Monteloeder spotlights clinically proven botanical supplement for UV skin protection

Monteloeder, a subsidiary of SuanNutra, has published clinical study results backing its natural, beauty-from-within formulation Nutroxsun. The two-phase trial supports Nutroxsun’s role in helping maintain the skin’s collagen integrity and visible radiance when exposed to environmental stressors such as ultraviolet (UV) radiation. 

Nutroxsun is a proprietary combination of extracts of rosemary (Rosmarinus officinalis) and grapefruit (Citrus paradise). It will be presented at Vitafoods Europe, Barcelona, Spain (May 20–22, 2025).

“Nutroxsun was developed as a dietary solution to support the skin’s natural defense mechanisms in response to UV-induced oxidative stress,” says Mariana Ortega, science marketing manager of SuanNutra.

“It acts from within to help maintain skin health when exposed to environmental aggressors. Rosemary and grapefruit extracts contain phenolic compounds that work synergistically to help neutralize free radicals generated by UV exposure.”

Ortega adds these effects are relevant to short-term or immediate responses, such as redness, and long-term factors associated with visible signs of photoaging, including collagen and elastin changes.

Science of sun aging

Photoaging is associated with a reduction in collagen and elastin production resulting from repeated UV radiation. Collagen is a key to the preservation of skin firmness and elasticity. 

“Skin redness is the most noticeable and immediate inflammatory reaction to solar radiation,” says Nuria Caturla, chief R&D officer at Monteloeder. “It usually appears three to five hours after exposure and peaks at 12–24 hours, fading gradually over 72 hours.”

Monteloeder highlights that UV exposure can accelerate reactive oxygen species, which contribute to oxidative stress that may impact DNA. While this may cause redness in the short term, exposure to both UVA and UVB radiation may contribute to collagen degradation over time.

This process may ultimately result in wrinkles and loss of skin structure, stresses Monteloeder.

Study findings

The study involving 20 volunteers, published in April in the International Journal of Molecular Sciences, authored by Pau Navarro and colleagues, first analyzed the photoprotective potential of Nutroxsun on UVR-exposed human dermal fibroblasts in vitro.

Participants took either 100 mg or 250 mg of the botanical formula or a placebo. All participants experienced increased skin redness 24 hours after UVB exposure, confirming an erythemal response. However, those who took Nutroxsun showed a milder increase in redness.

Redness increased by 62.7% in the placebo group, compared to 44.7% in the Nutroxsun 100 mg group, and 41% in the 250 mg group. Both the 100 mg and 250 mg doses led to significantly less redness 24 hours after UV exposure.

By 72 hours, redness in both Nutroxsun groups had nearly returned to baseline, while the placebo group still showed elevated levels, indicating slower recovery.

Among fair-skinned participants, the 250 mg dose was more effective in supporting skin recovery than 100 mg, with lower redness observed at all time points. However, the 100 mg dose also demonstrated a measurable benefit.

Results were expressed through reduced inflammatory markers, ROS, and the modulation of matrix metalloproteinases — enzymes involved in the breakdown of structural matrix components such as collagen and elastin fibers.

Follow-up to previous research

This study serves as a follow-up to the results observed in previous preclinical and clinical trials.

“The results from the present study reinforce and expand on previous evidence supporting Nutroxsun’s role in helping improve skin health and appearance when exposed to UV-related stressors,” says Caturla.

“Rosemary extracts have been shown to help slow down collagen degradation, further highlighting their potential to support dermal structure and resilience. Grapefruit flavones have been studied for their role in counteracting UVB-induced oxidative effects that may impact collagen integrity, helping protect the skin by stopping UVB rays from breaking down collagen.”

A previous clinical trial, involving 90 participants over a period of two months, resulted in a reduction in markers of skin lipid peroxidation associated with UVB and UVA exposure, and perceived improvements in skin texture, wrinkles, and elasticity.

In this trial, the participants said their skin felt “more moisturized.” Over three-quarters (77%) noticed an improved skin appearance and more even skin tone. Most participants (73%) said their skin “felt firmer,” and almost two-thirds (60%) observed a visible reduction in the appearance of wrinkles.

In other upcoming ingestible beauty features at Vitafoods 2025, Lubrizol’s Nutraceuticals Business is set to unveil clinical results for Curcushine microcapsules, its patented, water-dispersible curcumin extract designed to boost skin radiance and reduce signs of aging from within.