ABSTRACT
The purpose of this study was to explore the interaction mechanism between glycyrrhiza protein and berberine in the decocting process of Rhizoma Coptidis and Liquorice and its effect on the pharmacodynamic effect. In this experiment, licorice crude protein was obtained from licorice decoction pieces, and it was found that licorice crude protein and berberine could form spherical supramolecular particles after decocting together. Morphological characterization was carried out by using Malvin particle size analyzer and emission scanning electron microscopy, and the supramolecular particles were observed to be nanoscale, which was significantly different from the morphology of licorice protein and berberine. The results of ultraviolet, infrared and fluorescence spectroscopy showed that the mechanism of molecular interaction was induced by weak bonds such as electrostatic attraction and hydrophobic interaction. Furthermore, the antimicrobial activity of berberine was significantly affected by the supramolecular particles of licorice protein-berberine, which were significantly different from the mechanical mixture. This study reveals the pharmacological value of macromolecular substances such as proteins in the decoction of licorice and Coptis chinensis from a new perspective, which is helpful to promote the secondary development of clinical effective prescriptions, especially the research on the pharmacological substance basis of classic famous prescriptions.
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.
ABSTRACT
Objective To explore all sources of precipitation, parameters of interaction and binding abilities of different Chinese materia medica (CMM) combinations during the formation process of the precipitation in Huanglian Jiedu Decoction (HJD) using the thermodynamic method. The study was aim to reveal the mechanism of the formation of precipitation in CMM decoction. Methods First, the possible CMM combinations which had obvious precipitation phenomenon when combined were determined by the research on decomposed recipes. Then isothermal titration calorimetry (ITC) was used to determine the binding heat and thermodynamic parameters of binding reactions, thermodynamic parameters contents binding constant (Ka), dissociation constant (Kd), estimate of stoichiometric ratio (n), enthalpy change (ΔH), entropy change (ΔS), Gibbs free energy change (ΔG), these data were used to explain the differences in binding abilities between different CMM combinations. Results The original decomposed recipes experiment indicated the CMM combinations that could produce obvious precipitate when they were mixed were Scutellariae Radix-Coptidis Rhizoma and Scutellariae Radix-Phellodendri Chinensis Cortex. Precipitation amount of Scutellariae Radix-Coptidis Rhizoma was the most. There was no precipitate in Scutellariae Radix-Gardeniae Fructus, Coptidis Rhizoma-Phellodendri Chinensis Cortex, Coptidis Rhizoma-Gardeniae Fructus or Phellodendri Chinensis Cortex-Gardeniae Fructus. In ITC, the thermodynamic parameters of the three experience groups were the same, ΔH 0, ΔG |-TΔS|, indicating the three reactions were all enthalpy-driving reactions. The Ka of Scutellariae Radix decoction titrated Coptidis Rhizoma decoction was 1.283 × 104, Scutellariae Radix decoction titrated Phellodendri Chinensis Cortex deccotion was 4.680 × 103, Scutellariae Radix decoction titrated Gardeniae Fructus decoction was 1.973 × 103. The value decreased gradually. The binding heat of Scutellariae Radix and Gardeniae Fructus was much smaller than the binding heats of Scutellariae Radix and Coptidis Rhizoma, Scutellariae Radix and Phellodendri Chinensis Cortex. Conclusion During the formation process of the precipitation in HJD, the main source of acid-base complex-precipitation were Scutellariae Radix-Coptidis Rhizoma and Scutellariae Radix-Phellodendri Chinensis Cortex; Analysis of molecular thermodynamic indicates the binding energy of Scutellariae Radix and Coptidis Rhizoma was larger than that of Scutellariae Radix and Phellodendri Chinensis Cortex, compared with them, the binding energy of Scutellariae Radix and Gardeniae Fructus is tiny.