Evaluation Of Antioxidant Activity Of Total Flavonoids From Malus Hupehensis (Pamp.) Rehd In Vitro And Study On Liposome Emulsion

Objective:To study the antioxidant activity of total flavonoids from Malus hupehensis（Pamp.）Rehd in vitro.Optimization of preparation process of liposome emulsion and evaluation of its quality which to lay the foundation for the development of total flavonoids from Malus hupehensis（Pamp.）Rehd.Methods:1.DPPH free radical scavenging assay,ABTS free radical scavenging assay,superoxide free radical scavenging assay and tyrosinase activity inhibition assay were used to evaluate the antioxidant activity of total flavonoids in vitro.2.In order to optimize the formulation and preparation process of total flavonoids from Malus hupehensis（Pamp.）Rehd liposomes,response surface methodology（RSM）and factorial design were used to prepare liposomes of total flavonoids from Malus hupehensis（Pamp.）Rehd by film dispersion method to study the effects of several factors in preparation on encapsulation efficiency.Characterization,skin penetration in vitro,safety and stability about liposomes of total flavonoids from Malus hupehensis（Pamp.）Rehd were evaluated.3.The formulation and technology of total flavonoid liposomes emulsion were optimized by factor design with the indexes of viscosity and centrifugal retention rate.Meanwhile,the stability,safety and skin permeability of the prepared emulsion were evaluated.Results:1.The total flavonoids of Malus hupehensis（Pamp.）Rehd had good antioxidant activity in vitro.The IC₅₀ of scavenging DPPH free radical was 19.00μg·mL^-1,the IC₅₀ of scavenging ABTS free radical was 303.94μg·mL^-1,the IC₅₀ of scavenging superoxide free radical was 3.71 mg·mL^-1,and the IC₅₀ of inhibiting tyrosinase was 1.16 mg·mL^-1.2.When the ratio of lecithin to cholesterol（W/W）was 2.5:1,the concentration of lecithin was 30 mg·mL-1,the concentration of extracts was 5 mg·mL-1,the ultrasonic time was 3 min,and the ultrasonic frequency was 100 W,the prepared liposomes of total flavonoids had smaller particle size and larger encapsulation efficiency.The size of optimized liposomes was 102.74±1.61nm,PDI was 0.291±0.005,potential was-21.79±1.43 mV,the EE was 77.29±0.99%and the DL was 6.68±0.49%.The results of skin permeation test in vitro showed that the cumulative skin permeability of liposome(251.48±19.97μg·cm^-2)significantly higher than that of solution(212.11±10.42μg·cm^-2)（p<0.05）.The cumulative skin permeability of liposomes at 24 hours was higher than that of solution.The results of skin deposition experiment and CLSM observation showed that liposomes are more easily deposited in the skin.Skin irritation test showed that liposomes were suitable for skin use.The results of stability test showed that the EE,ZP,VS and PDI of liposomes did not change significantly（p>0.05）after storage for 30 days at 4±2℃and 25±2℃.And the results of the safety evaluation showed that the total flavonoid liposomes had no irritation and were suitable for skin use.3.The optimized formulation was GTTC:Isopropyl myristate:Squalane:Fatty alcohol polyoxyenthylene polyoxypropylene block polyether（AEO9P3）:Steareth-2:3%glycerol aqueous solution of mass ratio of 11.52:2.88:3.6:6:6:40.The emulsion showed uniform milky white,the viscosity was 159.64±4.25 cp,the centrifugal retention rate was 99.63±0.31%,the pH was 6.58±0.10,and the stability was good.Skin penetration experiments showed that emulsion of liposomes was superior to that of extracts（p<0.05）.And emulsion has the good security.Conclusions:The total flavonoids of Malus hupehensis（Pamp.）Rehd had good antioxidant activity in vitro.The liposomes of total flavonoids had small particle size,high encapsulation efficiency,excellent transdermal properties,good safety and stability.The liposomes emulsion has good permeability,safety,stability,suitable viscosity and easy coating.