Protective effects of SoyLife against protein glycation

Frutarom, by Dermscan Laboratoires, France, July 2000.

Skin ageing occurs under intrinsic and extrinsic influences, such as changes in estrogen production and exposure to free radicals. During and after menopause, falling estrogen levels cause a decrease in general skin tone, wrinkles and sagging. Ageing skin tissue typically stiffens and loses elasticity. The responsible process for this is called collagen protein glycation, and occurs because glucose forms cross-links between collagen molecules, making collagen protein less flexible.

Hormone replacement therapy (HRT) is known to preserve collagen content, elastic properties and thickness of the skin. Isoflavones are also suggested to exert anti-aging effects on the skin in a similar way. To test this, SoyLife EXTRA was tested for its effects against protein glycation in skin tissue.

Study design

In an in vitro study, a solution of collagen protein and glucose was incubated with a 10% dispersion of SoyLife EXTRA or a placebo. The series were incubated at 37°C (98.6 Fahrenheit) for 28 days. The non-enzymatic glycosylation was measured by analysis of the terminal reaction product of glycosylation. One of these so-called Advance Glycosylation Endproducts (AGE) is FFI (2-furanyl-4 (5)-(2-furanyl)1H-imidazole). The majority of these products are yellowish brown and are fluorescent due to their many double bonds.

The amount of FFI present in a solution can be quantified by measuring the relative fluorescence with a spectrofluorimeter. The fluorescence produced by the final product of the non-enzymatic glycosylation (glycation) reaction was measured for both treatments at day 0, 7, 14, 21 and 28.

Results and conclusion

The reduction in glycation rate for SoyLife and placebo is shown in the graph below. The glycation process was reduced by approximately 25% after the SoyLife treatment. This study shows that SoyLife EXTRA may have an anti-aging effect on skin tissue by reducing the glycation of collagen protein. As a result, the process of elasticity loss in the skin may be slowed down, according to this in vitro test.