Fernblock, a Nutriceutical with Photoprotective Properties and Potential Preventive Agent for Skin Photoaging and Photoinduced Skin Cancers

Abstract

Many phytochemicals are endowed with photoprotective properties, i.e., the capability to prevent the harmful effects of excessive exposure to ultraviolet (UV) light. These effects include photoaging and skin cancer, and immunosuppression. Photoprotection is endowed through two major modes of action: UV absorption or reflection/scattering; and tissue repair post-exposure. We and others have uncovered the photoprotective properties of an extract of the fern Polypodium leucotomos (commercial name Fernblock). Fernblock is an all-natural antioxidant extract, administered both topically (on the skin) or orally. It inhibits generation of reactive oxygen species (ROS) production induced by UV including superoxide anion. It also prevents damage to the DNA, inhibits UV-induced AP1 and NF-κB, and protects endogenous skin natural antioxidant systems, i.e., CAT, GSH, and GSSR. Its photoprotective effects at a cellular level include a marked decrease of UV-mediated cellular apoptosis and necrosis and a profound inhibition of extracellular matrix remodeling. These molecular and cellular effects translate into long-term inhibition of photoaging and carcinogenesis that, together with its lack of toxicity, postulate its use as a novel-generation photoprotective nutriceutical of phytochemical origin.

Oral administration of Polypodium leucotomos delays skin tumor development and increases epidermal p53 expression and the anti‐oxidant status of UV‐irradiated hairless mice

“…A potential improvement is the use of systemic (oral) photoprotection. Several botanical anti-oxidants have demonstrated their efficacy as systemic photoprotectors (5); among them, the extract from the leaves of the fern Polypodium leucotomos (PL) is endowed with anti-oxidant properties and photoprotective effects in animals and humans (6). In a previous study, oral administration of a PL extract to hairless mice prevented locally and systemic damage induced by short-term UVR demonstrating anti-oxidant properties, preventing Langerhans cells loss and increasing p53 expression and decreasing proliferation in epidermal cells (7), and we emphasized its potential value in preventing photoaging.…”

Antioxidants in dermatology

“…29 AP-1 is responsible for the production of metalloproteinases that promote collagen breakage, clinically inducing wrinkles. 36,37 …”

Natural products as photoprotection

“…Fernblock ( Polypodium leucotomos ) is a tropical fern plant belonging to a Polypodiaceae family. It is commonly used as a traditional medicine in South America to make poultices and treat psoriasis and other skin disorders, although with variable success . The hydrophilic extract of the leaves of P. leucotomos consists of coumaric acid, ferulic acid, caffeic acid, vanillic acid, 3‐caffeoylquinic acid, and chlorogenic acid .…”

“…This extract provided antioxidant activities, inhibiting of ROS generation, scavenging the superoxide anion, and SOD . At a cellular level, the extract showed a significant reduction in UV radiation‐mediated cellular apoptosis and necrosis and a profound inhibition of extracellular matrix remodeling . The important role in photoprotection of fernblock is inhibiting skin erythema, preventing damage to DNA, inhibiting UV‐induced AP‐1 and NF‐κB, and protecting endogenous skin natural antioxidant systems …”