Glycyrrhizin and Serum Testosterone Concentrations in Male Patients With Type 2 Diabetes
Michiaki Fukui, MD1, Yoshihiro Kitagawa, MD1, Naoto Nakamura, MD2 and Toshikazu Yoshikawa, MD2
1 Department of Endocrinology and Hematology, Osaka General Hospital of West Japan Railway Company, Osaka, Japan
2 First Department of Internal Medicine, Kyoto Prefectural University of Medicine, Kyoto, Japan
Address correspondence to Michiaki Fukui, MD, Department of Endocrinology and Hematology, Osaka General Hospital of West Japan Railway Company, 1-2-22 Matsuzaki-cho, Abeno-ku, Osaka 545-0053, Japan. E-mail:
sayarinapm@hotmail.com
Extracts of licorice root are widely used in many countries as flavoring agents, breath fresheners, and candy. Licorice consumption had been reported to decrease serum testosterone concentrations (1). An explanation for this result was that glycyrrhizic acid, the active component of licorice, interfered with 17ß-hydroxysteroid dehydrogenase, which catalyzes the conversion of androstenedione to testosterone. We were very interested in the effects of glycyrrhizic acid to decrease serum testosterone concentrations. Glycyrrhizin, which is extracted from the roots of the plant Glycyrrhiza glabra (licorice), is widely used for the treatment of chronic hepatitis in Japan and reportedly reduces the progression of liver disease to hepatocellular carcinoma. The efficacy of glycyrrhizin treatment is currently under investigation in Europe (2). There are few data available on the effects of glycyrrhizin on serum testosterone concentrations (3). We have recently reported that reduced serum testosterone concentrations could cause insulin resistance (4) and atherosclerosis (5) in male patients with type 2 diabetes. Therefore, we attempted to determine the effects of glycyrrhizin on serum testosterone concentrations in male patients with type 2 diabetes and chronic hepatitis.