Excipient effect on antimicrobial activity of Cinnamon (Cinnamomum zelylanicum album) oil, Thyme (Thymus vulgaris) oil and Ajowan (Trachyspermum ammi) oil

Background:Many herbal essential oils are potential antimicrobials but their pharmaceutical utility is restricted due to a lack of suitable excipients to mollify their dermatotoxicity and irritant property,and outcome of their therapeutic use may vary with different diluents used.Methods:Effect of 16 diluents(dimethyl sulfoxide,liquid paraffin,glycerine,oils of mustard,sunflower,rice bran,palm,groundnut,olive,coconut,sesame,avocado,jojoba,castor,linseed and soybean)was assessed on antimicrobial activity of 2%cinnamon(Cinnamomum zelylanicum album),thyme(Thymus vulgaris)and ajowan(Trachyspermum ammi)oils using agar well diffusion assay.The effect of excipients was evaluated on six Candida albicans,five Escherichia coli,four Acinetobacter lwoffii,two strains each of Staphylococcus aureus,Enterobacter agglomerans,and Enterococcus faecium and one strain each of Acinetobacter calcoaceticus,Escherichia fergusonii,Klebsiella oxytoca,K.pneumoniae ssp.pneumoniae,Leclercia adecarboxylata,Paenibacillus amylolyticus,Proteus mirabilis,P.vulgaris,Pseudomonas aeruginosa,Raoultella terrigena,Staphylococcus capitis ssp.capitis,S.chromogenes,S.epidermidis,S.warneri and Streptococcus pyogenes.Results:Thyme oil(2%)maintained it antimicrobial activity on dilution in dimethyl sulfoxide and glycerine,and ajowan oil(2%)completely lost its antibacterial activity in all diluents except dimethyl sulfoxide.However,cinnamon oil partially lost its antimicrobial activity upon dilution in glycerine,vegetable,and mineral oils in comparison to dimethyl sulfoxide.Olive oil was the best vegetable oil,almost comparable to dimethyl sulfoxide and castor oil was the worst diluent for maintaining antimicrobial activity of cinnamon oil.Conclusion:The study indicated the non-suitability of vegetable oils for pharmaceutical formulations of essential oils except olive oil for dilution of cinnamon oil and glycerol for thyme oil to replace dimethyl sulfoxide as diluent.

香辛料提取物对白色念珠菌的抑制及工艺优化研究

研究24种香辛料的抑菌作用,并比较其醇提取液的抑菌效果。通过大量的实验测定白色念珠菌抑菌圈,其中肉桂提取液对白色念珠菌抑制作用最佳。然后运用响应面(RSM)分析优化肉桂乙醇提取工艺条件。在单因素实验基础上,以白色念珠菌抑菌圈为指标,研究提取温度、液固比、提取时间及乙醇浓度对白色念珠菌抑菌圈的影响。结果表明,肉桂醇提法最佳提取工艺为提取温度69.24℃,液固比10:1(mL/g),提取时间5h,乙醇浓度95%,在此条件下提取液对念珠菌的抑菌圈是39.46mm。

环吡酮胺对耐药假丝酵母菌药物敏感性研究

目的研究环吡酮胺对耐药假丝酵母菌菌株的药物敏感情况。方法 2013年12月至2014年1月参照美国临床实验室标准化协会(CLSI)推荐的M27-A3方案的微量液基稀释法,测定环吡酮胺对120株耐药性白假丝酵母菌和7株非白假丝酵母菌的最低抑菌浓度(MIC)。结果 (1)并没有因为菌株对其他抗真菌药物耐药而发生环吡酮胺MIC增加,相反在耐克霉唑组和耐咪康唑组还有环吡酮胺MIC值进一步降低的现象。(2)环吡酮胺在耐咪康唑组的MIC值要低于耐克霉唑、耐氟康唑、耐伊曲康唑组的MIC值。结论对于耐其他抗真菌药物的假丝酵母菌,可以选择使用环吡酮胺进行治疗。

舍他康唑对于耐药假丝酵母菌药物敏感性研究

目的研究耐药真菌对抗真菌药物舍他康唑的药物敏感情况。方法 2015年6-8月于北京大学第一医院,参照美国临床实验室标准化协会(National Committee for Clinical Laboratory Standards,CLSI)推荐的M27-A3方案的微量液基稀释法,测量舍他康唑、伊曲康唑、咪康唑、克霉唑和氟康唑5种抗真菌药物对临床分离的120株耐药白假丝酵母菌、120株耐药光滑假丝酵母菌、30株敏感白假丝酵母菌株的最低抑菌浓度(MIC)。结果 (1)舍他康唑对白假丝酵母菌各耐药组的MIC值均高于非耐药组。(2)舍他康唑对光滑假丝酵母菌各耐药组的抗菌效果优于白假丝酵母菌组。结论舍他康唑在临床上治疗耐药光滑假丝酵母菌有一定的应用前景。