EFFECT OF LAURIC ACID ON ERECTILE AND TESTICULAR DYSFUNCTION IN DIABETIC MALE WISTAR RATS

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Department of Pharmaceutical Sciences

ABSTRACT
Diabetes mellitus is a risk factor for reproductive and sexual dysfunction. Standard medications are not completely satisfactory, hence the consideration of natural products as an alternative therapy. Lauric acid is the most abundant constituent of coconut oil, which is renowned for its therapeutic properties. This study sought to investigate the influence of lauric acid on testicular and erectile function in diabetic male Wistar rats. Seventy male rats (150-200 g) were divided into seven groups of ten each. Group 1 (NC): Normal control. Group 2 (DM-UT): Diabetic untreated. Group 3 (DM + LA 90): Diabetic treated with Lauric acid (90 mg/Kg). Group 4 (DM + LA 180): Diabetic treated with lauric acid (180 mg/Kg). Group 5 (DM + LA 360): Diabetic treated with lauric acid (360 mg/Kg). Group 6 (DM + CO): Diabetic treated with coconut oil (1.42ml/kg). Group 7 (DM + Sild): Diabetic treated with sildenafil (20 mg/Kg). Diabetes was induced by an intraperitoneal injection of streptozotocin (65 mg/Kg). Treatments were administered orally for four weeks after which the animals were euthanized. Gonadosomatic index, semen analysis, testicular histology and serum testosterone assay were then carried out. The corpus cavernosum was also extracted and contractile responses to phenylephrine and KCl; relaxant responses to acetylcholine and sodium nitroprusside (SNP); relaxation response to lauric acid in the presence of L-NAME; and contraction response to Ca2+ in the presence of lauric acid were evaluated. The gonadosomatic index in NC and DM + CO rats was significantly higher (p ? 0.05) compared to the other groups. Serum testosterone in all groups were respectively lower (p ? 0.05) compared to NC. Sperm count in NC and DM + CO rats respectively were significantly higher (p ? 0.05) compared to the other groups. The percentage of motile sperm cells in NC and DM + CO groups were significantly higher (p ? 0.05) compared to the other groups: The percentage of progressively motile sperm groups were significantly lower (p ? 0.05) compared to NC. The percentage of progressive motile sperm cells in DM + LA 90 and DM + CO were significantly higher (p ? 0.05) compared to DM-UT. The percentage of normal sperm cells in NC rats was significantly higher (p ? 0.05) compared to all the other treatment groups. The percentage of normal sperm cells in DM + LA 90, DM + LA 360, DM + CO, and DM + Sild were significantly higher (p ? 0.05) compared to DM-UT. The percentage of viable sperm cells in NC and DM + CO rats respectively were significantly higher (p ? 0.05) compared to other groups. Testicular histology showed degradation in DM-UT group and was considerably improved only in DM + LA 360 and DM + CO. Percentage contraction to KCl was significantly higher (p ? 0.05) in DM-UT and DM + CO rats respectively compared to the NC rats. The percentage relaxation of phenylephrine pre-contracted tissues to acetylcholine was significantly higher (p ? 0.05) in NC and DM + Sild rats compared to the other groups. The percentage relaxation of KCl pre-contracted tissues to acetylcholine was significantly higher (p ? 0.05) in NC and DM + LA 90 rats compared to the other groups. The percentage relaxation of phenylephrine pre-contracted tissues to sodium nitroprusside (SNP) was significantly lower (p ? 0.05) in DM-UT, DM + LA 360 and DM + CO rats compared to the NC rats. The percentage relaxation of KCl pre-contracted tissues to SNP was significantly lower (p ? 0.05) only in DM-UT rats compared to the NC rats. The percentage relaxation of phenylephrine pre-contracted corpus cavernosal tissues to lauric acid was significantly higher (p ? 0.05) in the presence of L-NAME compared to the control. The percentage relaxation of KCl pre-contracted cavernosal tissues to cumulative concentrations of lauric acid was significantly lower (p ? 0.05) in the presence of L-NAME compared to the control. It was therefore concluded that lauric acid rescued some but not all testicular dysfunctions in diabetic male rats. Lauric acid.