Antiglycation Activity of Iridoids and Their Food Sources

Abstract

Iridoids are dietary phytochemicals that may have the ability to inhibit the formation of advanced glycation end products (AGEs). Three studies were conducted to investigate this anti-AGE potential. First, the inhibition of fluorescence intensity by food-derived iridoids, after 4 days of incubation with bovine serum albumin, glucose, and fructose, was used to evaluate in vitro antiglycation activity. Next, an 8-week open-label pilot study used the AGE Reader to measure changes in the skin autofluorescence of 34 overweight adults who consumed daily a beverage containing food sources of iridoids. Finally, a cross-sectional population study with 3913 people analyzed the relationship between daily iridoid intake and AGE accumulation, as measured by skin autofluorescence with the TruAge scanner. In the in vitro test, deacetylasperulosidic acid and loganic acid both inhibited glycation in a concentration-dependent manner, with respective IC50 values of 3.55 and 2.69 mM. In the pilot study, average skin autofluorescence measurements decreased by 0.12 units (P < 0.05). The cross-sectional population survey revealed that, for every mg of iridoids consumed, there is a corresponding decline in AGE associated age of 0.017 years (P < 0.0001). These results suggest that consumption of dietary sources of iridoids may be a useful antiaging strategy.

The Potential Health Benefits of Noni Juice: A Review of Human Intervention Studies

“…The antiglycation potential of noni fruit juice was further demonstrated in an eight-week open-label intervention study and in a cross-sectional population study [ 66 ]. Both studies were conducted within the context of iridoid content, as iridoids are major phytochemicals in noni fruit and are well known for their anti-AGE biological activities [ 67 , 68 ].…”

Loganic acid and anthocyanins from cornelian cherry (Cornus mas L.) fruits modulate diet-induced atherosclerosis and redox status in rabbits

“…11 Loganic acid and other iridoids also showed antiglycation activity, decreasing the production of advanced glycation end products (AGE), the elevation of which may be triggered by oxidative stress. 32 However, we did not find any previous studies examining the direct effects of loganic acid on redox status.…”

Iridoids are natural glycation inhibitors

“…A cross-sectional population study involving 3913 adults suggests a correlation between daily iridoid intake and lowered skin autofluorescence, and indirect marker relative AGE burden in the body [122,123]. In this study, however, the total contribution of iridoids towards lowered skin autofluorescence is not entirely clear, since other factors may also have had an influence.…”