Consumption of Hibiscus sabdariffa L. aqueous extract and its impact on systemic antioxidant potential in healthy subjects

• Published in: Journal of the science of food and agriculture Vol. 92; no. 10; pp. 2207 - 2218
• Main Authors: Frank, Thomas, Netzel, Gabriele, Kammerer, Dietmar R, Carle, Reinhold, Kler, Adolf, Kriesl, Erwin, Bitsch, Irmgard, Bitsch, Roland, Netzel, Michael
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 15.08.2012; Wiley; John Wiley and Sons, Limited
• Subjects: administered dose; Adult; anthocyanins; Anthocyanins - pharmacology; Anthocyanins - urine; antioxidant activity; antioxidant potential; Antioxidants; Antioxidants - metabolism; Antioxidants - pharmacology; Aqueous solutions; Area Under Curve; ascorbic acid; Ascorbic Acid - blood; Biological and medical sciences; Biomarkers; Biomarkers - metabolism; Biotransformation; blood; chemistry; drug effects; excretion; Extraction processes; Female; Flowers & plants; Food industries; Food science; Fundamental and applied biological sciences. Psychology; Glucuronides; Glucuronides - pharmacology; Glucuronides - urine; Health; Hibiscus; Hibiscus - chemistry; Hibiscus sabdariffa; Hibiscus sabdariffa L; Hippurates; Hippurates - urine; hippuric acid; Humans; Male; malondialdehyde; Malondialdehyde - urine; metabolism; Oxidative stress; Oxidative Stress - drug effects; pharmacology; Plant Extracts; Plant Extracts - pharmacology; polyphenols; Polyphenols - pharmacology; Polyphenols - urine; Reference Values; uric acid; Uric Acid - blood; urine; volunteers; Young Adult; Malvaceae; Human; antioxidant potential; polyphenols; Hippuric acid; Healthy subject; Extract; Antioxidant; Hibiscus; Polyphenol; Dicotyledones; Angiospermae; Hibiscus sabdariffa L; Spermatophyta; malondialdehyde; humans
• ISSN: 0022-5142; 1097-0010; 1097-0010
• DOI: 10.1002/jsfa.5615

BACKGROUND: To evaluate health benefits attributed to Hibiscus sabdariffa L. a randomized, open‐label, two‐way crossover study was undertaken to compare the impact of an aqueous H. sabdariffa L. extract (HSE) on the systemic antioxidant potential (AOP; assayed by ferric reducing antioxidant power (FRAP)) with a reference treatment (water) in eight healthy volunteers. The biokinetic variables were the areas under the curve (AUC) of plasma FRAP, ascorbic acid and urate that are above the pre‐dose concentration, and the amounts excreted into urine within 24 h (Ae0–24) of antioxidants as assayed by FRAP, ascorbic acid, uric acid, malondialdehyde (biomarker for oxidative stress), and hippuric acid (metabolite and potential biomarker for total polyphenol intake). RESULTS: HSE caused significantly higher plasma AUC of FRAP, an increase in Ae0–24 of FRAP, ascorbic acid and hippuric acid, whereas malondialdehyde excretion was reduced. Furthermore, the main hibiscus anthocyanins as well as one glucuronide conjugate could be quantified in the volunteers' urine (0.02% of the administered dose). CONCLUSION: The aqueous HSE investigated in this study enhanced the systemic AOP and reduced the oxidative stress in humans. Furthermore, the increased urinary hippuric acid excretion after HSE consumption indicates a high biotransformation of the ingested HSE polyphenols, most likely caused by the colonic microbiota. Copyright © 2012 Society of Chemical Industry