Action of Ilex Opaca on the Heart.

Abstract

Ilex opaca or American holly is an evergreen tree growing throughout the Atlantic section of the United States. The leaves and fruit are the parts of the plant that have been used in medicine; in domestic practice alterative properties have been assigned to it and by eclectic practitioners it has been used as an anti-intermittent, febrifuge, tonic and diaphoretic. The “Black Drink” by which the Indians “cleansed” themselves by drinking sufficient to cause vomiting was an aqueous extract prepared from the leaves of the holly. The dried leaves of certain species of ilex are used by the inhabitants of Paraguay to prepare a stimulating beverage.

The present experiments were undertaken to determine the effects of extracts of the above fruit on the amphibian heart. Male frogs (Rana pipiens) were used. A cannula was tied in the inferior vena cava and the heart arranged for perfusion by the Symes'method, with Ringer's solution in one bottle and Ringer's solution plus the drug in the other. The movements of the lever were recorded on a smoked drum. The extract was prepared by macerating the dried fruit in number 20 powder with 70% alcohol for 4 days and filtering. When required for use the alcohol was evaporated off and the thick syrupy remains added to frog Ringer's solution.

Perfusion in a proportion of one part of the crude drug in 750 parts of Ringer's solution resulted in an increase in the amplitude of the beat. Although the diastole of the heart was increased to some extent the main effect was a more complete shortening of the muscle. After allowing the heart to return to normal by perfusing with Ringer's solution only, the above effects of the drug could be demonstrated as often as desired.