Garlic Supplementation Increases Testicular Testosterone and Decreases Plasma Corticosterone in Rats Fed a High Protein Diet

Yuriko Oi, Mika Imafuku, Chiaki Shishido, Yutaka Kominato, Syoji Nishimura, Kazuo Iwai
2001 Journal of Nutrition  
The effects of garlic supplementation on protein metabolism were investigated by measuring testis testosterone and plasma corticosterone in rats fed diets with different protein levels. In Experiment 1, rats were fed experimental diets with different protein levels (40, 25 or 10 g/100 g casein) with or without 0.8 g/100 g garlic powder. After 28 d of feeding, testosterone contents in the testis were significantly higher and plasma corticosterone concentrations were significantly lower in rats
more » ... d 40 and 25% casein diets with garlic powder than in those fed the same diets without garlic powder. Urinary excretion of 17-ketosteroid (an index of testosterone), nitrogen balance and hepatic arginase activity were significantly higher in rats fed the 40% casein diet with garlic powder than in the 40% casein controls. In Experiment 2, the effect of diallyldisulfide (a major volatile sulfur-containing compound in garlic) on the secretion of luteinizing hormone (LH) from the pituitary gland, which regulates testosterone production in the testis, was investigated in anesthetized rats. Plasma LH concentration increased dose dependently after administration of diallyldisulfide (P Ͻ 0.01, r ϭ 0.558). These results suggest that dietary supplementation with 0.8 g/100 g garlic alters hormones associated with protein anabolism by increasing testicular testosterone and decreasing plasma corticosterone in rats fed a high protein diet.
doi:10.1093/jn/131.8.2150 pmid:11481410 fatcat:42ldc6x5w5aqtiutrcydjlj5n4