Flavanoid myricetin can help protect skin against UVB damage

The flavonoid compound has not received as much attention as its more famous cousin quercetin, but its free radical scavenging behaviour make it a potential cosmetics ingredient, claim the scientists in a study published in the journal Toxicology in Vitro.

Like quercetin, myricetin is abundant in the skin of many fruits such as red grapes, but the researchers say theirs is the first study to investigate the compound’s photoprotective effects for the skin.

The team performed in vitro​ tests using spontaneously immortalized human keratinocyte cells (HaCaT cells) and exposing them to UVB radiation.

Increases cell proliferation​

According to the study, UVB radiation decreases the cell viability, which was successfully reversed by treatment with myricetin.

Interestingly, the application of myricetin to cells that had not been exposed to UVB also led to an increase in cell viability, suggesting that the compound has a positive effect on normal skin cell proliferation.

The scientists then checked to see whether it also had an effect on the cell viability of skin cancer cells, and found it did not. This, they hypothesised, might be because of different myricetin target sites in normal and tumour cells; however, further investigation is needed.

Myricetin was also found to inhibit the lipid peroxidation that was brought on by UVB radiation, as well as inhibiting the UVB-induced production of hydrogen peroxide.

As cell death is associated with the lipid peroxidation of cell membranes, the scientists suggested some of myricetin’s protective effect was down to its ability to inhibit oxidation.

In addition, hydrogen peroxide is known to cause damage in cells so myricetin’s ability to inhibit UVB-induced production of it could also add to its protective effect.

The scientists conclude that their in vitro ​tests suggest that myricetin is a potential cosmetic ingredient that can be added to skin care products to prevent UV light induced disorders.

Further in vivo ​tests are being considered by the team.

Source: Toxicology in Vitro​
​doi: 10.1016/j.tiv.2009.09.015
Protective effects of myricetin against ultraviolet-B-induced damage in human keratinocytes​
​Jhen-Hua Huang, Chieh-Chen Huan, Jia-You Fang, Cheng Yang, Chi-Ming Chan, Nan-Lin Wu, Shung-Wen Kang, Chi-Feng Hung