ABSTRACT
A UPLC-Q-Orbitrap-MS based metabolomic approach combined with biochemical assay and histopathological inspection were employed to study the intervention effects of Suanzaoren Decoction (SZRD) on chronic unpredictable mild stress (CUMS) depression rats, and to clarify the metabolic regulation pathway of SZRD. The rats were randomly divided into normal control group, CUMS model group, positive drug venlafaxine group, SZRD high (24 g·kg-1) and low (12 g·kg-1) dose groups, respectively. The CUMS model was replicated by subjecting to a variety of stimulus, such as thermal stimulation, ice water swimming, ultrasonic stimulation, tail clamping, day and night reversal, plantar electric shock and so on for rats. After oral administration of drugs for 28 days, the behavioral indexes of rats in each group were observed and the hippocampus and serum samples of rats were collected for biochemical assay and histopathological inspection. Compared with the CUMS model group, low dose and high dose SZRD groups can significantly reduce the immobility time of forced swimming (P < 0.001, P < 0.001), increase the sucrose preference rate (P < 0.01, P < 0.05), the number of crossings (P < 0.05, P < 0.01) and the number of uprights (P < 0.05, P < 0.01) in the open field test, suggesting that SZRD can significantly improve the depression-like behavior of CUMS model rats. In addition, SZRD could significantly reduce the levels of serum IL-6, IL-1β and TNF-α of CUMS model rats. A total of 21 differential metabolites in serum were identified by comparison with the data from the literature and databases. In addition, low-dose SZRD and high-dose SZRD improved the 8 and 11 perturbed potential serum biomarkers that were induced by CUMS, respectively, which related to alanine, aspartic acid and glutamic acid, tryptophan and arachidonic acid metabolism. This study provides a scientific basis for expanding the clinical indications of SZRD. This experiment was approved by the Animal Ethics Committee of Shanxi University (Approval No. SXULL2020028).
ABSTRACT
The aim is to study the tissue distribution characteristics of eight effective components in normal rats after oral administration of Ziziphi Spinosae Semen (ZSS) aqueous extract. An ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) analysis method was developed and validated for the determination of four flavonoids and four saponins in rat tissue using puerarin and ginsenoside Re as the internal standard (IS), respectively. Tissue samples including the heart, liver, spleen, lung, kidney, muscle, brain, small intestine, and serum, were collected from each rat at 0.5 h, 1.0 h, and 2.0 h after oral administration of ZSS aqueous extract (15 g·kg-1). All calibration curves exhibited good linearity (r > 0.994 6) over a wide concentration range for all components. The intra-day and inter-day precisions (RSD) at four different levels were both less than 19.77%, and the accuracies (RE) ranged from -19.68% to 19.46%; The extraction recoveries of the eight components ranged from 86.70% to 114.29%, and the matrix effects were from 82.14% to 114.57%. The validated method was successfully applied to the tissue distribution study of the eight components. The levels of swertisin, spinosin, 6‴-feruloylspinosin, and kaempferol-3-O-rutinoside in the small intestine were highest, then followed by the kidney, heart, and liver. Meanwhile, the levels of jujuboside A (JuA), jujuboside B (JuB), and jujuboside A1 (JuA1) in the small intestine were highest, then followed by the lung, spleen, and kidney. The concentrations of betulinic acid in the small intestine were higher than heart, lung, kidney, and liver. The flavonoids and saponins of ZSS with extremely low content could pass through the blood-brain barrier. The research results will provide an experimental basis for explaining the mechanism of nourishing the heart and tranquilizing the mind of ZSS. The animal experimental operations involved in this study followed the regulations of the Animal Ethics Committee of Shanxi University of Chinese Medicine and passed the animal experimental ethical review (No. 2021DW172).
ABSTRACT
Objective To investigate the methods of preparing high-quality successive paraffin sections of rat brain tissue. Methods Rats were anesthetized and transcardiac perfusion fixation was performed for collecting brain tissue. Then the brain was sequentially cut into 3mm-thick blocks and immersed in fixative; dehydrated in a gradient ethanol series, with 95% ethanol 2 times for 1 hour each, and ethanol 2 times for 30 minutes each; cleared with xylene 2 times for 10 minutes each; dipped wax at 60° with paraffin of melt point 56~58° for 1 hour then followed by melt point 58~60° for 2 hours; and embedded with the same paraffin as the second waxdip. 4μm sections were sliced with new knives, flattened with 42° water bath, and attached with adhesion slides. Results After perfusion fixation the brain tissue appeared milk-white and had certain toughness; through xylene clearing the brain presented totally transparent, without any cloudy structure; and at thickness counting approximate 80μm, we could harvest high-quality consecutive sections. The result of HE staining turned favourable, the microscopic histological structure were intact, cell nucleus and plasma were fresh; and there was also less section tissue fading during immunohistochemistry staining. Conclusion Perfusion fixation, time of dehydration and clearing, selection of waxdip and embedding, temperature of flattening water bath and the use of adhesion slides, are the key factors to the preparation of high-quality successive paraffin sections of rat brain tissue.