Thai researchers identify natural products with photo-protection properties against UVB from sunlight

12 Aug 2022 --- A study conducted by researchers in Thailand has found that Antidesma thwaitesianum fruit extracts may potentially be utilized as a skincare ingredient for preventing UVB-induced skin damage.

Antidesma thwaitesianum Müll. Arg., known as “Mao” in Thai, is a tropical plant in Northeast Thailand and its sweet and sour fruits are commonly used in jams, wines and soft drinks.

Significant amounts of bioactive polyphenol and flavonoid compounds, such as anthocyanin, catechin, gallic acid, quercetin, rutin, terpene, alkaloids, luteolin, tannin, sterols and saponins, have been found in this fruit. Previous studies have also revealed the fruit’s antioxidant, anti-inflammation and hypoglycemic properties.

To fill a research gap regarding the photo-protective effects of A. thwaitesianum fruit extract, researchers used UVB-irradiated HaCaT keratinocytes to identify the anti-apoptosis and anti-inflammatory effects of the fruit extract.

Key Findings
The study demonstrated the “antioxidant and nitric oxide scavenging properties” of the fruit extract. A molecular analysis revealed the “decrease in Mitogen-activated protein kinase (MAPK)-activated stress response, including cell death and inflammation, following fruit extract pre-treatment.”

MAPK are involved in directing cellular responses to stimuli, such as mitogens, osmotic stress, heat shock and proinflammatory cytokines. They regulate cell functions including proliferation, gene expression, differentiation, mitosis, cell survival and apoptosis.

Known as “Mao” in Thai, the fruits of Antidesma thwaitesianum plant, have antioxidant, anti-inflammation, and hypoglycemic properties.Studying the correlation between UVB exposure and cell viability, the study found that the pre-incubation with the ethanol extract of A. thwaitesianum fruit before UVB irradiation increased the percentage of cell viability in a concentration-dependent manner.

In addition, the A. thwaitesianum fruit extract at all tested doses had minimal cytotoxicity, which indicates the low toxicity of this fruit extract.

“[The study’s] result indicates the anti-inflammatory effect of the A. thwaitesianum fruit extract, which can be an effective adjuvant strategy for preventing skin inflammation and cancer after chronic exposure to UVB radiation,” says the researchers.

“Our finding offers a new herbal medicine as an alternative ingredient for skincare products to alleviate UVB-induced skin inflammation.”

Importance of UVB protection
UVB refers to radiation at the wavelength of 280–320 nm. It is an extrinsic environmental stimulus that can penetrate deeply through the epidermis layer of the skin.

The epidermis is the first layer of defense against invasive pathogens and protects us from external damage, such as ultraviolet (UV) irradiation. Upon sunlight exposure, keratinocytes, present in the outermost layer of the skin, are one of the targets that quickly respond to UVB radiation.

UVB exposure induces the generation of intracellular reactive oxygen species  and is mainly attributed to skin inflammation, such as erythema and edema. Overexposure to UVB results in uncontrolled inflammation in addition to DNA damage and chronic skin inflammation, which leads to skin cancer development.

Highlighting a herbal preference
Over the past few years, natural extracts have gathered interest as herbal remedies to help to prevent photoaging and UV-induced skin inflammation.

The researchers at the University of California, Santa Barbara, Guangdong Technion-Israel Institute of Technology and Rensselaer Polytechnic Institute reviewed the use and toxicity of preservatives like parabens, benzalkonium chloride and chlorphenesin used in personal care items and suggested, “Many compounds are bioactive, ecologically persistent and have the potential to bioaccumulate, posing a major hazard to the environment and human health.”

In a recent statement, the Personal Care Products Council said they are committed to fill the environmental and health data gaps identified by NAS. “Our industry’s research aims to develop UV sunscreen environmental monitoring data, a validated standardized toxicity testing model for coral and a multi-tiered ERA model for sunscreen UV filters that realistically reflects what occurs in nature.”

In light of the debate between environment protection and sun protection against skin cancer, new research and development that promote herbal remedies are of utmost importance. 

Edited By Radhika Sikaria