Lauric acid improves hormonal profiles, antioxidant properties, sperm quality and histomorphometric changes in testis and epididymis of streptozotocin-induced diabetic infertility rats.

Lauric acid, a 12‑carbon atom medium chain fatty acid (MCFA) has strong antioxidant and antidiabetic activities. However, whether lauric acid can ameliorate hyperglycaemia-induced male reproductive damage remains unclear. The study aimed to determine the optimal dose of lauric acid with glucose-lowering activity, antioxidant potential and tissue-protective effects on the testis and epididymis of streptozotocin (STZ)-induced diabetic rats. Hyperglycaemia was induced in Sprague Dawley rats by an intravenous injection of STZ at a dose of 40 mg/kg body weight (bwt). Lauric acid (25, 50 and 100 mg/kg bwt) was administered orally for eight weeks. Weekly fasting blood glucose (FBG), glucose tolerance and insulin sensitivity were examined. Hormonal profiles (insulin and testosterone), lipid peroxidation (MDA) and antioxidant enzyme (SOD and CAT) activities were measured in the serum, testis and epididymis. The reproductive analyses were evaluated based on sperm quality and histomorphometry. Lauric acid administration significantly improved FBG levels, glucose tolerance, hormones-related fertility and oxidant-antioxidant balance in the serum, testis and epididymis compared to untreated diabetic rats. Treatment with lauric acid preserved the testicular and epididymal histomorphometry, along with the significant improvements in sperm characteristics. It is shown for the first time that lauric acid treatment at 50 mg/kg bwt is the optimal dose for ameliorating hyperglycaemia-induced male reproductive complications. We conclude that lauric acid reduced hyperglycaemia by restoring insulin and glucose homeostasis, which attributes to the regeneration of tissue damage and sperm quality in STZ-induced diabetic rats. These findings support the correlation between oxidative stress and hyperglycaemia-induced male reproductive dysfunctions.