225 ENDOLICHENIC FUNGI EXTRACTS
as a natural sunscreen ingredient. These findings are consistent with previous literature on
the photoprotective properties of lichen species and their compounds.
TYROSINASE INHIBITION ACTIVITY
Continuous exposure to UV rays is known to cause skin pigmentation. Therefore, tyrosinase
inhibitors are used in cosmetic products, especially in skin whitening products.57 Products
naturally containing tyrosinase are often preferred. The tyrosinase inhibitor activity of
lichen species has been proven by previous studies.58,59 However, studies on tyrosinase
inhibitor activities of ELF samples isolated from lichens are limited. Determining the
tyrosinase inhibitory activities of ELF samples is thought to have the potential to be used
in skin whitening products, especially in the cosmetic industry.
In this study, potential tyrosinase inhibitory activities of three different lichen extracts
(1 mg/mL) and isolated ELF extract (1 mg/mL) were determined in vitro and the results are
given in Table IV. Among the tested lichens and their ELF extracts, L. pulmonaria and T04-
P01, B. capillaris and T20-B02, T20-P26, Usnea sp., and T22-P07 were found to have no
detectable tyrosinase inhibitory activities at the tested concentration. However, T04-P03,
T04-P13, T20-P07, T20-P10, and T22-B07 extracts showed varying degrees of tyrosinase
inhibition. T04-P03 and T04-P13 exhibited 14.67–23.37% inhibition, respectively, while
T20-P07 and T20-P10 showed 33.22–38.44% inhibition, respectively. T22-B07 also
demonstrated significant tyrosinase inhibitory activity at 33.78%. The highest tyrosinase
inhibitor activity was found to be in the ELF extracts obtained from B. capillaris, specifically
for the T20-P10 sample.
Higuchi et al. reported that the lichens Hypogymnia physodes, Letharia vulpina, and Cetraria
juniperina exhibited strong tyrosinase inhibitory activity, and that the mycobiont partner of
H. physodes showed higher activity than the lichen itself.60 Verma et al. reported that extracts
obtained from lichen symbionts of Arthothelium awasthii had higher tyrosinase inhibitory
activity (67.2%) when compared to Heterodermia podocarpa and Parmotrema tinctorum.61 Kim
Table IV
Tyrosinase Inhibition Activity of Lichen and ELF Extracts
Name of the lichen and ELF Tyrosinase %inhibiton at 1 mg/mL
Kojic acid (1 mg/mL standard) 45.63 ± 0.003
Lobaria pulmonaria Nd
T04-P01 Nd
T04-P03 14.67 ± 0.006
T04-P13 23.37 ± 0.005
Bryoria capillaris Nd
T20-B02 Nd
T20-P07 33.22 ± 0.001
T20-P10 38.44 ± 0.001
T20-P26 Nd
T20-P27 2.49 ± 0.003
Usnea sp. Nd
T22-P07 Nd
T22-B07 33.78 ± 0.002
ND: No data

226 JOURNAL OF COSMETIC SCIENCE
and Cho reported that the methanol extract of U. longissima reduced melanin levels in
human melanoma cells through its tyrosinase inhibitory activity.62 Similarly, Aydın et al.
investigated the tyrosinase inhibitory activity of methanol and ethyl acetate extracts of U.
longissima lichen and detected tyrosinase inhibitory activity at increasing concentrations for
both solvents.63 P. austrosinense lichen. In other studies, Phanerochaete sordida ELF extracts
obtained from Bactrospora myriadea lichen exhibited moderate tyrosinase inhibitory activity,
and a similar study reported that various ELF extracts obtained from 29 different lichens
showed varying levels of tyrosinase inhibitory activity, with particularly high activity
reported for Chaetomium globosum extract (308.4 ± 2.49 µg/mL), Hypoxylon lividipigmentum
(121.2 ± 2.55 µg/mL), and Cytospora xylocarpi (68.50 ± 0.34 µg/mL). The authors reported
that C. globosum and H. lividipigmentum exhibited higher activity compared to the positive
control, kojic acid.64,65
Based on previous studies, it is known that several species of lichens exhibit tyrosinase
inhibitory activity.58,63 However, in our study, no tyrosinase inhibitory activity was
detected in the extracts of three different lichen species tested at a concentration of 1 mg/
mL. However, it was found that the isolated ELF species exhibited tyrosinase inhibitory
activity. Specifically, high tyrosinase inhibition activity was detected in T20-P07 (33.22)
and T20-P10 (38.44) isolated from the B. capillaris species, as well as in T22-B07 (33.78)
isolated from Usnea sp. From this point of view, considering that lichens reproduce slowly
in nature and are limited in number, it does not seem appropriate to use lichens in the
cosmetic industry for their tyrosinase inhibitory activity. Instead, it can be predicted that
ELFs isolated from lichens can be used as a potential source of tyrosinase inhibitors for in
the cosmetic industry, as it is both sustainable and economically viable due to its ease and
rapidity of production.
CONCLUSION
In recent years, there has been focus on finding new compounds that can be obtained from
natural sources with anti-tyrosinase activity and a high SPF number. Especially considering
that consumers prefer more natural cosmetic products, the search for potential natural
resources is also important for research and development companies and researchers in the
sector. Although plants are used as natural resources, lichens have unique molecules and
numerous bioactivities that make them especially important for the cosmetic industry.
However, given the slow growth and limited availability of lichens in nature, researchers
have turned to ELF. Studies conducted in recent years are thought to be a potential resource
for the cosmetics industry, as ELF have unique bioactivities. In our study, we compared
the tested parameters (total antioxidant activities, total phenolic and flavonoid contents,
SPF values, and anti-tyrosinase activity) of selected lichens (Usnea sp., L. pulmonaria, and
B. capillaris) and isolated ELF samples from them. As stated in the literature, lichens
have many positive biological activities as well as some limitations (poor stability, risk of
degradation in active components, and toxicity to normal cells). However, these problems
are not insurmountable. It is possible to develop a suitable formulation for improving the
stability, dispersal, protection, and effectiveness of lichens and ELF. Furthermore, our
results revealed that sunscreen products with anti-tyrosinase activity can be obtained
from lichen species and their ELF. Encapsulation of these extracts into biodegradable
and biocompatible nanoparticles can increase their bioactivity, reduce toxicity, improve
water solubility, and protect against degradation. For these reasons, despite the promising