Naturally occurring Ca++ channel blockers

ABSTRACT

Ion channel are the set of integral membranes proteins that produce and transduce the electrical signals crucial to the maintenance and function of all living cells, therfore these gate and regulate the flow of ions between the cytoplasmic compartment, and the extracellular space and between subcellular compartment. Ion channels open and close in response to changes in membrance potential and ion concentration. The activity of ion channel is modulated directly through interaction with drugs. It was notied in 1964, that effects of phenylamine and verapamil on cardiac muscles were indistinguishable from the effect of Ca++ withdrawal. Therefore those drugs that inhibited the excitation-contraction couplings are termed as calcium antagonists to indicate that these counteract the effect of Ca++ on the contractile system. Therefore primary objectives of these drugs is inhbition of inward movement of Ca++ through voltage dependent Ca++ channels located in cell membrance. This effect is termed as calcium channel blockers. During the past few years, we have been searching for new calcium-channel blockers from herbal soruce. The reason behind this approach is simple If cellular calcium regulation is so important in living forms, celluar calcium modulators must be present in plants. Such compounds, if effective as therapeutic agents, would have minimum side effects. Any herb with serous side effects would not have persisted through the years of clinical trials. Plants, therefore, may be potential source of new compounds as calcium channel blockers