Methods of treating Alzheimer's disease and other amyloidoses using

1. A method for inhibiting the formation, growth or persistence of Aβ fibrils or disrupting preformed Aβ fibrils in a patient, the method comprising the step of administering to the patient a therapeutically effective amount of a water extract of plant matter from a plant of the genus Hypericum, species perforatum.

2. The method of claim 1 wherein the plant matter comprises leaves, flowers or buds of the plant.

3. A method for promoting, maintaining or enhancing in a patient one or more of the mental or cognitive qualities associated with inhibiting the formation, growth or persistence of Aβ fibrils, the qualities selected from the group of mental or cognitive qualities consisting of memory, concentration, and short term memory, the method comprising the step of administering to the patient a therapeutically effective amount of a water extract of plant matter from a plant of the genus Hypericum, species perforatum.

4. A method for reducing in a patient one or more of the mental or cognitive effects associated with Aβ fibril formation selected from the group of mental or cognitive effects associated with Aβ fibril formation, the effects consisting of age associated cognitive or memory decline and mental decline, the method comprising the step of administering to the patient a therapeutically effective amount of a water extract of plant matter from a plant of the genus Hypericum, species perforatum.

5. A method for treating in a patient mental states associated with Aβ fibril formation or persistence, the method comprising the step of administering to the patient a therapeutically effective amount of a water extract of plant matter from a plant of the genus Hypericum, species perforatum.

6. The method of claim 5 wherein the plant matter comprises leaves, flowers or buds of a plant.