Aq. infusions of com. green, white, red and black teas were prepd. by flooding with boiling water and extg. for 1–30 min. The inhibition of acetylcholinesterase activity (AChE), the antioxidant activity and the total polyphenolic content in tea exts. were studied. The strongest inhibitor of AChE was pure green tea extd. for 30 min. Red tea exts. showed the lowest inhibiting activity.