Study On The Interaction Of Evodialine And Evodialine With Liposome Mimicking Biofilm

As the material basis of the traditional Chinese medicine Euodia rutaecarpa(Juss.)Benth,Evodiamine(EVO)and rutaecarpine(RUT)both have a variety of pharmacological activities.It is important to study the interaction of drugs with biomembrane to understand the drug efficacy and to reveal the mechanism of its action on the organism.However,the structure of biomembrane is complex and the composition of biomembrane is various,so it is not convenient to study drugs and biomembrane directly.Therefore liposome is often used as a model of biomembrane to reveal the interaction between drug molecules and biomembrane by exploring the interaction between drug molecules and biofilm phospholipids.Research Objective:In this study,liposomes were used as the model of biomembrane,and the interaction of evodiamine and rutaecarpine molecules with liposome membrane was studied and compared,in order to provide a theoretical basis for the mechanism of evodiamine and rutaecarpine on the organism from the perspective of biofilm.Research Methods:1、Differential scanning calorimetry was used to detect the interaction of evodiamine and rutaecarpine molecules with liposome membranes at different molar concentrations The effects of evodiamine and rutaecarpine on the thermodynamic properties of liposomes bilayers were explained by the thermodynamic parameters,such as the pre-transition temperature(Tp),the main phase transition temperature(Tm),the peak width at half peak height of main phase transition(△T1/2),and the enthalpy of phase transition(△H),varying with the concentration of mole fraction of the drug.2、The microscopic phase states of evodiamine/DPPC liposomes and rutaecarpine/DPPC liposomes at specific temperatures were determined by synchrotron X-ray diffraction technique,and the effect of drug molecules on the interlayer distance of liposomes and the hydrophobic tail chain spacing of DPPC molecules were also determined by the synchrotron X-ray diffraction technique,in order to clarify the effect of both on the structure of liposomes.3、Fourier transform infrared spectroscopy was used to study the effects of evodiamine and rutaecarpine molecules on the characteristic functional groups(CH3、CH2、C=O、PO2-)of DPPC molecules in liposomes.The effects of evodiamine and rutaecarpine on the bilayer membrane of liposomes were elucidated from the molecular level.4、The interaction of evodiamine and rutaecarpine molecules with DPPC bilayer membrane was compared.Research Results:1、Differential scanning calorimetry heating experiment of evodiamine/DPPC liposomes showed that when the drug concentration was less than 10mol%,the temperature and enthalpy of phase transition decreased.When the drug concentration was up to 10mol%,the temperature and enthalpy of phase transition reached the minimum.When the drug concentration was more than 10mol%,the temperature and enthalpy of phase transition increased.The addition of evodiamine molecules at different molar concentrations resulted in the broadening of the half-peak width of the main phase transition of liposomes.The differential scanning calorimetry cooling experiment showed that the main phase transition temperature was delayed.The phase diagram of evodiamine/DPPC liposomes showed that when the drug concentration was 10mol%,the effect of evodiamine on the fluidity of liposomes membrane was the greatest.Differential scanning calorimetry heating experiment of rutaecarpine/DPPC liposomes showed that when the drug concentration is in the range of 0mol%to 5mol%,the temperature and enthalpy of phase transition decreased with the increase of drug concentration,and when the drug concentration is in the range of 5mol%to 15mol%,with the increase of drug concentration,the phase transition temperature and the enthalpy of main phase transition first increased and then decreased,while the enthalpy of pre-transition increased gradually,when the drug concentration is in the range of 15mol%to 20mol%,with the increase of drug concentration,the temperature and enthalpy of phase transition increased.The half-peak width of the main phase transition of liposomes was broadened by the addition of rutaecarpine at different molar concentrations.The differential scanning calorimetry cooling experiment showed that the main phase transition temperature was delayed.The phase diagram of rutaecarpine/DPPC liposomes showed that when the drug concentration was 15 mol%?the effect of rutaecarpine on the fluidity of liposomes membrane was the greatest.2、The synchrotron X-ray diffraction of evodiamine/DPPC liposomes showed that at a specific experimental temperature,the liposomes of evodiamine/DPPC liposomes had a specific phase state,and the resulting liposomes were layered structure.The addition of evodiamine molecules increased the interlayer distance of the liposomes which were in the lamellar gel phase,but did not affect the hydrophobic tail chain spacing of DPPC.The synchrotron X-ray diffraction of rutaecarpine/DPPC liposomes showed that the liposomes of rutaecarpine/DPPC had a specific phase state at a specific experimental temperature,and the resulting liposomes were layered structure.The addition of rutaecarpine molecules increased the interlayer distance of the liposomes which were in the lamellar gel phase,but did not affect the hydrophobic tail chain spacing of DPPC.3、Fourier transform infrared spectroscopy of evodiamine/DPPC liposomes showed that the band of the characteristic functional group of DPPC molecules could be shifted by the addition of evodiamine molecules.The shift of the band of functional groups is related to the molar concentration of evodiamine.Fourier transform infrared spectroscopy of rutaecarpine/DPPC liposomes showed that the bands of characteristic functional groups of DPPC molecules could be shifted by the addition of rutaecarpine molecules.Moreover,the shift of the band of functional groups is related to the molar percent concentration of rutaecarpine.Research Conclusion:1、The addition of evodiamine and rutaecarpine molecules did not affect the aggregation state of liposomes,and did not cause the disappearance of a phase state of DPPC liposomes.2、The entrapment sites of evodiamine and rutaecarpine molecules in DPPC liposomes were concentration-dependent.Evodiamine:in the concentration range of 0mol%<x<10 mol%,the drug molecules mainly entered the hydrophobic tail chain region of DPPC molecules,and a small number of drug molecules acted on the carbonyl groups in the interface region of DPPC molecules.In the concentration range of 10mol%≤x<20mol%,the drug molecules mainly entered the head region of the DPPC molecules,acted on the phosphate groups in the head region,and a few of the drug molecules existed in the hydrophobic tail and interface region of the DPPC molecules,acted on the hydrophobic tail chains and carbonyl groups in the interface region of DPPC molecules.Rutaecarpine;in the concentration range of 0mol%<x≤5mol%,the drug molecules mainly entered the hydrophobic tail chain region of DPPC molecules,and a small number of drug molecules acted on the carbonyl groups in the interface region of DPPC molecules.In the concentration range of 5mol%<x≤15mol%,the drug molecules had a certain degree of distribution in the hydrophobic region and the hydrophilic region of the DPPC molecules,and the drug molecules acted on the hydrophobic tail chains and the carbonyl groups in the interface region of DPPC molecules.In the concentration range of 15mol%<x≤20mol%,the drug molecules mainly entered the head region of DPPC molecules and acted on the phosphate groups in the head region.3、Both evodiamine and rutaecarpine could increase the fluidity of the liposome membrane and cause the phase separation of the membrane,which may be related to their various pharmacological activities.4、Both evodiamine and rutaecarpine could affect the bilayer distance of phospholipid bilayer of liposome in the lamellar gel phase,which can make the fatty acyl chain of DPPC molecule became more vertical to the surface of the membrane.At the same time,the orientation of evodiamine and rutaecarpine molecules into the hydrophobic region of liposomes was parallel to that of the hydrophobic tail chains of DPPC molecules.5、Through the comprehensive comparison of the experimental parameters,rutaecarpine molecules are easier to enter the bilayer membrane of liposomes than evodiamine molecules,and the influence of rutaecarpine on the bilayer membrane of liposomes is greater than that of evodiamine.