Polypodium leucotomos: A Potential New Photoprotective Agent

Abstract

As the understanding of the immune system pathways, cytokine balances, and cellular interactions continues to expand, so must the potential applications of therapies that can impact the process of diseases instead of just controlling their symptoms. In the case of Polypodium leucotomos extract, which is derived from a tropical fern of the Polypodiaceae family, the future potential of applications in dermatology and beyond will be better understood as its incorporation into daily routines gives rise to the development of new regimens. Clinicians may position this agent as an option for daily maintenance, accept its use in combinations, or use it as a template for further development of oral supplementation that may evolve into a true immunomodulator. The antioxidant activity of P. leucotomos extract is primarily driven by caffeic acid and ferulic acid, resulting in the control of cutaneous responses to ultraviolet-induced erythema, in the interception of inflammatory mechanisms, and the promotion of other cytotoxic responses. Histologically, the impact of P. leucotomos extract induces an effect on the overall reduction of angiogenesis, photocarcinogenesis, and solar elastosis, while on the cellular level there are improvements in cell membrane integrity and elastin expression. Future applications for P. leucotomos extract could include the potential for photoprotective effects, and subsequent research efforts should focus on determining the optimal dosage regimen, duration of action, and utility of combinations with sunscreens, among other outcomes. Recently published data have also demonstrated how the antioxidant effects of oral P. leucotomos extract can delay tumor development in mice models, suggesting there might be a protective role that could be described with further clinical research. In addition, it is important to recognize the distinction between photoprotection and chemoprevention, in that there has yet to be any in vivo or controlled clinical trial data in human subjects that show a role for P. leucotomos extract in the prevention of carcinogenesis.

Fernblock (Polypodium leucotomos Extract): Molecular Mechanisms and Pleiotropic Effects in Light-Related Skin Conditions, Photoaging and Skin Cancers, a Review

“…The interest in the mechanism of action and overall properties of PL has spiked in recent years, mainly focusing on its antioxidant properties [ 58 , 59 , 60 , 61 , 62 ]. PL displays anti-inflammatory and immunoregulatory effects and also suppresses tumor growth [ 57 ].…”

Handbook of Integrative Dermatology

“…PLE may achieve these effects via oral antioxidant and immunomodulatory effects. PLE prevents apoptosis and promotes DNA repair via the p53 tumor suppressor gene and other pathways (Bhatia 2015 ). Containing phenolic antioxidants such as caffeic and ferulic acids, PLE can diminish UV induced erythema and inhibit UV induced immunosuppression.…”

“…Further research is needed to determine optimized dosing, duration of effect, and the utility of using PLE in combination with topically-applied sunscreens (Bhatia 2015 ). Murine models suggest a potential for PLE as a chemopreventative agent, however, to date, there are no controlled trials in humans demonstrating this effect.…”

Nicotinamide for skin cancer chemoprevention

“…Botanical agents such as the carotenoid antioxidant lycopene can reduce sensitivity to UV‐induced erythema. Leucotomos extract and flavonoids also reduce UV‐induced immune suppression, which plays a key promotional role in skin carcinogenesis . As yet there is no evidence of these agents’ ability to reduce skin cancer incidence in humans.…”