A PRELIMINARY PHARMACOLOGICAL INVESTIGATION OF THE TANNIN OBTAINED FROM PINUS CARIBAEA, MORELET

¹ Department of Pharmaceutical Chemistry of the College of Pharmacy and the Department of Pharmacology of the Medical School, University of Minnesota, Minneapolis

Tannic acid, injected intraperitoneally into mice, caused necrosis of the liver whereas phlobatannin produced a different type of liver injury, namely, a diffuse hepatitis.

The LD₅₀ of tannic acid intraperitoneally in mice was calculated to be 54.32 ± 2.25 mgm./kgm. whereas the LD₅₀ of the phlobatannin of Pinus Caribaea, Morelet, was 319.9 ± 13.2 mgm./kgm. Thus phlobatannin has approximately onesixth of the acute toxicity of tannic acid.

In the local treatment of burns, solutions of phlobatannin and of tannic acid were about equal in respect to time required for the formation of a complete eschar over the burned area. However, the eschars formed with phlobatannin remained completely intact slightly longer, were less stiff and brittle and were lighter in color than those produced by tannic acid.

This experimental work indicates that Pinus Caribaea phiobatannin possesses the beneficial properties of tannic acid in the local therapy of burns, but is decidedly less toxic.