Cardioprotective effects of Ilex paraguariensis extract: evidence for a nitric oxide-dependent mechanism.
OBJECTIVE
To examine the effects of an Ilex paraguariensis (Ip) extract on postischemic alterations derived from 20 min of global ischemia and 30 min of reperfusion.


METHODS
Isolated rat hearts were treated 10 min before ischemia and the first 10 min of reperfusion with Ip 30 microg/ml. In other hearts, chelerythrine (1 microM), a protein kinase C blocker, or l(G)-nitro l-arginine methyl ester (l-NAME), a nitric oxide synthase inhibitor, were administered prior to Ip infusion. Left ventricular developed pressure (LVDP), +dP/dt(max), -dP/dt(max), and left ventricular end diastolic pressure (LVEDP) were used to assess myocardial function. Thiobarbituric acid reactive substances (TBARS) were measured.


RESULTS
Ip treatment produced an improvement of postichemic recovery (LVDP=96+/-8%; +dP/dt(max)=95+/-10%; -dP/dt(max)=90+/-12% vs. 57+/-6%, 53+/-6% and 57+/-8%, respectively, in untreated hearts) and an attenuation of the increase of LVEDP and TBARS content. Chelerythrine did not modify and l-NAME abolished the protection induced by Ip.


CONCLUSIONS
These data are the first demonstration that Ip extract attenuates the myocardial dysfunction provoked by ischemia and reperfusion and that this cardioprotection involves a diminution of oxidative damage through a nitric oxide-dependent mechanism.
Schinella
Guillermo
G
Cátedra de Farmacología, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, CIC, La Plata 1900, Buenos Aires, Argentina.
Fantinelli
Juliana C
JC
Mosca
Susana M
SM
D000470:Alkaloids; D000818:Animals; D053119:Benzophenanthridines; D002316:Cardiotonic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D030019:Ilex paraguariensis / Q000737:chemistry*; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects; D017682:Myocardial Stunning / Q000188:drug therapy* / Q000378:metabolism; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D052247:Nitric Oxide Synthase Type II; D010617:Phenanthridines / Q000494:pharmacology; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D018515:Plant Leaves / Q000737:chemistry; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000188:drug therapy*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D000470:Alkaloids; D053119:Benzophenanthridines; D002316:Cardiotonic Agents; D010617:Phenanthridines; D010936:Plant Extracts; D010975:Platelet Aggregation Inhibitors; D047428:Protein Kinase Inhibitors; D017392:Thiobarbituric Acid Reactive Substances; D009569:Nitric Oxide; C016299:chelerythrine; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D011493:Protein Kinase C; D019331:NG-Nitroarginine Methyl Ester