Polypodium Leucotomos
Polypodium leucotomos (PL) is a fern native to Central and South America, used medicinally for its photoprotective, antioxidant, and anti-inflammatory properties. Its extract, rich in phenolic compounds like ferulic and caffeic acids, is taken orally or applied topically to reduce UV-induced skin damage, prevent sunburn, and support skin health in conditions like psoriasis, vitiligo, and polymorphic light eruption. PL neutralizes free radicals, protects DNA, and modulates inflammation, making it a valuable adjunct in dermatology.
Benefits
Skin Protection Against UV Damage
PL has strong antioxidant properties, reducing UV-induced skin damage by up to 80% in some studies. It decreases sunburn severity, protects against photoaging (wrinkles, pigmentation), and may lower the risk of skin cancer by neutralizing free radicals and reducing DNA damage. Studies show it preserves skin cells (Langerhans cells) and reduces inflammation post-UV exposure.
Anti-Inflammatory Effects
PL inhibits pro-inflammatory molecules like TNF-alpha and reduces oxidative stress, which may help with conditions like psoriasis, eczema, and vitiligo. Clinical trials indicate it can improve symptoms in these conditions when taken orally or applied topically.
Photodermatosis Management
For conditions like polymorphous light eruption (PMLE), PL reduces symptoms such as itching and rashes triggered by sun exposure. It’s been shown to allow longer sun exposure without reactions in sensitive individuals.
Antioxidant Support
PL contains phenolic compounds (e.g., ferulic acid, caffeic acid) that scavenge free radicals, protecting cells from oxidative stress. This supports overall skin health and may have broader anti-aging benefits.
Immune Modulation
PL may enhance immune function by protecting immune cells and reducing systemic inflammation, potentially aiding autoimmune skin disorders.
Potential Anticancer Properties
Preliminary studies suggest PL’s antioxidant and DNA-protective effects could reduce the risk of UV-related skin cancers, though more research is needed
Mechanism of Action
Antioxidant Activity
PL contains phenolic compounds (e.g., ferulic acid, caffeic acid, chlorogenic acid) that act as potent antioxidants. These neutralize reactive oxygen species (ROS) generated by UV radiation or other stressors, preventing oxidative damage to DNA, lipids, and proteins in skin cells. This reduces UV-induced cellular apoptosis and photoaging.
Photoprotection
Reducing cyclobutane pyrimidine dimers (CPDs), which are DNA lesions caused by UV exposure, thus lowering the risk of mutations and skin cancer. Preserving Langerhans cells (immune cells in the skin) critical for immune surveillance, which are typically depleted by UV radiation. Decreasing erythema (redness) by limiting UV-induced vasodilation and inflammation.
Anti-Inflammatory Effects
PL suppresses pro-inflammatory cytokines (e.g., TNF-alpha, IL-6) and reduces the expression of inflammatory mediators like cyclooxygenase-2 (COX-2). This mitigates inflammation in conditions like psoriasis, eczema, or UV-induced sunburn.
Immune Modulation
By protecting immune cells and regulating inflammatory pathways, PL supports immune homeostasis, potentially benefiting autoimmune skin disorders (e.g., vitiligo, polymorphous light eruption).
Matrix Protection
PL inhibits matrix metalloproteinases (MMPs), enzymes that degrade collagen and elastin in the skin due to UV exposure. This helps maintain skin structure and prevents photoaging signs like wrinkles.
DNA Repair Support
PL enhances DNA repair mechanisms by promoting the activity of nucleotide excision repair pathways, which correct UV-induced DNA damage.
Clinical Trials
Safety and Efficacy of Oral Polypodium leucotomos Extract in Healthy Adult Subjects
Study: A randomized, double-blind, placebo-controlled trial conducted at a single clinical research center with 40 healthy adults (18–65 years, Fitzpatrick skin types I–IV). Participants received either 240 mg PLE (Heliocare®) twice daily or placebo for 60 days. Safety was assessed via physical exams, vital signs, and clinical lab parameters (hematology, metabolic panel, prothrombin time). Efficacy was evaluated through minimal erythema dose (MED) testing, UV-induced erythema intensity, and sunburn history
Findings: No significant changes in safety parameters (physical exams, vital signs, or lab results). Mild side effects included fatigue, bloating, and headaches in four PLE-treated subjects and fatigue in one placebo subject. PLE group had a 22-fold greater likelihood of increased MED (p=0.01) at day 28, indicating enhanced UV tolerance. PLE at 240 mg twice daily is safe and effective for reducing UV damage.
Link: PubMed
The Impact of Oral Polypodium leucotomos Extract on Ultraviolet B Response: A Human Clinical Study
Study: A clinical trial with 22 subjects (Fitzpatrick skin types I–III) irradiated with visible light, UVA1, and UVB (308-nm excimer laser) on day 1. Evaluations occurred immediately and 24 hours post-irradiation. On days 3 and 4, the process was repeated after two doses of oral PLE. Clinical assessments, colorimetry, and histology were used to evaluate UVB-induced changes.
Findings: Clinical and colorimetry data showed reduced UVB-induced changes in 17 of 22 subjects post-PLE. Histology confirmed reduced UVB damage (e.g., fewer cyclobutane pyrimidine dimers, sunburn cells, and COX-2 expression) in all 22 subjects. PLE is a potential adjunct to reduce UVB-related photobiologic damage.
Link: PubMed
Double-blind, Placebo-controlled Trial to Evaluate the Effectiveness of Polypodium Leucotomos Extract in the Treatment of Melasma in Asian Skin: A Pilot Study
Study: A randomized, double-blind, placebo-controlled trial at the National Skin Centre, Singapore, with 40 patients with melasma. Participants used topical 4% hydroquinone cream and SPF 50+ sunscreen and were randomized to receive oral PLE (Fernblock®) or placebo for 12 weeks. Assessments at baseline, days 28, 56, and 84 used the modified Melasma Area and Severity Index (mMASI), melanin/erythema indexes, VISIA® photography, and Melasma Quality of Life (MelasQoL) questionnaire.
Findings: Both PLE and placebo groups showed improved mMASI scores, but PLE group had statistically significant reductions (p≤0.01) at days 56 and 84 compared to baseline. No significant between-group differences in mMASI, but PLE group showed trends toward better melanin index and MelasQoL scores. PLE may enhance melasma treatment as an adjunct, but further studies are needed.
Link: PubMed
Oral Administration of a Hydrophilic Extract of Polypodium leucotomos for the Prevention of Polymorphic Light Eruption
Study: A randomized, controlled trial with 61 patients with polymorphic light eruption (PLE, a photosensitivity disorder). Participants received oral PLE (dose range: 120–1080 mg/day) or placebo. Efficacy was assessed by symptom reduction and ability to tolerate sun exposure without reactions.
Findings: PLE significantly reduced symptoms of polymorphic light eruption, including itching and rashes, compared to placebo. Oral PLE is effective for preventing polymorphic light eruption.
Link: PubMed
Polypodium leucotomos Extract in Atopic Dermatitis: A Randomized, Double-blind, Placebo-controlled, Multicenter Trial
Study: A randomized, double-blind, placebo-controlled trial with 105 patients with atopic dermatitis. Participants received oral PLE (anapsos) or placebo for varying durations. Efficacy was assessed by improvements in eczema severity and symptoms.
Findings: PLE group showed significant improvement in atopic dermatitis symptoms compared to placebo, including reduced itching and inflammation. PLE is a beneficial adjunct for managing atopic dermatitis.
Link: PubMed
Treatment of Vitiligo Vulgaris with Narrow-band UVB and Oral Polypodium leucotomos Extract: A Randomized Double-blind Placebo-controlled Study
Study: A randomized, double-blind, placebo-controlled trial with 50 patients with vitiligo. Participants received narrow-band UVB therapy plus either oral PLE or placebo. Efficacy was measured by repigmentation rates over 6 months
Findings: PLE group showed enhanced repigmentation compared to placebo, particularly in combination with UVB therapy. PLE is a safe and effective adjunct for vitiligo treatment when combined with UVB.
Link: PubMed
Decrease of Ultraviolet A Light-induced “Common Deletion” in Healthy Volunteers After Oral Polypodium leucotomos Extract Supplement in a Randomized Clinical Trial
Study: A randomized clinical trial with healthy volunteers receiving oral PLE (dose not specified) before UVA exposure. Efficacy was assessed by measuring UVA-induced “common deletion” (a mitochondrial DNA mutation linked to photoaging)
Findings: PLE supplementation significantly reduced UVA-induced mitochondrial DNA damage. PLE offers photoprotective benefits against UVA-induced genetic damage.
Link: PubMed
Photoprotective Activity of Oral Polypodium leucotomos Extract in 25 Patients with Idiopathic Photodermatoses
Study: A clinical trial with 25 patients with idiopathic photodermatoses (e.g., solar urticaria, chronic actinic dermatitis). Participants received oral PLE (dose range: 120–1080 mg/day). Efficacy was assessed by symptom reduction and improved light tolerance
Findings: PLE significantly improved light tolerance and reduced symptoms (e.g., itching, erythema) in most patients. PLE is effective for managing idiopathic photodermatoses.
Link: PubMed
Potential Side Effects
Gastrointestinal Upset
Mild stomach discomfort, nausea, or bloating may occur, particularly at higher doses or in sensitive individuals.
Drowsiness
Some users report mild sedation or fatigue, which is uncommon but noted in a few studies and anecdotal reports on X.
Allergic Reactions
Rare cases of allergic responses, such as skin rashes or itching, may occur, especially in those with plant allergies (e.g., to ferns).
Photosensitivity (Paradoxical)
In very rare instances, PL might increase light sensitivity in certain individuals, though it’s primarily used to reduce photosensitivity.