Artificial sunscreens are losing attention regarding protecting the skin from sunburns, photoaging and photocarcinogenesis. Further, their efficacy and safety are impeded by their photostability, toxicity and harm to marine ecosystems. 

Natural selection and evolution have confirmed that plants and animals have grown adequate protective mechanisms against the harmful side effects of oxidative stress and ultraviolet radiation (UV). Thus, natural antioxidants like sun blockers are attracting notable attention. Although their exact mechanism to act as sunscreen molecules is not known, yet, the conjugated π system is said to play a vital role in defending the vital genetic material within the organism. Contrasting artificial sunscreens, natural sunscreens with strong UV absorptive powers are mainly restricted by low specific extinction value and by their inability to outstretch in large-scale sunscreen cosmetic applications. 

Evidence suggests that natural components exercise their photoprotective effects like improved skin elasticity and hydration, skin texture and wrinkles via their antioxidant effects, and regulating UV-induced skin inflammation, barrier impairment and aging. 

Natural antioxidant topical formulations with a sun protection factor (SPF) have been discussed in detail in a recent study. Lignin, melanin, silymarin and other ingredients are added to high sun protection nature sunscreens in the absence of any physical or chemical UV filters. Novel technical measures (extracting high content components, changing the type of solution, optimizing formulation, applying Nanotechnology, et al) can be adopted to design and prepare nature sunscreen formulations like commercial sunscreen formulations. Further, natural antioxidants from plants, animals, microorganisms and marine organisms can also be added as selected enhancers or modifier elements to strengthen SPF values.

Despite the known photoprotective effects of natural components, their deleterious side effects are yet to be elucidated.

Source: He H, Li A, Li S, et al. Natural components in sunscreens: topical formulations with sun protection factor (SPF). Biomed Pharmacother. 2021;134:111161.