Study On Effects Of Hesperetin On The Growth And Caspase-3Gene Expression Of HepG2Cell

Objective:Hesperetin which is a kind of natural flavonoid compounds insists in citrus, it has many pesticide effect such as anti-inflammatory, oxidation resistance, resistance to allergy, protect the cardiovascular and antitumor. And its Mainly comes from the hydrolysis of orange peel glucoside. Under the effect of intestinal flora, the glucoside is hydrolyzed into hesperetin and come into play. Hesperetin contents very high in crude medicine such as dried and green orange peel, and becomes one of their active ingredient. After several decades of research, researchers have been convinced that hesperetin has a special effect in reducing blood lipids, blood sugar, prevent cancer and so on. The effect and mechanism of tumor suppression has been preliminarily discussed, and research has found that hesperetin ameliorated doxorubicin-induced cardiotoxicity by reducing oxidative stress, abnormal cellular morphology and DNA damage in rat. However, studies on hepatocellular carcinoma cells rarely relevant reports at home and abroad.The experiment was made on the purpose of laying a theoretical foundation for further study on finding low toxic and high efficiency natural anti-tumor drugs by observing the Hesperetin inhibited the HepG2cells proliferation and induced its apoptosis and a preliminary study on mechanisms of impaction of expression of Caspase-3protein.Methods:1. MTT assay was used to determine to different concentrations (4mmol·L-1、1mmol·L-1、0.25mmol·L-1、0.0625mmol·L-1) of Hesperetin and different concentrations (50μg·ml-1、25μg·m-1、12.5μg·ml-1、6.25μg·ml-1of Cisplatin at different times (24h,48h,72h,96h) under the action of the HepG2cell proliferation and inhibition in vitro.2. Inverted phase contrast microscope was used to observe the HepG2cells morphological changes under impaction of different concentrations (1mmol·L-1、0.5mmol·L-1) of Hesperetin and25μg·ml-1of Cisplatin.3. Fluorescence microscope was used to observe apoptotic cells by using hochest33342staining which appeared from Hesperetin after impact by ethanol extract (1mmol·L-1、0.5mmol·L-1) of HepG2cells.4. Flow cytometry was used to analysis different concentrations (1mmol·L-1、0.5mmol·L-1) of the alcohol extract of Hesperetin impact on HepG2cell cycle and apoptosis.5. Protein blotting techniques (Western Blot) was used to detect the expression of caspase-3protein impacted by various concentrations (1mmol/L0.5mmol/L) of Hesperetin.Results:1. Hesperetin has effect on inhibiting the proliferation of the HepG2cells growth, which presented a character of time and dose dependent, with the time going and concentration rising, the inhibitory effect increasing gradually. Compared the affection of ethanol soluble extract of Camellia concentration greater than62.5μmol·L-1to the negative control group, the difference was significant in statistically (p<0.05).2. Under observation by the inverted phase contrast microscope, as drug concentration increased, the HepG2cells grow slowly after48h impacted by the Hesperetin, cell shrinkage gradually and became smaller and more round, shedding, and finally see a large number of contracted, broken and exfoliated cells suspended in culture medium.3. Under the fluorescence microscope, different concentration of Hesperetin impacted on HepG2cells was observed after48h.It could be observed that cells revealed a dense concentration of the strong blue fluorescence staining, nuclear condensation, nuclear cleavage, nuclear chromatin aggregation apoptosis cell morphology. As the concentration increased, the apoptosis cells increased.1. After impacted by Hesperetin48h, with the concentration increased, the proportion of cells in G1phase increased in HepG2cells, while the G2. S phase cells have different levels of reduction, cells were arrested in G1phase. At the same time, as the concentration increased, the apoptosis rate also increased. Compared to the negative control group, the differences of apoptosis rate had statistically significant (p<0.05).5. Western Blot:With the increase of drug concentration, activation of the Caspase-3protein bands gradually deepened, expression of Caspase-3protein increased. Analysis of gel image processing system with integrated optical density measured with the β-actin band and the negative control group integrated optical density were statistically significant differences (p<0.05).Conclusions:1. Hesperetin can inhibit the proliferation of HepG2cells in vitro, and presents the dose and time effects.2. The mechanism of induction of apoptosis may be induced G2arrest and the promot activation of Caspase-3.