Meridian tropism of Scutellaria baicalensis based on molecular thermodynamic characteristics / 药学学报

ABSTRACT

The property of medicine is the "identity card" of traditional Chinese medicine (TCM), and the key to crack the theory of property of TCM. Based on molecular thermodynamics, the effects of interaction between TCM and organs in vitro were studied from the perspective of micro-energy release and absorption in order to construct a new idea of characterizing meridian theory. Scutellaria baicalensis, for example, application of isothermal titration calorimetry (ITC) were used to determine the energy changes during the interaction of Scutellaria baicalensis and its main active ingredient baicalin with brain, heart, lung, spleen and kidney in vitro, comparison including the association constant (Ka) and disassociation constant (Kd), combined with thermodynamic parameters, such as stoichiometry ratio (n), enthalpy change (ΔH), entropy change (ΔS), Gibbs free energy (ΔG), it is found that the interaction intensity between Scutellaria baicalensis and lung is significantly stronger than that of other organs, which is consistent with the theory of the return of Scutellaria baicalensis in ancient books. In addition, baicalin, the main active ingredient, showed the same action pattern as Scutellaria baicalensis. The thermodynamic parameters analysis showed that the action was a weak bond-induced spontaneous chemical binding reaction driven by both entropy and enthalpy. The results of specific curl measurement further proved the interaction between baicalin and lung, and were consistent with the results of ITC titration, indicating that ITC could be used to characterize the meridian tropism of TCM. Therefore, based on ITC, it is scientific and feasible to characterize the meridian of TCM by the energy change of the interaction between the decoction of TCM and its active components and the in vitro tissues respectively. This experiment provides a new idea for the discussion of meridian of TCM.