Bark of Chinese ash may help protect against sun damage
damage and could be incorporated into cosmetics applications,
according to new research.
Scientists at the Chungbuk National University, Korea, in collaboration with the Dalhouse University, Nova Scotia, have investigated the antioxidative and photoprotective effects of the bark extract. The Chinese ash (Fraxinus chinensis) extract contains compounds known for their antioxidant properties, although little is known about the possible protective effects of the compounds against UV exposure, say the researchers. The scientists, led by Bum-Chun Lee, identified within the extract a number of compounds belonging to the coumarin family with antioxidative effects. Esculetin exhibited the strongest antioxidative effect according to the team, which the researchers posited may be linked to a greater number of hydroxyl groups attached to the compound. Lee and his colleagues then investigated the ability of FCE to inhibit the production of matrix metalloproteinases (MMPs), enzymes that play an important role in skin aging. MMPs are enzymes that break down extracellular matrix proteins, performing many diverse functions. Their role in skin aging is due to the fact that they degrade both collagen and elastin, leading to a loss of elastictity and firmness of human skin. In addition, radiation with UV rays, particularly UVA rays, increase MMP levels, leading to photo aging. In this case Lee and the team noted an increase of MMP-1 expression in human dermal fibroblasts of 46 percent after UVA exposure compared to non-irradiated cells. The treatment of UVA-irradiated fibroblasts with FCE decreased the expressions of MMP-1 by 10.1, 18.7 and 25.5 per cent at concentrations of 10, 50 and 100 mg/mL respectively, according to Lee. Although the exact mechanism of the MMP-1 inhibition is not known Lee and colleagues conclude that the FCE and its constituents could protect the skin from sun damage stating that it may be useful as an ingredient in anti-aging cosmetics. Natural extracts that show MMP inhibiting properties are becoming increasingly popular within the industry. Blackberry leaf extract was recently found to have MMP-1 inhibiting properties, according to scientists at Symrise, Germany-based ingredients supplier. In addition, the team found the anti-oxidant properties of the blackberry leaf extract to be similar to that of green tea.
