Development and assessment of tyrosinase inhibitory activity of liposomes of Asparagus racemosus extracts

The purpose of this study was to develop liposomal formulations of Asparagus racemosus root extract(AR1-6)as well as evaluate the physicochemical properties and in vitro tyrosinase inhibitory activity.Liposomes composed of AR1-6 to lipid weight ratio of 1:10 and lecithin(LEC)or Phospholipon
90G(PC90G)as structural phospholipid at 7:3 molar ratio to CHOL were prepared by various methods,i.e.chloroform-film(CF),reverse-phase evaporation(REV),polyol dilution(PD),and freeze-drying of monophase solution(MFD)methods.The results revealed that vesicles prepared by CF and MFD were multilamellar whereas those prepared by REV and PD were oligolamellar in nature with particle sizes ranging from 0.26 to 13.83 mm.The zeta potentials were in the range of
1.5 to
39.3 mV.AR1-6 liposomes with LEC possessed significantly higher entrapment than those with PC90G.The highest entrapment efficiency and in vitro tyrosinase inhibitory activity of 69.08%and 25%,respectively,were obtained from liposomes having LEC and prepared by PD method.The tyrosinase inhibitory activity were in the rank order of LEC>PC90G,and PD>CF>REV>MFD.It could be concluded that the mechanism of vesicle forming in each method of preparation was the key factor influencing physicochemical properties,particularly vesicle type,size,surface charge,and entrapment,which were well correlated with the biological activity.

Improved extraction efficiency of bakuchiol with antioxidant and whitening bioactivities from the seeds of Psoralea corylifolia L.

Background:Mining new whitening ingredients from plants is an effective way to develop new cosmetic products.Bakuchiol,as one of the main active ingredients from the seeds of Psoralea corylifolia L,displays whitening,antioxidant,antiaging,and free radical-scavenging activities and attracts wide attention especially in the cosmetics industry.However,environmentally friendly extraction technologies with high efficiency and high product purity remain to be developed for the scale production of bakuchiol.Objective:In this study,a new approach(acetic acid–steaming–assisted technique)was developed to improve the extraction efficiency of bakuchiol.Methods:The factors influencing the extraction efficiency of bakuchiol,including seed powder granularity,acetic acid volume,temperature,and time,were optimized based on single-factor experiments.Results:The extraction conditions were optimized as steaming the seed powder(100 g)of 40–100meshes with acetic acid(50 mL)for 10 minutes,from which a crude extract(25.1 g)containing bakuchiol was obtained.High purity(99.1)of bakuchiol(6.02 g)was then prepared by silica gel column chromatography in a one-step process.The method established in this study had higher extraction rate than other methods.The antioxidant potential of bakuchiol was evaluated based on the ABTS free radical scavenging activity and ferric reducing antioxidant power.Furthermore,bakuchiol demonstrated stronger tyrosinase inhibitory activity than the positive control(arbutin).Conclusions:Compared with the available methods,the method established in this study has increased extraction rate of bakuchiol and is environmentally friendly and economical,demonstrating the potential for industrial production.