Preparation And Evaluation Of Taxus Polysaccharide Nanomaterials

Melanin is a natural biological pigment widely distributed in hair,eyes,skin and other organs.It prevents UV radiation and protects against light damage.Its synthesis process involves a series of complex chemical reactions and enzymatic reactions.Excessive synthesis of melanin can cause pigmentation,causing diseases such as stains,chloasma,and melanosis,and the lesions not only occur in the skin but also in the organs,affecting the endocrine,metabolism,and organ functions of the human body.Endangering human health.At present,many active ingredients that can effectively inhibit melanin synthesis have been discovered,but these drugs have been proven to have more or less side effects,which can cause allergies,irritant dermatitis,and weak oxidation.Therefore,this paper provides an experimental basis for searching for natural and safe melanin synthesis inhibitors by studying the activity of Taxus chinensis fruit polysaccharides in inhibiting melanin synthesis and the preparation and evaluation of nanoliposomes preparations.The main research contents of this paper are as follows:(1)The first chapter of the paper: Introduction.First,the introduction background introduces the research background and significance of this subject.Secondly,a brief introduction to yew polysaccharides,mainly including yew,polysaccharides and yew fruit polysaccharides.At the same time,this chapter briefly introduces the synthesis and regulation of melanin,mainly from the aspects of melanin biosynthesis,regulation of melanin synthesis by PI3 K / Akt signaling pathway,and commonly used melanin synthesis inhibitors.In addition,this chapter also provides an overview of liposomes transdermal administration,including the system of transdermal administration,the characteristics of liposomes transdermal administration,mechanism of action,and research status.Finally,this chapter mainly summarizes the topic selection and research content of this topic.(2)The second chapter of the thesis: the activity of yew polysaccharide.First of all,yew polysaccharides from different sources(including yew leaf-derived polysaccharide TMLP and yew fruit-derived polysaccharide TMFP)were selected to determine the activity of drugs on human epidermal immortalized cells(HACAT)and mouse melanoma cells(B16F10).As a result,the safer yew fruit polysaccharide TMFP was screened out.After confirming that the research target of the follow-up experiment is the yew fruit polysaccharide TMFP,the effect of TMFP on cell viability,melanin content and tyrosinase activity was measured based on mouse melanoma cells(B16F10),and the yew fruit polysaccharide was initially proved TMFP’s antimelanin production activity.At the same time,the possible mechanism of action was explored through Western Blot experiments,and it was found that this activity may be related to the activation of PI3 K / Akt signaling pathway.In addition,in order to further prove the antimelanogenesis activity of TMFP,through experiments related to zebrafish embryos,it was found that the zebrafish embryos treated with TMFP showed an obvious albino state.At the same time,PCR test results showed that TMFP treatment can significantly reduce Tyr m RNA expression.Finally,this chapter also carried out a study on the antioxidant activity of scavenging oxygen free radicals,which proves that TMFP has a more obvious scavenging effect on hydroxyl radicals and a certain degree of scavenging effect on ABTS free radicals.(3)The third chapter of the thesis: Preparation and evaluation of yew fruit polysaccharide TMFP liposomes.First,a variety of liposomes with different particle sizes were prepared by using different preparation methods and applying different experimental conditions.The liposomes E with the highest cumulative skin penetration and accumulated skin retention was screened by in vitro percutaneous penetration experiments.Subsequent related experiments will focus on this kind of TMFP-liposomes.(4)Chapter 4 of the thesis: Evaluation of the efficacy of the yew fruit polysaccharide TMFP liposomes.First,by measuring the effect of TMFP-liposomes on the cell viability,melanin content and tyrosinase activity of mouse melanoma cells(B16F10),it was proved that TMFP-liposomes on mouse melanoma cells Anti-melanin production effect.In addition,the skin blackening model was established by irradiating the skin of ICR mice with ultraviolet rays,and continued to administer the skin of each group of skin blackening model mice and the normal skin of each group of non-irradiated mice through tissue sections to evaluate the efficacy.The results show that liposomes as a drug carrier for transdermal administration can effectively improve the transdermal efficiency of the water-soluble polysaccharide TMFP and help TMFP to better exert its efficacy.(5)The fifth chapter of the thesis: safety evaluation of yew fruit polysaccharide TMFP liposomes.First,the effect of TMFP-liposomes on the cell viability of human epidermal immortalized cells(HACAT)was determined,and the safety of TMFP-liposomes on HACAT cells was proved.At the same time,TMFP-liposomes were continuously administered to the normal skin of mice,and the safety of TMFP-liposomes to the animal body was evaluated by observing liver and kidney tissue sections and combining with the mental state of the mice.The results showed that the liver and kidney structures of the mice were intact without pathological changes,proving that TMFP-liposomes are safe for animals.(6)The sixth chapter of the thesis: summary and prospect.It summarizes the problems encountered during the experiment of this subject,the deficiencies that need to be improved and perfected,and looks forward to the direction of further research of this subject.