Prospecting In Vitro Antioxidant and Photoprotective Properties of Rosmarinic Acid in a Sunscreen System Developed by QbD Containing Octyl p-Methoxycinnamate and Bemotrizinol

Enhancing Photoprotection and Mitigating Ex Vivo Stratum Corneum Oxidative Stress: A Multifunctional Strategy Combining Rosmarinic Acid with UVB Filters

Exposure to ultraviolet (UV) radiation is a major contributor to skin injury, including sunburn, photoaging, and augmented risk of skin cancer, primarily through the generation of reactive oxygen species (ROS) that induce oxidative stress. Rosmarinic acid (RA), a natural phenolic compound with antioxidant and several other biological properties, has shown promise in mitigating such damage when incorporated into sunscreens. We evaluated RA's possible interactions and potential to enhance the efficacy of three worldwide known UVB filters-ethylhexyl methoxycinnamate (EHMC), octocrylene (OCT), and ethylhexyl salicylate (EHS). The performance of sunscreens with and without RA (0.1% w/w) was analyzed through in vitro and in vivo photoprotective assessments. The HPLC-TBARS-EVSC (high-performance liquid chromatography-thiobarbituric acid reactive substances-ex vivo stratum corneum) protocol, which quantified oxidative stress reduction in the human stratum corneum, was also used. The in vitro photoprotective assays showed that RA had distinct levels of interactions with the UVB filters. When associated with EHMC, RA exclusively acted in the UVB range (SPF-enhancing effect). Remarkably, for EHS, RA contributed to a higher efficacy profile in the total UV spectrum. OCT-RA was the sample that reached the highest critical wavelength value parallelly to OCT, boosting the in vivo SPF by more than 157% in comparison to OCT. However, its in vitro SPF performance was not affected by the RA addition, being comparable to OCT, EHS, and EHS-RA. Furthermore, the HPLC-TBARS-EVSC protocol highlighted RA's ability to reduce lipid peroxidation, with OCT-RA exhibiting the most notable protective effect. These findings underscore RA's potential as a multifunctional additive in sunscreen systems, enhancing both photoprotection and oxidative stress mitigation.

1,3-Naphthoxazine derivatives: Synthesis, in silico pharmacokinetic studies, antioxidant and photoprotective properties

Investigation into the interactions between photoprotective agents and skin can offer a precise understanding of their biological behaviors in vitro and in vivo, providing crucial insights for generating new substances. For this purpose, we designed and synthesized a series of naphthoxazine derivatives and examined their photoprotective properties. 1,3-naphthoxazine derivatives were synthesized through the multi-component reaction of 2-naphthol, arylamines and aromatic aldehydes in the presence of copper(II) trifluoromethanesulfonate (Cu(OTf)2) and (±)-Camphor-10-sulfonic acid ((±)-CSA) catalyst system under sonication. The potential of these synthesized 1,3-naphthoxazine derivatives as antioxidants and viable organic structural-based sunscreen ingredients has been investigated. Sun protection factor (SPF) assay results showed that especially compounds 4i, 4c, 4k, 4d, 4r, and 4h had remarkably high activity (23.65, 23.57, 23.04, 21.94, 20.80, and 20.26, respectively at 900 µg/mL concentration). Additionally, antioxidant activity of the synthesized compounds was evaluated and compounds 4h, 4e, 4b, and 4j exhibited the highest activities in DPPH scavenging activity assay (86.46 %, 82.83 %, 80.78 %, and 80.65 % respectively at 400 µg/mL concentration). The synthesized compounds exhibit promising characteristics for effective UV radiation absorption, suggesting their suitability for inclusion in sunscreen formulations. Cytotoxic activity of compound 4k against normal human fibroblast cell line (MRC-5) was determined by CVDK-8 method. The results revealed that the compound provided remarkable viability (87.55 %) of MRC-5 cells at concentration of 100 µM. The study explores their efficacy in providing broad-spectrum protection against UVA and UVB rays, degradation and photostability, ADMET profile, and other pharmacokinetic properties.

Exposure to UV-B filter octylmethoxycinnamate and human health effects: Focus on endocrine disruptor actions

Human skin is the first line of photoprotection against UV radiation. However, despite having its defence mechanisms, the photoprotection that the skin exerts is not enough. To protect human skin, the inclusion of UV filters in the cosmetic industry has grown significantly as a photoprotection strategy. Octylmethoxycinnamate, also designated by octinoxate, or 2-ethylhexyl-4-methoxycinnamate (CAS number: 5466-77-3) is one of the most widely used UV-B filter in the cosmetic industry. The toxic effects of OMC have alarmed the public, but there is still no consensus in the scientific community about its use. This article aims to provide an overview of the UV filters' photoprotection, emphasizing the OMC and the possible negative effects it may have on the public health. Moreover, the current legislation will be addressed. In summary, the recommendations should be rethought to assess their risk-benefit, since the existing literature warns us to endocrine-disrupting effects of OMC. Further studies should be focus on the toxicity of OMC alone, in mixture and should consider its degradation products, to improve the knowledge of its risk assessment as EDC.

Potential of rosmarinic acid from Orthosiphon aristatus extract for inflammatory induced diseases and its mechanisms of action

Orthosiphon aristatus has been traditionally used as a medicinal herb for various illnesses in Southeast Asia and Europe. The most dominant bioactive compound of the herb is rosmarinic acid (RosA) which has been demonstrated for its remarkable anti-inflammatory properties. This review describes the recent progress of studies on multi-target molecular pathways of RosA in relation to targeted inflammatory-associated diseases. An inclusive literature search was conducted using electronic databases such as Google Scholar, Scopus, Springer Link, PubMed, Medline, Wiley and Science Direct for studies reporting on the anti-inflammatory actions of RosA from 2008 until 2023. The keywords of the search were RosA and anti-inflammatory in relation to hepatoprotective, chondroprotective, cardioprotective, neuroprotective and toxicity. Only publications that are written in English are included in this review. The inhibition and deactivation of pro-inflammatory biomolecules by RosA were explained based on the initial inflammation stimuli and their location in the body. The activation of Nrf2/HO-1 expression to inhibit NF-κB pathway is the key mechanism for hepatoprotection. Besides NF-κB inhibition, RosA activates PPARγ to alleviate ischemia/reperfusion (I/R)-induced myocardial injury for cardioprotection. The regulation of MAPK and T-cell activation is important for chondroprotection, whereas the anti-oxidant property of RosA is the main contributor of neuroprotection. Even though less studies on the anti-inflammation of RosA extracts from O. aristatus, but the effective pharmacological properties of RosA has promoted it as a natural potent lead for further investigation.

Photoprotective Efficacy of the Association of Rosmarinic Acid 0.1% with Ethylhexyl Methoxycinnamate and Avobenzone

Innovative prototype sunscreens with reduced ultraviolet (UV) filters are required to achieve safer, more effective, and more environmentally friendly formulations. Rosmarinic acid (RA) is a phenolic antioxidant and potential candidate for multifunctional sunscreens. We used RA (0.1% w/w) in combination with avobenzone (2.5% and 5.0% w/w), a UVA filter, and ethylhexyl methoxycinnamate (10.0% w/w), a UVB filter, to evaluate in vitro sun protection factor (SPF) and critical wavelength, photostability, and the in vivo SPF. RA, in vitro, improved the SPF of F2 (ethylhexyl methoxycinnamate 10.0% w/w + avobenzone 2.5% w/w + RA 0.1% w/w) and F3 (ethylhexyl methoxycinnamate 10.0% w/w + avobenzone 5.0% w/w + RA 0.1% w/w), which also presented broad-spectrum profiles; however, no expressive effects were observed for the critical wavelength (nm). By the in vivo trial, RA showed an increment in the F3 SPF value and maintained the F2 effectiveness, even when avobenzone was at 2.5%. Nonetheless, no increase in photostability was observed. Our findings suggest that incorporating natural molecules with antioxidant activities into sunscreens could decrease the proportion of conventional UV filters in the final product, with the advantage of providing other functional properties. Further investigation of higher RA concentrations, even from other sources, and other UV filter combinations could reveal important data for the development of multifunctional sunscreens.

Phytocompounds Recovered from the Waste of Cabernet Sauvignon (Vitis vinifera L.) Vinification: Cytotoxicity (in Normal and Stressful Conditions) and In Vitro Photoprotection Efficacy in a Sunscreen System

We investigated plausible reuse for the dermocosmetic industry of byproducts from the winemaking process of red grapes (Vitis vinifera L. cv. C. Sauvignon) through the evaluation of one extract (grape pomace extract, GPE) and two fractions (one chloroform, GPE-CHF; one ethyl acetate, GPE-EAF). The samples were characterized analytically by liquid chromatography (HPLC) using a NIH 3T3 fibroblast cell culture to verify a cytosafety profile in normal and stressful environment (presence of H2O2), and by using it in a sunscreen system to observe improvements in the in vitro efficacy by diffuse reflectance spectrophotometry with an integrating sphere. The HPLC results for GPE-EAF and GPE-CHF samples with the best profile of syringic and p-coumaric acids, quercetin, and trans-resveratrol were used in the further assays. GPE-EAF and GPE-CHF, both at 30.00 µg/mL, maintained the cell viability in the absence of H2O2 (normal condition). In the sequence, GPE-EAF and GPE-CHF were evaluated against the oxidative stressor H2O2 in NIH 3T3 cells. A sharp drop in viability was only observed for GPE-CHF, and cytotoxicity of GPE-EAF was considered absent even in a hostile environment. Since GPE-EAF previously developed the best results, its potential performance was investigated in a sunscreen system. The in vitro sun protection factor of the phytoderivative-free formulation was 9.0 + 2.5; by adding GPE-EAF at 10.0%, its efficacy was elevated to 15.0 + 2.5. Both samples suffered a negative effect after artificial ultraviolet exposition (500 W/m2); however, the presence of GPE-EAF improved the photostability of the sunscreen system.

Dietary Supplements and the Skin: Focus on Photoprotection and Antioxidant Activity—A Review

Skin health is not only significantly affected by ageing, but also by other lifestyle-related factors, such as sun exposure, exercise and eating habits, smoking or alcohol intake. It is known that the cutaneous tissue can exhibit visible signs of senescence, in the form of, for example, dull complexion, loss of firmness, or changes in pigmentation. Consumers attempt to improve skin health and appearance not only by cosmetic products, but also with the consumption of food supplements. Recently, there has been an increase in the amount of food supplements with claims that are related to skin and hair health. Nevertheless, the literature is still scarce in evidence of the efficacy of this type of products. Considering this scenario, we aim in this review to assemble studies and methodologies that are directed at the substantiation of the cutaneous health claims of food supplements. For example, we reviewed those that were indicative of antioxidant properties, improvement in pigmentation disorders, increased hydration or protection against the damages caused by ultraviolet radiation.