| Aloe is the concentrated and dried juice of the leaves of Aloe barbadensis Miller and Aloe ferox Miller or other related plants of the same genus.It has the functions of anti-inflammatory,bacteriostatic,diarrhea and defecation.It is mainly used to regulate gastrointestinal dysfunction and improve constipation.Anthrones,anthraquinones,chromones and pyranones are the mainly classes of Aloe.Pharmacological studies show that Aloe and aloin(main component)both have antibacterial,anti-tumor,anti-inflammatory and purgative activities.However,the in vivo process mainly focused on the pharmacokinetics of the components with higher content,such as aloin,which is not enough to comprehensively and completely reflect the quality of it.Therefore,in order to establish quality markers for systematical evaluation of Aloe,this paper carried out qualitative and quantitative analysis on its chemical constituents.A fingerprinting analysis method was established to identify the components of Aloe extract after oral administration in rats,and the pharmacokinetics of the main components were studied.Therefore,we established the qualitative analysis method of Aloe based on UPLC-QTOF/MS technology.A total of 34 chemical constituents were identified from Aloe including10 anthrones(aloin A,aloin B…),16 chromones(aloesin,7-O-methylaloeresin A,aloeresin D…),5 pyranones(aloenin,aloenin B…)and 3 others.A fingerprinting analysis method of Aloe was established by UPLC.The results of methodological investigation showed that the method had good precision,stability and reproducibility,and could meet the requirements of fingerprinting in Chinese Pharmacopoeia.The method was applied to 15 batches of Aloe,and18 common peaks were identified.The results of similarity evaluation showed that the Aloe from the same origin had high similarity.15 batches of Aloe were divided into two types through principal component analysis(PCA)and cluster analysis.The relative peak area of aloin A and aloin B in the first type(Aloe barbadensis Miller)was higher,whose relative contents were 18.08 % and 14.39 %,respectively,while the contents of aloin A and aloin B in the second type(Aloe ferox Miller)were lower,whose relative peak area were 4.17 % and3.76 %,respectively.Then,an UFLC-MS/MS method was established for the simultaneous determination of aloesin,aloenin,aloeresin D,aloin B,7-O-methylaloeresin A,aloin B,aloin A and aloe-emodin in Aloe by ESI source and multiple reaction monitoring(MRM)mode under negative ion mode.The contents of 7 components in 15 batches aloe were determined.Aloeresin D was higher in two kinds of Aloe,and the content in Aloe ferox Miller was higher than that in another.Meanwhile,the quantitative results were imported into SIMCA software for PCA analysis,and the results showed that aloin A,aloin B and aloeresin D could be used as potential index components to identify the quality of Aloe.Next,UPLC-Q-TOF/MS was used to study the metabolism of aloin A,aloin B,aloesin by iv.and ig.and Aloe by ig.in rats.The possible metabolites were screened by metabolynx XS software,and their structures were analyzed and identified according to the accurate mass number and mass spectrum fragment information.Rats were given aloin A and aloin B by oral administration and tail intravenous injection,The two compounds can be transformed into each other in vivo,and aloin A has been detected in plasma,urine and feces.26 metabolites were identified from plasma,urine and feces of rats,of which 19 were found in plasma,11 in urine and 13 in feces.The main metabolic pathways include hydroxylation,hydroxylation desasturation,methylation,acetylation and glucuronidation.After given aloesin by oral administration and tail intravenous injection,aloesin has been detected in plasma,urine and feces in rats.Three metabolites(two in plasma,three in urine and none in feces)were also identified.It main exists in aloesin and the metabolic pathways included glucuronidation,hydroxylation desasturation and hydroxylation.After oral administration of Aloe,19 prototype components(7 in plasma,11 in urine and 19 in feces)and 56 metabolites(5 in plasma,36 in urine and 34 in feces)were identified from rats.The main types of metabolic reactions include hydroxylation,hydroxylation desasturation,reduction,methylation,glucuronidation,sulfation and acetylation.In summary,aloeresin D,aloin A and aloin B were the main blood components of Aloe.Finally,an UFLC-MS/MS method was established to determine the contents of aloesin,aloenin,aloeresin D,aloin B,aloin A and aloe-emodin in plasma of rats after oral administration of Aloe.1,8-dihydroxyanthraquinone was used as internal standard(IS).Multiple reaction monitoring(MRM)mode was used in negative ion mode with ESI source.The results of methodological investigation showed that the established method had good specificity,precision,accuracy and stability,and could meet the requirements of biological sample analysis without matrix effect.The extraction recoveries of aloesin,aloenin,aloeresin D,aloin B,aloin A and aloe-emodin ranged from 58.02 % to 106.81 %.The peak time(Tmax)were 0.54 ± 0.39 h,0.51 ± 0.40 h,0.92 ± 0.58 h,1.60 ± 1.41 h,1.60 ± 1.41 h,0.44 ± 0.31 h,respectively.The results showed that the absorption of aloesin,aloenin,aloeresin D and aloe-emodin was fast,while the absorption of aloin A and aloin B was slow.In addition,aloin A and aloin B are chiral isomers with the same parent nuclear structure and substituent groups,and their pharmacokinetic parameters in rats are similar.In summary,through qualitative analysis of chemical constituents,fingerprinting and multivariate statistical analysis methods,we confirmed that in addition to aloin A and aloin B,there is aloeresin D can be used as the potential indicator for quality control of Aloe.In addition,through the study of the chemical components and metabolites in the plasma,urine and feces of Aloe in vivo,the possible metabolic pathway of metabolites was summarized and analyzed,and the metabolic process of the main components of Aloe were basically defined.The pharmacokinetics of aloeresin D,aloin B,aloin A,aloesin,aloenin and aloe-emodin were also studied.The results of this study can provide scientific basis for screening for potential indicators of quality control and revealing the effective substances of Aloe. |
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