Autophagy is a cellular process that nonspecifically degrades cytosolic components and is involved in many cellular responses. We found that amino sugars with a free amino group such as glucosamine, galactosamine and mannosamine induced autophagy via an rnTOR-independent pathway. Glucosamine-induced autophagy at concentrations of at least 500 mu M to over 40 mM. In the presence of 40 mM glucosamine, autophagy induction was initiated at 6 h and reached a plateau at 36 h. Glucosamine-induced autophagy could remove accumulated ubiquitin-conjugated proteins as well as 79-glutamine repeats. Therefore, Orally administered glucosamine could contribute to the prevention of neurodegenerative diseases and promotion of antiaging effects. (C) 2010 Elsevier Inc. All rights reserved.