A NOVEL INHIBITOR OF BACTERIAL-ENDOTOXIN DERIVED FROM CINNAMON BARK

A substance that inhibits the activity of bacterial endotoxin (LPS) wa s found in cinnamon bark. The inhibitor, extracted from dry cinnamon b ark with 67% ethanol/water, was purified by using Limulus gelation act ivity as an indicator of endotoxin activity. The inhibitor suppressed the activity of the LPS when it was mixed with the inhibitor prior to the assay. The reduction of the LPS activity depended on the concentra tion of both the inhibitor and LPS when mixed, and also on the incubat ion time. The inhibitor suppressed the activity of all LPS and lipid A preparations tested regardless of the origin of the bacteria. The inh ibitor alone did not affect the Limulus system. These results indicate that the inhibition was caused by direct interaction of the inhibitor with the LPS molecule. Furthermore the inhibitor abrogated the pyroge nicity of the LPS. Although it is uncertain whether the inhibitor actu ally plays a role in the defense mechanism in cinnamon bark, this is t he first report that an inhibitor of bacterial endotoxin exists in a p lant. (C) 1997 Academic Press.