Effects Of Processing On Bioavailability Of Semen Cassiae And Chemical Study On The Procedure Of Semen Cassiae Processing

Semen Cassiae is the ripe seed of Cassia obtusifolia L.or Cassia tora L.of the family Leguminosae.It was initially recorded in Shennong Bencao Jing and listed as the top grade.It was described for use as a laxative and for reversing“liver fire”to improve vision,and therefore named as Juemingzi(counterpart name of improving vision in Chinese).It is sweet,bitter,salty in flavor,slightly cold in nature and attribute to the liver,kidney,large intestine meridians,mainly used for the swelling and pain of eyes,headache and dizziness,improve eyesight,constipation and other symptoms.Moden research showed that the main chemical constituents in Semen Cassiae are anthraquinones and naphthopyranones.And pharmacological studies indicate that Semen Cassiae has diarrhea effects,improve eyesight,antihypertensive,hypolipidemic,hepatoprotective activities,antioxidants activities and antimicrobial effects.In the clinical practice of Chinese medicine,Semen Cassiae is used as raw Semen Cassiae and parched Semen Cassiae.The usually used processing method of Semen Cassiae is simple parching(parching into yellowish).The raw Semen Cassiae is good at clearing away liver-heat and moistening the intestines.The parched is generally associated with decreased purgative effects and with the power of tranquilizing liver and nourishing kidney.Why does Semen Cassiae need parch?In the Ming Dynasty,Luo Zhouyan’s "Medical Tribune" says:"Semen Cassiae,Semen Raphani,Semen Sinapis,Semen Perillae,Semen Allii Tuberosi,Semen Celosiae,where the seeds are used,all have to parch and smash before decoction.If it is not broken,such as the rice in the shell,although the rice is cooked on the day,the rice fragrant can not produce.”From which we can see that,the ancients believe parch help the dissolution of"pharmacological component".Modern study think parch could increase the dissolution rate of active ingredients and improve bioavailability.However,there were no studies reported in this aspect until now.Based on the study of the chemical constituents of Semen Cassiae,the changes of bioavailability before and after processing of Semen Cassiae were studied and the chemical study on the procedure of Semen Cassiae processing was explored to further reveal the processing mechanism of Semen Cassiae.This paper is mainly divided into four parts.Firstly,review of literature.By reviewing relevant books on pharmacokinetics and related literatures on the pharmacokinetics of TCMs,the multi-component pharmacokinetics study of TCMs was reviewed.The experimental subjects of pharmacokinetics of TCMs are mainly rats.Most of the samples are plasma samples.The pretreatment methods of the samples mainly include protein precipitation,liquid-liquid extraction and solid phase extraction.The detection methods are mainly UPLC-MS/MS.The multi-component pharmacokinetics is now used to study the multi-component pharmacokinetics in TCMs,and to have a deeper understanding of the in vivo pharmacokinetics of various components in TCMs.In addition,the multi-component pharmacokinetics of TCMs has also been applied to study the processing mechanism of TCMs,and it has been shown that processing can improve the bioavailability of TCMs,and to some extent,it reveals the processing mechanism of TCMs.Second,the extraction and separation of aglycone ingredients.13 aglycone components were separated from silica gel column,all of them were identified by spectrum analysis,including 10 anthraquinone aglycones,2 naphthopyrone aglycones and 1 dianthrone aglycone.The 10anthraquinone aglycones were:1,6,8-trihydroxy-2,7-dimethoxy-3-methylanthraquinone(1),chrysophanol(2),physicon(3),obtusifolin(5),chrysophanol 8-methyl ether(6),obtusin(71).chryso-obtusin(8),aurantio-obtusin(9),questin(12),2-acetyl physcion(13);2 naphthopyrone aglycones were:rubrofusarin(10),toralactone(11);1 dianthrone aglycone was:crisofanol-10,10’-biantrona(3).Third,the study of bioavailability.In this study,a total of 27 compounds isolated from Semen Cassiae were first selected as candidates for quantitative components in the pharmacokinetic study.The results suggested that most of the anthraquinone aglycones in the blood could be detected and the content was suitable for quantitative analysis.All of the anthraquinone glycosides,naphthopyrone glycosides and naphthalene glycoside provided cannot be detected in the blood or the content is too low for quantitative analysis.Using butylparaben as an internal standard,acetonitrile was used to precipitate the protein,and UPLC-MS/MS was used to detect the 7 anthraquinone aglycones(aurantio-obtusin,obtusifolin,questin,2-hydroxyemodin-1-methyl-ether,rhein,emodin,1,2,7-trimethoxyl-6,8-dihydroxy-3-methylanthraquinone)concentration in blood after oral administration of the same dosages of raw and parched Semen Cassiae.All pharnacokinetic parameters were calculated using DAS 3.0.5 software and SPSS 21.0 was tused for statistical analysis.Compared with the raw Semen Cassiae group,Cmax and AUC tended to be higher in the parched Semen Cassiae group.In particular,Cma.values for aurantio-obtusin,obtusifolin,questin,2-hydroxyemodin-l-methyl-ether and rhein were significantly higher in the parched Semen Cassiae group(p<0.05).But the AUC was no significant between two groups.Tmax values of the 7 anthraquinone aglycones were similar(all<15 min).And Tmax values in parched Semen Cassiae group were tended to be lower.Specifically,Tmax for aurantio-obtusin and 2-hydroxyemodin-l-methyl-ether were significantly higher in the parched Semen Cassiae group(p<0.05).Our results indicated that processing can increase Cmax and AUC,decrease the Tmax of the seven analytes,thus improving the bioavailability of Semen Cassiae.Fourth,chemical study on the procedure of Semen Cassiae processing.The study found the glycoside hydrolases exist in Semen Cassiae and could convert anthraquinone glycosides and naphthopyrone glycosides to their corresponding aglycones in suitable temperature with sufficient water.The content of glycosides decreased,while the content of aglycones increased after processing.It is presumed that the change of content before and after processing may be caused by glycoside hydrolases under the action of a small amount of water,or it may be caused by high temperature during processing.Both hypotheses were verified by HPLC.The reason of the contents of glycosides decreased,while the contents of aglycones increased In processed Semen Cassiae was not caused by glycoside hydrolases effect,it caused by glycoside bond cracking at high temperature.