1.Establishment of LC-MS/MS method for the determination of forsklin in rat plasma and its pharmacokinetics
Dianwei SONG ; Decai WANG ; Zhiyun MENG ; Ruolan GU ; Meihui SHI ; Zhuona WU ; Jingze WANG ; Guifang DOU
Journal of International Pharmaceutical Research 2012;(2):149-153
Objective To develop a sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the determination of forsklin in rat plasma.Methods After extraction with methyl tert-butyl ether,chromatographic separation was performed on a C18 column with the mobile phase consisting of water ( 0.1% formic acid)-acetonitrile in a gradient elution mode.A tandem mass spectrometer equipped with electrospray ionization (ESI) source was used as detector in the positive ion mode.Quantification was performed using multiple reaction monitoring (MRM) with the precursor product combination ions of m/z 411→375.3 and 285→193 for forsklin and diazepam.Results Good linearity was obtained in the 0.5-1000 ng/ml range for the analyte and the analytical method was validated in terms of specificity,precision,accuracy,recovery,stability and matrix effect.These assays gave RSD values always lower than 14.4% and RE values between -3.5 % and 3.8%.In addition,the specificity,extraction recovery,stability and matrix effect were satisfactory.Conclusion Due to its high sensitivity,specificity and simplicity,the method could be used for pharmacokinetic studies of forsklin.
2.Method for the detection of human immunoglobulin Fc function based on surface plasmon resonance: preliminary establishment and validation
Fangyu DONG ; Jiuyue ZHOU ; Chen CHEN ; An ZHOU ; Dianwei SONG ; Jianfeng GAO ; Xi CHEN ; Xiao LI ; Jiawei WU ; Jiacheng DU ; Bo ZHOU ; Changyong JIAN
Chinese Journal of Blood Transfusion 2022;35(4):396-399
【Objective】 To establish a method for detecting human immunoglobulin Fc function based on surface plasmon resonance technology. 【Methods】 Based on the characteristic that FcγRI can be binded to the Fc segment of IgG, the affinity constant of the sample was detected by surface plasmon resonance, and its Fc function was the KD ratio of the sample to the standard. The method was validated for specificity/specificity, precision and robustness. The method and the pharmacopoeia method were used to detect the Fc function of 30 human immunoglobulins, and the correlation and consistency of the detection results were analyzed. 【Results】 The method validation results showed that this method has strong specificity/specificity (t values were 0.15, 0.22, both P>0.05), good precision (CV value 5.37%~10.69%) and good robustness (CV value 10.06%). The detection results of this method and the pharmacopoeia method have high correlation (r=0.96, P<0.05) and high consistency (Bias-2.060, 95% Limits of Agreement-5.628~1.508). 【Conclusion】 A method for detecting human immunoglobulin Fc function based on surface plasmon resonance has been successfully established.
3.Effect of Porcine Large Intestine-processed Dahuang (Radix et Rhizoma Rhei) on Defecation and Colon Pathological Changes in Constipation Model Mice
Xiaotian RAO ; Linjin HUANG ; Peisen ZHENG ; Bangyang CHEN ; Dianwei WU ; Maosheng HUANG ; Qiuming CHEN ; Dongjin HUANG ; Hongyue ZHAN ; Yinghua YAO ; Chao CHEN
Journal of Traditional Chinese Medicine 2023;64(18):1916-1921
ObjectiveTo investigate the effect of porcine large intestine-processed Dahuang (Radix et Rhizoma Rhei) on defecation in constipation model mice and the possible mechanism. MethodsFifty Kunming mice were randomized to blank group (n=10) and model group (n=40). Loperamide suspension at the dose of 8 mg/(kg·d) was given by gavage for four consecutive days to establish a model of constipation. The 24 successfully modeled mice were randomly divided into model group, processed Dahuang group, lactulose group, raw Dahuang group, with six mice in each group. Moreover, six randomly selected mice were chosen as control group. Since the fifth day, 8 mg/(kg·d) of loperamide suspension by gavage was given to the model group, processed Dahuang group, raw Dahuang group, and lactulose group; two hours later, the processed and raw Dahuang groups were administered with 0.6 g/(kg·d) of processed and raw Dahuang suspension, respectively, while the lactulose group was given 0.6 g/(kg·d) of latulose suspension, and the blank group and the model group were given 0.2 ml/10 g of distilled water by gavage, all for four days. The general condition, body weight after the last gavage, number of fecal particles within six hours, fecal wet weight, fecal water content ratio, intestinal propulsion rate and colonic histology changes by HE staining of each group were detected. ResultsThe body weight of the mice in the raw Dahuang group was significantly lighter than that in the other groups (P<0.05 or P<0.01). The number of fecal particles, fecal wet weight and intestinal propulsion rate of mice significantly decreased in the model group than in the blank group (P<0.05 or P<0.01). Compared to those in the model group, the number of fecal particles and fecal wet weight in the processed Dahuang group, lactulose group and raw Dahuang group significantly increased, and the fecal water content ratio in the raw Dahuang group increased as well (P<0.05 or P<0.01). Compared to those in the processed Dahuang group, the number of fecal particles and fecal wet weight in the raw Dahuang group decreased, while the fecal water content ratio increased (P<0.05 or P<0.01), and the fecal water content ratio in the lactulose group increased significantly (P<0.05). The intestinal propulsion rate in the processed Dahuang group was higher than that in the model group, lactulose group and raw Dahuang group (P<0.05 or P<0.01). Histopathological analysis showed that the colonic crypts and goblet cells in the blank group were normal and clear, and the colonic muscular layer was thicker. The colonic crypts of the mice in the model group were damaged, with reduced goblet cells to varying degrees and changed colonic muscularis. In the lactulose group and raw Dahuang group, part of the crypts were broken, and the goblet cells were damaged to varying degrees, while in the processed Dahuang group, still the colonic tissue structure of the mice was relatively clear, and the colonic crypts and goblet cells were relatively normal, with thickened muscular layer of the colon. ConclusionPorcine large intestine-processed Dahuang could improve defecation in constipation model mice, and reduce the drastic purgation function of raw Dahuang, for which the mechanism may be related to the protection of colon histopathological damage.