x
Resveratrol exhibits lipophilic characteristics, which lead to a high absorption. However, it should be noted that resveratrol absorption can vary depending on the way it is consumed and the kind of food ingested. Low bioavailability of resveratrol is a factor that may reduce the efficacy of resveratrol. Although in vitro studies show a high efficacy in biologically beneficial effects of resveratrol in cells, it is known that its distribution in tissues is very low. Consequently, in vitro studies must be interpreted with caution when trying to extrapolate its effect in in vivo studies.
Despite its low bioavailability, resveratrol shows efficacy in vivo. This may be explained by the conversion of both sulfates and glucuronides again to resveratrol in target organs such as the liver. Another possible explanation could be the enterohepatic recirculation of resveratrol metabolites, followed by its deconjugation in the small intestine and its reabsorption. Finally, in vivo effects could be explained by the activity of its metabolites. Glucuronidation of the cis-form is faster (5–10 times) than that of the trans-form, thus leading to a lower bioavailability of the cis-form. The presence of hydroxyl groups allows polyphenols to associate with proteins and other nutrients. The solubility of these compounds determines its physiological effects. Thus, complexes including these macronutrients and polyphenols, which maintain solubility, can be absorbed in the small intestine, while insoluble complexes are eliminated in feces, reducing their availability.
Two of the first human studies on the absorption and bioavailability of resveratrol used a single oral dose treatment of 25 mg. Despite the use of high sensitivity methods and a specific molecular analysis, it was difficult to detect the nonmetabolized resveratrol in circulating plasma. Approximate calculations showed maximal concentrations of <10 ng/mL (≈40 nM), 0.5–2 hours after the oral dose. Estimates of the plasmatic concentrations of resveratrol plus total metabolites were considerably higher, around 400–500 ng/mL (≈2 μM), indicating a very low oral bioavailability of free resveratrol, but a significant one of its metabolites. Urinary excretion of total metabolites after a radio-labeled dose was administered showed that about 75% of orally or intravenously administered resveratrol was absorbed. This is an unusually high absorption for a dietary polyphenol, particularly in view of the poor aqueous solubility of this compound.
Several approaches have been used to increase the bioavailability of resveratrol in humans. The dose concentration curve seems to be a logical method, and it has been examined in two studies, with a dose range from 25 to 1000 mg, covering the wide range used in chemoprevention studies. The absorption in these cases reached a maximum of between 0.3 and 2.4 μM, which does not reach the anticancer properties found at concentrations higher than 5 μM. Furthermore, in these studies an increase in the bioavailability of resveratrol during the treatment was found and a lack of metabolism saturation with the highest concentrations (500 mg/mL). Nevertheless, other studies in rats, which were administered resveratrol for 15–20 weeks, showed that a saturation of metabolites exists, and it leads to an increase of resveratrol in plasma and thus in tissues. A pharmacokinetic study of repeated doses over two days concludes that tolerance is good, concentrations in plasma do not increase over time and even decrease, and the bioavailability is higher when administered in the morning.
Vitaglione et al. carried out an interesting study on the bioavailability of free trans-resveratrol present in red wine in humans. Subjects were randomly divided into three experimental groups, consuming different types of food and red wine. The first group consumed 300 mL of red wine with a free trans-resveratrol content of 0.82 mg/L with a meal consisting of beef, egg, bread, corn oil, and French fries. The second group consumed 600 mL of red wine containing 3.2 mg/L free trans-resveratrol while fasting (before breakfast). Lastly, the third group consumed two different meals with different lipid content and 600 mL of red wine, which assured a free trans-resveratrol total ingestion of 0.48 mg. The authors concluded that the kind of food does not affect resveratrol bioavailability and found much variability between individuals. However, these results are inconsistent with those of other studies, in which a high-fat meal decreased its absorption. Thus, we conclude that the different sample processing methods and the kind of analysis are the key to detect both free or conjugated resveratrol.
Article Produced By
Neelam Khaper
Academic Editor:
Department of Physiology, Faculty of Medicine, University of Valencia, INCLIVA, Blasco Ibáñez Avenue 15, 46010 Valencia, Spain.Department of Physiotherapy, Faculty of Physiotherapy, University of Valencia, Gascó Oliag Street 5, 46010 Valencia, Spain.Sports Research Centre, Miguel Hernández University of Elche, University Avenue, s/n, 03202 Elche, Alicante, Spain
*J. Gambini: se.vu@inibmag.naujAcademic Editor: Neelam Khaper
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4499410/
(All these Articles can be read from this URL:
https://markethive.com/group/ama/blog/the-role-of-resveratrol-in-achieving-optimal-health-p5
Posted by
Chuck Reynolds
The reasoning for this article is to supply you information about this wonderful product and also for me to find at least two or more people for this simply Amazing Opportunity.. You just need to follow the 4 simple steps.. (Join,Train,sigup 2 or more people and then you duplicate. It's that simple..). This business can make you money in the thousands or just be a customer for a very satisfying experience.
View this video as it helps you to understand a very simple Business Plan. Check it out, then
View these videos (4 of them, very short (total less then 5 min)) that explains how simple
this business works and if so inclined, click on my name above, call me or just sign up
either as a Customer or Distributor.
