Structure-activity differences of chlorogenic acid and its isomers on sensitization via intravenous exposure.

Chlorogenic acid (CGA) is found in many plants that are used as medicinal substances in traditional Chinese medicine injectables (TCMIs). However, to date, there is controversy as to whether CGA is the major cause of TCMIs-related hypersensitivity administered intravenously. Therefore, the aim of this study was to evaluate the potential sensitization of CGA and structure-activity differences between its isomers using an intravenous exposure mouse model. The results showed that popliteal lymph nodes proliferation was significantly induced by CGA and its isomers. Both CGA and isochlorogenic acid A (iso-CGA A) significantly enhanced the secretion of trinitrophenyl (TNP) ovalbumin-specific immunoglobulin (Ig)G1; and iso-CGA B significantly induced TNP-specific IgG1, IgM, and IgG2b secreting. Furthermore, the results of quantitative structure-activity relationship analysis suggested that chemical structure factors, including atomic mass, electronegativity, atom shape and size, atom distribution, atomic weight, and atomic polarizabilities, the ionic currents, were significantly correlated with the potential sensitization of CGA and its isomers. In summary, when administered intravenously, the strength and type of sensitization may be correlated with structure differences in the CGA family.