A highly soluble form of rutin for instant resolution of mask-wearing related disorders.

BACKGROUND: The COVID-19 pandemic brought about a new normal, necessitating the use of personal protective equipment (PPE) like face shields, surgical masks, gloves, and goggles. However, prolonged mask-wearing introduced skin-related issues due to changes in the skin's microenvironment, including increased humidity and temperature, as well as pressure on the skin. These factors led to skin deformation, vascular issues, edema, and inflammation, resulting in discomfort and cosmetic concerns. Clinical reports quickly highlighted the consequences of long-term mask use, including increased cases of "maskne" (mask-related acne) or mask-wearing related disorders such as rosacea flare-ups, skin-barrier defects, itching, erythema, redness, hyperpigmentation, and lichenification. Some of these issues, like inflammation, oxidative stress, and poor wound healing, could be directly linked to acne-related disorders or skin hypoxia. AIM: To address these problems, researchers turned to rutin, a well-known flavonoid with antioxidant, vasoactive, and anti-inflammatory properties. However, rutin's poor water solubility presented a challenge for cosmetic formulations. To overcome this limitation, a highly water-soluble form of rutin was developed, making it suitable for use at higher concentrations. METHODS: In vitro and ex vivo tests were conducted, as well as an innovative clinical trial including volunteers wearing surgical masks for at least 2 h, to evaluate the biological activity of this soluble rutin on the main skin concerns associated with mask-wearing (inflammation, oxidative stress, skin repair, hyperpigmentation, and skin redness). RESULTS: The in vitro results showed that the active ingredient significantly reduced oxidative stress, improved wound healing, and reduced inflammation. In dark skin explants, the active ingredient significantly reduced melanin content, indicating its lightening activity. This effect was confirmed in the clinical study, where brown spots decreased significantly after 4 days of application. Moreover, measurements on volunteers demonstrated a decrease in skin redness and vascularization after the active ingredient application, indicating inflammation and erythema reduction. Volunteers reported improved skin comfort. CONCLUSION: In summary, the COVID-19 pandemic led to various skin issues associated with mask-wearing. A highly soluble form of rutin was developed, which effectively addressed these concerns by reducing inflammation, oxidative stress, and hyperpigmentation while promoting wound healing. This soluble rutin offers a promising solution for the rapid treatment of maskne-related disorders and other skin problems caused by prolonged mask use.

Enzymatic Synthesis of α-Glucosyl-Baicalin through Transglucosylation via Cyclodextrin Glucanotransferase in Water.

Baicalin is a biologically active flavone glucuronide with poor water solubility that can be enhanced via glucosylation. In this study, the transglucosylation of baicalin was successfully achieved with CGTases from Thermoanaerobacter sp. and Bacillus macerans using α-cyclodextrin as a glucosyl donor. The synthesis of baicalin glucosides was optimized with CGTase from Thermoanaerobacter sp. Enzymatically modified baicalin derivatives were α-glucosylated with 1 to 17 glucose moieties. The two main glucosides were identified as Baicalein-7-O-α-D-Glucuronidyl-(1→4')-O-α-D-Glucopyranoside (BG1) and Baicalein-7-O-α-D-Glucuronidyl-(1→4')-O-α-D-Maltoside (BG2), thereby confirming recent findings reporting that glucuronyl groups are acceptors of this CGTase. Optimized conditions allowed for the attainment of yields above 85% (with a total glucoside content higher than 30 mM). BG1 and BG2 were purified via centrifugal partition chromatography after an enrichment through deglucosylation with amyloglucosidase. Transglucosylation increased the water solubility of BG1 by a factor of 188 in comparison to that of baicalin (molar concentrations), while the same value for BG2 was increased by a factor of 320. Finally, BG1 and BG2 were evaluated using antioxidant and anti-glycation assays. Both glucosides presented antioxidant and anti-glycation properties in the same order of magnitude as that of baicalin, thereby indicating their potential biological activity.

Targeting SDF-1 as an efficient strategy to resolve skin hyperpigmentation issues with Himanthalia elongata extract.

BACKGROUND: During aging, human skin is facing hyperpigmentation disorders: senile lentigo (chronobiologic aging) leads to loss of melanogenesis' control while solar lentigo (UV exposure) promotes an increase of oxidized proteins, melanogenesis, and lipofuscin. AIMS: Stromal-cell-derived-factor-1 (SDF-1) was identified as key regulator of hyperpigmentation and its expression is reduced in senescent fibroblasts, highlighting this protein as new target for skin hyperpigmentation. MATERIALS: We developed two skin explant models mimicking of senile and solar lentigo, based on H2 O2 systemic treatment and UV irradiation, respectively. We evaluated Himanthalia elongata extract (HEX) on these models after 5 days of treatment and analyzed SDF-1 expression and skin pigmentation. For solar lentigo, we also analyzed oxidized proteins and lipofuscin accumulation. Finally, we evaluated HEX in vivo on nearly 100 multi ethnicities' volunteers. RESULTS: SDF-1 expression decreased in senile lentigo model, associated with hyperpigmentation. HEX application restored SDF-1 expression, leading to skin pigmentation decrease. For solar lentigo, we showed an impact of UVs on SDF-1 expression linked to hyperpigmentation, while the application of HEX restored SDF-1 expression and reduced skin pigmentation. On same model, HEX reduced oxidized proteins quantity and lipofuscin which increased after UV exposure. Clinically, HEX reduced dark spot pigmentation on Caucasian volunteers' hands and on Asian and African volunteers' face after 28 days. DISCUSSION: We have developed ex vivo models mimetic of senile and solar lentigo and showed for a very first time that SDF-1 can be also a key regulator for UV-induced hyperpigmentation. CONCLUSION: Our ex vivo and clinical studies highlighted the power of HEX with strong reduction of dark spots regardless of volunteers' ethnicities.