The Polyphenol Content and Antioxidant Activities of the Main Edible Vegetables in Northern Vietnam

Abstract

SummaryOxidized low-density lipoprotein (LDL) is considered a risk factor in atheroscle rosis, and polyphenols are the potential agents to inhibit the oxidation of LDL. We deter mined the polyphenol contents and the antioxidant activities of commonly consumed vegetables in Vietnam and assessed the quantity of the polyphenol intake from vegetables in the current Vietnamese diet. The polyphenol contents in 30 kinds of vegetables was deter mined by the Folin-Ciocalteu method. The antioxidant activities of vegetables were evalu ated by measuring the oxidation of LDL and the reduction of the 1,1-Biphenyl-2 -picrylhydrazyl (DPPH) radical. In this study, some herbs and edible wild vegetables possessed high contents of polyphenols and antioxidant activities. Among green vegetables, sweet potato leaves showed both a high polyphenol content and antioxidant activity. The mean polyphenol daily intake of the Vietnamese was a 595mg catechin equivalent. Water spin ach, a kind of green vegetable, contributed the highest amount (45%) of the total polyphe nol intake, followed by other green vegetables. Neither herbs nor edible wild vegetables contributed significantly to the total polyphenol intake due to their low consumption. Green vegetables are therefore considered very important sources of polyphenol intake for the Viet namese.

Alpha-Glucosidase Inhibitory and Antioxidant Activities of Vietnamese Edible Plants and Their Relationships with Polyphenol Contents

“…2A and B of this study. These results support the role of polyphenolic compounds in the antioxidant activities of these plants, in agreement with previous reports (17,19,28) which indicated that the antioxidant capacity of vegetables depends on the amount of flavonoids that each vegetable possesses. The plant materials with high polyphenol contents had both strong ␣-glucosidase inhibitory activity and strong antioxidant activity.…”

“…The polyphenol amounts in aqueous and methanolic extracts were determined according to the Folin-Ciocalteu colorimetric method, as modified by Thu et al ( 17 ). Briefly, to 50 Assay for ␣ -glucosidase inhibitory activity.…”

“…To date, there have been few studies on the polyphenol contents of Vietnamese plants ( 17 ), and no scientific information about edible plants which have both ␣ -glucosidase inhibitory activity and antioxidant activity is available. The relationships of these two activities to the polyphenol contents of edible plants have yet to be investigated.…”

Antioxidant Activity ofIpomoea batatasL. Lam. Leaf Grown in Continental Croatia and Its Effect on Glutathione Level in Glucose-Induced Oxidative Stress

“…[9] Finally, I. batatas from Asia and North America displayed notable antioxidant activity. [10][11][12] There is no published report on composition or activity of I batatas grown in European continental climate. In this work, aqueous and ethanolic extracts of I. batatas leaf grown in continental Croatia were prepared.…”

Nonextractable polyphenols, usually ignored, are the major part of dietary polyphenols: A study on the Spanish diet

“…In the Vietnamese, diet intake was 595 mg/day/person, with leafy vegetables as the main contributors [37]. In Spain, EPP intake was estimated around 1100 mg/day/person, where beverages (juice, coffee, and wine) are the main source of EPP [38].…”