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J. Cosmet. Sci., 74.4, 216–230 (July/August 2023)
*Address all correspondence to Nuzhet Cenk Sesal, csesal@yahoo.com
Endolichenic Fungi Extracts: A Promising Alternative for
Ultraviolet Protection in Cosmetics?
ORCUN TOKSOZ, JAE-SEOUN HUR AND NUZHET CENK SESAL
Institute of Pure and Applied Sciences, Marmara University, Istanbul, Turkey (O.T.)
Korean Lichen Research Institute, Sunchon National University, Suncheon, South Korea (J.H.)
Department of Biology, Faculty of Science, Marmara University, Kadıköy, Istanbul, Turkey (N.C.S.)
Accepted for publication August 13, 2023.
Synopsis
Lichen-derived extracts are a potential source for skin health products due to their antioxidant activity that can
prevent damage caused by ultraviolet (UV) rays. The slow natural growth and limited reproduction of lichens
limit their use. However, endolichenic fungi (ELF) from lichen thalli can serve as a more efficient, rapid, and
standardized biological resource for the cosmetic industry. We aimed to investigate the UV protection of
Lobaria pulmonaria, Bryoria capillaris, and Usnea sp., and isolated ELF extracts. Total antioxidant, phenolic-
flavonoid content, sun protection factor (SPF), and tyrosinase inhibitory activities of lichen and ELF extracts
were also investigated. As a result, ELF extracts were found to have antioxidant content close to, and in some
cases, much higher than lichen species. While SPF values of lichen species varied between 31.45–31.80, results
close to lichens were found in the range of 6.54–32.01 values of ELF extracts. Interestingly, lichen extracts
did not have tyrosinase inhibitory activity, while some ELF extracts had tyrosinase inhibitory activity in the
range of 2.49–38.44. The results of this study suggest that ELF extracts may have the potential to be used as
innovative UV protectants in the cosmetic industry.
INTRODUCTION
Lasting exposure to harmful solar ultraviolet (UV-C (100–280 nm), UV-B (280–320 nm),
and UV-A (320–400nm)) radiation causes chronic or acute skin damage such as skin cancer,
photoaging, wrinkles, and sunburn.1–3 As a result of photoaging, thickening of the skin,
wrinkles, and chronological damage known as pigmentation occur. In this case, excessive
production of intracellular reactive oxygen species (ROS) is known to cause photoaging,
excessive melanin production, DNA damage, and skin cancer. The mechanism of skin
pigmentation protects the skin from UV damage. Melanin, which causes skin pigmentation,
also protects our skin from UV damage by absorbing UV rays.4,5 However, excessive melanin
production is closely related to problems such as solar lentigo and freckle formation.6,7
Therefore, tyrosinase inhibitors are being investigated for application in cosmetic products
for skin lightening and depigmentation. There are many known tyrosinase inhibitors such
as hydroquinone, arbutin, and kojic acid. However, most of them are reported to have low

217 ENDOLICHENIC FUNGI EXTRACTS
activity or to have negative effects such as mutagenicity and cytotoxicity.8,9 Therefore, there
has been a recent need to identify effective and safer tyrosinase inhibitors from natural
sources, especially for the cosmetic industry.10
Since it is known that UV increases ROS and that antioxidants prevent the damage caused
by ROS, antioxidants have recently come to the fore in the cosmetic industry. Antioxidants
play an active role in preventing, repairing, and reducing cellular damage caused by free
radicals.11 Recently, there is increased focus on taking precautions against photoaging and
pigmentation problems caused by UV damage. UV radiation is emphasized as one of the
main causes of photoaging and structural changes in the skin, and other forms of solar
radiation, including visible and infrared light, may also play a role in photoaging.12 UV
radiation increases the risk of long-term damage such as photoimmunosuppression and
photocarcinogenesis as well as photoaging.13 There has also been an increase in UV-induced
melanoma cases in various countries in recent years, and many health authorities are
working intensively on increasing the awareness of this issue and increasing the use of
sunscreen products.14,15 Therefore, the discovery of natural products with high antioxidant
activity is believed to be important.
The need for cosmetic products is increasing every year all over the world. While the
world cosmetics market had a market share of US $380.2 billion in 2019, it is expected to
reach US $463.5 billion with a compound annual growth rate of 5.3% (CAGR) from 2021
to 2027.16 Sun care products are especially among the products with the fastest growth
potential in the cosmetics market. The market for these products was valued at US $11.4
billion in 2021 and is expected to increase to US $17.6 billion by 2027 with a 7.3% CAGR
over 2022 to 2027.17 One of the main reasons for this growth is the increased awareness
of the harmful effects of UV rays. Sunscreens are widely used in daily life due to their
functions such as filtering, reflecting, and dispersing UV rays.18 In particular, consumers’
preference for organic-based products and the development of innovative and advanced sun
care products also contribute to the growth of this market.
Natural products have been the cornerstone of cosmetics and pharmaceutical production
in many parts of the world for years. Recently, there has been an increasing interest in
cosmetic products containing natural herbal extracts, especially for components such as
pigment removers and sunscreens, leading to a growing demand for natural extracts in
the global cosmetics market. Due to the increasing demand of consumers for healthy and
environmentally friendly products, the use of natural herbal ingredients has increased in
the cosmetics sector.19
Lichens are symbiotic associations of fungi (mycobionts), green algae and/or cyanobacteria
(photobionts). In addition to the fungal partner in this mutualism, lichens are also associated
with endolichenic fungi that reside within their thalli.20 Lichens producuse nearly 1,050
specific secondary metabolites that have antioxidant and antimicrobial effects. Despite the
unique biological activity of lichens, their slow growth rate, and limited numbers in nature
make their application in various industries difficult.21 There are also difficulties in the in
vitro production of lichens. However, ELFs are fungal species that live in the lichen thallus
and are easy to grow in lab scale in a shorter time and in large quantities. Therefore,
the importance of producing ELF with similar bioactivities that are not being used in
industries has emerged. ELF are considered promising biological resources for various
fields, given their ability to produce many valuable bioactive metabolites.22 Studies on the
bioactivities of ELF isolated from lichens are quite limited. Identifying and evaluating