The Floral Markers Of Litchi Honey And The Effects Of Jujube Honey On Apoptosis Of HepG2 Cells

Litchi honey and jujube honey are two of the most commonly consumed monofloral honeys in the Chinese market.Jujube honey is mainly produced in northern China,while litchi honey is produced in southern China.Although collected from different plants and with different color and taste,litchi honey and jujube honey are both rich in nutritions.However,the current researches on litchi honey and jujube honey are inadequate.Very few researches on the floral markers and the effects on harmful cells are available.The identification of honey floral markers is an effective method for identifying honeys and distinguishing adulterated honeys.And the study on cell-level acticities is of great significance to understand the medicinal values as well as the functional development of honey.Therefore,this study focused on the floral markers of litchi honey and the effects of jujube honey on inducing apoptosis in human hepatoblastoma cancer cells(HepG2).1.The HPLC-DAD fingerprints of 13 of litchi honeys and 13 of jujube honeys collected from different regions of China were established,and the cluster analysis was performed based on the correlation coefficient matrix.The results showed that 28 common peaks and 32 common peaks were observed in litchi honeys and jujube honeys,respectively.Moreover,2 compounds were discovered in litch honeys and 4 compounds were discovered in jujube honeys,which can be used as floral markers of litchi honey and jujube honey,respectively.The result of cluster analysis showed that the maximum distance cluster analysis based on the correlation coefficient matrix can analyze the geographical origin of the samples,and provide support for the study of geographical differences.2.Isolation and structure identification of two floral markers(B1 and B2)of litchi honey were performed.22.5 mg of B1 and 4.7 mg of B2 were obtained by XAD-2 resins and Semi-Preparative High Performance Liquid Chromatography.The Q/TOF-MS result showed that their molecular weight was both 264,which indicated that they were abscisic acid and its isomers.3.The antioxidant activities of litchi honey and jujube honey were studied,including the determination of the contents of total phenolics,DPPH-radical scavenging activity and oxygen radical scavenging activity(ORAC).The results showed that the total phenol content of jujube honey was higher than that of litchi honey,the mean value was 525.1±72.35 mg GAE/kg.The mean values of DPPH·assay(IC50)and ORAC assay determined in jujube honeys were 32.55±4.16 mg/mL and 3.39±0.85 ?mol TE/g,respectively,which were significantly higher than that of litchi honey.This results showed a positive correlation between the antioxidant activity and the contents of total phenolics.Therefore,jujube honey was selected to perform the next step.4.The effects and the molecular mechanisms of jujube honey on inducing apoptosis of HepG2 human hepatoblastoma cancer cells were discussed.The results showed that jujube honey could inhibit the activities of HepG2 cells.With the increase of concentration,the proportion of apoptotic cells increased correspondingly,and the apoptosis characteristics appeared,including the nucleus ruptured.Furthermore,jujube honey showed a positive correlation with some apoptosis characteristics,including reducing mitochondrial membrane potential,increasing the expression of Bax and Bad,reducing the expression of Bcl-2 and Bcl-xL.At the same time,the expression of antioncogene p53 protein was increased,all of which increased the protein expression of caspase-9 and caspase-3 and caused the apoptosis of HepG2 cells.Therefore,jujube honey may induce apoptosis of HepG2 cells through the mitochondrial pathway of p53 induced.