Binding of Breviscapine Toward Serum Albumin Studied by Spectroscopic and Electrochemical Techniques

Breviscapine, a cerebrovascular drugs extracted from the Chinese herb Erigeron breviscapinus, has been frequently used to clinically treat cerebrovascular diseases such as cerebral thrombosis, cerebral infarction, and cerebral circulation insufficiency. In order to understand its pharmacology or toxicity, the binding mechanism of breviscapine to a model protein, human serum albumin (HSA), was probed by fluorescence, circular dichroism, Fourier transform infrared spectroscopy (FTIR), and electrochemical impedance spectroscopy approaches. The binding affinities and number of the drug with HSA were about 1.73 × 10⁴ M^?1 and 0.99 at 293 K, respectively. The conformation of the protein was slightly altered after interacting with breviscapine. The drug–protein complex was mainly stabilized by electrostatic forces.