Several extracts of the leaves and fruits of Juglans regia L. were assessed for their neuroprotective effects through antioxidant and anti-cholinesterase methods. Anticholinesterase activity was determined against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), the enzymes vital for Alzheimer's disease, at 50, 100 and 200 mu g ml(-1). Antioxidant activity was tested using radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH), N,N-dimethyl-p-phenylenediamine (DMPD), superoxide (SO), nitric oxide (NO) and hydrogen peroxide (H2O2) radicals, as well as ferric ion-chelating capacity, ferric-and phosphomolybdenum-reducing antioxidant power at 500, 1000 and 2000 mu g ml(-1). Total phenol and flavonoid quantification of the extracts was calculated. The extracts scavenged DPPH radical in varying degrees; however, they did not scavenge DPMD and H2O2. Only the dichloromethane and water extracts were able to quench SO (10.09 +/- 1.38%) and NO (24.09 +/- 2.19%) radicals, respectively, at low level. The extracts showed either low or no BChE inhibition and no AChE inhibition.