Aframomum melegueta prevents the ejaculatory complications of propylthiouracil-induced hypothyroidism in sexually experienced male rats: Evidence from intravaginal and fictive ejaculations.

Abstract

OBJECTIVE\nHypothyroidism has been claimed to generate sexual dysfunctions such as ejaculatory disorders. Aframomum melegueta is an aphrodisiac plant with pro-ejaculatory properties. We investigated the protective effects of aqueous extract (AE) and methanolic extract (ME) of A. melegueta on the ejaculatory function of hypothyroid male rats.\n\n\nMETHODS\nForty sexually experienced male rats were partitioned into 8 groups (5 rats per group) and treated for 28 d as follows: Group 1, Control; Group 2, propylthiouracil (PTU, 10\u202fmg/kg)\u202f+\u202fdistilled water (DW, 10\u202fmL/kg); Group 3, PTU\u202f+\u202f5% Tween 80 (10\u202fmL/kg); Group 4, PTU\u202f+\u202fbromocriptine (6\u202fmg/kg); Group 5, PTU\u202f+\u202fAE (20\u202fmg/kg); Group 6, PTU\u202f+\u202fAE (100\u202fmg/kg); Group 7, PTU\u202f+\u202fME (20\u202fmg/kg), and Group 8, PTU\u202f+\u202fME (100\u202fmg/kg). On days 0, 7, 14 and 28 of treatment, each male rat was paired with primed receptive female for measurement of ejaculatory latency time (ELT) and post-ejaculatory interval (PEI) for 1.5\u202fh. On day 29, each male rat was urethane-anesthetized and the spinal cord was transected. Thereafter, following urethral/penile stimulations and intravenous injection of dopamine, contractions of the bulbospongiosus muscles and the intraseminal pressure were registered. After these recordings, blood was collected through the catheterization of abdominal artery and plasma was used for thyroid-stimulating hormone (TSH), prolactin and testosterone assays.\n\n\nRESULTS\nPTU-induced hypothyroidism was characterized by a significant elevation (P\u202f<\u202f0.001) of plasmatic TSH and prolactin levels, but a decline (P\u202f<\u202f0.001) in plasmatic testosterone, compared to untreated group. ELT, PEI, contractions of the bulbospongiosus muscles and the intraseminal pressure were also altered by PTU treatment. On the contrary, A. melegueta extracts elevated testosterone (AE, 100\u202fmg/kg, P\u202f<\u202f0.01; ME, 100\u202fmg/kg, P\u202f<\u202f0.05) and decreased prolactin (AE, 100\u202fmg/kg, P\u202f<\u202f0.05; ME, 20\u202fmg/kg, P\u202f<\u202f0.05) levels, compared to corresponding controls. With regard to DW\u202f+\u202fPTU group, prolactin concentration was lowered (P\u202f<\u202f0.05) in rats administered with bromocriptine. Treatment with A. melegueta extracts significantly prevented the lengthening of ELT (P\u202f<\u202f0.05) and PEI (P\u202f<\u202f0.001). Hypothyroid state also altered the fictive ejaculation by increasing the latency and decreasing the number and frequency of bulbospongiosus muscle contractions. There was also a decrease in the intraseminal pressure. These alterations were significantly (P\u202f<\u202f0.05) alleviated in plant extract-treated groups.\n\n\nCONCLUSION\nThis study highlighted the ejaculatory disturbance of hypothyroidism in male rats and its prevention with A. melegueta extracts.