Bloqueador

“Año de la Integración Nacional y El Reconocimiento de Nuestra Diversidad”
FERIA DE CIENCIAS
EL PROTECTOR SOLAR

Integrantes:
#17 García Rivera María Fernanda
#24 Olaechea Grados Patricia
#34 Veliz Cuadros Eliana
#37 Yori Dávila Valeria

Asignatura: Biología
Grado: III
Sección: B
Profesor: Jorge Pérez

2012

Can Natural Herbs Protect Your Skin From the Sun?This summer, before you head outdoors, you’re likely slathering on sunscreen—if you forget to do so, you’re risking a sunburn in the short-term and the possibility of skin cancer down the road. But what if there was a way to acquire protection from the sun’s harsh ultraviolet radiation without having to apply a chemical coating?
Researchers have been looking into the possibility that thecompounds inside various herbs can confer some degree of sun protection for some time. A new review of such work, published yesterday in the Journal of Alternative and Contemporary Therapies, indicates that several herbs, including golden serpent fern and Asian ginseng, might help protect our skin from UV light.
To be clear, all major medical organizations still recommend the use of conventionalsunscreen. But several studies have shown that extracts made from these herbs, when taken orally or applied directly on the skin, were associated with a reduction in the amount of damage caused by UV light and an increase in the amount of exposure necessary to cause a burn.
Golden serpent fern (known to scientists as Phlebodium aureum) is the herb for which the most evidence has been amassed. The plantgrows wild in Florida and Georgia but is most commonly found in Central and South America, where it is called calaguala. It is used in the treatment of some inflammatory diseases, and research indicates that it might be useful for sun protection in the general population as well.
In one study, nine participants took an oral dose of the herb extract and were then exposed to UV light. Twenty-fourhours later, they exhibited significantly less sunburn than a control group, and when their skin cells were examined under a microscope, the researchers saw less inflammation and damage. In another experiment, the amount of UV exposure needed to trigger sunburn was nearly three times higher for people who had been given the extract, as compared with others that had been given a placebo. Scientistsspeculate that antioxidant compounds in the herb—including phenolic and hydroxycinnamic acids—may protect skin cells at the molecular level.
Other research has revealed that chemicals known as polyphenols from green tea might confer some sun protection as well. In one study, participants drank a green tea beverage daily for several months and were exposed to slightly more UV light than wasnecessary to initially cause sunburn. After six weeks, they showed 16 percent less sunburn than a group simply drinking water who were exposed to the same UV light, and after 12 weeks, that number increased to 25 percent. In another experiment, green tea extract was applied directly to the skin; after UV exposure, biopsies of skin cells showed fewer sunburned cells and less DNA damage.
In addition tosunburn, excessive exposure to UV light can also lead to what scientists call photoaging, a gradual process of skin deterioration with both aesthetic effects (wrinkles, aging spots, skin looseness) and functional impacts (immune system repression, DNA mutation). The review also looked at several studies that tested the effectiveness of Asian ginseng extracts in preventing these types of effects.
Inan experiment using mice, the application of compounds isolated from ginseng root directly to the skin reduced the formation of wrinkles and a loss in skin elasticity after long-term UV exposure. And in a study with human participants that already exhibited symptoms of photoaging, daily consumption of an herbal mixture that included red ginseng extract was associated with a reduction in...