Anti-cancer Activity,Absorption And Transportion Of Phenolic Compounds In Typical Grains

Not only playing an imperative role in Chinese dietary pattern,grain also serves as the main staple food among other Asian countries.Except for abundance in carbonhydrate,protein,vitamins and minerals,whole grain contains a certain amount of active substances exhibiting an ability of regulating physiological properties.Among them,phenolic compounds are known with their antioxidant,antineoplastic and cancerostasis effect yet with limited research records.This paper investigated the composition,antioxidant and cancerostasis effect of phenolic compounds in typical whole grain?sorghum,buckwheat,barley,rice and wheat?.Systematic experiments were conducted to investigate the inhibitory effect of phenolic compounds from sorghum?SP?on the proliferation activity of human colon carcinoma cells,with analysis in molecular mechanism.Based on that,the intestinal absorption and transportation of SP was studied by constructing Caco-2 cell models.This paper is aimed at providing basis and reference for deeper researches of whole grain phenolic compounds in future,whose main contents are as follows:1 The performance of phenolic compounds from typical grain on antioxidant ability and anti-proliferative activity of cancer cells.The phenolic compounds of sorghum,buckwheat,barley,rice and wheat were extracted with 70%?v/v?ethanol solutions and purified by AB-8 macroporous resin.Total polyphenol and flavonoid contents of the grain were quantified.Meanwhile,we used LC-MSn to investigate the phenolic composition of grains.The antioxidant properties of grain,including reducing power,scavenging effect on 2,2-diphenyl-1-picrylhydrazyl?DPPH?,were investigated.The anti-proliferative activity of grain extracts was analyzed using MTT analysis to human colon adenocarcinoma Caco-2 cells.Correlation effect was also considered and analyzed.The results was as follows:?1?In conclusion,sorghum had the highest TPC?651.73±8.81 GAE mg/100 g dw?and TFC?1385.93±12.21 RTE mg/100 g dw?,followed by buckwheat,barley,rice,and wheat.Among the grain we tested,29 major phenolic compounds weresuccessfully identified in the grain extracts.?2?In addition,SP had the highest biological activities?94.82% for DPPH·;70.75% for inhibition effect on Caco-2 cells?followed by buckwheat,barley,rice and wheat.Experimental results shown that: both TPC and TFC had remarkable correlations with antioxidant activity and inhibiory effect to Caco-2 cells' proliferation?r > 0.85,P < 0.05?.Besides,the two kinds of effect?antioxidant and anti-proliferative activity?were also verified with high correlation?r > 0.9,P < 0.05?.2 Anti-proliferative performance and its mechanism of phenolic compounds from sorghum toward human colon carcinoma Caco-2 cells.MTT assay was used to investigate the inhibitory effect of SP on Caco-2 cell lines.The morphological changes of cells was observed through AO/EB fluorescence staining and Hoechst 33342 nucleus staining.Intracellular reactive oxygen species?ROS?level was detected by DCFH-DA and DHE fluorescence probe.JC-1 probe was used to detect the mitochondrial membrane potential.We detected Ca2+ level of cell by Fluo-3 fluorescence probe.Western blotting assay was used to determine the expression levels of apoptotic protein?Cytochrome C,Bcl-2/ Bax,caspase-3 and caspase-9?.The results was shown below.?1?Results demonstrated that SP leads to growth arrest and cell death in a doesand time-dependent manner.After treatment for 24 h with SP,the morphological changes of apoptotic cells appeared.SP induced apoptosis in Caco-2 cells.After treatment for 12-120 h,the content of IC50 was between?344.749 ±1.35??g/mL and?41.694 ±2.09??g/mL.?2?Treatment of Caco-2 cells with SP triggered ROS generation,which reached a maximum level after 12 h.When the Caco-2 cells were treated with SP of 200?g /mL for 24 h,the Ca2+ level is 3.3 times higher than that in comparison group.In addition,mitochondrial membrane potential decreased?P < 0.05?,and the expression level of Cytochrome C,caspase-3,caspase-9 protein were 5.96,5.87,3.19 times higher respectively than that comparison groups,while the protein level of the ratio of Bcl-2/ Bax decreased to 0.45?3.01 in comparison group?.Consequently,SP wasproved to be capable of inhibiting Caco-2 cell proliferation by inducing apoptosis.3 Vitro absorption and transportation of taxifolin in phenolic compounds from sorghum.We contructed vitro absorption model and assess Caco-2 cells in laboratory experimental conditions.Monolayer integrity was verified by measuring TEER value,polarity evaluated by alkaline phosphatase vitality,and permeability by apparent permeability coefficient of Lucifer Yellow(P_app).Based on that,the Caco-2 cell model was used to evaluate the transmembrane intestinal absorption and transportation of taxifolin in SP and compared with taxifolin standard.The results were listed below.?1?The Caco-2 cell model constructed under the laboratory conditions could be used to study in vitro absorption and transportation with TEER > 800?·cm²,ALP vitality ratio?AP/BL?is about 3.0 and P_app?LY?< 1.0 × 10^-6?2?Compared with the taxifolin standard,the P_app of taxifolin in SP increases significantly?P < 0.05?and ER decreased to 1.34.Our results shown that the bioavailability of taxifolin in SP is higher than taxifolin standard.P_app and ER did not change significantly with additional cerapamil,but additional cyclosporine A increased the P_app of taxifolin and the ER decreased nearly to 1.0.The efflux protein MRP2 affected the transmembrane transportation of taxifolin in the Caco-2 cell model,which might be a main factor of bioavailability.