#UV #Sunscreen #Oncology #Cannabidiol #nCBD
UV-A radiation is a major contributor to skin
photoaging and
photocarcinogenesis due to its ability to penetrate deep into
the dermis. Unlike UV-B rays, which cause visible sunburn, UV-A rays produce
large amounts of
reactive oxygen species (ROS), leading to persistent damage to
both
nuclear and mitochondrial DNA, as well as
chronic inflammation. Among the
most common alterations are 8-oxoguanine base oxidation and mitochondrial DNA
deletions such as ND1 and ND4. These lesions are directly linked to accelerated
skin aging and an increased risk of skin cancer.
In this context,
sunscreens provide a strong
preventive option. These products work by absorbing, reflecting, or scattering
UV rays at the skin’s surface, depending on whether they contain
chemical or
mineral agents. UV-B filters are generally effective in preventing sunburn, but
UV-A filters—which protect against deeper damage—are often less efficient.
As a result, current sunscreens offer
limited
protection against UV-A, highlighting a pressing need for more effective
photoprotective solutions.
Cannabidiol (CBD), a non-psychoactive compound
derived from hemp, has demonstrated
antioxidant and anti-inflammatory
properties in vitro, particularly under UV-induced oxidative stress conditions.
This study aimed to evaluate the ability of a
topical cream formulated with nanoencapsulated CBD (nCBD) to reduce
UV-A-induced damage to both nuclear and mitochondrial DNA.
CBD & UV: shield or illusion?
In this study,
19 healthy volunteers (skin
types I to III, aged 23–64) were randomly divided into two groups:
- One group
applied a cream containing nCBD on a designated skin area;
- The other
group applied a control cream (VC).
Participants applied the treatments twice daily
for 14 days. Following the treatment period, both skin areas were exposed to
UV-A radiation at
33 times the minimal erythema dose (MED-A). Biopsies were
taken 24 hours later for histological, immunohistochemical (IHC), and PCR
analyses targeting mtDNA mutations.
Clincally, 21% of participants had reduced erythema in the area treated with CBD.
Histological analysis showed that nCBD significantly reduced epidermal
hyperplasia, with an average rate of 11.3% versus 28.7% for the control cream.
Immunohistochemical analysis revealed a significant decrease in the expression
of OGG1—a marker of oxidative DNA damage—in the nCBD-treated skin.
At the molecular level, UV-A-induced mitochondrial DNA deletions were significantly reduced, including
a notable decrease in ND4 and ND1 deletions. Semi-quantitative PCR analysis
also revealed a downward trend in the 762 bp mutant product in nCBD-treated
subjects, although this difference was not statistically significant.
A next-generation skin protector?
Photoaging results from cumulative, chronic
exposure to UV-A, leading to visible and invisible damage, such as
DNA
mutations and
chronic inflammation that contribute to the progressive breakdown
of skin structures. One of the main current challenges is to develop
effective
preventive strategies against UV-A, which penetrates deeper into the skin than
UV-B. Traditional sunscreens offer only
partial surface-level protection and do
not address the deeper
molecular damage.
In this context, the study evaluated the
effectiveness of an innovative topical treatment based on nanoencapsulated CBD,
targeting
early photodamage biomarkers such as epidermal hyperplasia, OGG1
expression, and ND1/ND4 mitochondrial DNA deletions.
The results show that nCBD significantly
reduces these alterations, which are often associated with a
higher risk of
skin cancer. These findings suggest that CBD may offer
photoprotective
potential at the cellular and subcellular levels, beyond the physical barrier
provided by UV filters.
However, several limitations must be
considered, suggesting the need for further research. Additional studies with
larger and more diverse cohorts, direct comparisons with established
photoprotectants, and
long-term safety evaluations will be essential to confirm
these results. If substantiated,
nanoencapsulated topical CBD could represent a
novel approach in molecular prevention of UV-A-induced skin aging and
precancerous lesions.
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