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Original
ArticlesAuthors:
Sergio Schalka1
Maria Alejandra Vitale-Villarejo2
Christiane Monteiro Agelune3
Patricia Camarano Pinto Bombarda4

1

Clinical Director, Medicin Instituto daPele - São Paulo (SP), Brazil

2

Medical
Director,
Innovation
Department, Medicin Instituto da
Pele; Medical Marketing, Industrial
Farmaceutica Cantabria (IFC Group),
Spain

3

Biomedical
Physician;ClinicalResearch Manager, Medicin Institutoda Pele4

Pharmaceutical Biochemist; ClinicalResearch Manager, Medicin Institutoda PeleCorrespondence:
Dr. Sergio Schalka
Av. Carlos de Moraes Barros, 304 –Campesina
Cep: 06023-000 – Osasco (SP), Brazil
E-mail: Schalka@earth.com.br
Received on: 5 November 2014
Approved on: 17 December 2014
This study was performed at Medicin
Instituto da Pele - São Paulo (SP), Brazil.
Financial support: The study received
financial support from Melora do Brasil
Produtos Dermatológicos Ltda.
Conflict of interest: None

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The benefits of using a compound contai­
ning Polypodium leucotomos extract for
reducing erythema and pigmentation
resulting from ultraviolet radiation
Benefícios do uso de um composto contendo extrato de polypo­
dium loucotomos na redução da pigmentação e do eritema
decorrentes da radiação ultravioleta
ABSTRACTIntroduction: Solar radiation can produce erythema and pigmentation in the skin, interfering with pigmentary dermatoses such as melasma. Photoprotection is essential in thetreatment or prevention of hyperpigmentation. The use of Polypodium leucotomos extract
was effective in reducing the damage resulting from solar radiation, through antioxidant andimmunomodulatory mechanisms.
Objective: To evaluate the efficacy of Polypodium leucotomos extract in reducing theerythema and pigmentation following exposure to solar radiation.
Methods: Twenty volunteers were exposed to UVB and UVA radiation emitted by a solar
simulator. The reading of the minimum pigmentary and erythema doses were performed
after two and 24 hours of exposure, respectively. After seven, 14 and 28 days use of
Polypodium leucotomos extract (1,000 mg daily), the minimum pigmentary erythemadoses were re-assessed.
Results: There was an increase in mean values for the minimum pigmentary and erythemadoses in all visits, with a statistical significance of (p <0.05) after 28 days for the minimum
pigmentary dose and after 14 and 28 days for the minimum erythema dose.
Conclusions: The continued use of a compound containing Polypodium leucotomos
extract was effective in increasing individual resistance to pigmentation and erythema resulting from UV radiation, meaning it can contribute to the treatment of skin pigmentation
disorders such as melasma.
Keywords: chemexfoliation; antioxidants; cosmetics; efficacy; shikimic acid.
RESUMO
Introdução: A radiação solar é capaz de produzir eritema e pigmentação na pele, interferindo em dermatoses pigmentares como o melasma. A fotoproteção é essencial no tratamento ou prevenção da hiperpigmentação. A utilização do extrato de Polypodium leucotomos demonstrou ser efetiva na redução dos
danos decorrentes da radiação solar, através de mecanismos antioxidantes e imunomoduladores.
Objetivo: Avaliar a eficácia do uso de extrato de Polypodium leucotomos na redução do eritema epigmentação após exposição à radiação solar.
Métodos: 20 voluntários foram expostos à radiação UVB e UVA, através do uso de simulador solar.
A leitura da dose pigmentária mínima e da dose eritematosa mínima foram realizadas após duas e
24 horas da exposição, respectivamente. Após o uso durante sete, 14 e 28 dias do extrato de
Polypodium leucotomos (1000mg ao dia), novas determinações da dose pigmentária mínima e dose
eritematosa mínima foram realizadas.
Resultados: Observou-se aumento das médias da dose pigmentária mínima e dose eritematosa mínima em todas as visitas, com significância estatística (p<0,05) após 28 dias para a dose pigmentária
mínima e após 14 e 28 dias para a dose eritematosa mínima.
Conclusões: O uso continuado de um composto contendo extrato de Polypodium leucotomos foi eficaz
no aumento da resistência individual à pigmentação e eritema decorrente da radiação UV, podendo cooperar no tratamento de transtornos pigmentares da pele, como o melasma.
Palavras-chave: raios ultravioleta; queimadura solar; pigmentação da pele; substâncias protetoras.

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Polypodium leucotomos and photoprotection

INTRODUCTION
With a more intense or prolonged exposure to ultraviolet
radiation, cutaneous tissue will react – to a greater or lesser
extent, depending on individual’s susceptibility – 1 presenting aclinical picture of erythema and pigmentation, as seen in Table 1.
Erythema – or sunburn – is more evident in fair-skinned
individuals, beginning after a period of two to four hours of
exposure to sunlight, and reaches its greatest intensity after
around 24 hours. Its onset results from vasodilation and the subsequent migration of polymorphonuclear leukocytes, characterizing an acute inflammatory reaction. UVB radiation is the main
determinant of the onset of erythema.1
Solar pigmentation can be immediate, persistent, or late.
Immediate and persistent pigmentations are due to the action of
UVA radiation. Resulting from photo-oxidation of the preformed melanin and from melanin transfer from themelanocytes to keratinocytes, these pigmentations are more
apparent in darker skinned individuals, arising a few minutes
after exposure to sunlight, reaching their peak in two hours andregressing around 72 hours after the exposure.
On the other hand, late pigmentation results from theincreased production of melanin due to the action of UVB and
UVA, and also affects darker or dark-skinned individuals. Its
onset begins three days after exposure to sunlight and can lastfor months.
The ability to respond to solar radiation through skin pigmentation (tanning) or the production of erythema (sunburn) is
genetically determined by ethnic characteristics of individuals.2
Fairer-skinned individuals respond predominantly withsunburn, while darker-skinned individuals willexperience a
more intense pigmentation rather than erythema.1
To quantify an individual’s susceptibility to erythema
and/or pigmentation, visual measurements, such as the minimal
erythemal dose (MED) and the minimum pigmentary dose
(MPD), can be used.
The MED can be defined as the smallest amount ofeffective erythematogenic energy, enough to produce the first
perceptible erythema reaction with clearly defined borders.3 For
its determination, an individual must be exposed to increasing
doses of UV radiation (through a device called solar simulator,
whose radiation spectrum is similar to that of the sun).The reading of the erythema and MED are carried out 24 hours after.3
Similarly, Moyal et al.4,5 described the MPD as the lowest
UV dose required for producing an area of persistent pigmentation. For this determination, an individual must be exposed

only to UVA radiation in the solar simulator, with the readingof the MPD being carried out after 2 hours.
The greater the MED or MPD, the greater the resistanceof an individual to the production of erythema or pigmentation,
respectively.
Prevention of erythema is desirable for individuals withacute exposure to the sun, due to the evident discomfort it causes during leisure or work activities. It was in search of a solution
for this problem that the first sunscreens were developed earlyin the last century.
Conversely, prevention of pigmentation is particularly
relevant for individuals predisposed to develop pigmentary dermatosis, such as melasma and post-inflammatory hyperchromia.
In these situations, the use of topical sunscreens is also recommended, specifically those that have protection against UVA.
In addition to topical sunscreens, some oral use agentswith photoprotective action have been developed more recently, with an aim at interfering with the molecular and cellularmechanisms linked to the development of acute and chronic
actinic damage.
Among these agents, the Polypodium leucotomos extract(PLE), rich in phenolic derivatives, enjoys an extensive bibliography demonstrating its benefits as a photoimmunomodulator
agent capable of reducing acute and chronic actinic damage.6
The effect created by the aqueous extract of Polypodium
leucotomos leaves is intrinsically related to its antioxidant andanti-inflammatory activity, reducing the erythematogenic
response triggered by solar radiation and the phototoxic reaction triggered by the use of psoralen associated with the exposure to UVA radiation-emitting devices.7
Furthermore, there is evidence that the systemic use of
PLE is capable of preventing the depletion of epidermal antigen
presenting cells (Langerhans cells).7
The combination of these effects has demonstrated theextract’s photoprotective capacity for the prevention of the erythematogenic and phototoxic response to solar radiation.
A study by González et al.8 was considered a milestone
in the establishment of the mechanisms of action of that phytoextract. The authors evaluated a group of 21 volunteers who
received topical or oral PLE and were exposed to varying dosesof natural solar radiation, with or without psoralen ingestion for
triggering a phototoxic reaction. Twelve patients were treatedorally with PLE, four of which had received psoralens and eight
who had not. The results showed that the use of topical and sys-TABLE 1: CARACTERÍSTICAS DOS PRINCIPAIS EFEITOS AGUDOS DA RADIAÇÃO SOLAR
Erythema (sunburn)Responsible wavelength
More frequently affected individuals
Etiopathogenic mechanisms
Onset
Peak
Duration

Immediate + persistent pigmentation

UVB
UVA(I a III) = Lower phototypes (I to III) Higher phototypes * (III to VI)
Acute inflammatory reaction
Photooxidation of preformed melanin
2 to 4 hours
Minutes
24 hours
2 hours
48 hours
72 hours

Late pigmentation
UVB + UVA
Higher phototypes * (III to VI)
Increased production of melanin
From 72 hours
From days to weeks*Phototype classification according to the Fitzpatrick scale.2

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Schalka S, Vitale-Villarejo MA, Agelune CM, Bombardia PCP

temic PLE promoted in their respective groups a statistically significant increase in MED and MPD in the non-sensitized group
and a significant increase in the minimum phototoxic dose
(MFD) in the photosensitized group.
Other studies published subsequently9,10 have demonstrated that the use of oral PLE in varied doses and administeredin an acute fashion a few hours before exposure to UV radiation, was capable of raising the MED, increasing the volunteers’
individual resistance to UV-induced erythema.
Moreover, the effect of PLE’s in the treatment of pigmentary dermatosis – such as melasma – has been proposed
through antioxidant mechanisms (bearing in mind that the pigment is derived from the photo-oxidative process of melanin)
and anti-inflammatory mechanisms.
Two studies11,12 have demonstrated that patients withmelasma showed clinical and colorimetric improvement oflesions with continued use of PLE after 12 weeks of treatment.
OBJECTIVES
Primary Objective: To evaluate, by determining the
MPD, the effectiveness of the continued use of a formulation
containing Polypodium leucotomos extract in reducing pigmentation.
Secondary objectives:To evaluate, by determining the MED, theeffectiveness of the continued use of a formulation containing
Polypodium leucotomos extract in reducing sunburn.
To evaluate the tolerability to the product after continued use.
METHODS
Study design
Clinical, open, monocentric study with clinical evaluations.
Study population
After having been granted approval by the Research
Ethics Committee (REC), the study took place in the period
from June to August 2013. Twenty female volunteers were initially recruited and included in the study (ages between 18 and60 years old, skin phototypes II and III, absence of active skincondition, absence of continuing use of systemic medication).
All volunteers signed the Free and Informed Term of Consent(FITC) before undergoing any procedures described in the
study’s protocol.
In addition to the required characteristics of the population and in order to ensure the eligibility of each of the volunteer, none of the following criteria could be met: pregnancy or
potential risk of pregnancy, lactation, use of anti-inflammatory
medications and/or topical or systemic immunosuppressants,
use of antihistamines for up to 15 days before the beginning of
the study, atopic or allergic history, active skin conditions (local
and/or disseminated) that could impact the results of the study,
conditions that could cause immune suppression, intense exposure to sunlight up to 15 days prior to the inclusion in the study,
and other conditions considered to be reasonable for disqualification by the investigator.

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Methodological procedures
After initial clinical evaluation for verification of eligibility criteria, each volunteer was referred to the demarcation oftest areas and subsequent irradiation. One of the demarcatedareas received UVA irradiation, and the other, UVB irradiation.
In the irradiated areas, UV radiation exposures were performed in six subsites (six gates) with areas of 50cm2 each. The
irradiations emitted by the solar simulator were delivered with
progressive doses.
For the UVA irradiated area, these doses were predetermined by a UVA radiation detector, with each being 25% higher than the previous one, according to a geometric progression– the series of six UVA irradiation doses should cover the range
8J / cm2 to 25J / cm2.
For the UVB irradiated area, the doses were predeterminedby a UVB radiation detector, with each dose being 12% higher
than the previous one, according to a geometric progression.
After the exposure, each volunteer had to wait for 15
additional minutes in order that any immediate reaction to the
UV radiation, such as tanning, reflection erythema, and vesicant
eruption could be observed. Any possible reaction was recordedin the medical record accordingly.
After 2 and 24 hours of the irradiation, readings of theareas irradiated with UVA and UVB were carried out with anaim at determining the MPD and the MED, respectively.
MPD’s values are expressed in joules per square centimeter (J / cm2).
MED is defined as the amount of radiant energy
required to produce the first perceptible erythematous reaction
with clearly defined borders, observed at between 16 and 24
hours after the exposure to UV radiation. It is expressed in millijoules per square centimeter (mJ / cm2).
After determining the pre-treatment MPD and MED,
the volunteers were released to start the treatment.
During a 28-day period the volunteers made use of thecompound containing PLE (Fernblock®, Melora, São Paulo,
Brazil), with a daily dose of 4 capsules of 250 mg each (1,000 mg/ day) – 2 capsules taken at 9:00 and 2 capsules taken at 13:00.
After 7, 14, and 28 days of medication use, the volunteers
returned to the study center for new measurements of the MPD
and MED.
On the days of the intermediate exposures (D7 andD14), the volunteers came to the study center and received the
UVA and UVB doses before taking the first capsule of the day(at 9:00). This ensured that the last ingestion of the complex had
taken place at least 19 hours prior to exposure to the UVR.
These procedures were repeated in new areas of eachvolunteer’s dorsum.
The results were tabulated and the statistical analysis performed using the Student’s t-test for paired samples.
RESULTS
All of the 20 included volunteers completed the study,
with none having presented a picture characterized by a serious
adverse event. Notwithstanding, one volunteer had an adverse

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Polypodium leucotomos and photoprotection

event with mild abdominal colic, which regressed spontaneously
and did not require early withdrawal from the study.
MPD PROGRESSION THROUGHOUT THE VISITS
Graph 1 shows the percentage change between the meanvalues of MPD at the experimental times D0, D7, D14, and D28.
It is possible to notice that the studied product provided a statistically significant increase (p = 0.021) on MPD values after 28
days of continuous use, suggesting preventive action against UVAcaused photodamage. In particular there was preventive action bystimulation of production of persistent solar pigmentation.
The percentage change shows a gain of up to 17.41% in
the MPD, i.e. an increase in the individual resistance to the production of pigmentation.

Improvement percentage

MED PROGRESSION THROUGHOUT THE VISITS
Graph 2 shows that the studied drugs provided a statistically significant increase in MED values, after 15 days (p =0.012) and 29 days (p = 0.044) of continuous use, thus demonstrating the presence of a preventive action against photodamage
caused by UVB, particularly in preventing solar erythema.
The percentage change indicates a gain of up to 20.37%
in MED, meaning increased individual resistance to the production of solar erythema.
25%
17,41%*(0,021)20%
15%

11,50%(0,095)

10%
5%

3,08%
(0,242)0%
D7­D0

D14­D0

D28­D0Difference between experimental times

Improvement percentage

GRAPH 1: Percentage change in MED at different experimental times regar­
ding the baseline (p­value) * statistical significance (p <0.05)

25%
20,37%*(0,044)20%
14,57%(0,012)

15%
10%

4,79%
(0,221)

5%
0%
D8­D0

D15­D0

D29­D0Difference between experimental times

GRAPH 2: depicts the percentage change between mean values of MED at
the experimental times D1, D8, D15 and D29

DISCUSSION
Photoprotection can be conceptualized as a set of measures aimed at reducing or minimizing the harmful effects ofsolar radiation on the skin.
Of these harmful effects, the development of sunburnand pigmentation has the most acute onset and usually becomesthe primary motivation for the establishment of photoprotection measures.1,4,5
Among pigmentary dermatoses, melasma is the mostcommon, and is a frequent complaint in dermatologic practices,
constituting one of the main motivations for prescribing photoprotective measures.
It is known that immediate and persistent pigmentation
results from the photo-oxidation of the preformed melanin,
making it therefore an oxidative phenomena triggered by UVA
radiation and visible light, that has an intrinsic correlation withthe etiopathogeny of the melasma.1
Thus, the introduction of new oral photoprotective
active principles, capable of providing a reduction in UV-caused
pigmentation through antioxidant and immunomodulatory
action, is desirable.
PLE was proven to have significant antioxidant andimmunomodulatory capacity in laboratory experiments.6 In
addition, previous clinical studies have indicated that intense useof PLE can produce an increase in MED, showing a clear photoprotective effect.7-10
More recently, two clinical studies with melasma patients
indicated that the continued use of PLE can produce clinical andcolorimetric reduction of lesions, confirming its effectiveness asa therapeutic option in the treatment of this condition.11,12
A study evaluating the effect of the continued use of PLE
in preventing solar pigmentation (i.e. in the increase of MPD)
had not been published to date, and the experimental model
employed in the present study is widely used in photobiology todemonstrate the photoprotective efficacy of sunscreen against
UVA radiation. Also, there is an absence of studies proving theeffectiveness of continued use of PLE in the prevention of solar
erythema (i.e. in the increase of MED).
The present study was aimed at evaluating the effects ofthe continued use of PLE in reducing solar pigmentation, by
evaluating the MPD, and the reduction of solar erythema by
evaluating the MED changes between experimental times.
The findings have demonstrated that the continued useof a compound containing PLE, at 1,000 mg / day dose produced a positive effect on the increase of MPD, leading to an
improved resistance to pigment production due to exposure tosolar radiation.
The authors observed a positive effect already at the evaluation on D14, with an improvement greater than 11%.
Nevertheless, it was at the evaluation on D28 that the best result
was observed, with a statistically significant improvement inexcess of 17%.
As already mentioned, the increase in MPD produced by
the use of PLE generates a higher resistance to pigmentation
and, therefore, a greater photoprotective action against pigmen-

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tation – a development that is particularly desirable in patients
suffering from pigmentary dermatoses, such as melasma.
It was also possible to note that continued use produces
better effects, which reinforces the observation of previous clinical studies showing results in the treatment of melasma within
12 weeks of use.11,12 Regarding the production of erythema, theauthors of the present study observed a similar behavior, thoughwith different numbers.
In the evaluation after 15 days of use, the authors
observed a statistically significant increase of roughly 15% in
MED, which increased to the even higher level of 20% (withstatistical significance) after 29 days of use.
Prior studies to evaluate protection against erythema bydetermining the MED were aimed at verifying the effect of theintensive use of PLE.8-10
Middelkamp-Hup MA et al.10 carried out a study withclinical assessments of erythema and histological evaluations involunteers irradiated with solar simulator before and after
receiving acute doses of PLE up to a maximum of 24 hours
prior to exposure.
The assessment of erythema was not based on the determination of MED, but on the use of a scale to evaluate erythema, which makes comparisons with the results of the present
study difficult. It is, however worth noting that the authors
found a statistically significant reduction in erythema in irradiated sites after taking PLE up to 2 hours after the ingestion of

the last dose of the extract. In the present study, the objective
was not to identify the acute effect linked to the ingestion ofPLE, but rather to identify some continued benefit regardless ofthe time of ingestion of the doses (as mentioned above, the volunteers received UVA and UVB doses after at least 19 hours had
passed since the last ingestion of the investigated product),which is of particular interest for the understanding of the benefits found in patients with chronic photodermatoses, such asmelasma.
The results found in the present study demonstrate thatthe continued use of PLE provides a slow and gradual increaseof MPD and basal MED. This is not exactly a cumulative effect,
but a gradual increase in the individual’s tolerance to pigmentation and erythema triggered by UV.
CONCLUSION
The continued use of a compound containing PLE produced a significant reduction in MED within 14 days of use, anda significant reduction of MPD within 28 days of use, after
exposure to solar simulator irradiation. This has demonstrated
the presence of the positive effect in the anti-erythematogenic
and anti-pigmentary actions following ultraviolet exposure. This
compound can provide benefits to users who bear photodermatoses or dermatoses that may be exacerbated by exposure to
UV radiation, such as melasma.●

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