Although the exact mechanism behind the discoloration of the fragile skin is unknown, the study (in this month’s Journal of Cosmetic Dermatology) claims it is related to bad blood circulation in the under eye area.
The scientists investigated herbal compound PPLAC, manufactured by Brazilian personal care ingredients supplier Chemyunion Quimica. A number of the study’s authors work for this company.
A cosmetic product containing 5 percent PPLAC was applied to the face of 21 female volunteers and skin color and luminosity measurements were taken before and after the 28 day study period.
There was no use of a placebo control and each subject’s initial measurements served as a control in order to measure improvement.
Tone and luminance
According to the authors, led by Mary Luci de Souza at the State University of Campinas, improvements in tone and luminance of the eye area were seen in about 90 percent of the volunteers.
The researchers also investigated the effects of the compound on human keratinocytes in vitro, in order to understand the mechanism.
Incubating keratinocytes with PPLAC significantly decreased the synthesis of inflammatory mediators, according to the scientists.
According to the authors, the inflammatory response dependent on the release of inflammatory mediators is an important trigger in the darkening of the under eye area.
In addition, PPLAC treatment significantly increased the superoxide dismutase activity (one of the body’s antioxidant enzymes).
This combination of anti-inflammatory and antioxidant activity is put forward by the researchers to explain the activity of the compound.
Although the scientists concluded this study encourages the use of PPLAC in under eye formulations, they highlighted limitations of the study, such as the lack of a placebo control group, and argued that more research be carried out on the compound.
Source: Journal of Cosmetic Dermatology2009, 8, pages 127-135Effects of a Brazilian herbal compound as a cosmetic eyecare for periorbital hyperchromia (‘dark circles’)Samara Eberlin, Maria Del Carmen Velazquez Pereda, Gustavo de Campos Dieamant, Cecilia Nogueira, Rejane Maria Werka, Mary Luci de Souza Queiroz,