['Chlorogenic acid (CA) exits widely in those Chinese herbal injections that have antibacterial and antiphlogistic effects and belongs to the ethnopharmacological family of medicines. Chinese herbal injections containing high levels of CA have been reported to increase the adverse drug reactions, but the mechanism for which is still unclear. In this study, we investigated the mechanism of the CA derived adverse drug reactions.', 'The present study was to explore the potential role of CA in initiating inflammatory reaction and the underlying mechanism.', 'Male Wistar rats were treated with different dosages of CA for different time period. The variables examined included microcirculation by intravital microscopy, histology of ileum tissue, expression of adhesion molecules CD11b and CD18 on leukocytes by flow cytometry, myeloperoxidase activity and maleic dialdehyde content in ileum tissue by spectrophotometry, activity of superoxide dismutase and catalase in serum by ELISA, and expression of NADPH oxidase subunits by PCR and Western blot.', 'High-dose CA increased the number of adherent leukocytes, generation of peroxides in the venular walls and induced albumin leakage from mesentery venules. High-dose CA induced changes also included an increase in maleic dialdehyde, myeloperoxidase, inflammatory cytokines and NADPH oxidase activities, and a decline in activity of superoxide dismutase and catalase.'] Does high-dose chlorogenic acid induce inflammation reactions and oxidative stress injury in rats without implication of mast cell degranulation?