Lipoic acid improves nerve blood flow, reduces oxidative stress, and improves distal nerve conduction in experimental diabetic neuropathy.

Abstract

OBJECTIVE:

To determine whether lipoic acid (LA) will reduce oxidative stress in diabetic peripheral nerves and improve neuropathy.

RESEARCH DESIGN AND METHODS:

We used the model of streptozotocin-induced diabetic neuropathy (SDN) and evaluated the efficacy of LA supplementation in improving nerve blood flow (NBF), electrophysiology, and indexes of oxidative stress in peripheral nerves affected by SDN, at 1 month after onset of diabetes and in age-matched control rats. LA, in doses of 20, 50, and 100 mg/kg, was administered intraperitoneally five times per week after onset of diabetes.

RESULTS:

NBF in SDN was reduced by 50%; LA did not affect the NBF of normal nerves but improved that of SDN in a dose-dependent manner. After 1 month of treatment, LA-supplemented rats (100 mg/kg) exhibited normal NBF. The most sensitive and reliable indicator of oxidative stress was reduction in reduced glutathione, which was significantly reduced in streptozotocin-induced diabetic and alpha-tocopherol-deficient nerves; it was improved in a dose-dependent manner in LA-supplemented rats. The conduction velocity of the digital nerve was reduced in SDN and was significantly improved by LA.

CONCLUSIONS:

These studies suggest that LA improves SDN, in significant part by reducing the effects of oxidative stress. The drug may have potential in the treatment of human diabetic neuropathy.

• Authors: M Nagamatsu, K K Nickander, J D Schmelzer, A Raya, D A Wittrock, H Tritschler, P A Low
• Journal: Diabetes care (Diabetes Care) Vol. 18 Issue 8 Pg. 1160-7 (Aug 1995) ISSN: 0149-5992 [Print] United States
• PMID: 7587852 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Vitamin E
• Thioctic Acid
• Glutathione

Topics

• Animals
• Diabetes Mellitus, Experimental (metabolism, physiopathology)
• Diabetic Neuropathies (drug therapy, metabolism, physiopathology)
• Ganglia, Spinal (metabolism)
• Glutathione (metabolism)
• Humans
• Neural Conduction (drug effects)
• Oxidative Stress (drug effects)
• Rats
• Regional Blood Flow (drug effects)
• Sciatic Nerve (blood supply, drug effects, physiopathology)
• Thioctic Acid (pharmacology)
• Time Factors
• Vitamin A Deficiency (physiopathology)
• Vitamin E (metabolism)
• Weight Loss