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(1) Background: Ultraviolet radiation takes part in photoaging and pigmentation disorders on skin. Epigallocatechin gallate (EGCG) is a well-known brightening and photoprotective compound but it faces limitations in terms of stability and solubility. (2) Methods: A more stable and water-soluble glucoside called EGCG-G1 was obtained by enzymatic glucosylation of EGCG. In vitro and ex vivo experiments evaluated EGCG-G1 skin penetration, antioxidant activity, and antimelanogenic properties compared to EGCG. This gene expression study characterized the pathways impacted by EGCG-G1. Four clinical studies covering phototypes I to V, at various ages, and different skin areas, using several tools, were conducted to assess the effect of EGCG-G1 on skin hyperpigmentation and tone. The impact of glucoside on skin microbiota, especially Lactobacillus sp., was assessed through in vitro and in vivo investigations. (3) Results: EGCG-G1 better penetrated the epidermis than EGCG due to a possible interaction with GLUT1. EGCG-G1 presented similar antioxidant activity to that of EGCG and decreased melanogenesis through the inhibition of 13 genes, including MITF. The skin Lactobacillus population increased with EGCG-G1, which promoted bacterial growth in vitro as prebiotic, and induced the release of a microbial brightening metabolite. Clinical trials demonstrated EGCG-G1 to decrease hyperpigmented spots and increase skin brightness and homogeneity in a large panel of phototypes, outperforming EGCG and vitamin C. (4) Conclusions: Glucosylation of EGCG maintained its photoprotective antioxidant properties and enhanced penetration across the epidermis. EGCG-G1 demonstrated brightening properties on all skin types by down-regulation of melanogenesis pathways and indirectly by skin microbiota stimulation.

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.

(1) Background: Preclinical studies report that the ethanolic fraction from Mangifera indica leaves is a potential anti-acne agent. Nevertheless, the biological activity of Mangifera indica leaves has scarcely been investigated, and additional data are needed, especially in a clinical setting, for establishing the actual effectiveness of Mangifera indica extract as an active component of anti-acne therapy. (2) Methods: The evaluation of the biological activity of Mangifera indica extract was carried out through different experimental phases, which comprised in silico, in vitro, ex vivo and clinical evaluations. (3) Results: In silico and in vitro studies allowed us to identify the phytomarkers carrying the activity of seboregulation and acne management. Results showed that Mangifera indica extract reduced lipid production by 40% in sebocytes, and an improvement of the sebum quality was reported after the treatment in analyses performed on sebaceous glands from skin explants. The evaluation of the sebum quantity and quality using triglyceride/free fatty acid analysis conducted on Caucasian volunteers evidenced a strong improvement and a reduction of porphyrins expression. The C. acnes lipase activity from a severe acne phylotype was evaluated in the presence of Mangifera indica, and a reduction by 29% was reported. In addition, the analysis of the skin microbiota documented that Mangifera indica protected the microbiota equilibrium while the placebo induced dysbiosis. (4) Conclusions: Our results showed that Mangifera indica is microbiota friendly and efficient against lipase activity of C. acnes and supports a role for Mangifera indica in the therapeutic strategy for prevention and treatment of acne.