RESUMO
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-(1â4')-O-α-D-Glucopyranoside (BG1) and Baicalein-7-O-α-D-Glucuronidyl-(1â4')-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.
Assuntos
Antioxidantes , Água , Glucosídeos/química , Glucosiltransferases/químicaRESUMO
Digital stress is a newly identified cosmetic stress that is mainly characterized by blue light exposure. The effects of this stress have become increasingly important with the emergence of personal digital devices, and its deleterious effects on the body are now well-known. Blue light has been observed to cause perturbation of the natural melatonin cycle and skin damage similar to that from UVA exposure, thus leading to premature aging. "A melatonin-like ingredient" was discovered in the extract of Gardenia jasminoides, which acts as a filter against blue light and as a melatonin-like ingredient to prevent and stop premature aging. The extract showed significant protective effects on the mitochondrial network of primary fibroblasts, a significant decrease of -86% in oxidized proteins on skin explants, and preservation of the natural melatonin cycle in the co-cultures of sensory neurons and keratinocytes. Upon analysis using in silico methods, only the crocetin form, released through skin microbiota activation, was found to act as a melatonin-like molecule by interacting with the MT1-receptor, thus confirming its melatonin-like properties. Finally, clinical studies revealed a significant decrease in wrinkle number of -21% in comparison to the placebo. The extract showed strong protection against blue light damage and the prevention of premature aging through its melatonin-like properties.
Assuntos
Senilidade Prematura , Gardenia , Melatonina , Senilidade Prematura/metabolismo , Melatonina/farmacologia , Pele/metabolismoRESUMO
BACKGROUND: The dermis is composed of a tangle of macromolecules that provides the skin its biomechanical properties. During chronological aging, fibroblasts lose their ability to synthesize collagen and an accumulation of matrix metalloproteinases leads to an increase in collagen degradation. As a result, there is a decline in the biomechanical properties of the skin. Skin aging is accelerated by external factors such as UV radiation and pollution, which induce accumulation of oxidants, and so of oxidized proteins in the skin. AIMS: Atomic force microscopy (AFM) has emerged as an alternative method for studying the biomechanical properties of skin cells and tissues. METHODS/RESULTS: Thus, we identified mannose-6-phosphate complex as a new powerful molecule capable of reversing the visible signs of aging by reorganizing the collagen network of the dermis and by improving the skin biomechanical properties. This effect was correlated with clinical studies that showed a marked antiaging effect through a reduction in the number of crow's feet and in the depth and size of neck wrinkles. CONCLUSION: Mannose-6-phosphate complex appeared to be able to protect proteins in the dermis scaffold against oxidation and degradation, allowing an improvement in the skin biomechanical properties.