, viability and count were determined by microscopy. Serum from 4 mL of blood per mouse was analysed for testosterone, Luteinizing Hormone (LH), Follicle Stimulating Hormone (FSH), Prolactin and cortisol by Enzyme Immunoassay (EIA) technique. Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Superoxide Dismutase (SOD), catalase, malondialdehyde and blood haemoglobin (Hb) levels were measured spectrophotometrically. Red and White Blood Cells (RBC and WBC) counts were measured using haemocytometry while Packed Cell Volume (PCV) was determined using micro haematocrit reader. Testicular histology was done using heamatoxylin and eosin stain. Data were analysed using ANOVA and Student’s t-test at p = 0.05. The 1, 4-naphthoquinone (2 mg/kg) significantly decreased sperm motility (70.3 ± 1.5 vs 41.3 ± 8.3%), viability (88.3 ± 4.7 vs 63.0 ± 2.7%) and count (20.8 ± 2.5 vs 9.4 ± 3.0 million/mL) relative to controls. Similarly, chloroquine (20mg/kg) significantly decreased sperm motility (72.3 ± 2.1 vs 42.0 ± 2.0 %), viability (87.3 ± 4.0 vs 64.3 ± 4.0%) and count (21.2 ± 2.6 vs 9.8 ± 0.9 million/mL). There was a significant decrease in testosterone (4.8 ± 0.7 vs 2.4 ± 0.4 ng/mL) and LH (4.3 ± 0.2 vs 2.6 ± 0.6 ng/mL) levels in mice treated with 1, 4-naphthoquinone (2 mg/kg) when compared with the controls. However, prolactin (1.6 ± 0.4 vs 2.7 ± 0.5 ng/mL), FSH (2.8 ± 0.9 vs 3.2 ± 0.4ng/mL) and cortisol (1.0 ± 0.0 vs 3.1 ± 0.2 ng/mL) significantly increased in 1, 4-naphthoquinone (2 mg/kg) and chloroquine-treated groups. Administration of 1, 4-naphthoquinone decreased all haematological indices except granulocytes while chloroquine decreased RBC, WBC, Hb and PCV. Treatment with 1, 4-naphthoquinone significantly increased ALT (115.7 + 20.0 vs 134.9 + 9.4 IU/L), AST (632.5 + 70.6 vs 667.3+ 62.6 IU/L), SOD (2.6 ± 0.8 vs 4.5 ± 0.4 IU/L) and catalase (78.3 ± 4.8 vs 96.2 ± 4.0 IU/L) but decreased malondialdehyde (0.42 ±0.02 vs 0.21 ± 0.02 units/mg protein). The 1, 4-naphthoquinone caused greater seminiferous tubules damage than chloroquine. The 1, 4-naphthoquinone altered parameters of male reproductive functions in mice. These effects were not mediated via oxidative stress mechanism.