Protective effects of 3,4 ',5,7-tetrahydroxyflavone against squalene monohydroperoxide-induced skin wrinkles and its green extraction using deep eutectic solvents

Three flavone derivatives, 3,4 ',5,7-tetrahydroxyflavone (3,4 ',5,7-THF) and their glycosides 3,4 ',5,7-tetrahydroxyflavone-3-rhamnoglucoside, and 3,4 ',5,7-tetrahydroxyflavone-3-glucoside, were identified by partial enzymatic conversion of Camellia sinensis seed extract (CSSE). 2,2-Diphenyl-1-picrylhydrazyl radical scavenging activity of these compounds and lipid peroxidation inhibition effects of 3.4 ',5,7-THF were tested to evaluate their antioxidant properties. To investigate the effects of 3,4 ',5,7-THF on squalene monohydroperoxide (SQLOOH)-induced wrinkle formation, the dorsal skin of SKH1 hairless mice was used. Four weeks of treatment with 3,4 ',5,7-THF reduced wrinkle formation, in contrast to that observed in the group treated with SQLOOH only. A green and simple method has been suggested for the extraction of 3,4 ',5,7-THF from CSSE hydrolysate with nine deep eutectic solvents. A mixture of choline chloride and xylose yielded the best extraction result. These findings suggest that 3,4 ',5,7-THF is a natural compound with potential application in preventing SQLOOH associated skin aging.