Plant extracts that provide sun protection
Here are a few of the leaves, petals and stalks that are acquiring a body of research. On dull days, it might be worth skipping the sunscreen and getting hold of some pomegranate or milk thistle.
More than 40 components isolated from the ginkgo tree have been identified, but only two are believed to be responsible for beneficial effects in humans -- flavonoids and terpenoids. Flavonoids (such as quercetin and rutin) have potent antioxidant effects. As an antioxidant and anti-inflammatory, ginkgo has an impressive research pedigree. And at least one study has shown that it boosts collagen production. In addition, a study on rats demonstrated that ginkgo protected skin against UVB damage. Extract of gingko biloba goes by the name of EGb 761 in science labs and one test (on mice) prompted the researcher to say that "our results suggest that EGb 761 may have an important effect, both as a protective and therapeutic agent, in sunburn after UVB irradiation.
Silymarin is an extract taken from the milk thistle plant, containing three flavonoid components: silybin (silibinin), silydianin, and silychristine. A 2007 study by the Palacký University showed that topical application of Silymarin prevented oxidative stress caused by exposure to UVA light. Another study in 2008, which looked at the causes of UV induced stress, found that CD11b cells are responsible for many of the problems caused by UVB exposure. Applying Silymarin before or after UV light exposure greatly reduced their negative effects. Dermatologists experimented with mice under UV irradiation with or without topical treatment with Silymarin. After 48 hours, it was found that the damage to skin cells in silymarin-protected cases were a negligable 0.4%, in comparison with the unprotected skin (31.8%). A Chinese study claims that "silymarin pre-treatment reversed the effect of UV irradiation." Meanwhile, researchers at the University of Alabama have shown that silymarin inhibits UVB-induced photocarcinogenesis in mice.
Dr Murad (he of the Murad skincare line) is a pomegranate-ofile. After a small trial (on eight people), he concluded that adding pomegranate extract boosts the SPF of sunscreen formula by 20% and an oral supplement provides an additional 25% improvement in the SPF. Meanwhile, a University of Texas team found that the extract reversed UV-induced up-regulation of collagenases, specifically matrix metalloproteinases MMP1 and MMP13. The active in pomegranates is ellagic acid. In one study, it not only inhibited sunburn in young women, but also created subjective improvements by the subjects in their own complexions. Ellagic acid has been shown to have an inhibitory effect on slight pigmentation in human skin caused by UV irradiation. This is backed up by additional research that suggests pomegranates can be used to protect against UVA and UVB rays.
This American fern, supposedly used by native Indians, is particularly promising as a sunscreen in pill form. Studies so far have been small, but they suggest that polypodium leucotomos can significantly reduce sunburn severity, may help prevent skin aging and decrease the risk of cancer from UV radiation. In a test on nine people with oral administration of PL, there were less sunburn cells and a trend toward Langerhans cell preservation was seen. The researchers concluded that it gave significant protection of skin against UV radiation. Sun protection pills are marketed as Fernblock and Heliocare.
A peach to you and me. According to a Hong Kong study, peach extract protects against UVB rays. Meanwhile, over in Korea, researchers found that extract of peach flowers inhibited UVB-induced lipid peroxidation, although they tentatively concluded that this might be due to antioxidant properties. A Czech study singles out peach for inhibiting UVB/UVC DNA damage and lipid peroxidation due the high concentration of phenolics.
Moldavian dragonhead and viola tricolor
An Iranian study looked at 16 botanicals, including peach, to study their efficacy against UV radiation. The two that most excited researchers were moldavian dragonhead and viola tricolor (heartsease). The first contains high amounts of phenolic acids, while the viola has a very high concentration of rutins. In the opinion of the researchers, this makes them both potential candidates for topical sunscreens.