Abstract
The scavenging effects of two hyaroxycinnamic acids such as caffeic acid and chlorogenic acid on paraquat induced pulmonary toxicity were investigated. The results are summerized as follows: 1. In the 5-lipoxygenase assay, caffeic acid and chlorogenic acid inhibited the enzyme activities whose inhibition concentration (IC$\_$50/) were 4.1 and 9.6 ${\mu}$M respectively. 2. To evaluate the antiinflammatory effects on mediator related to the mechanism of inflammation, ADP-induced platelet aggregation assay and histamine degranulation assay were used. Caffeic acid and chlorogenic acid inhibited on ADP-induced platelet aggregation and histamine release at a concentration dependent manners. 3. Arachidonic acid-induced ear edema were inhibited by administration of caffeic acid and chlorogenic acid. 4. Cytologicad analysis of branchoalveolar lavage fluid (BALF) which was the useful tool for detection of an inflammatory response in the lungs of animals intoxicated with chemicals were used. Alveolar macrophages and neutrophils in BALF, as well as the protein content and the LDH activity in BALF supernatant increased by intoxication of paraquat, but decreased by administration of caffeic acid and chlorogenic acid. Therefore, two hydroxyeinnamic acids tested were the useful candidates for scavenger and antiinflammatory agents on paraquat induced pulmonary toxicity.
