Free radical-scavenging activity of Korean red ginseng for erectile dysfunction in non-insulin-dependent diabetes mellitus rats
Received 5 August 2004; accepted 20 October 2004.
Abstract
Objectives
To investigate the antioxidant activity of Korean red ginseng (KRG) and its effect on erectile function in non-insulin-dependent diabetes mellitus (NIDDM) rats. Oxidative stress is an important factor in vascular complications of diabetes.
Methods
A total of 84 male Sprague-Dawley rats were included in this study. NIDDM was induced by an intraperitoneal injection of 90 mg/kg of streptozotocin on day 2 after birth. According to the diabetic period, they were classified as either short-term (22 weeks, n = 32) or long-term (38 weeks, n = 32) diabetics. Of those, 20 (10 short-term and 10 long-term) were fed 30 mg/kg of KRG three times weekly for 1 month. The remaining diabetic rats (22 short-term and 22 long-term) and their age-matched controls (n = 10 each for each group) were fed a normal diet. Erectile function was measured after electrostimulation of the cavernous nerve. The total cavernous malondialdehyde and glutathione levels were measured using a spectrophotometric assay.
Results
The intracavernous pressure after nerve stimulation and cavernous glutathione level were significantly lower in the long-term than the short-term diabetics with a normal diet and were markedly decreased compared with their age-matched controls (P <0.01 and P <0.05, respectively). The malondialdehyde content was markedly increased in the short-term diabetics compared with the controls (P <0.05). In contrast, erectile function was not impaired in the diabetic group treated with KRG. Furthermore, both glutathione and malondialdehyde levels in those treated with KRG were comparable to their age-matched controls.
Conclusions
Oxidative stress to cavernous tissue may be a contributory factor in erectile dysfunction in diabetics. KRG may preserve potency in the NIDDM rats through its antioxidant activity.
aDepartment of Urology, Inha University School of Medicine, Incheon, Republic of Korea
bDepartment of Anatomy, Inha University School of Medicine, Incheon, Republic of Korea
cDepartment of Anesthesiology, Inha University School of Medicine, Incheon, Republic of Korea
dClinical Research Center, Inha University School of Medicine, Incheon, Republic of Korea
Reprint requests: Jun-Kyu Suh, M.D., Ph.D., Department of Urology, Inha University Hospital, 7-206 Third Street, Shinheung-Dong, Jung-Gu, Incheon 400-103, Republic of Korea.
This study was supported by the Korea Tobacco and Ginseng Central Research Institute.
ABSTRACT