title: Consumption of purple sweet potato leaves decreases lipid peroxidation and DNA damage in humans.
abstract: Consumption of polyphenols is associated with reduced risk of chronic diseases, possibly via a variety of bio-mechanisms, including antioxidation and anti-inflammation. Purple sweet potato leaves (PSPL) commonly consumed in Asia possess polyphenols. In this study, we aim to investigate antioxidant effect of 200 g/d PSPL containing 902 mg polyphenols in a clinical trial. This randomized, crossover clinical study included 16 healthy adults (7 M, 9 F; aged 20-22 y). After a 1-wk run period, subjects were assigned randomly to receive either PSPL or low polyphenol diet (LPD) for 2 wks, followed by a 2-wk washout period before crossing over to the alternate diet. Fasting blood and 24-h urine samples were collected from each subject at day 0, 7 and 14 of each phase. Our data showed PSPL consumption enhanced urinary total phenol excretion by 24.5% at day 14 as compared to day 0, while the LPD decreased total phenol content in plasma and urine by 3.3 and 16.3%, respectively (p< or =0.05). Low-density lipoprotein lag time and glutathione concentration in erythrocytes at day 14 was significantly enhanced by 15.0 and 33.3% by PSPL as compared to day 0, respectively, while their values were not altered by the LPD. Urinary 8-hydoxy-deoxyguanosine (8-OHdG) excretion decreased significantly by PSPL consumptoin by 36.7% at day 7 as compared to day 0, yet unchanged by the LPD (p< or =0.05). In conclusion, our results suggest that polyphenols in 200 g PSPL were bioavailable and could enhance antioxidant defense and decrease oxidative stress in young healthy people.
authors.affiliation: Graduate Institute of Pharmacy, Taipei Medical University, Taipei, Taiwan.
authors.forename: Chiao-Ming
authors.initials: CM
authors.lastname: Chen
authors.forename: Ya-Ling
authors.initials: YL
authors.lastname: Lin
authors.forename: C-Y Oliver
authors.initials: CY
authors.lastname: Chen
authors.forename: Ching-Yun
authors.initials: CY
authors.lastname: Hsu
authors.forename: Ming-Jer
authors.initials: MJ
authors.lastname: Shieh
authors.forename: Jen-Fang
authors.initials: JF
authors.lastname: Liu
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D001682:Biological Availability; D018592:Cross-Over Studies; D004249:DNA Damage / Q000187:drug effects*; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000652:urine; D005260:Female; D005419:Flavonoids / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D006801:Humans; D027723:Ipomoea batatas / Q000737:chemistry*; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects*; D010636:Phenols / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D018515:Plant Leaves / Q000737:chemistry*; D059808:Polyphenols; D055815:Young Adult
chemical_list: D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine