In an article published in June in , leading American herbalists Eric Yarnell and Kathy Abascal analysed herbal extracts to assess their ability to reduce the negative effects of UV light when taken orally or applied topically.

They found that the extract of golden serpent fern ( ) could be used to combat the effects of excessive UV exposure. When the fern was applied on patients with polymorphic light eruptions (itchy rashes caused by UV exposure), 30 per cent of patients were protected from artificial UV light-induced eruptions, and the other patients did not get rashes unless they were exposed to higher amounts of UV light.

In another study, of 57 patients with the light eruptions or solar urticaria (hives) who took golden serpent fern, 74 per cent had less severe photodermatitis.

The extract appears to work as an antioxidant and protects DNA and skin compounds from damage. The study authors say the data on golden serpent fern extracts is promising for reducing negative effects of UV exposure in healthy people and in patients with conditions aggravated by the sun. Further research is needed, but it appears this herb is safe and effective for clinical use as one of the first oral herbal photoprotectives.

Unoxidised young green tea leaves ( ) have shown to be able to abate the negative effects of excessive UV exposure. In the study, topical green tea extract significantly reduced signs of UV damage on the skin. An application of 10 per cent green tea cream combined with an oral intake of 300mg of green tea extract improved skin elasticity, and appeared to be photoprotective.

Tannic acid (an astringent) and theobromine (a phytonutrient) in tea are said to help cool sunburn, and compounds called catechins help prevent and repair skin damage caused by UV rays. Both green and black teas are also antioxidants.

In a study published in the , Dr Stephen Hsu, a cell biologist at the Medical College of Georgia, found a link between green tea and skin cell rejuvenation. He proved that a compound in green tea, epigallocatechin gallate, reactivates dying skin cells and accelerates the differentiation process among new cells.

It also inhibits UVB radiation-induced erythema response (redness) in the skin. Green tea supports the production of melanin, the skin's own sunburn protection.

According to a study published in the , strawberry extract provides protection against UV radiation and reduces skin damage from overexposure to the sun. Compounds called anthocyanins, which give strawberries their red colour, contain sun protection properties. Study co-author Dr Sara Tulipani from the University of Barcelona in Spain says: "These compounds have important anti-inflammatory, antioxidant and anti-tumour properties. The results are the basis for future studies evaluating the 'bioavailability' and 'bioactivity' of anthocyanins in the dermis and epidermis layers of the human skin, whether by adding them to formulations for external use or by ingesting the fruit itself."

Asian ginseng ( ) may be helpful in preventing the harm done by excessive UV light on local and general immune function, according to Yarnell and Abascal. Many studies in animals show that whole-root extracts and isolated saponins (a class of chemical compounds found in natural sources) protect the body against photo-immunosuppression.

When asked about the efficacy of these extracts, whether applied topically or orally, Ophelia Chan, founder of local organic beauty brand, Herbal Bliss, says: "In my opinion, these herbal extracts do not have a specific UV protection factor. If they can have any protection at all, the effect is minimal and cannot be measured like the approved physical sunblocks or chemical sunscreens. These herbs are antioxidants at most; they may be able to offset some of the free radical damage caused by UV rays but, in themselves, are definitely not effective sunscreens.

"The only safe and effective sunblock ingredients are non-micronised or non-nano zinc oxide, and to a lesser extent, titanium dioxide. I know some oils like jojoba, coconut and hazelnut offer a very low amount of UV protection - not more than SPF 2. We need a minimum of SPF 15 to make a sunscreen worthwhile.

"While oral intake of these herbal extracts may seem beneficial, it's not advisable as their suitability depends on each person's requirements. I don't believe it can be an effective sun-protection measure."