SPERMATOGENIC AND ERECTOGENIC ACTIVITIES OF THE ETHANOL EXTRACT OF Sphenocentrum jollyanum PIERRE ROOT IN RATS AND RABBITS

Abstract

Infertility and sexual dysfunction exert psychological tolls on humans. This is characterised by anxiety and debilitating feeling of inadequacy. Hence, use of aphrodisiacs and sex enhancing drugs is common among people experiencing infertility. Sphenocentrum jollyanum root is widely used for its aphrodisiac effect in folkloric medicine. However, there is dearth of information on its mechanism of action on erectile dysfunction. This study was carried out to investigate the spermatogenic and erectogenic activities of ethanol extract of Sphenocentrum jollyanum root in rats and rabbits. Sphenocentrum jollyanum root was harvested from Oniganbari via Ibadan and authenticated at Forestry Research Institute Nigeria (FHI No. 106994). The dry root powder was macerated in ethanol and the filtrate was evaporated to dryness in a water bath heated at 40ºC. The phytochemical constituents of the extract were identified using the Gas chromatography Mass spectrometry (GC-MS). Spermatogenic activities were determined in 35 male Wistar rats (180- 210 g) divided into seven groups (n=5) and treated orally thus: distilled water (0.5 mL/kg), extract (300, 600 and 1000 mg/kg) for 56 days and extract (300, 600 and 1000 mg/kg) for 56 days +28 days recovery. Sperm profile was analysed by microscopy; testicular Glutathione Peroxidase (GPx) and Superoxide Dismutase (SOD) activities by spectrophotometry. Mating behaviour was evaluated on 40 Flemish rabbits (3.0-3.5 kg) and were treated orally for five days thus: control (0.5 mL/kg, distilled water), extract (600 mg/kg), paroxetine (10 mg/kg), extract paroxetine (600 mg/kg), linoleic acid (0.03 mg/kg), linoleic acid-paroxetine (0.03 mg/kg), sildenafil citrate (0.50 mg/kg), and sildenafil citrate-paroxetine (0.50 mg/kg). In vitro contractile activities of extract were assessed in strips of rabbit corpus cavernosa (CC) pre-contracted with 10-7M Phenylephrine followed by introduction of blockers among which were;Nifedipine (10- 4M), Verapamil (10-4M), L-NAME (10-4M) and Indomethacin (10-4M) before treatment with graded doses of Sodium nitropusside SNP (10-9 -10-5M), Acetylcholine ACh (10-9 -10-5M) or extract (0.1-3.2 mg/mL). Data were analysed using ANOVA at α0.05. Thirty-four chemical constituents were identified in the extract and linoleic acid was the most abundant (73.5%). Sperm motility (93.0±1.2%), livability (97.2±0.6%) and count (193.50±15.25 million/mL) increased significantly in the 1000 mg/kg extract treated relative to control (83.0±2.3%; 89.0±2.8%; 145.50 ± 12.25 million/mL) respectively. Testicular GPx (U/L) and iii SOD (U/mL) activities increased in 300 (268.3±13.57 and 1.92±0.13), 600 (338.2±14.69 and 1.64±0.05) and 1000 (393.6±18.12 and 1.49±0.28) mg/kg extract compared with control (193.6±10.74 and 0.47±0.05). Increased activities were however reversed after recovery. The extract reduced mount latency by 98.0%, while intromission frequency was increased by 150.0% in paroxetine-treated rabbits. Significant contractile inhibition was produced by extract (33.3±2.4%), ACH (42.8±2.3%) and SNP (52.8±1.6%) in corpus cavernosa strips of normal rabbits. Maximal contraction of CC strips was reduced by extract to11.3±1.5% and 14.6±1.1% in the presence of nifedipine (42.8±2.1%) and Verapamil (22.0±1.5%), respectively. Relaxation response of CC to extract increased by 228.2% and 143.1% in the presence of Indomethacin and L-NAME in strips of rabbits pretreated with paroxetine. The ethanol extract of Sphenocentrum jollyanum root improved spermatogenic profile, increased antioxidant activities and ameliorated paroxetine-induced erectile dysfunction. These actions may be linked to linoleic acid.