Red blood cells harbor Pycnogenol metabolite, research shows
But the company’s latest in vitro research shows that metabolites of the ingredient are resident in red blood cells, appearing to solve one of the mysteries about how the ingredient gets to where it’s going.
Horphag, which has developed and studied Pycnogenol, their branded form of French maritime pine bark extract, over a period of decades, had a good handle on the ingredient’s effects on the macro level. The company advertises research results pertaining to a wide variety of benefits and health conditions. The company’s website lists dozens of research papers on Pycnogenol’s antioxidant benefits, anti inflammatory properties, on its applications in cardiovascular health, in cognitive and mood support, eye health, menstrual support and joint health. And the list, as they say, goes on.
What the company didn’t know precisely is how the molecule was getting to the locations where it was doing its work. After it passed the lips, its voyage was something of a mystery until the benefits of supplementation made themselves felt on a cellular level.
“Pycnogenol consists of procyanadins which are very large molecules which by themselves could never reach the bloodstream,” Frank Schönlau, PhD, chief science officer for Horphag, told NutraIngredinets-USA at the recent VitaFoods 2013 trade show in Geneva, Switzerland. “We knew the gut microflora are breaking it down into metabolites that are then able to enter the bloodstream.”
Mystery of the metabolites
It was those metabolites, then, not the ingested form of the ingredient, that were conferring the health benefits. But where were they going, and more importantly, how where they getting there?
“The first we discovered that it takes four hours to see the metabolites. The second thing that puzzled us was why there is so little in the plasma. Where is this stuff?” Schönlau said.
The study, conduced at the Institute of Pharmacy and Food Chemistry at the University of Würzburg in Germany, found that a specific metabolite, “d-(3,4-dihydroxy-phenyl)-c- valerolactone (M1), that had been previously detected in plasma samples of human consumers of pine bark extract Pycnogenol, to human erythrocytes. We found that caffeic acid, taxifolin, and ferulic acid passively bind to red blood cells, but only the bioactive metabolite M1 revealed pronounced accumulation. The partitioning of M1 into erythrocytes was significantly diminished at higher concentrations of M1 and in the presence of glucose, suggesting a facilitated transport of M1 via GLUT-1 transporter,” the authors wrote.
The authors noted that the M1 metabolite share significant structural similarities with the glucose molecule.
“GLUT-1 is actively pumping into red blood cells, endothelial cells and white blood cells. And this transporter exits only in those mammals that cannot synthesize vitamin C, and that would be our closest relatives the monkeys, us and hamsters. It probably developed during evolution because this GLUT-1 transporter metabolizes vitamin C, reduces it and pumps out active vitamin C in the form of ascorbic acid into the bloodstream,” Schönlau said.
Even with all of the research Horphag has done on the ingredient, there is still more to know, Schönlau said.
“What we don’t know and what we’d love to know is what it does in red blood cells,” he said.
Source: Facilitated Uptake of a Bioactive Metabolite of Maritime Pine Bark Extract (Pycnogenol) into Human Erythrocytes. Max Kurlbaum, Melanie Mülek, Petra Högger, PlosONE, April 30, 2013.