Plant Metabolite Brachycerine Shields Human Skin Samples From UV Damage

A leaf alkaloid extracted from a small South American tree may offer a new route to natural sun protection. Researchers report that brachycerine, a major glucoside monoterpene indole alkaloid produced by the leaves of Psychotria brachyceras, absorbs light in the ultraviolet range and acts as a powerful antioxidant that protects the plant’s photosynthetic machinery against UV radiation. When skincare formulations containing the purified compound or a foliar extract were applied to human skin samples, they preserved the integrity of nerve endings and prevented DNA damage under exposure to both UV-A and UV-B light. The study, published in Photochemistry and Photobiology, also found that brachycerine is not toxic to mammalian cells, a critical safety signal for any candidate topical ingredient.

The researchers describe the alkaloid as having a dual mode of action, both shielding skin against UV and mitigating the destructive chemicals that this radiation produces in cells. The Brazilian team, led by corresponding author Arthur Germano Fett-Neto of the Federal University of Rio Grande do Sul, turned to a compound the plant itself deploys as a chemical shield. Because brachycerine evolved to intercept ultraviolet photons and quench the reactive molecules that radiation generates, the investigators reasoned that it might perform a similar double duty when transferred to human skin.

The dual mechanism is central to the findings. According to Fett-Neto, the alkaloid seems to shield skin against UV while simultaneously mitigating the destructive chemicals that this radiation produces inside cells. According to Fett-Neto, the alkaloid seems to have a dual mode of action, both shielding skin against UV and mitigating the destructive chemicals that this radiation produces in cells.

In the reported experiments, formulations containing either brachycerine or the foliar extract were applied to human skin samples before the samples were exposed to UV-A and UV-B light. The treated samples retained the structural integrity of nerve endings, and the formulations prevented DNA damage that would otherwise accompany such exposure. The absence of toxicity toward mammalian cells in the study supports the compound’s suitability for topical use, although the evidence comes from skin samples rather than from clinical trials on living volunteers.

The source plant adds a practical dimension to the discovery. The researchers note that they know how to vegetatively propagate the source plant, Psychotria brachyceras. Fett-Neto said this finding represents a promising, sustainable key component for novel broad-spectrum natural sunscreens. Fett-Neto describes the finding as representing a promising, sustainable key component for novel broad-spectrum natural sunscreens, framing the compound as an ingredient that could be supplied through cultivation rather than through synthetic manufacture alone.

Brachycerine is a major leaf glucoside alkaloid from the tree Psychotria brachyceras. The metabolite absorbs light in the UV range and is a powerful antioxidant protecting the plant's photosynthetic machinery against this radiation.

The investigators found that the formulations protected skin samples when they were exposed to UV-A and UV-B light. The treated skin samples retained the structural integrity of nerve endings, and the formulations prevented DNA damage under UV-A and UV-B exposure.

The study's title frames the work as an evaluation of brachycerine for potential protection of human skin against ultraviolet damage. In the reported experiments, the formulations prevented DNA damage in human skin samples exposed to UV-A and UV-B light. However, the current evidence stops short of demonstrating cancer prevention itself. The study evaluated protection in skin samples under controlled UV exposure, not disease outcomes in people over time, and translating sample-based protection into reduced cancer incidence would require further development and testing.

The findings were published under the title Evaluation of the Plant Glucoside Monoterpene Indole Alkaloid Brachycerine for Potential Protection of Human Skin Against Ultraviolet Damage, with the article carrying the DOI 10.1111/php.70171 and a publication date of 4 November 2026. The journal, published by Wiley, covers photoscience from the primary interaction of light with molecules, cells and tissue through the subsequent biological responses, an interdisciplinary scope spanning chemistry, physics, biology and medicine that fits the compound’s dual optical and antioxidant profile.

For now, the study positions brachycerine as a candidate ingredient at an early stage of translation. The combination of UV absorption, antioxidant activity, demonstrated protection of human skin samples against UV-A and UV-B damage, and lack of mammalian cell toxicity gives the alkaloid a coherent scientific rationale. The sustainable propagation of its source plant addresses supply, and the researchers’ description of a dual mode of action highlights why a plant metabolite might succeed where single-function filters fall short. Whether the compound can be formulated into stable, effective and commercially viable sunscreens that protect living skin and ultimately reduce skin cancer risk remains the question that future work must answer.

Subject of Research: A plant alkaloid from Psychotria brachyceras that absorbs ultraviolet light and acts as an antioxidant was tested in skincare formulations on human skin samples.

Article Title: Could a plant metabolite act as a natural sunscreen to help prevent skin cancer?

Article References: Could a plant metabolite act as a natural sunscreen to help prevent skin cancer?. Original publication (Bibliographic details unavailable.)

Image Credits: AI Generated

DOI: Not provided

Keywords: brachycerine, Psychotria brachyceras, natural sunscreen, ultraviolet radiation, DNA damage, antioxidant, skin cancer, photochemistry, plant alkaloids, photoprotection, UV-A, UV-B