Antioxidant Activity And Anti-proliferative Activity Of Caco-2 Cell Of Phenolic Compounds In Extruded Black Wheat Bran

Wheat bran,as a by-product of wheat,a major food crop in China,is easy to obtain and rich in a large number of nutrients.The phenolic compounds are important active substances and have biological activities such as antioxidant activity,anti-inflammatory,anti-mutation and anti-cancer effects.Extrusion treatment can improve the edible quality of wheat bran,prolong shelf life and improve the extractability of phenolic compounds.At present,the effects of extrusion treatment on the antioxidant properties of wheat phenolic compounds have been studied,but the effects on the composition of specific phenolic compounds and the proliferation activity of anticancer cells are rare.Jizi439 black wheat bran(BWB)was used as raw material and treated by twin-screw extrusion process in this study.The effects of extrusion process on total phenol content(TPC),antioxidant activity(AA)and phenolic composition of wheat bran were studied.The effect of phenolic extracts on the proliferation of cancer cells was studied.The best extrusion process was determined.The main results were as follows:(1)Three extrusion process parameters(extrusion temperature,feed water content and screw speed)of twin screw extruder were selected and optimized by orthogonal test.The optimized extrusion combination was: extrusion temperature 110 ?,feed water content25%,screw speeds 140 r/min.Result of verification experiment showed the TPC is 2304.3± 127.4 ?g GAE/g dry weight and the AA is 86.2 ± 0.8%.Meanwhile Ultrasound assisted extraction parameters(temperature,time,ultrasonic frequency and power)were optimized by orthogonal test.The optimum ultrasound assisted extraction combination was:temperature 50 ?,time 40 min,35 k Hz and 300 W for ultrasonic frequency and power.TPC of 2856.3 ± 57.7 ?g GAE/g dry weight and AA of 85.5 ± 1.1% were obtained in verification experiment.(2)The TPC,DPPH radical scavenging activity,ABTS radical scavenging activity and FRAP antioxidant activity of extruded black wheat bran(EBWB)were significantly increased by extrusion process,and they were 63.92 ± 3.86 ?mol GAE /g dry extract,32.36 ± 1.97 ?mol TE/g dry extract,67.35 ± 2.33 ?mol Trolox /g dry extract and 65.07 ±2.29 ?mol TE/g dry extract,respectively.The content of vanillin and apigenin was significantly increased after extrusion.By UPLC-TOF-MS analysis,10 phenolic compounds were detected in white wheat bran(WWB),12 phenolic compounds were detected in unextruded black wheat bran and 18 phenolic compounds were detected in extruded black wheat bran.(3)The phenolic extracts of WWB,BWB and EBWB had significantly inhibition on cell proliferation of Caco-2 human colorectal cancer cells and showed significant dose and time dependent effects.After 72 h of treatment of three extracts at 400?g/mL,the apoptosis rates of Caco-2 cells were 6.2%,7.6% and 10.01%,respectively.Phenolic compounds in EBWB can significantly promote the apoptosis of Caco-2 cells.The phenolic extracts of BWB and EBWB had significant effect on the cell cycle of Caco-2cells.It is inferred that S phase arrest may occur,thus inducing apoptosis,which may attributed to chlorogenic acid by correlation analysis.Extruded black wheat bran exhibits the unique phenolic compound profile with potential health benefits,and it may serve as ingredients for functional foods.