Effects Of Tea Extractions On Candida Albicans And Its Application In Denture Cleaning

Objective:The purpose of this study was to investigate the susceptibility of Candida albicans to different tea extractions,analyzing and comparing 4 kinds of catechins content in Anji white tea(AG)?Tie Guanyin(TM)and Da Hong Pao(HM)for revealing the relation between tea extractions'antifungal activity and catechins content.And evaluate the capacity of tea extractions on reducing the Candida albicans biofilm which were adhesion in the polymethyl methacrylate(PMMA)surface.Verifing the possibility of tea extractions become denture cleansers and antifungal drugs,therefore providing clinical guidance.Methods:(1)Using the agar dilution method,boards containing 1.25,2.50,5.00,10.00,and 20.00 mg/mL of extractions were prepared for each type of tea(n=10).Distilled water was used as control group.Aliquots of 5?L of C.albicans suspensions of 10~4cfu/mL was planted on these plates.The growth of colonies were then counted and used to screen the optimum tea extractions against C.albicans.Data was analyzed by using both One-Way ANOVA with the significance level of 5%,and least Significant difference(LSD test).(2)High performance liquid chromatography(HPLC)method system was used to analyze and compare 4 kinds of catechins content in AG,TM and HM extractions.Then,the correlation analysis with the anti-fungal activity of the tea extractions using Pearson was performed.The chromatographic conditions were as follow:ZORBAX SB-C18(5.0?m,4.6 mm×150.0 mm)was used,the mobile phase was1%acetonitrile-methanol and the flow rate was 1 mL/min,at the detection wavelength of 280 nm,and the column temperature was 30 centigrade.(3)PMMA(10.0 mm×20.0mm×2.5 mm)specimens contained C.albicans biofilm were randomly distributed into the 4 groups(10.0 mg/mL AG extractions,2.5 mg/mL HM extractions,0.5%sodium hypochlorite(NaClO)as positive control,and distilled water as negative control)(n=6).The specimens were immersed in respective solutions for 10 min.The number of colonies growing on Sabouraud's dextrose medium was counted.Data was analyzed by using both One-Way ANOVA with the significance level of 5%,and least Significant difference(LSD test).Results:(1)The results showed that the inhibitory effect of 10.0 mg/mL Anji white tea extractions,2.5 mg/mL Da Hong Pao extractions were significantly different camparing with control group(P<0.05),but the rest teas of different concentrations were not significantly different with control group(P>0.05).(2)There was a good linear relationship between the concentration and peak area(r?0.9991).The average recoveries were range from 97.75%to 100.39%.RSD was less than 5.00%(n=3).AG has highest tea catechins content in three kinds of tea extractions.HM's epigallocatechin gallate(EGCG),epicatechin(EC),epicatechin gallate(ECG)content higher than TM's.TM's epigallocatechin(EGC)content higher than HM's.Pearson correlation analysis showed that tea extractions of antifungal activity was not significantly associated with tea catechins content:EGC(r=-0.126,P=0.656),EGCG(r=0.139,P=0.621),EC(r=0.197,P=0.482);ECG(r=0.268,P=0.334).(3)The result of 10.0 mg/mL AG extractions(P=0.979)and 2.5 mg/mL HM extractions(P=0.652)colonies counting was not significantly different among sterile water,0.5%sodium hypochlorite solution had no colony growth.Conclusion:10.0 mg/mL AG extractions and 2.5 mg/mL HM extractions suffieicently inhibited C.albicans.However,no effects of tea extrations were found on C.albicans biofilm formed on the PMMA surface.The antifungal activities of tea extractions were not correlated with their tea catechins concentrations.