A comparison of the effects of commercially available hawthorn preparations on calcium transients of isolated cardiomyocytes.
We studied the potential cardiac effects of two alcohol extracts of commercially available hawthorn using rat cardiomyocytes and measuring calcium transients by real-time fluorescence spectrophotometry. One preparation was a blend of hawthorn flowers, leaves, and berries (extract #1), and the other (extract #2) was from a "berries-only" preparation. Fluorescent images and calcium transients were acquired concurrently. Addition of extract #1 resulted in the initiation of robust calcium transients and eventual calcium overload, while addition of extract #2 caused increased calcium sparking, initiation of calcium transients, and an increased beating rate but no calcium overload. To identify the mechanisms of increased calcium influx, adult rat cardiomyocytes were challenged with 10 microM ouabain, a Na(+),K(+)-ATPase inhibitor, and the calcium channel blocker nifedipine. The findings revealed that equal volumes of the two readily available hawthorn preparations demonstrated markedly different effects on isolated adult rat cardiomyocytes, suggesting important implications for patients who are using these preparations to supplement or even replace their prescribed cardiac medications as to which preparation(s) to use, and potential dire consequences, particularly in cardiac patients. Our study indicates that the mechanism of cardiac activity of hawthorn is via the Na(+),K(+)-ATPase and intracellular calcium concentrations are influenced.
Rodriguez
Michelle E
ME
Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, University of Texas Health Science Center, Houston, Texas 77030, USA.
Poindexter
Brian J
BJ
Bick
Roger J
RJ
Dasgupta
Amitava
A
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002316:Cardiotonic Agents / Q000494:pharmacology; D027825:Crataegus; D006333:Heart Failure / Q000188:drug therapy; D041743:Herb-Drug Interactions; D006973:Hypertension / Q000188:drug therapy; D008297:Male; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism; D009543:Nifedipine / Q000494:pharmacology; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D018514:Plant Structures; D051381:Rats; D017207:Rats, Sprague-Dawley; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
D002121:Calcium Channel Blockers; D002316:Cardiotonic Agents; D010936:Plant Extracts; D000254:Sodium-Potassium-Exchanging ATPase; D009543:Nifedipine; D002118:Calcium