Centella Asiatica Selected Triterpenes (CAST) for Diabetic Neuropathy

This study is a clinical trial investigating the effect of an herbal supplement called CAST on diabetic neuropathy. CAST is an herb commonly used in traditional Indian medicine. In this tradition, it is used to increase memory, treat wounds and sores, skin diseases, and neurological conditions such as epilepsy. The herb has had growing popularity in the US; parts are sold as the dietary supplement "gotu kola" and used to improve blood circulation and help heal wounds. Unlike many other herbs, CAST has been extensively researched for many of the above conditions. The compounds found in CAST make it a very promising potential treatment for diabetic neuropathy because of its effect on blood circulation and growth of nerves. Subjects will receive informed consent. They will then be screened for eligibility before entering the study. A medical history will be taken and subjects will have a neurological exam and vital signs taken. Subjects will have their blood drawn and will also give a urine sample for routine testing. Subjects will have an electrocardiogram (ECG) to check their heart. If a subject is a woman who is at risk of getting pregnant, she will have a urine pregnancy test. If the subject is eligible for participation in the study, they will return for a total of nine additional study visits over the course of a year. Subjects will be randomly assigned to either receive the active supplement (CAST) or a placebo. A placebo is a pill that tastes, looks, and smells like the study drug but has no real medicine (or supplement) in it. Subjects have a 50% chance of receiving the active supplement. Neither the subject nor the study staff will know who receives the active supplement or the placebo. At visits 2, 7 and 10, subjects will get a comprehensive assessment of their neuropathy symptoms. This will include a Neurological Disability Score assessment, a nerve conduction study and a Quantitative Sensory Test. Subjects enrolled in the study will begin taking their study pills at the beginning of week 1 of the study. During the first 12 weeks, subjects will be asked to increase their dose by one pill every four weeks. Therefore, they will increase the number of CAST or placebo pills from 60mg twice daily to 60mg four times daily, or the highest dose that does not cause side effects. Dr. Lou will monitor subjects for side effects of the study supplement. At each study visit, blood and urine samples will be taken for safety analysis, including liver and kidney function, and glucose control, and an ECG will be done to monitor heart activity. Subjects will be contacted by the study coordinator via phone call once per week during the first three months of the study. During the remainder of the study, they will be called once each month that they are not scheduled for an appointment. Treatment will conclude after one year.