Research On The In Vitro Xanthine Oxidase Inhibitory Activity And Technology For Compound Beverage Of Chinese Herbal Extracts

Xanthine oxidase (XO) is a kind of enzyme in the human body which can catalyse theformation of uric acid from purine. Inhibition of xanthine oxidase activity can indirectlyinhibit the generation of uric acid. The main kind of drugs for treating hyperuricemia and goutare inhibitor of xanthine oxidase.The use of Allopurinol which is a traditional drug as XOinhibitor is limited because of its severe side effects. So finding new kinds of xanthineoxidase inhibitor is very significant. Chinese herbal medicine has a long applied history，XOinhibitors from Chinese herbal source has vast potential for future development for treatinggout. In this paper，38kinds of Chinese herbal medicine were selected， and the in vitroxanthine oxidase inhibitory activity of their water extracts has been studied. Four kinds ofherbal medicine with both higher xanthine oxidase inhibitory activity and sensory evaluationwere selected， and technology for compound beverage of Chinese herbal extracts has beeninvestigated.Firstly，the in vitro xanthine oxidase inhibitory activity of the water extracts of38kindsof Chinese herbal was evaluated. The results showed that33kinds of Chinese herbal aqueousextracts showed xanthine oxidase inhibitory activity， in which, the in vitro xanthine oxidaseinhibitory activity of chicory， sophora flower bud， peppermint and dandelion leaves in thetest conditions was greater than50%. Furthermore， the water extracts of chicory，sophoraflower bud，lotus leaf and peppermint have higher sensory scores and higher total flavonoidcontent.Secondly，the conditions of extraction of chicory， sophora flower bud, lotus leaf andpeppermint have been optimized based on the single factors test and the orthogonal test. Theoptimum extracting conditions of chicory was showed as following: solid (g)-liquid (mL)ratio1∶30， extracting temperature90℃， extracting time15min. The optimum extractingconditions of sophora flower bud and lotus leaf was: solid (g)-liquid (mL) ratio1∶30，extraction temperature90℃， extraction time30min; The optimum extracting conditions ofpeppermint was: solid (g)-liquid (mL) ratio1:20， extraction temperature80℃， extractiontime45min. For different materials，the primary and secondary factors which affected theextraction were significantly different. Response surface analysis (Mixture design) was usedto study the in vitro xanthine oxidase inhibitory activity of the mixture of the above4kinds ofwater extacts， the optimal mixture ratio in volume percentage was: chicory38.5%， sophora flower bud31%, peppermint10%and lotus leaf20.5%. The in vitro xanthineoxidase inhibitory activity of the optimal mixture was up to70.76±0.05%.Xylitol, citric acid, β-cyclodextrin and floral fragrance were choosed as beverageadditives and their effects on the in vitro xanthine oxidase inhibitory activity and the sensoryevaluation were studied. Results showed that addition of certain extent of xylitol and β-cyclodextrin could somewhat increase the in vitro xanthine oxidase inhibitory activity. Theoptimal additive formula for the compound herbal beverage was: xylitol13%, citric acid0.5%，β-cyclodextrin0.8%and floral fragrance0.015%. Solid phase microextraction (SPME)and GC-MS were used to determine the aroma of the compound herbal drinks andpeppermint extract.35kinds of volatile compounds were found in the compound herbal drink,including5kinds of alcohol,4kinds of aldehydes,4kinds of ketone,7kinds of aromaticcompounds,2kinds of esters, and11kinds of hydrocarbons, as well as eucalyptol and epoxy4a,7-methano-4aH-naphth(1,8a-b) oxiren, octahydro-4,4,8,8-tetramethyl-.Of which methylcyclopent-enolone (16.73%) had a great influence on the aroma components of compoundherbal drink. The aroma of the compound herbal drink was characterized by the aramelaroma and floral fragrance of herbaceous plant， which offered the compound herbal drink agood sensory.