ABSTRACT
Alkaloids........................................................................................... 418 11.2.5 Homoharringtonine and Protein Synthesis ..................................................................... 419 11.2.6 Rhein and Necrosis ......................................................................................................... 420 11.2.7 Mistletoe and Apoptosis.................................................................................................. 421 11.2.8 Section Summary ............................................................................................................ 421
11.3 Transmembrane Signaling............................................................................................................ 422 11.3.1 Opening Remarks............................................................................................................ 422 11.3.2 Ligand-Gated Ion Channels ............................................................................................ 422 11.3.3 G-Protein and Second Messengers ................................................................................. 423 11.3.4 Section Summary ............................................................................................................ 424
11.4 Immunomodulation ...................................................................................................................... 426 11.4.1 Opening Remarks............................................................................................................ 426 11.4.2 Echinacea......................................................................................................................... 426 11.4.3
Aloe vera
......................................................................................................................... 427 11.4.4 Plant Contact Dermatitis ................................................................................................. 427 11.4.5 Section Summary ............................................................................................................ 429
11.5 Toxic Effects................................................................................................................................. 429 11.5.1 Opening Remarks............................................................................................................ 429 11.5.2 Teratogenesis ................................................................................................................... 429 11.5.3 Carcinogenesis................................................................................................................. 429 11.5.4 Toxicity............................................................................................................................ 430 11.5.5 Section Summary ............................................................................................................ 431
11.6 Molecular Mechanisms at Target Sites........................................................................................ 431 11.6.1 Opening Remarks............................................................................................................ 431 11.6.2 Effects of Plant Natural Products on Human Cytochrome P450 Enzymes................... 432 11.6.3 Interactions of Plant Natural Products with Nuclear Receptors That Regulate
CYP450 Activity ............................................................................................................. 433 11.6.4 Photodynamic Therapy (PDT) and the Anticancer Action of Hypericin in
St. John’s Wort (
Hypericum perforatum
) ....................................................................... 433 11.6.5 Section Summary ............................................................................................................ 434
11.7 Conclusions .................................................................................................................................. 434 References .............................................................................................................................................. 435
Plants and humans have sustained each other for eons. All cultures have some definable plant knowledge that includes appropriate edible plants, medicinal plants, and ceremonial plants. Even in the Western tradition, the first botanists were physicians who kept their own herb gardens for treating the sick. Modern allopathic medicine is derived predominantly from the alchemical practice, but even here, some wellknown plants have become part of the scene.
