Nowadays several millions of people suffer from Alzheimer’s disease and other types of dementia. Etiology of these diseases is not known very well. There occur different levels of neurotransmitters, the level of acetylcholine in the brain is decreased and pathological changes affect the brain tissue. Organic and toxic damage of the brain, free radicals, and other changes participate in the development of these diseases. Drugs as nootropics, cognitives, and neuroprotectives are commonly used to treat these diseases. Some of these drugs have often side and undesirable effects. In recent years some natural substances (galanthamine, huperzine A, vinpocetine), and standardized plant extracts (Ginkgo biloba L., Centella asiatica L.) Urban, Bacopa monniera L., Evolvulus alsinoides L.) are often used. These plant preparations produce fewer undesirable effects and the same effectiveness as the classic therapy, or these preparations are used as a supplement to the classic therapy.

        Key words: plant metabolites – cognitives – nootropics – neuroprotectives – free radicals