Fernblock® Upregulates NRF2 Antioxidant Pathway and Protects Keratinocytes from PM_2.5-Induced Xenotoxic Stress

Abstract

Humans in modern industrial and postindustrial societies face sustained challenges from environmental pollutants, which can trigger tissue damage from xenotoxic stress through different mechanisms. Thus, the identification and characterization of compounds capable of conferring antioxidant effects and protection against these xenotoxins are warranted. Here, we report that the natural extract of Polypodium leucotomos named Fernblock®, known to reduce aging and oxidative stress induced by solar radiations, upregulates the NRF2 transcription factor and its downstream antioxidant targets, and this correlates with its ability to reduce inflammation, melanogenesis, and general cell damage in cultured keratinocytes upon exposure to an experimental model of fine pollutant particles (PM2.5). Our results provide evidence for a specific molecular mechanism underpinning the protective activity of Fernblock® against environmental pollutants and potentially other sources of oxidative stress and damage-induced aging.

Therapeutic Potential of Centella asiatica and Its Triterpenes: A Review

“…An in vivo experiment showed that asiatic acid had a visible effect on doxorubicin (DXR)-induced organ toxicities, showing the best effect at 20 mg/kg by affecting the expression of Nrf2 ( Kamble and Patil, 2018 ). Doxorubicin causes the peroxidation of organs and reduces the activity of innate antioxidant factors ( Sonawane et al, 2018 ) while upregulating the expression of Nrf2 effectively promotes antioxidant activity and protects cells from the damage caused by oxidative stress ( Qi et al, 2017 ; Delgado-Wicke et al, 2020 ). In vivo and in vitro experiments also found that asiatic acid reduced the levels of inflammatory factors (IL-1β ↓, IL-6 ↓) by affecting the Notch signaling pathway, weakened liver and kidney damage, and improved the survival rate in the experimental sepsis mice model ( Yuyun et al, 2018 ).…”

The Aqueous Extract of Polypodium leucotomos (Fernblock®) Regulates Opsin 3 and Prevents Photooxidation of Melanin Precursors on Skin Cells Exposed to Blue Light Emitted from Digital Devices

“…The photoprotection activity of a hydrophilic botanical extract from Polypodium leucotomos , FB, against potential blue light-induced skin damage was also evaluated. FB is an interesting candidate for providing protection against the previously-stated alterations due to its antioxidant and anti-inflammatory properties [ 29 ]. It has been shown to exert an effect on preventing immunosuppression and DNA damage induced by UV and VIS and reducing inflammation, among others [ 17 ].…”

“…Our study has shown how shorter wavelength VIS is also capable of triggering melanin photooxidation and promoting darkening of melanosomes, contributing to the overall development of hyperpigmentation. Our group previously studied the effect of FB on melanin production but no differences were observed in tyrosinase activity, thus we decided to focus on the antioxidant mechanisms in terms of photooxidation [ 29 ].…”

Environmentally-Induced (Extrinsic) Skin Aging: Exposomal Factors and Underlying Mechanisms

“…Accordingly, epidemiological studies showed that the association between traffic-related PM and skin aging traits is not mediated by a systemic effect involving the inhalation of PM and a subsequent pulmonary inflammatory reaction, indicating exposure through the skin surface as the most relevant route (Vierkö tter et al, 2017). We therefore view the increasing number of in vitro studies in which PM is added into the medium of twodimensional cultures to learn about the effects of air pollutants on human skin as difficult to interpret (Delgado-Wicke et al, 2020;Lin et al, 2016;Qiao et al, 2017;Ryu et al, 2019).…”