1.Determination of the activity of human hepatic cytochromes P450 CYP2C8/9,CYP2E1
Jing MA ; Beili QIAN ; Xingchu GU ; Binghua YANG ; Genbao WANG
Chinese Pharmacological Bulletin 1987;0(01):-
AIM To establish the methods for assaying the activities of tolbutamide hydroxylase (CYP2C8/9) and chlorzoxazone 6-hydroxylase(CYP2E1) from adult human livers microsomes. METHODS The microsomes was isolated from human adults liver and the contents of microsomal protein were determined. Using the tolbutamide and chlorzoxazone as substrates, the amount of hydroxytoblbutamide and hydroxychlorzoxazone formed during the incubation period was quantified by extroppolating from the standard curve and the specific activity of CYP2C8/9 and CYP2E1 were calculated. RESULTS There was no siginificant influence on the activities of CYP2C8/9 and CYP2E1 in different times. CONCLUSIONS The methods utilized to estimate the activity of CYP2C8/9 and CYP2E1 were simple, stable, and repeatable. These methods can be used in new drug screening, safety evaluation and reseasch on pathology and toxicology of liver.
2.Cancer promoting effects of N-nitrosodiethylamine (DEN) and 2-acetylaminofluorene (2-AAF) with medium term rat liver bioassay
Xingchu GU ; Beili QIAN ; Huijuan ZHANG ; Jianqiang JIANG ; Huiying YE ; Yuzhen ZHU ; Jicheng WANG ;
Chinese Pharmacological Bulletin 1987;0(03):-
AIM To study the cancer promoting effects of N nitrosodiethylamine (DEN) and 2 Acetylaminofluorene (2 AAF). METHODS Medium Term Rat Liver Bioassay (MTRLB). Male SD rats were initially given a single dose (200 mg?kg -1 ) of DEN ip and starting 2 weeks later, were treated with 10, 33 and 100 ppm DEN in drinking water, or with 2 2, 6 6 and 22 mg?kg -1 2 AAF by gavage for 6 weeks. All rats were subjected to two thirds partial hepatectomy at week 3 and killed at the end of week 8. Carcinogenic potential was scored by comparing the numbers and areas in induced glutathione S transferase placental form (GST P) positive foci in the liver with those of corresponding control group given DEN alone. RESULTS Both DEN and 2 AAF caused the increases of the numbers and areas of GST P positive foci in the liver, and showed dose response relationship. CONCLUSION Both DEN and 2 AAF shows cancer promoting effects, and MTRLB was a convenient, economical and effective tool to study the cancer promoting effects of test chemicals.
3. Discussion on several statistical problems in establishing quality standards of standard decoctions
Shishi GU ; Peiying LIN ; Runling OU ; Xingchu GONG ; Junlin GUO ; Xingchu GONG
Chinese Herbal Medicines 2022;14(1):36-47
Since 2016, a number of studies have been published on standard decoctions used in Chinese medicine. However, there is little research on statistical issues related to establishing the quality standards for standard decoctions. In view of the currently established quality standard methods for standard decoctions, an improvement scheme is proposed from a statistical perspective. This review explores the requirements for dry matter yield rate data and index component transfer data for the application of two methods specified in “Technical Requirements for Quality Control and Standard Establishment of Chinese Medicine Formula Granules,” which include the average value plus or minus three times the standard deviation (X-±3SD) or 70% to 130% of the average value (X-±30%X-). The square-root arcsine transformation method is used as an approach to solve the problem of unreasonable standard ranges of standard decoctions. This review also proposes the use of merged data to establish a standard. A method to judge whether multiple sets of standard decoction data can be merged is also provided. When multiple sets of data have a similar central tendency and a similar discrete tendency, they can be merged to establish a more reliable quality standard. Assuming that the dry matter yield rate and transfer rate conform to a binomial distribution, the number of batches of prepared slices that are needed to establish the standard decoction quality standard is estimated. It is recommended that no less than 30 batches of prepared slices should be used for the establishment of standard decoction quality standards.