Liquid chromatography tandem mass spectrometry identification of proanthocyanidins in rat plasma after oral administration of grape seed extract

Abstract

Proanthocyanidin rich plant extracts derived from grape seed extract (GSE), hawthorn and cranberry are on markets for their preventive effects against cardiovascular diseases and uroinfections in woman. However, the importance of these health beneficial effects of these botanicals remains elusive due to incomplete understanding of uptake, metabolism and bioavailability of proanthocyanidins in vivo. In the present study rats were given GSE orally (300 mg/kg, twice a day) and blood and urine were collected over a 24 h period. Monomeric catechins and their methylated metabolites, and proanthocyanidins up to trimers were detected in blood samples treated with GSE using LC-MS/MS operating in the multiple reaction monitoring (MRM) mode. A new tetramethylated metabolite of dimeric proanthocyanidin (m/z 633) in GSE-treated urine was tentatively identified. Using LC-MS/MS, (+)-catechin and (−)-epicatechin were identified in the brain conclusively. These data suggested that GSE catechins cross the blood brain barrier and may be responsible for the neuroprotective effects of GSE.

Oligomeric Cocoa Procyanidins Possess Enhanced Bioactivity Compared to Monomeric and Polymeric Cocoa Procyanidins for Preventing the Development of Obesity, Insulin Resistance, and Impaired Glucose Tolerance during High-Fat Feeding

“…The finding that an oligomer-rich fraction was generally more effective than a monomerrich fraction is intriguing, as the epithelial absorption and systemic bioavailability of PCs is generally regarded to be inversely proportional to size [125][126][127] , consistent with "Lipinski's Rule of 5" for drug bioavailability. This suggests that oligomers, which are largely unabsorbed in their native form, likely act primarily through a mechanism located in the gut.…”

Protective effects of berry polyphenols against age-related cognitive impairment

“…Some studies have reported that polyphenols can be found in brain tissue after oral ingestion. For instance, some flavanols, such as metabolites of catechin and epicatechin, can be found in the rat brain following oral intake [9,97,[192][193][194]. Some flavonoids, including dietary anthocyanins such as cyanidin-3-rutinoside and pelargonidin-3-glucoside, are also able to cross the BBB in relevant in vitro and in situ models [195].…”

Pine Bark Extracts: Nutraceutical, Pharmacological, and Toxicological Evaluation

“…Lower-molecularweight components and metabolites are more easily absorbed (Fernandes et al, 2012;Kosi nska and Andlauer, 2012). Most in vivo studies suggest that procyanidin dimers can be absorbed (Baba et al, 2002;Tsang et al, 2005;Shoji et al, 2006;Prasain et al, 2009). The gut is the predominant location for absorption, a large percentage of the parent compound may be transformed by gut microflora, and the resulting metabolites may constitute the predominant form of absorption (Stoupi et al, 2010).…”