Separation, Purification and Identification of Antioxidant Compositions in Black Rice

To separate, purify and identify the antioxidative compositions of black rice, using total antioxidation capacity （TAC） as an activity-monitoring parameter, different fractions of black rice antioxidative extracts were obtained using solvents of different polarities such as petroleum ether, chloroform, ethyl acetate and normal butyl alcohol. The main anfioxidative components were separated from the strongest antioxidative fractions by using Sephadex LH-20 resin and the structures were analyzed by ultraviolet-vis, infra-red, ESI-MS, ^1H-NMR and ^13C-NMR spectrums. Results showed that the water fraction and normal butyl alcohol antioxidafive extract fraction of black rice had the strongest antioxidation capacities and their TACs reached 383 and 392 ku g^-1, respectively. Four main antioxidative components were separated from the water fraction and their TACs reached 976, 878, 1 134 and 1087 ku g^-, respectively. The spectroscopy analysis indicated that the four active components of the antioxidative extract of black rice were four anthocyanin compounds of malvidin, pelargonidin- 3, 5-diglucoside, cyaniding-3-glucoside and cyaniding-3, 5-diglucoside. It is concluded that the anthocyanin compounds are the most important substantial foundations for antioxidation.

Association between composite dietary antioxidant index and stroke among individuals with diabetes

BACKGROUND Recent research has underscored the potentially protective role of dietary antioxidants against chronic conditions,such as cardiovascular diseases and stroke.The composite dietary antioxidant index(CDAI),which reflects the overall intake of key dietary antioxidants,has been identified as a crucial metric for exploring this relationship.Although previous research has shown a negative correlation between CDAI levels and stroke risk in prediabetic individuals,there remains a substantial gap in understanding this association among individuals with diabetes,who are at an inherently greater risk for cerebrovascular events.AIM To investigate the association between CDAI and stroke risk in individuals with diabetes.METHODS Using a cross-sectional study design,this investigation analyzed data from the National Health and Nutrition Examination Survey spanning from 2003 to 2018 that included 6735 participants aged over 20 years with diabetes.The CDAI was calculated from 24-h dietary recalls to assess intake of key antioxidants:Vitamins A,C,and E;carotenoids;selenium;and zinc.Multivariate logistic regression and restricted cubic spline analysis were used to rigorously examine the relationship between CDAI and stroke risk.RESULTS The participant cohort,with an average age of 59.5 years and a slight male majority,reflected the broader demographic characteristics of individuals with diabetes.The analysis revealed a strong inverse relationship between CDAI levels and stroke risk.Remarkably,those in the highest quintile of CDAI demonstrated a 43%lower prevalence of stroke compared to those in the lowest quintile,even after adjustments for various confounders.This finding not only highlights the negative association between CDAI and stroke risk but also underscores the significant potential of antioxidant-rich diets in reducing stroke prevalence among patients with diabetes.CONCLUSION Our findings suggested that CDAI was inversely associated with stroke prevalence among patients with diabetes.These results suggest incorporating antioxidant-rich foods into dietary regimens as a potential strategy for stroke prevention.