Research On Antioxidant And Anticancer Activity Of Four Black Grains Extracts

Oxidative damage is one of the important factors that cause disease. Antioxidantscan prevent the risk of diseases, especially in cancer. Black food is rich in a variety ofactive components, such as polyphenols, flavonoids, anthocyanins, etc, which have agood health-care efficacy. Black food gain more attention in recent years, and it is thefocus of many researchers.In this study, black rice, black bean, black kidney bean, panda bean were chosenas the experimental material and the content of active components were determined. Itshowed a certain of polyphenols, flavonoids, anthocyanins and proanthocyanidinsexsited in four black rice, black bean, panda bean, as the typical grain, the contents ofpolyphenols and flavonoids were very high. Four black grains showed strong freeradical scavenging ability and ferric reducing antioxidant power with a significantdose-response relationship. Black rice is the best antioxidant, IC50was3.96×10-4g/mL(·DPPH),1.2×10-2g/mL(ABTS·+),8.55×10-2g/mL(·OH), respectively.Correlation analysis showed polyphenols and flavonoids were the major componentsof antioxidant ability.Breast cancer cells MCF-7and Caco-2colon cancer cells were chosen as targetcells to measure the anticancer capacity of four black grain extracts. The result ofMTT analysis showed, four black grain extracts can inhibit the proliferation of humanbreast cancer cell MCF-7and human colon cancer cell Caco-2with a significantdose-response relationship. Black rice has the highest antiproliferation activity againstMCF-7(IC50was181.34μg/mL), and as for Caco-2, panda bean is the most effective(IC50was306.38μg/mL). The results of correlation analysis showed, polyphenolsand flavonoids were the basis of anticancer activity.On the basis of MTT, panda bean was selected as the object, Caco-2was thetarget cell, by agarose gel electrophoresis, Flow cytometry and Elisa to detectapoptosis-inducing mechanism against Caco-2. After exposed in variousconcentration of panda bean extract for72h, proliferation ratio decreased，typicalopoptotic DNA ladder can be observed by agarose gel electrophoresis. Flowcytometry analysis showed that panda bean extract induced cell cycle arrest at G1phase and apoptosis was induced, especially late apoptosis. The expression ofapoptosis related proteins such as CytC, caspase-9and caspase-3was increased. It corroborated that panda bean extract act as an apoptotic inducer against Caco-2celland induce apoptosis via mitochondria pathway. The results provide a theory basisfor development of new drug or to be an adjuvant therapy for cancer.