Efficacy of benfotiamine versus thiamine on function and glycation products of peripheral nerves in diabetic rats

In rats with streptozotocin (STZ) induced diabetes the effect of (watersolu ble) thiamine nitrate and of (lipidsoluble) benfotiamine on peripheral nerv e function (motor nerve conduction velocity) as well as on the formation of advanced glycation end-products in peripheral nerve tissue was studied. In one group of animals drug administration was started immediately after dia betes induction (prevention study) and in another group two months after di abetes induction (treatment study). Motor nerve conduction velocity (NCV) d ropped by 10.5% in diabetic animals, carboxymethyl-lysine (CML) rose to a 3 .5fold concentration,deoxyglucosone (3DG)-type AGE formation was increased 5.1fold compared with controls. After three months preventive administratio n of both vitamin 131 preparations NCV had increased substantially compared with results in diabetic controls. It was nearly normal after six months w ith benfotiamine, while the administration of thiamine nitrate resulted in no further amelioration. NCV was nearly normalized after six months of benf otiamine application but not with thiamine. Furthermore, benfotiamine induc ed a major inhibition of neural imidazole-type AGE formation and completely prevented diabetes induced glycoxidation products (CML). Treatment with th iamine did not significantly affect AGE or cmL levels. Unlike treatment wit h watersoluble thiamine nitrate timely administration of liposoluble prodru g benfotiamine, was effective in the prevention of functional damage and of AGE and cmL formation in nerves. of diabetic,rats.