|Image 1: Dried Goji or Wulfberries, a |
natural source of powerful VitaminS(!) C.
1 gram of the dried fruit contains about
5mg of the power-antioxidant AA-2βG
(data from Toyoda-Ono. 2004)
For the alpha- variety, AA-2αG (also known as AA-2G), which has a D-glucose moiety and an α-glucoside linkage at the C2 position, studies similar to the one performed by Zhang et al. had already found that despite the reduced amount of donable hydrogen radicals or electrons (see above), compared to normal ascorbic acid, the AA-2G radical that formed in the process of a first DPPH [2,2-diphenyl-1-picrylhydrazyl is a dark-colored crystalline powder composed of stable free-radical molecules used to test the in-vitro anti-oxidant capacities of various chemicals compounds] scavenging was "able to react with another DPPH molecule to form a covalent adduct", this covalent adduct from the second reaction was then capable of "slowly quenching a third DPPH radical molecule to generate an unidentified product", so that one molecule of this vitamin C analogue, despite ostensible structural inferiorities, scavenges one additional DPPH radical compared to plain L-ascorbic acid. And while the 2-O substituted AA derivative does lack the ability to to scavange O2−radicals in vitro,
[...] it was more efficient at scavenging H2O2 and OH- than AA (p < 0.01 and p < 0.05, respectively) (Figs. 2B, 3A). This implied that the AA-2βG and AA [ascorbic acid] antioxidant mechanisms differ such that the antioxidant activities of AA-2βG are efficient at scavenging H2O2 and OH- instead of directly scavenging O2−radicals.With different mechanisms of action, however, the radical scavenging effects of L-ascorbic acid and its derivative(s) add up. This makes the naturally occuring mix of vitamins C an even more potent weapon in the nutritional, supplemental and pharmacological war against oxidative stress reduction and the prevention of lipid peroxidation and cell damage (e.g. erythrocyte hemolysis; cf. figure 1).
|Figure 1: Percentage of hemolytic red blood cells in a solution with 500µM H2O2 at various concentrations of Ascorbic Acid (AA) and AA-2βG cells vs. control (0µM) without added anti-oxidants (data adapted from Zhang. 2011)|
|Figure 2: Liver-protective effect of different doses of AA-2βG(dose in mg/kg) in CCl4-induced mouse injury|
model; ALT, AST on primary, MDA on secondary axes (data adapted from Zhang. 2011)
[...] serum ALT and AST levels in animals pretreated with AA-2βG were reduced significantly compared to those in the untreated group (Table III) [and] AA-2βG exhibited dose-dependent protection against liver injury, as serum ALT and AST activities in mice given a high AA-2βG dose (300 mg/kg) decreased dramatically to levels similar to those in untreated animals.So, after all, this seems to be another instance, where nature knew best. Even with all the bioflavonoids, esters, minerals or whatever else supplement producers keep adding to plain L-ascorbic acid to justify the exorbitant prices of their products, the natural vitamin C mix in a bunch of fresh Goji or Wulfberries still outperforms the fanciest supplement.