Effect Of Tartary Buckwheat Extract On Amylase And Antioxidant Property In Vivo

Tartary buckwheat is rich in rutin and other flavonoids,which means it has more edible and medicinal values than other cereal crops.Due to the toxic effect of reactive oxygen species(ROS)induced by postprandial glucose spike generated by rapidly digestible starch,the effects of tartary buckwheat extract on starch digestibility and ?-amylase activity were studied,and then the protective effect on alcohol-induced liver injury through its antioxidant properties was investigated.The tartary buckwheat extract was prepared by 70% ethanol solvent in a ratio of 1:35(g/mL)at 80?,and the extraction rate was 6.26%.A thin layer chromatography(TLC)and ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF/MS)results showed that the majority of the extract were rutin(198.89 mg/g),quercetin(3.56 mg/g),and several other types of flavonoids including kaempferol-3-o-rutinoside and some pigments,polysaccharide and phenols.The starch digestibility of tartary buckwheat powder was lower than its extracted by-product of tartary buckwheat indicated that tartary buckwheat extract could inhibit the digestion of tartary buckwheat starch.The analysis of the inhibition rate,inhibition type and fluorescence quenching of ?-amylase showed that the inhibition of tartary buckwheat extract on ?-amylase was dependent on its concentration,and the IC50 was 3.35 mg/mL.The tartary buckwheat extract noncompetitively affected the activity of ?-amylase,which was confirmed by its ability to statically quench the fluorescence of ?-amylase through binding to the enzyme.The postprandial glycemic response of mice showed that tartary buckwheat extract have an obviously effect on digestibility of corn starch in vivo.The FRAP(Ferric reducing antioxidant power)test demonstrated the antioxidant activity of tartary buckwheat extract,and then it's in vivo antioxidant property was investigated using an animal model of C57BL/6 male mice fed on high fat diet combined with treatment by alcohol in the last week.The experimental results showed the body weight at the end of the last week was significantly decreased while the tartary buckwheat extract alleviated the reduction of body weight,indicating the protective effect of tartary buckwheat extract on the toxic effect of alcohol.Furthermore,the reduced activity of serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)in mice fed on tartary buckwheat extractcontaining high fat diet also suggested its protective effect on alcohol-induce liver injury.Additional experiment on the activities of Superoxide dismutase(SOD),Glutathione peroxidase(GSH-Px)and Malondialdehyde(MDA)content in liver and small intestine revealed that both high fat diet and alcohol induced the decreased activity of these antioxidant enzymes and the increased level of MDA.On the contrast,the tartary buckwheat extract increased the activity of those enzymes with lowered content of MDA in liver and small intestine tissues.The histopathological sections of liver and abdominal adipose tissues of mice confirmed the liver damage caused by high fat diet and alcohol treatment as well as the protective effect of tartary buckwheat extract on alcohol-induced liver damage with reduced inflammatory infiltration between liver cells.Considering the higher activities of antioxidant enzymes after treatment by tartary buckwheat extract with high antioxidant properties,the antioxidant property could be the basis to its protective effect on alcohol-induced liver injury,and the detailed mechanism warrant further investigation.