Document Type

Article

Source of Publication

Photochemical and Photobiological Sciences

Publication Date

6-7-2025

Abstract

In Australia, skin cancer has the highest incidence of all cancer types, where Therapeutic Goods Association-approved, broad-spectrum sunscreens are recommended to prevent skin carcinogenesis. Commercial sunscreen ingredients, however, have been associated with negative impacts on human health, animal health and the environment. Together, the perceived harmful effects of commercial sunscreens have driven a trend towards home formulation of natural sunscreens, recipes for which are widely available online. Scientific evidence to support the efficacy of natural sunscreens, however, is lacking. We tested the efficacy of a natural homemade sunscreen (NHSS) published online by a wellness blogger with the aim to determine its photoprotective properties, beyond its ability to protect against erythema, compared to a commercially available SPF50 + sunscreen. The NHSS contained almond oil, coconut oil, shea butter, beeswax, red raspberry seed oil, carrot seed oil and zinc oxide. Skin explants were treated with either a commercial SPF50 + sunscreen, NHSS or base lotion prior to ultraviolet irradiation. Skin explants were assessed using immunohistochemistry for the levels of UVR-induced DNA damage in the form of cyclobutane pyrimidine dimers and 8-oxo-7, 8-dihydro-2’-deoxyguanosine, as well as for sunburn cells and epidermal thickness. We demonstrate herein that NHSSs can reduce UVR-induced DNA damage and epidermal thickness, but do not effectively protect against the generation of sunburn cells. In comparison, SPF50 + sunscreen provided effective protection against all investigated parameters. These factors, however, are markers of short-term UVR-induced damage and there is as yet no evidence for NHSSs in prevention of skin carcinogenesis. Therefore, we recommend the continued use of TGA-approved commercial sunscreens for sun protection. Further studies are required to test water resistance, variation in homemade formulation, shelf life, and protection against skin carcinogenesis in a chronic UVR model.

ISSN

1474-905X

Publisher

Springer Science and Business Media LLC

Volume

24

Issue

6

First Page

1017

Last Page

1029

Disciplines

Medicine and Health Sciences

Keywords

Natural sunscreens, Skin cancer, Sunscreens, UV-induced DNA damage

Scopus ID

105007322995

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Indexed in Scopus

yes

Open Access

yes

Open Access Type

Hybrid: This publication is openly available in a subscription-based journal/series

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