Preparation And Characterization Of Harmine Hydrochloride-loading Nanoparticles And Its Effect On Apoptosis Of Gastric Cance Cells

Objective: Harmine hydrochloride(HM)--loading nanoparticles(HM-NPs)were generated form food grade biodegradable polymer materials and characterized.Their antitumor activities were investigated in vitro.Methods: Polycaprolactone polyethylene glycol(PCL-PEG)was prepared by ring opening polymerization method of block copolymer.Harmine hydrochloride nanoparticles were prepared by the method of solvent dispersion.Form of nanometer microspheres were scaned by electron microscope and transmission electron microscopy.Particle size of nanometer microspheres was determined by using a dynamic light scattering instrument.Drug loading rate,coating rate and release curve of HM-NPs were measured by using a high performance liquid chromatography(HPLC)in vitro.The kill power of HM-NPs and harmine hydrochloride alone on gastric cancer cell line SGC-7901 were examined by MTT(methyl thiazolyl tetrazolium).Intake of nanometer microspheres into tumor cells were observed under a fluorescence microscope.A fluorescent inverted microscope was used to inspect the output of ROS(reactive oxygen species)within the tumor cells.Apoptosis of gastric cancer cells was detected by flow cytometry.Western blot was used to detect the protein expression level of p-AKT,AKT,Bcl-2,Bax,and Caspase 3.Results: HM-NPs were roundness and had a smooth surface.The particle size is relatively uniform,about 100 nm in diameter.The drug-loading rate of HM-NPs was 4.97 ± 0.26%.The encapsulation efficiency of HM-NPs was 82 ± 4.8%.The drug-loading nanoparticle had good release characteristics in vitro.Within the first five hours,about 30% of the drug was released,and a total of about 60% was released in the first five days.We found that both HM and HM-NPs could inhibit survival of SGC-7901 cells concentration-and time-dependently.The anti-tumor effect of HM-NPs was stronger than HM alone.Coumarin nanoparticles could enter into the cell after 2 hours of incubation as measuremed by absorption experiment.Gastric cancer cells was divided into blank control group,empty nanoparticles group,harmine hydrochloride,harmine hydrochloride nanoparticles group,harmine hydrochloride and N-acetyl-L-cysteine cysteine group,and harmine hydrochloride nanoparticles and N-acetyl-L-cysteine cysteine group,etc.,given corresponding drugs respectively.Fluorescent inverted microscope was used to inspect the expression levels HM-NPs treatment caused a stronger increase in output of ROS by tumor cells than HM alone.Ability order stimulating ROS production in SGC-7901 cells is as follows:: HM-NPs > HM > HM-NPs plus N-acetyl-L-cysteine cysteine(NAC)> HM plus NAC.HM-NPs also exhibited the strongest effect to promote apoptosis of tumor cells.The order is tha: HM-NPs > HM > HM-NPs plus NAC > HM plus NAC.Compatibly,the order of expression levels of p-AKT in tumor cells is that: HM-NPs < HM < HM-NPs plus NAC < HM plus NAC.There were not significant differences between these groups in AKT expression level.Measurements of Bcl-2,Bax,and Caspase 3 confirmed that HM-NPs had the strongest effect to promote apoptosis of tumor cells.Conclusion: This study newly generated the harmine hydrochloride drug-loading nanoparticle and depicted its characteristcs.HM-NPs exhibited good slow-release characteristics and better antitumor activity than HM alone.The mechanism may be associated with induction of intracellular ROS production,which mediates PI3K/AKT signaling pathway to promote cell apoptosis.Thus,HM-NPs may be an effective drug delivery means to treat gastric cancer.