Preparation Of Centella Asiatica Extract And Its Application In Cosmetics

The dry whole grass of Centella asiatica?L.?Urb.has been used in many countries and areas for hundreds of years and widely distributed in the world.Modern medical research shows that the pharmacological effects of Centella asiatica are antidepressant,promoting the wound healing,treat scar,anti-tumor,anti-gastric ulcer,antibacterial,antioxidant and so on.The active constituents of Centella asiatica are saponins and saponins metaclass,including asiaticoside,hydroxy asiaticoside,asiatic acid and hydroxy asiatic acid.Therefore,the separation and purification of these active ingredients of natural products and application have always been raised the concern of the researchers.In this paper,hydroxy asiaticoside and asiaticoside were extracted by ultrasonic assisted extraction.The optimal extraction parameters were determined according to the orthogonal optimization experiment and considering the cost.The ratio of material to liquid 1:20,ethanol concentration 70%,extraction temperature 50?,ultrasonic power 100%,extraction time 1h.Activated carbon was used as decolorizer for decolorizing the crude extract of Centella asiatica.Finally,the addition of activated carbon was 0.5%,the decolorization time was 15 min,and the decolorization temperature was 40?.The decolorization of Centella asiatica extract was further impaired by chitosan flocculation,the flocculation temperature was set at 0.5%,the flocculation temperature was 40? and the flocculation time was 3h.The extract of Centella asiatica was purified by macroporous adsorption resin.Resin type D-4020 resin was determined by static adsorption and analysis.The adsorption capacity was 52.93mg/g,the adsorption rate was 79.36%,the adsorption time was 5h,the resolution was 97.6%,and the concentration of eluent was 70%.By dynamic adsorption and analysis,under the conditions of loading concentration of 0.69mg/m L and flow rate of 5m L/min,the amount of 400 m L was determined and eluted with 70% ethanol,and the elution curve was obtained.The precipitation of crude extract was studied,Centella asiatica extract B was prepared.The main components of cinnabaric acid and asiatic acid were obtained by thin layer chromatography and high performance liquid chromatography.Two extracts of Centella asiatica,including Centella asiatica extract A and Centella asiatica extract B,were tested for in vitro efficacy.The inhibition rates of hyaluronidase A and Centella asiatica extract B were 96.94% and 51.43%,respectively,showing a strong anti-allergic effect.The removal rates of DPPH of Centella asiatica extract A and Centella asiatica extract B were 93.2% and 56.69%,respectively.The FRAP values of Centella asiatica extract A and Centella asiatica extract B were 7.78 mmol Fe²⁺ / g and 3.67 mmol Fe²⁺ / g;Centella asiatica extract A and Centella asiatica extract B have a significant effect on O2-,and the scavenging effect of Centella asiatica extract A is more pronounced;Centella asiatica extract A and Centella asiatica extract B on tyrosinase inhibition rates were 19.13% and 12.30%,indicating that the two in the whitening effect is not obvious.The human body effect experiment,by analyzing the proportion of red area,wrinkle ratio and cheek and eye picture comparison,we can know that Centella asiaticus repair essence has the effect of reducing redness.In summary,the effective separation and purification of Centella asiatica extract can be easily achieved by ultrasonic alcohol extraction,decolorization,flocculation and so on,which provides a solid technical basis for the efficient preparation of Centella asiatica extract.At the same time,the in vitro efficacy of Centella asiatica extract and the results of the determination of human safety showed that Centella asiatica extract can be used as a potential utility extract for the promising cosmetic market.