Study Of Gambogic Acid And Curcumin Micelle System With Computational Pharmaceutics

As a new drug in China,the anti-tumor activity of gambogic acid(GA)has been confirmed by many studies.However,the hepatotoxicity and nephrotoxicity of GA limits its clinic applying.Combined administration is one of the methods to enhance drug activity and reduce the toxicity of drugs.Curcumin is a natural product which has anticancer bioactivity.Many studies have found that curcumin can enhance the anticancer activity of many anticancer drugs,and curcumin also can treat the injury of liver and kidney.The bioavailability of GA and curcumin is limited due to their low water solubility.Nano micelles is a new drug pharmaceutical dosage form used to solve poorly water-soluble drugs.Nano micelles enhances the water solubility and stability of the drug through the nuclear-shell structure,and it can also give the micelles different properties by modifying the structure of the micelle material.In this study,we make the GA and curcumin combined with medication.In order to reduce the toxicity of GA,enhance the anticancer activity,water solubility and bioavailability of GA and curcumin,we have designed and screened the nano micelles with good drug loading ability and solubilization by computational pharmaceutics method.We first examined the synergistic anti-tumor activity of the combination of GA and curcumin through the cell survival experiment in vitro,and the synergistic antitumor effect of the combination was evaluated by the combination index and the Q value.The study showed that the combination of GA and curcumin could significantly reduce the survival rate of HepG2 and SMMC-7721 cells.Some concentrations of the drug combination in HepG2 and SMMC-7721 cells showed synergism and all concentrations of the drug combination in LO2 showed antagonism.The mechanism of combined anti-tumor effect of GA and curcumin in HepG2 was investigated by Annexin V-FITC/PI kit,active oxygen detection kit and Westen Blot method.The results showed that in contrast to the single drug group,the combination of GA and curcumin could significantly increase the apoptosis rate and necrosis rate of HepG2,significantly increase the ROS level of HepG2 cells,increase the expression of cleavecaspase-3 of apoptosis related protein in HepG2,and significantly reduce the expression of anti-apoptosis related protein pAKT of HepG2 cells under the condition that the total AKT protein level is unchanged.In this study,we also designed and screened nano micelles which can simultaneously contain GA and curcumin by computational pharmaceutics method.The hydrophobic segments of the micelles were screened by Hanson solubility parameters.The results showed that the Flory-Huggins interaction parameter between GA and curcumin was 0.19.It was better than the FloryHuggins interaction parameters between other hydrophobic segments(PCL and PLA)and curcumin.Then we study the binding process and free binding energy between three kinds of micelles(mPEG-GA,mPEG-PCL,mPEG-PLA)and drug by molecular dynamics simulation.Research shows that the three micelles were formed,and the free binding energy between mPEG-GA and drugs is stronger than that of the other two kinds of micelles.Computer simulation showed that the drug loaded nano micelles made from mPEG-GA and curcumin had good drug loading ability and solubilization.Subsequently,we synthesized mPEG-GA and prepared the synergistic nano micelles loaded gambogic acid and curcumin by thin film hydration method.The micelle solution was clear and it has an obvious Tyndall effect.The size of the micelles is 83.28±0.92 nm and the high-resolution transmission electronic microscope shows that the size of the micelles is around 80 nm,the size of the micelles is equal and the nuclearshell structure is obvious.The drug loading rate and encapsulation rate of the micelles were 24.46±0.41% and 86.76±1.96% respectively.The solubility of GA and curcumin in micelles increased 383 times and 2070 times respectively.The cumulative release of GA and curcumin were 21.96% and 43.19% respectively at 12 h,the cumulative release of GA and curcumin were 34.2% and 59.63% respectively at 48 h,the cumulative release of GA and curcumin were 39.45% and 60.67% respectively at 72 h and the micelles have synergistic antitumor effects.