by The Cosmetic Chemist Staff
A new study in Korea reports the protective effects of an ethanol extract of spent coffee grounds in the prevention of UVB-induced photoaging.1 Relative to the control, treatment with the coffee ground extract results in a 30% reduction in wrinkles accompanied by a 25% decrease in epidermal thickness, 35% decline in erythema formation, and 20% less trans-epidermal water loss. It was also found that the coffee ground extract treatment leads to a reduction in the expression of collagen degrading matrix metalloproteinase 2 (MMP2) and 9 (MMP9).
As the world’s population increasingly drinks coffee, more spent coffee grounds are available for other uses. It is a nutrient rich substance and is used in agriculture, for the removal of lead from water, and the production of biodiesel.1 In addition to a host of other compounds, spent coffee grounds contain appreciable amounts of caffeine, chlorogenic acids, and polyphenols.
The work by Hyung Joo Suh and coworkers focuses on a number of biological and clinical endpoints that demonstrate a quantifiable defense against photoaging. The majority of the experiments were conducted on hairless mice, while some basic studies to understand MMP expression were carried on cell culture systems (HaCaT cells). The finding that the compounds from the spent coffee ground extract are responsible for the down regulation of MMPs is especially interesting since these enzymes are implicated in the degradation of collagen degradation—a hallmark of photodamage.
Over the last decade, there have been numerous studies focused on the advantages of using botanicals for the protection of skin against UV radiation. Polyphenols and other antioxidant types of ingredients are normally credited with providing efficacy.2 In most cases, we are only able to provide descriptive data in regard to the function of these active ingredients. In the future, it would be interesting to better understand some of the mechanisms behind these benefits.
1. H.-S. Choi, E.D. Park, Y. Park, and H.J. Suh, Spent coffee ground extract suppresses ultraviolet B-induced photoaging in hairless mice, J. Photchem. Photobiol. B, 153, 164-172 (2015).
2. R.L. McMullen, Antioxidants and the Skin, Allured Books: Carol Stream, IL (2013).