Herbal Therapies and "Smart" Drugs

I.  General Concerns
    A.  Lack of regulation
        1. Review FDA drug development sequence
        2. Safety, efficacy
    B. Variability - dose, purity, potency

II.  "Smart" Drugs  - nootropics;  "noos" = mind, "tropin" = to bend/turn
                            - cognitive enhancers
    A. General Strategy
        1. Neurotransmitter support - precursors, cofactors
        2. Nutritional support - amino acids, nutrients, herbs
        3. drugs
    B. Representative Examples
        1. Piracetam
            a. increase membrane permeability
            b. speeds up interhemispheric flow of information
            c. increases Ach receptor density in frontal cortex
            d. increases NMDA receptor density in hippocampus
        2. Gingko Biloba - Egb-761
            a. antioxidant effects - scavenge free radicals implicated in Alzheimer's
            b. empirical results mixed
            c. most doses in commercial drinks at placebo level
        3. Ginseng - HT1001
            a. effects on Ach - blocks amnestic effects of scopolamine (in rats)
                                     - improved learning in rats with frontal damage
            b. adaptogen and aphrodisiac

III.  Herbal treatment of disorders
    A. St. John's Wort - hypericum
        1. treats mild-moderate depression
        2. mechanisms of action - reuptake blockade (5-HT, DA, NE)
                                            - binds to GABA (bzd) receptors
                                            - NMDA receptors
                                            - long term effects to increase 5-HT receptor density
        3. efficacy - mixed, generally effective in mild cases
    B. Valerian - anxiolytic, hypnotic
        1. mechanisms of action - GABA agonist at bzd receptor (pass BBB?)
                                            - 5-HT1a agonist
        2. efficacy mixed
        3. side effects include liver toxicity, interacts with alcohol, SSRIs
    C. Kava
        1. mechanisms of action - GABA agonist at bzd receptor
        2. efficacy and side effects (similar to valerian)