Polypodium Extract for Preventing Skin Damage?

[Dean Pomerleau]

Has anyone looked into or is anyone taking Polypodium leucotomos extract (PLE) for protection against sun-induced skin damage? My wife's friend swears by it. I was skeptical. But I looked at the evidence on Pubmed and it looks pretty compelling. Here is a 2021 review paper [1] that discusses a lot of evidence in both vitro, mice and humans trials that show benefits. Here is the section of the paper on human trials of UV exposure with oral PLE:

2.3 In vivo (human)
Kohli et al.evaluated the efect of oral PLE on COX-2 in UV 
irradiated skin of humans [22]. Twenty-two subjects with 
Fitzpatrick skin phototype I to III were irradiated with UVB 
(using 308-nm excimer laser) with doses ranging from 100 
to 350 mJ/cm2
. Pre-PLE minimal erythema dose (MED)/
trace erythema assessment and biopsy were performed 24 h 
after irradiation. On day 3 subjects took PLE 240 mg 2 h 
and 1 h (480 mg total) before irradiation was repeated as on 
day 1. On day 4 a biopsy was taken from the site of MED/
trace erythema. A statistically signifcant decrease of COX-2 
was found post-PLE consumption (p<0.0005), indicating 
PLE’s anti-infammatory efect. A signifcant improvement 
in erythema was noted after PLE administration. Overall, 
the results showed that PLE was able to lessen the negative 
photobiologic efects of UVB [22]. Middelkamp-Hup et al. 
studied the efects of PLE on dermal mast cell infltration 
after UV irradiation [20]. The back skin of nine participants 
with Fitzpatrick skin phototype II and III were exposed to 
UVR (305–400 nm) doses ranging up to 2–3 times the MED 
dose, before and after taking PLE at diferent timepoints 
[20]. After receiving an initial dose of UVR, initial biopsies 
were taken from pre-PLE irradiated sites from 5 participants 
after 24 h and from 2 participants 72 h after irradiation. The 
evening before the second exposure of UVR, the frst dose 
of PLE (7.5 mg/kg) was given to participants. The next day, 
a second dose of PLE was administered and participants 
were exposed again at the same UVR fuences 30 min, 1 h, 
1.5 h, 2 h and 3 h after the second dose of PLE. A second 
biopsy was taken from the same participants who had an 
initial biopsy done from the site at the timepoint showing 
maximal photoprotection (5 participants after 24 h and 2 
participants 72 h after irradiation.) Compared to pre-PLE 
irradiated sites, a reduction in mast cells of the papillary 
dermis was noted from biopsies taken from post-PLE irradi-
ated sites at either 24 or 72 h after irradiation [20]. Mast cell 
products are thought to play a role in photoaging by induc-
tion of fbroblast elastin production. The ability of PLE to 
down-regulate UV-induced mast cell responses suggested 
that PLE might play a role in reducing changes of photoag-
ing [20, 41].
Villa et al. evaluated the efect of PLE on a photoaging-
associated mitochondrial common deletion (CD) after UVA 
irradiation (320–400 nm with a peak of 350 nm) [21]. In 
this randomized, investigator-blinded, controlled trial, ten 
participants with Fitzpatrick skin phototype II and III were 
irradiated with UVA two to three times the MED (using 
doses of 10–35 J/cm2
) either having taken a single dose oral 
PLE 480 mg before exposure or no PLE. Forearm biopsies 
taken 24 h after irradiation demonstrated that at two times 
the MED, the average CD values decreased by 84% in the 
group taking PLE, compared to the 217% increase over base-
line in the non-PLE treated group, trending toward signif-
cance (p=0.06). The CD is a specifc mitochondrial DNA 
deletion induced by chronic UVA radiation in fbroblasts 
and keratinocytes, and this study’s fndings suggested that 
PLE’s efect on photodamage may be through preventing 
UVA-dependent mitochondrial DNA damage [21, 42, 43].
More recently, Granger et al. conducted a clinical trial 
investigating the effects of an antioxidant food supple-
ment containing a non-Fernblock extract of P. leucoto-
mos on the antioxidant capacity and lipid peroxidation of 
the skin after UVA irradiation. Thirty participants with 
Fitzpatrick skin phototype I to III consumed 480 mg daily 
for 12 weeks and UV irradiation was performed on the back skin at various timepoints over 12 weeks to achieve ne MED, with doses ranging from 38 to 41 mJ/cm2. The

mean Ferric Reducing Antioxidant Power (FRAP) meas-

urement significantly decreased. Lipid peroxidation was

also measured via malondialdehyde (MDA) 4 h and 24 h

after UVA irradiation (5 J/cm2

) at each visit, and was

found to decrease with the supplement. Radiance, mois-

ture, elasticity and skin lightness were also significantly

increased after supplementation. The authors concluded

that this supplement improved photoprotection, enhanced

the antioxidative status of the skin and improved general

skin condition [44].

-----------------------

Here is the review paper's conclusion:

P. leucotomos may protect against UV and VL-induced photoaging of the skin through regulation of enzymes involved in ECM remodeling, upregulation of ECM proteins, downregulation of infammation and ROS due to its anti-infammatory and antioxidant properties and cytoprotective efects on fbroblasts and keratinocytes. P. leucotomos extract is a well-tolerated and safe agent with photoprotective properties, making it potentially a suitable adjunct in combating UVR and VL-induced skin aging.

Clearly you'd still want to apply a good sunscreen when going out in the sun. But I'm wondering if anyone else has considered oral PLE as an additional step to prevent skin damage from sun exposure. Skin cancer is one type of cancer that I (and my wife) feel like we might be most susceptible to. It is $0.11 per capsule (Amazon link) for the dose used in many of these human studies.

--Dean

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[1]  Photochem Photobiol Sci. 2021 Sep;20(9):1229-1238.

doi: 10.1007/s43630-021-00087-x. Epub 2021 Aug 27.

The potential effect of Polypodium leucotomos extract on ultraviolet- and 
visible light-induced photoaging.

Pourang A(1), Dourra M(2), Ezekwe N(1), Kohli I(1), Hamzavi I(1), Lim HW(3).

Author information:
(1)Photomedicine and Photobiology Unit, Department of Dermatology, Henry Ford 
Health System, 3031 W. Grand Blvd, Suite 800, Detroit, MI, 48202, USA.
(2)College of Medicine, Michigan State University, East Lansing, MI, USA.
(3)Photomedicine and Photobiology Unit, Department of Dermatology, Henry Ford 
Health System, 3031 W. Grand Blvd, Suite 800, Detroit, MI, 48202, USA. 
hlim1@hfhs.org.

Photoaging induced by both ultraviolet and visible light has been shown to lead 
to increased inflammation and dysregulation of the extracellular matrix. 
Standardized extract of the Polypodium leucotomos fern, PLE, possesses 
anti-inflammatory and antioxidant properties, and has been shown to potentially 
mitigate photoaging through various mechanisms. This comprehensive review 
presents the data available on the effects of P. leucotomos extract on UV and 
VL-induced photoaging in vitro as well as in vivo in murine and human models.

DOI: 10.1007/s43630-021-00087-x
PMID: 34449075 [Indexed for MEDLINE]

 

[Saul]

9 minutes ago, Dean Pomerleau said:

Clearly you'd still want to apply a good sunscreen when going out in the sun

Yes.

  --  Saul