ProShield® Propolis and ProShield® Mustard: Sealing the Absorption "Leakage"
Absorption “leakage” is an unavoidable phenomenon associated with the interactions between UV filters and light. The ideal transmission spectrum of a sunscreen is shown on the left side of Figure 1, while the best possible transmission spectrum is shown on the right side. The difference between the ideal spectrum and the best possible spectrum is the area of absorption “leakage” on the best possible spectrum.
Our ProShield® Aline products enable uniform sunscreen coverage while further preventing oxidative leakage by positioning potent antioxidants in the sunscreen layer. This combination achieves the highest sun protection performance (SPF) using minimum levels of UV filters; however, we knew we could do more.
To completely prevent all oxidative stresses and totally seal off the damages caused by the absorption “leakage,” we developed ProShield® Propolis and ProShield® Mustard. Based on Proscien’s patent pending extraction technology and its implementation on local French agricultural processes, both products contain powerful, antioxidative natural molecules that are concentrated and delivered in a formulation-friendly matrix.
ProShield® Propolis (propolis extract, Theobroma cacao (cocoa) seed butter) is derived from the extraction of local honeybee propolis. Propolis is generally known as “bee glue,” referring to the resinous substance accumulated by the bees; it is used to seal holes and cracks in the construction of the beehive. It also smooths the inner surface of the beehive, allowing the hive to maintain its internal temperature and prevent weather damage or predator invasions. Upon heating, propolis becomes soft and sticky, and it possesses a pleasant smell.
Propolis and its extracts have been used to treat various diseases due to its antiseptic, anti-inflammatory, antioxidant, antibacterial, antimycotic, antifungal, antiulcer, anticancer, and immunomodulatory properties. Naturally, propolis has also been used in dermatological products such as creams and ointments. Having a promotive action on collagen synthesis, propolis also displays positive collagen metabolism in wounds during the healing process, since it increases the collagen content of tissues.
Using Proscien’s proprietary technology, the extract from the local propolis is particularly rich in caffeic acid phenethyl ester (CAPE, Figure 2), a bioactive compound with proven antimicrobial, antioxidant, and anti-inflammatory properties. As such, when used in sunscreen formulation, ProShield® Propolis helps eliminate leaked oxidative stresses and improve sunscreen performance.
We studied the inhibitory effect of ProShield® Propolis against ultraviolet (UV) irradiation-induced matrix metalloproteinase 1 (MMP-1) expression and its underlying molecular mechanism. ProShield® Propolis treatment suppressed UV-induced MMP-1 levels in both human dermal fibroblasts (HDF) and foreskin fibroblasts (Hs68) (Figure 3). ProShield® Propolis also suppressed UV-induced acetyl-histone H3 (Lys9) and total lysine acetylation in HDF cells and attenuated UV-induced lysine acetylations in human skin tissues. The working mechanism is displayed by the dose-dependent attenuation ProShield® Propolis impacted on UV-induced histone acetyltransferase (HAT) activity in HDF (Figure 4).
ProShield® Mustard (Lactobecillus/Brassica nigra seed ferment extract and glycerin) is based on Proscien’s patent-pending extraction method using local mustard seed products. It is derived from the valorization of mustard seed byproducts generated by local mustard producers in the Drôme region of the south of France. These byproducts are an interesting and readily available renewable material that contains highly valuable sinapic acid (Figure 5) and its derivatives. Repurposing these byproducts can provide financial support to cultivate the crops in the region.
We studied the protective effects of ProShield® Mustard against the photoaging in human skin fibroblasts induced by UVB irradiation (30 mJ/cm2). Exposure to this amount of UVB irradiation reduced cell viability by approximately 33% compared to the non‐UVB irradiated control. ProShield® Mustard significantly reduced the UVB irradiation‐induced cytotoxicity (Figure 6). ProShield® Mustard also inhibited the release of MMP‐1 and reduced the expression of MMP‐1 mRNA in UVB‐irradiated Hs68 cells (Figure 7). Furthermore, ProShield® Mustard reduced UVB‐induced production of reactive oxygen species (ROS) in Hs68 cells, (Figure 8).