Study On Bioactive Chemical Constituents,Antioxidant And Anti-proliferative Activities Of Black And White Sesame Seeds

Sesame seeds contain many bioactive compounds including polyphenols,flavonoids,vitamins,unsaturated fatty acids and so on.Antioxidant,hypolipidemic,and other bioactive functions of sesame seeds have been reported.However,comparison of antioxidant activity between different varieties are still lack of data.This paper compared bioactive compounds,cellular antioxidant activity and Hep G2 cell antiproliferative activity of three kinds of black sesame(Changzhi II,Liangzhi I and Bawangbian F1)and three white sesame(Aijiao Bawangbian,Zheng Taizhi I and Zheng 95-8).The bioactive components and antiproliferative activity of black and white sesame seeds before and after in vitro digestion were studied.The results are as follows:1.The phenolics in sesame seeds were mainly in the form of free extract,and the average ratio of free phenolics to total phenolics was 63.28%.The free,bound and total phenolic contents of black sesame seeds were higher than those of white sesame seeds.The total phenolic contents of Changzhi II(246.18 ± 4.63 mg GAE/100 g,DW)and Liangzhi I(252.11 ± 6.44 mg GAE/100 g,DW)were significantly higher than other four varieties.Similarly,the flavonoids in sesame seeds were mainly in the form of free extract,and the average proportion of free flavonoids was 81.36%.The free,bound and total flavonoids contents of black sesame seeds were higher than white sesame seeds.The total flavonoid contents of Liangzhi I(1,558.91±208.63 mg CE/100 g,DW)and Bawangbian F1(1,662.77±50.50 mg CE/100 g,DW)were significantly higher than other four varieties.Black and white sesame seeds both contain sesamol,pinoresinol diglucoside,ferulic acid,pinoresinol,sesamin and sesamolin.The total content of six kinds of compound in Aijiao Bawangbian was higher than other five varieties.2.The total antioxidant capacity(ORAC value)of black sesame seeds was higher than white sesame seeds.The total ORAC value of Changzhi II(78.44 ?mol TE/g,DW)was the largest.The cellular antioxidant capacity(CAA)of black sesame seeds was stronger than white sesame seeds.The free extract of Changzhi II had the highest CAA value(33.73 ± 2.46 and 105.04 ± 6.75 ?mol QE/100 g,DW).There was significant correlation between phenolics, flavonoids and antioxidant activity(p<0.05).Changzhi II and Aijiao Bawangbian had highest content of bioactive compounds and highest antioxidant activity among black sesame and white sesame seeds,respectively.3.Therefore,the in vitro digestion experiment was carried out to study Changzhi II and Aijiao Bawangbian.The phenolic contents of free and bound extracts of two selected varieties state were significantly higher than phenolic contents of the oral digestion production.However,the phenolic contents of free and bound extracts of two selected varieties state were significantly less than the digestion productions of stomach,small and large intestine.Most of phenolics were released in the small intestine.The phenolic content Changzhi II and Aijiao Bawangbian after small intestine digestion were 790.34 ± 4.97 and 530.46 ± 4.78 mg GAE/100 g,DW.Total flavonoid content of Changzhi II after small intestine was significantly higher than Aijiao Bawangbian(p<0.05).Total flavonoids of Changzhi II and Aijiao Bawangbian showed no significant difference(p>0.05)after oral,stomach and large intestine digestion.Most of sesamol,pinoresinol diglucoside,ferulic acid,pinoresinol sesamin and sesamolin were released after small intestine digestion.Total content of six compounds of Changzhi II after small and large intestine digestion was significantly higher than Aijiao Bawangbian.4.ORAC value showed no significant difference between Changzhi II and Aijiao Bawangbian after digestion.The cellular antioxidant activity of Changzhi II after in vitro digestion was stronger than Aijiao Bawangbian.The total ORAC values of free and bound extracts were significantly higher than ORAC values after oral digestion,which were significantly lower than that in stomach,small and large intestine.The ORAC value in the small intestine digestion was the highest,while that in the oral was the lowest.The CAA values of small intestine digestion products of Changzhi II and Aijiao Bawangbian were significantly higher than free and bound extract,which were reversed after oral,stomach and large intestine digestion.5.The antiproliferative activities of black sesame seeds were stronger white sesame seeds in both free and bound extracts.Correlation analysis showed that the higher the polyphenol content,the stronger the antiproliferative effect;the stronger the antioxidant activity,the stronger the antiproliferative effect.Compare the antiproliferative effects before and after in vitro digestion of Changzhi II and Aijiao Bawangbian.Small intestine digestion product of Changzhi II and Aijiao Bawangbian were significantly higher than free and bound extracts(p<0.05).The free extracts and small intestine digestion product of Changzhi II and Aijiao Bawangbian mainly arrested G2/M or S phase of Hep G2 cell cycle.6.The ORAC values of six kinds of compounds(sesamol,pinoresinol diglucoside,ferulic acid,pinoresinol,sesamin and sesamolin)in decrease order were ferulic acid,sesamol,pinoresinol,pinoresinol diglucoside,sesamolin and sesamin.Sesamin and ferulic acid showed cell antioxidant activity,but other four compounds did not show significant cell antioxidant activity.The cytotoxicities of six compounds on Hep G2 were not obvious.Sesamol,pinoresinol ferulic acid showed significant antiproliferative activity,and ferulic acid had strongest antiproliferative activity.