What is Polypodium Leucotomos?
Latin name: Polypodium leucotomos
Other names: calaguala, anapsos, Heliocare, Kalawalla, Polypodiaceae
Polypodium leucotomos is a type of fern native to the tropical and subtropical regions of the Americas. It has a long history of use as a folk remedy in Honduras, where it is used for a wide variety of ailments. Commercial extracts of Polypodium leucotomos, which are also called "anapsos," have been available since the 1970s.
Why Do People Use Polypodium Leucotomos
Studies on Polypodium leucotomos, which have mainly been animal or test tube studies, have found that Polypodium leucotomos is an antioxidant and has anti-inflammatory and immune effects. Although these results are intriguing, only a handful of human studies have been conducted. More research is needed before Polypodium leucotomos can be recommended as a treatment for any health condition.
Polypodium leucotomos 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 and that it may help prevent skin aging and decrease the risk of cancer from UV radiation. Larger trials are needed to confirm its effectiveness and to determine if there are any side effects at the required doses.
Polypodium extracts have been used for psoriasis in Europe and Central and South America for the last 30 years. Large, well-designed studies, however, are needed before it can be recommended as a treatment for psoriasis.
A study examined whether Polypodium leucotomos could reduce side effects of PUVA. PUVA is a treatment for moderate-to-severe psoriasis and consists of psoralen (a light-sensitizing medication) plus ultraviolet light A. This would potentially be helpful for people with lighter skin (skin types II and III), because the use of PUVA is currently limited by risks of skin damage and skin cancer. A small pilot study looked at PUVA alone compared with PUVA plus Polypodium leucotomos taken orally. Skin cells of the study participants were examined under microscope, and those taking polypodium were found to have less skin damage compared with those taking the placebo.
In animal and test tube studies, Polypodium leucotomos has been found to inhibit immune factors called cytokines, particularly the cytokines associated with autoimmune diseases. In small amounts, cytokines are needed for proper healing. But if overproduced, they can cause inflammation and tissue damage.
A study involving 50 people with vitiligo vulgaris compared the effectiveness of oral Polypodium leucotomos extract (250 mg three times per day) combined with narrow-band ultraviolet B treatment (twice weekly for 25 to 26 weeks) to narrow-band UVB treatment and a placebo. Researchers found an increase in repigmentation in the head and neck area in the polypodium group compared to the placebo group. This effect was more pronounced in people with lighter skin (skin types II and III).
Side Effects and Safety Concerns
Side effects of polypodium may include indigestion and skin itchiness. People with allergies to ferns should avoid polypodium.
Other fern species have been linked with drowsiness, low blood pressure and increased heart rate. Until we know more about whether these side effects are limited to that species (Polypodium vulgare), people with heart disease should avoid polypodium. It should not be taken before driving or operating heavy machinery.
The safety of polypodium in pregnant or nursing women, children and people with liver or kidney disease isn't known. The long-term safety of polypodium isn’t known.
Polypodium should not be used in place of proven sun protection measures, such as using sunscreen and avoiding sun exposure during the peak hours of 10 a.m. and 4 p.m.
Possible Drug Interactions
A related fern species, Polypodium vulgare, has been found to cause drowsiness. Theoretically, Polypodium leucotomos could have the same effect, so it may have an additive effect if taken with drugs that cause drowsiness, such as benzodiazepines lorazepam (Ativan) or diazepam (Valium), some antidepressants, narcotics such as codeine, barbituates such as phenobarbitol, alcohol and herbs that cause drowsiness, such as hops, valerian, kava and chamomile.
The other fern species, Polypodium vulgare, has been found to lower blood pressure and affect heart rate. Theoretically, Polypodium vulgare may increase the effect of drugs that affect heart function, blood pressure or heart rate, such as beta-blockers, calcium channel blockers or (Lanoxin) digoxin.
Gonzalez S, Alcaraz MV, Cuevas J, Perez M, Jaen P, Alvarez-Mon M, Villarrubia VG. An extract of the fern Polypodium leucotomos (Difur) modulates Th1/Th2 cytokines balance in vitro and appears to exhibit anti-angiogenic activities in vivo: pathogenic relationships and therapeutic implications. Anticancer Res. (2000) 20.3A: 1567-1575.
Middelkamp-Hup MA, Bos JD, Rius-Diaz F, Gonzalez S, Westerhof W. Treatment of vitiligo vulgaris with narrow-band UVB and oral Polypodium leucotomos extract: a randomized double-blind placebo-controlled study. J Eur Acad Dermatol Venereol. (2007) 21.7: 942-950.
Middelkamp-Hup MA, Pathak MA, Parrado C, Garcia-Caballero T, Rius-Díaz F, Fitzpatrick TB, González S. Orally administered Polypodium leucotomos extract decreases psoralen-UVA-induced phototoxicity, pigmentation, and damage of human skin. J Am Acad Dermatol. (2004) 50.1: 41-49.