Granatapfel hebt die Auswirkugnen von AGE (Crosslinks in Proteinen, die diese funktionsunfähig machen können) teilweise wieder auf! So können etwa auch Crosslinks in Collagen aufgelöst werden..
The accumulation of advanced glycation endproducts (AGEs) is a risk factor of glycation stress for age-related deterioration and diseases. AGE degeneration and excretion is a method reducing glycation stress. The purpose of the present study is to elucidate whether pomegranate (Punica granatum) can be a functional food which ruduces glycation stress. The
AGE-derived and collagen-derived crosslink cleaving reactions were evaluated in pomegranate extracts and ellagitannins isolated and purified from pomegranates.
For evaluation of AGE-derived and collagen-derived crosslink cleaving activity, 22 pomegranate-related samples were used and compared with
N-phenacylthiazolium bromide (PTB) as a positive control and 6 hydroxybenzene compounds. To evaluate the AGE crosslink activity, by HPLC analysis we measured the amount of benzoic acid which was formed as a result of C-C binding breaking of α-diketone structure in 1-phenyl-1,2-propanegione (PPD), a model compound for AGE degeneration. For evaluation of collagen crosslink cleaving activity, using collagen-coated 96-well microplates, AGE-formed bovine serum albumin (AGE-BSA) was added to the wells and reacted with collagen, thus forming collagen crosslinks, followed by measuring residual AGE-BSA amount by ELISA. AGE-derived and collagen-derived crosslink cleaving ratio was
calculated as a relative ratio with the ratio of PTB assumed to be 100.
AGE crosslink cleaving activity of 6 pomegranate extracts was higher than that of 0.4 mmol/L PTB. The activity ratio was highest in gallic acid (26.02%) and lowest in ellagic acid (3.24%) among the 16 pomegranate-derived compounds. Regarding the hydroxybenzene compounds, the activity ratio in trihydroxybenzene was higher in hydroxyquinol (51.62%) and pyrogallol (42.13%) than in phloroglucinol (6.06%), and the activity ratio in dihydroxybenzene was higher in hydroquinone (15.73%) and pyrocatechol (14.70%) than in resorcinol (6.88%).
Collagen crosslink cleaving activity was noted in 4 pomegranate extracts from pomegranate juice powder (78.50%), condensed and dried polyphenols (I) (24.99%), ellagitannins (74.75%), and leaf (62.44%). Also, 12 of 16 pomegranate-derived compounds showed collagen crosslink cleaving activity which was significantly correlated with AGE crosslink cleaving activity. The activity was not noted in delphinidin chloride, delphinidin 3,5-diglucoside chloride, gallic acid, and cyanidin 3-glucoside.All of the samples of pomegranate extracts and related compounds showed AGE crosslink cleaving activity, and some of them showed collagen crosslink cleaving activity. A significantly positive correlation was noted between two actions (r = 0.635,
p = 0.034). These findings indicate that the trihydroxybenzene structure of ellagitannins may be involved in the AGE crosslink cleaving activity of pomegranate.
Pomegranate extracts and related compounds are confirmed to show AGE crosslink cleaving activity in addition to anti-oxidation, α-glucosidase inhibition and the prevention of AGE formation as previously reported, indicating that they can reduce glycation stress in various way