What Octopus Skin Can Do To Protect Us From The Sun

It’s summer (for half the planet). While we should protect our skin from the Sun all year round (even if you live in Britain), it’s time to lather on sunscreen. Sunscreen products protect us from the UV light of the Sun, but they have come under scrutiny because of their toxic effects on both humans and marine creatures. A new study proposes to use a compound derived from octopus and squid skin to make sunscreen more safe and effective.

Xanthommatin is a chromophore found in the skin of cephalopods and some arthropods. Chromophores are colored molecules that give cephalopods their changing colors. They do so by absorbing certain wavelengths of light and emitting others. Their ability to absorb light is what could be potentially harnessed in sunscreen.

Most sunscreens work by absorbing the harmful UV light from the Sun. Different sunscreens contain different active compounds: some are organic compounds, some are minerals like zinc oxide. Leila Deravi and colleagues propose to supplement zinc oxide sunscreen with a synthetic version of xanthommatin (we won’t need to harvest this molecule from octopuses!).

To understand if this proposed new product is safe and effective, the researchers had a few questions to explore.

Is xanthommatin safe for marine life?

We put on sunscreen, but when we go for a swim or take a shower the sunscreen washes off and goes into the sea . Combined with the sunscreen compounds from industrial discharge, that adds up to a lot. In the sea they can be taken up by marine life, and at high concentrations can have a whole host of negative effects, like coral bleaching and impaired sea urchin development.

Deravi and colleagues tested the safety of xanthommatin for coral fragments and found no polyp retraction or fragment bleaching even at high dosages.

Is xanthommatin safe for humans too?

Deravi said in a statement that some sunscreens “are known to create reactive oxygen species that are not only bad for the environment but can also seep into our skin and cause systemic toxicities”. Her interest in xanthommatin came from her co-author Camille Martin’s work showing that these molecules in the cephalopod skin “have really interesting antioxidant properties”.

They showed that xanthommatin does not cause irritation or contact allergy upon repeated exposure. More research is needed to understand if xanthommatin’s antioxidant properties could provide additional benefits.

Does it improve the Sun protection of zinc oxide?

It appears that on its own xanthommatin does not significantly absorb UV light, but added to zinc oxide it improves the absorption of UVA and visible wavelengths of light. The UV light that can affect human health is divided into two groups: UVA and UVB .

UVB is only able to penetrate the upper layers of your skin where it causes sunburn and increases the risk of skin cancer . UVA (with a longer wavelength) can penetrate more deeply and is associated with photoaging of the skin. Most sunscreens protect predominantly against UVB , with a need for the more broad spectrum protection that the xanthommatin and zinc oxide combination could fulfill.

Xanthommatin shows that inspiration from nature could be harnessed to create products that are safer for humans as well as the environment.

The study is published in the International Journal of Cosmetic Science .