The Research Of Several Natural Extracts In Functional Cosmetics

Yam polysaccharide, 40% punicalagins, licorice polysaccharide are studed in this paper. Moisture retention properties of yam polysaccharide and it’s in cosmetic formulation are determined by the method of measuring weight in vitro. Tyrosinase inhibition activities of the 40% punicalagin and cosmetic formulation containing 40% punicalagin are studied by biochemical enzymatic assay by studying its whitening and sunscreen effect. The moisture resistance of licorice polysaccharide was measured.The main three contents are as follows:1. Study on moisturizing properties of yam polysaccharides in moisturizing cosmetics.Yam Polysaccharide was isolated by fractional precipitation with gradient concentrations of aqueous ethanol(0%, 20%, 40%, 60%). Four isolated polysaccharide fractions were obtained, named YP-0, YP-1,YP-2 and YP-3. Finally, using glycerin as a reference substance, the moisture resistance of four isolated polysaccharide fractions was measured. The results showed that four Yam Polysaccharides have better moisture resistance, but the difference is not evident, so it was not isolated by fractional precipitation in following work. Directly adding the YP-0 and HA(hyaluronic acid) by different ratio into the formula, the results showed good moisturizing properties.2.Study on tyrosinase inhibition activities of the forty percent of punicalagin and whitening sunscreen effectThe activity and inhibition mechanism of forty percent punicalagin on tyrosinase activity was estimated by measuring the oxidation rate of L-dopa. Then Lineweaver-Burk curve was made, on which the inhibiting types of forty percent of punicalagin was deduced. The results showed that forty percent of punicalagin inhibited the tyrosinase activity with the IC50 0.5700 g/L. The results provided that forty percent of punicalagin had strong inhibitory effect on tyrosinase. When 40% punicalagins and Vitamin C complexed and the best ratio was choosen to add into cosmetic formulations, the results showed that the whitening effect was good. Adding 40% punicalagins with nano titanium oxide in different ratio, the results showed that cmpared with the single addition of titanium dioxide or 40% punicalagins,the complexed products have the better the sunscreen effect.3. Study on moisturizing properties of licorice polysaccharidesIn this part, licorice pieces was taken as raw materials, licorice polysaccharides was isolated by water extraction and alcohol precipitation. Using glycerin as a reference, its moisture retention is measured at a certain relative humidity by the method of controlling the dryer, The results showed that liquorice polysaccharide had a certain moisture property and can be used as a potential cosmetic moisturizers, which needs further study.