Isolation,Purification And Biological Activity Of Polysaccharide From Akebia Trifoliate (Thunb).Koidz And Its Application In Skin Cream

Akebia trifoliate(Thunb).Koidz,a kind of medicinal plant with many functions,belonging to the family of Akebia,had been included in Chinese Pharmacopoeia(2015edition).Polysaccharides is one of the main effective components of the stem which is the main medicinal part of Akebia trifoliate(Thunb).Koidz.However,there are few studies on the Akebia trifoliate(Thunb).Koidz polysaccharides(ATKP)at home and abroad.This paper mainly studied the extraction,purification,in vitro biological activity and application in skin care products of ATKP.Besides,the antioxidant activity,antibacterial activity,in vitro moisture absorption and moisturizing activity and structure characteristics of ATKP were determined and analyzed.The main conclusions were as follows:(1)Response surface optimization showed that the optimal condition for ultrasonic extraction of polysaccharides was solid-liquid ratio(1:20),ultrasonic time(52 min),ultrasonic temperature(79 ?)and ultrasonic power(175 W).And under this condition,the extraction yield of ATKP was 3.23%,which was close to the theoretical predicted value.(2)The purification of polysaccharides: the enzymatic method,Sevage method and enzymatic+Sevage method were compared in the deproteinization effect.The results showed that the enzyme+Sevage method had the best effect and the optimal condition was enzyme concentration(10 mg/mL),PH value(7),enzymolysis temperature(60 ?),enzymolysis time(1.0 h),and Sevage treatment(3 times).Under this protein removal condition,the protein removal rate and polysaccharides retention rate of was 87.52% and56.55%,respectively.Five constituents for ATKP ?,ATKP ?,ATKP-?,ATKP ?,ATKP ? were separated by deae-cellulose column chromatography.(3)There are three aspects studied in the in vitro activity of ATKP: in vitro antioxidant capacity,antibacterial capacity and in vitro moisture absorption and moisturizing activity.When the concentration of ATKP was 10 mg/mL,the scavenging rates of DPPH,hydroxyl radical and superoxide anion reached 90.78%,68.44% and70.19%,respectively.Besides,reduction force test results show that ATKP has a certain reduction capacity and they are all weaker than the activity of Vitamin C.The in vitro antioxidant capacity of a variety of purified polysaccharides(ATKP-I,ATKP-II,ATKP-III,ATKP-IV,ATKP-V)were studied.The results showed that all purified polysaccharides had a certain of antioxidant capacity and ATKP-II had the higest antioxidant activity among the five purified polysaccharides.When the concentration of ATKP-II was 10 mg/mL,the scavenging rates of DPPH,hydroxyl radical and superoxide anion reached 85.63%,57.22% and 63.87%,respectively.Besides,the results of reducingpower test show that the ATKP-? have certain reduction ability of iron ion,and assumes the concentration-response relationship However,the antioxidant activity of ATKP-II was weaker than the activity of ATKP.In addition,the result of antibacterial test showed that ATKP had inhibitory effect on bacillus subtilis,staphylococcus aureus,salmonella,penicillium italiana,rhizopus and aspergillus Niger.The best inhibitory effect were staphylococcus aureus and bacillus subtilis and the minimum inhibitory concentration of both was 2.5 mg /mL.Moreover,we found that pH had a certain effect on the antibacterial effect of ATKP.By comparing the in vitro moisture absorption and moisturizing capacity of ATKP with three commonly used moisturizers(glycerol,chitosan and sodium alginate),it is found that the in vitro moisture absorption and moisturizing effect of ATKP is only lower than glycerol,indicating that ATKP has good moisture absorption and moisturizing performance.(4)The physicochemical properties and structure characteristics of ATKP and ATKP-II were determined and analyzed.The result showed that the content of neutral polysaccharide,protein,uronic acid and total phenol in ATKP were 68.29%,3.11%,23.23% and 0.37%,respectively and the content of neutral polysaccharide,protein,uronic acid and total phenol in ATKP-II were 86.5%,0.59%,12.08% and 0.08%,respectively.Besides,the infrared spectra of both showed the absorption peaks of-OH and-CH which are the characteristic functional groups of polysaccharides.In addition,both of them had-COOH absorption peaks,indicating the existence of uronic acid in ATKP and ATKP-II,which was consistent with the determination results of physicochemical properties.The analysis result of HPGPC showed that ATKP was composed of a variety of molecular weight of polysaccharides.ATKP-? was mainly composed of two kinds of polysaccharides with different molecular weight which were9.37 kDa and 3.12 kDa.Furthermore,both of ATKP and ATKP-II were composed of six monosaccharides which were rhamnose,arabinose,xylose,mannose,glucose and galactose.And the molar ratio of ATKP and ATKP-II were 1.6:22.1:3.6:6.3:55.7:10.7 and0.5:22.1:3.7:10.2:42.1:21.4,respectively.(5)ATKP was added in skin cream with a common moisturizing agent(glycerol),which was used as a moisturizing additive.And the moisturizing effect of each sample was measured by in vitro weighing method.The result showed that a new skin cream with good moisturizer,yellowish color,uniform texture,fine texture,good stability and no irritation to skin can be obtained by adding ATKP and glycerol in the formula of skin cream at the ratio of 0.8% to 4.2%.In conclusion,ATKP has certain antioxidant capacity,antibacterial capacity and in vitro moisture absorption and moisturizing activity,which expected to join in the field of cosmetics as a natural moisturizer.Besides,The ATKP-II had the higest antioxidant activity among the five purified polysaccharides.The biological activity and structurecharacteristics of ATKP and ATKP-II were preliminarily understood,which provided a certain basis for the later research and a new idea for the further development of the stem resources of Akebia trifoliate(Thunb).Koidz.