Antifungal Constituents Recognition Of Water Extract Of The Leaves Of Artemisia Selengensis On Candida Albicans By Constituent Knock-out/knock-in Strategy And Research On Strengthening Measures Of The Antifungal Efficacy

Artemisia selengensis is a valuable vegetable that is widely distributed in southern China and has been shown to possess hypertension,antioxidant and antibacterial activities.In this research,we focused on the anti-candida efficacy of the leaf of artemisia selengensis.Macroporous resins were used to separate and purify its water extract(WE)and to remove impurities such as polysaccharides and proteins.The method of constituent knock-out/knock in was used to identify the beneficial components of WE.The effects of alcohol sedimentation and mixing with some natural plants ingredients on the anti-candida efficacy of WE were studied.Based on this study,we aim to develop WE as an antifungal agent which is natural,safe and efficient,against infection of Candida albicans(C.albicans).In this way,we can study the comprehensive uses of artemisia selengensis.The main contents and results of this study were:1.HPD600,the best resin for purification of WE had been screened out by static and dynamic absorption-desorption test.The best process parameters of the resin purification were also determined:"sampling amount was 0.11 g WE/g resin;the sample concentration was 40 g·L-1 and flow rate was 2 BV h-1;70%ethanol solution was the best solvent for desorption and its flow rate was 2.5 BV·h-1."2.We aimed to identify the antifungal constituents of WE on C.albicans by constituent knock-out/knock-in strategy,focusing on each elution composition of resin purification.The results showed that fraction C may be the pharmacodynamics composition of anti-candida albicans activity,and showed dose-effect relationship.Preliminary analysis showed that the total terpene content of fraction C was 59.61±2.89%.Mass spectrometry analysis showed that fraction C mainly contained diterpenoid tanshinones and nalidixic acid compounds.3.In vitro antifungal action of WE to C.albicans that was treated with different dosages of ethanol was determinated by micro-broth dilution assay,and was found to cause the inhibition of cell growth,biofilm formation and germination of the cells.Alcohol sedimentation reduced the minimum inhibitory concentration(MIC)of WE to C.albicans from 200 to 8 g·L-1.Besides,the inhibition activities of biofilm formation,the germination of the cells of C.albicans were also improved.4.The effect of mixing with some natural plants ingredients on the anti-candida albicans activity of WE had been studied by microdilution checkerboard techniques.Of all the plants ingredients treated,the Lavandula angustifolia,Scutellaria baicalensis and Curcuma phaeocaulis showed significant synergistic effect,and fractional inhibitory concentration index(FICI)was less than 0.5.The MIC80 of WE was reduced to 0.60 g· L-1.