Polypodium leucotomos (PL) is a tropical fern plant that’s native in South and Central America. It grows in rain forests and it has been used as an oral herbal medicine for various skin diseases and inflammatory disordersfor decades. Commercial extracts of the plant, such as Polypodium leucotomos extract,have been available since the 1970s. Clinical research has asserted that Polypodium leucotomosextracts have antioxidants with potential to protect the skin from the deadly effects of Ultraviolet (UV) radiation.
What are UV radiations and why are they harmful?
The sun, despite its beneficial aspects, produces harmful Ultraviolet (UV) rays in the form of Long Wave Ultraviolet (UVA), Short Wave Ultraviolet (UVB), and UVC (1). UVC is absorbed before it reaches the earth's atmosphere, therefore, it poses no threat to humans. UVA and UVB, on the other hand, have the capability of penetrating not only glass but also the thickest of clouds, and as such, they reach the earth's surface. UVA attacks the dermis (the thickest part of the skin) causing effects like photo aging (wrinkling) and skin aging (1). UVB, on the other hand, attacks the superficial layer of the skin causing sunburns (burning, reddening and swelling of the skin) and promoting development of skin cancer (1).
Active Ingredients in Polypodium leucotomos Extract
The stem (rhizomes) and the leaf of the plant have been used for medicinal purposes for decades. The main active ingredients in Polypodium leucotomos are antioxidant polyphenols such as 4-hydroxycinnamoyl-quinic (quinic), 4-hydroxybenzoic, 4-dihydroxybenzoic, 3-caffeoylquinc (chlorogenic), 4-hydroxycinnamic (caffeic), 3-methoxy-4-hydroxybenzoic (vanillic), fumaric, ferulic, and phenolic acids p-coumaric. It also contains five phenolic chlorogenic acid isomers. The leaf extract of Polypodium leucotomos is rich in flavonoids (powerful antioxidants with immune system benefits and anti-inflammatory properties) and monosaccharaides (simplest forms of sugars) (2).
How does Polypodium leucotomos (PL) help against Ultraviolet (UV) radiation?
Antioxidant phenols inhibits formation of free radicals that result from effects of Ultraviolet radiation. This may prevent oxidative damage to the skin. Also, by inhibiting the free radicals, including the reactive oxygen species on the skin's surface, PL may prevent the occurrence of photoaging (wrinkling) and DNA damage. PL could also be used to neutralize free radicals such as lipid peroxides, hydroxides, and superoxide onions (2).
Polypodium leucotomos has anti-inflammatory properties that may curb the immune-suppression caused by UV radiation (3). Immunosuppression, if unchecked, causes detrimental skin cells changes. The anti-inflammatory properties also reduce the itchiness of an inflamed skin in people affected by eczema and psoriasis. They can also inhibit infiltration of immune cells thereby preventing further tissue damage and inflammation.
Immune cells such as Cytokines release chemical as part of body's natural inflammatory response to aid in the healing of a damaged skin and this causes itching and redness. The anti-inflammatory properties of PL may suppress production of cyclooxygenase-2 (an enzyme that promotes inflammation), which could help decrease the abnormal vasodilation that results from inflammation.
Polypodium leucotomos may also prevent against skin cancers caused by UBV rays (4). First, it may protect you against sunburn and skin reddening which promote development of skin cancer. Second, by inhibiting the reactive oxygen species, it could prevent against long-term DNA damage. For instance, it may inhibit the formation of a type of DNA damage called cyclobutane pyrimidine dimers that result from UBV radiation. This means that there will be reduced ultraviolet –induced mutation.
Polypodium leucotomos may also promote photo-protection (a biochemical process that helps the body deal with molecular damage caused by ultraviolet radiation). This is attained by extremely efficient internal conversion of melanin, proteins, and DNA. In doing so, DNA damage (both direct and indirect) is prevented. This is essential because the continued damage of DNA and melanin leads to the development of skin cancer.
Polypodium leucotomos could also make the skin thicker by stimulating the production of collagen (the main structural protein found on the skin), thereby preventing against photo aging and skin aging (5). The moment the collagen level of the skin reduces, the skin starts to lose its elasticity and firmness which encourages sagging and wrinkling.
Polypodium leucotomos may also inhibit the depletion of Langerhans cells. Langerhans cells are the antigen-presenting immune cells of the skin (6). They reside in the suprabasal and basal layers of the epidermis and along the urogenital, digestive and respiratory tracks. They have strong immunogenic properties, and they help in skin immune-surveillance in pathogenesis of chronic inflammatory conditions of the skin. By making the skin more immune, they may protect it from the harmful effects of the ultraviolet rays such as sunburns and inflammation.
For people undergoing UV treatments for skin conditions, Polypodium leucotomos could not have come at a better time. This is because it may have the potential decreases the incidences of phototoxicity that may bring about negative effects on the skin such as premature skin aging (wrinkling, freckling, and increased skin dryness) and even development of skin cancer. Besides, it is highly advocated for by dermatologists to those individuals who are photosensitive as it may significantly protect them from UV radiation.
Polypodium leucotomos and its extracts are highly rated in the herb world, and for good reason. The herb may have the potential to protect you from the harmful ultraviolet rays and its effects from inside-out. Its photo-protective, antioxidant, and anti-inflammatory properties may help in keeping UV radiations in check. With Polypodium leucotomos, going outdoors or basking in the sun may became much safer.