Tamoxifen can reverse multidrug resistance of colorectal carcinoma in vivo

AIM: To investigate the effect of tamoxifen (TAM) on multidrug resistance (MDR) of colorectal carcinoma in vivo and its relationship with estrogen receptor (ER). METHODS: Multidrug resistance was determined by means of semi-quantitative retro-transcription polymerase chain reaction (RT-PCR) to test mdr1 gene mRNA and ER expression was studied by immunohistochemistry. Tumor tissues from three cases of human colon carcinoma, which had mdr1(+)/ER(+),mdr1(+)/ER(-), mdr1(-) expressions, were planted subcutaneously in the neck of nude mice to establish three xenograft models. These models were subdivided into four subgroups randomly: Doxorubicin (DOX)-treated group, TAM-treated group, DOX and TAM group and control group. The dimensions of these xenografts were measured after each course of treatment and the xenografts were removed at the end of the experiments for measurements of weight and the variation of mdr1 mRNA level with RT-PCR. In each course, TAM [15 mg/(kg/d)] was administrated orally per day in the first seven days and DOX (3.6 mg/kg) was injected peritoneally on the first day. Data was evaluated by q and t tests. RESULTS: In the animal models with mdr1(-) tumor, the weights and volumes of the planted tumor in DOX group [(39.1±2.29) mg, (31.44±1.61) mm3] and TAM and DOX group [(38.72±2.56) mg, (31.31v1.74) mm3], which were lesser than that of control group [(45.48±3.92) mg, (36.42±2.77) mm3, P= 0.037, P= 0.016 respectively] significantly. In the animal models with mdr1(+)/ER(+) tumor, the weights and volumes of planted tumor were not affected by DOX or TAM treatment; however, in TAM and DOX group [(425.5±28.58) mg, (340.35±22.28) mm3], they were significantly less than that of control group [(634.23±119.41) mg, (507.45±93.34) mm3, P= 0.022, P = 0.045 respectively], which are similar to that in the models with mdr1(+)/ER(-) tumor. No significant changes were found in the expressive level of mdr1 mRNA following these treatments. CONCLUSION: The expression of mdr1 gene corresponds to the sensitivity of colon cancer to anti-tumor drugs in vivo. TAM can reverse the MDR of colorectal carcinoma in nude mice, which is independent of the expression of ER; however, no change was observed in the expressive level of mdr1 mRNA.

Experiment study of Swainsonine's antineoplastic activity

ED50 of Pure Swainsonine (SW) to EMT6 cell strain is 1.2 (0.8-1.6) mg/L and the dose of entire lethal is 6.4 mg/L with MTT method. After ig crude extraction of SW to S180 sareoma rooted in mouse and EMT6 model mice with breast carcinoma for 12 d at dose of 16 mg/kg, the inhibitory rates of weight amounts to 49.7% and 49.4% respectively (P<0.01). Given crude extraction of SW at 4 mg/kg combined with irradiation at 5 Gy60Co-γ, the inhibitory rate of weight of S180 amount to 64.5% (P<0.01). It shows that SW has obviously antineoplastic.

Glutamine is highly effective in preventing in vivo cobalt-induced oxidative stress in rat liver

AIM: To evaluate the in vivo effect of glutamine on cobaltgenerated oxidative stress and (HO-1) induction in rat liver.METHODS: Fasted female Wistar rats received a single injection of cobalt chloride (375 μmol/kg body weight) and then were killed at different times. Lipid peroxidation and soluble and enzymatic antioxidant defense system (reduced glutathione (GSH), catalase (CAT), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD)) were measured in liver homogenates. Ferritin and ferritin iron contents as well as heme oxygenase-1 (HO-1) activity and expression were also determined. The antioxidant properties of glutamine (Gin) were also evaluated. RESULTS: Cobalt chloride increased lipid peroxidation (50% over control values) 1 h after treatment. GSH reached a minimum at 3 h (40%) increasing thereafter. Twelve hours after CoCl2 injection, the antioxidant enzymes CAT, GSH-Px and SOD also diminished by about 30%. Heme oxygenase-1 induction was observed 6 h after treatment reaching a maximum value of 14-fold over the controls, 12 h after cobalt treatment. A 1.7-fold increase in ferritin and ferritin-bound iron 24 h after treatment were also obtained. Administration of glutamine (300 mg/kg body weight) by gavage 24 h before CoCl2 treatment entirely prevented the increase in thiobarbituric acid reactive substances (TBARS) content, the decrease in GSH levels, and partially reverted heme oxygenase-1 induction. CONCLUSION: These results suggested that a natural product such as glutamine prevents glutathione depletion and consequently heme oxygenase induction.

Effect of Astragalus complanatus flavonoid on anti-liver fibrosis in rats

AIM： To observe the anti-liver fibrosis effect of Astragalus complanatus fiavonoids （ACF） in rats. METHODS： The liver fibrosis model in rats was established by injecting interperitoneally 0.2 mL/100 g 0.5% dimethylnitrosamine, thrice a week. Meanwhile, the rats were administered ACF （30, 60, 120 mg/kg） or colchicine （0.1 mg/kg） once a day for 1 mo. Serum N-propeptide of type Ⅰ procollagen （PINP） and type Ⅲ procollagen （PⅢNP） was measured using ELISA. Malondialdehyde （MDA） and superoxide dismutase （SOD） in hepatic tissue were evaluated. Matrix metal protease-1 （MMP-1） mRNA expression was assayed by RT-PCR and the protein expression of tissue inhibitor of metal protease-1 （TIMP-1） was analyzed by immunohistochemistry. RESULTS： In the ACF groups, SOD activity increased and MDA content decreased in comparison to the liver fibrosis model group. The serum PINP and PⅢNP contents in ACF-2 and -3 group decreased compared to those in model group. In ACF-2 and -3 group, the expression of MMP-1 mRNA increased significantly and the protein expression of TIMP-1 decreased compared to that in model group. CONCLUSION： The antifibrotic mechanisms of ACF are associated with its influence on lipid peroxidation and collagen synthesis and degradation.

Effects of emodin and baicalein on rats with severe acute pancreatitis

AIM: To investigate the therapeutic effects of emodin in combination with baicalein on severe acute pancreatitis (SAP) rats and to explore the mechanism of SAP. METHODS: A total of 112 SAP rats induced by retrograde injection of 5% sodium taurocholate into the biliarypancreatic duct, randomly assigned to a untreated group and three treated groups emodin group, combined emodin and baicalein group, and sandostatin group. Meanwhile, another 28 other rats were selected as sham operation (SO) group. There were 28 rats in each group, 8 rats were in 3 and 6 h groups respectively, and 12 rats in 12 h group. At each time-points, survival rates, ascites volumes, pathological lesion scores of pancreas tissues, serum amylase, tumor necrosis factor-α and IL-6 levels were determined as the indexes of therapeutic effects. RESULTS: The survival rate at 12 h was significantly higher in three treated groups than in untreated group. The ascites volume at 12 h was remarkably less in combined and sandostatin groups than in emodin group, but there was no difference between combined group and sandostatin group (P＞0.05). Serum amylase levels at all time-points were significantly lower in three treated groups than in untreated group. However, they had no difference among treated groups (P＞0.05). Serum TNF-α were lower in three treated groups than in untreated group at all time points. Among the three treated groups, at 6 h, the TNF-α levels of combination and sandostatin groups were lower than those of emodin group. These was no difference between combined and sandostantin. Serum IL-6 concentration at 3 h were lower in combined and sandostatin groups than in untreated group, but at 6 and 12 h they were lower in all treated groups than in untreated group and the combined and sandostatin groups and in emodin group, no difference was found between combined and sandostatin groups at all time-points (P＞0.05). The pathological scores of pancreas at all time points were significantly lower in three treated groups than in the untreated group, and at 6, 12 h, the scores of combined and sandostatin groups were lower than in emodin group. There was no difference between combined and sandostatin groups (P＞0.05). CONCLUSION: Combination of emodin with baicalein has significant therapeutic effects on SAP rats.

Effect of emodin on small intestinal peristalsis of mice and relevant mechanism

AIM: To investigate the effect of emodin on small intestinal peristalsis of mice and to explore its relevant mechanisms.METHODS: The effect of emodin on small intestinal peristalsis of mice was observed by charcoal powder propelling test of small intestine. The contents of motilin and somatostatin in small intestine of mice were determinated by radioimmunoassay. The electrical potential difference (PD) related to Na+ and glucose transport was measured across the wall of reverted intestinal sacs. Na+-K+-ATPase activity of small intestinal mucosa was measured by spectroscopic analysis.RESULTS: Different dosages of emodin can improve small intestinal peristalsis of mice. Emodin increased the content of motilin, while reduced the content of somatostatin in small intestine of mice significantly. Emodin 0.2, 0.4, 0.8, and 1.6 g/L decreased PD when there was glucose. However, emodin had little effect when glucose was free. The Na+-K+-ATPase activity of small intestinal mucosa of mice in emodin groups was inhibited obviously. CONCLUSION: Emodin can enhance the function of small intestinal peristalsis of mice by mechanisms of promoting secretion of motilin, lowering the content of somatostatin and inhibiting Na+-K+-ATPase activity of small intestinal mucosa.

Sacral anterior root stimulated defecation in spinal cord injuries: An experimental study in canine model

AIM: To investigate whether there was a dominant sacral root for the motive function of rectum and anal sphincter, and to provide an experimental basis for sacral root electrically stimulated defecation in spinal cord injuries. METHODS: Eleven spinal cord injured mongrel dogs were included in the study. After L4-L7 laminectomy, the bilateral L7-S3 roots were electrostimulated separately and rectal and sphincter pressure were recorded synchronously. Four animals were implanted electrodes on bilateral S2 roots. RESULTS: For rectal motorial innervation, S2 was the most dominant (mean 15.2 kPa, 37.7% of total pressure), S1(11.3 kPa, 27.6%) and S3 (10.9 kPa, 26.7%) contributed to a smaller part. For external anal sphincter, S3 (mean 17.2 kPa, 33.7%) was the most dominant, S2 (16.2 kPa, 31.6%) and S1(14.3 kPa, 27.9%) contributed to a lesser but still a significant part. Above 85% L7 roots provided some functional contribution to rectum and anal sphincter. For both rectum and sphincter, the right sacral roots provided more contribution than the left roots. Postoperatively, the 4 dogs had electrically stimulated defecation and micturition under the control of the neuroprosthetic device. CONCLUSION: S2 root is the most dominant contributor to rectal pressure in dogs. Stimulation of bilateral S2 with implanted electrodes contributes to good micturition and defecation in dogs.

Impact of release characteristics of sinomenine hydrochloride dosage forms on its pharmacokinetics in beagle dogs

AIM： To investigate the effect of release behavior of sustained-release dosage forms of sinomenine hydrochloride （SM·HCl） on its pharmacokinetics in beagle dogs. METHODS： The in vitro release behavior of two SM·HCl dosage forms, including commercial 12-h sustained-release tablets and 24-h sustained-release pellets prepared in our laboratory, was examined. The two dosage forms were orally administrated to beagle dogs, and then the in vivo SM.HCI pharmacokinetics was investigated and compared. RESULTS： The optimal SM·HCl sustained-release formulation was achieved by mixing slow- and rapidrelease pellets （9：1, w/w）. The SM·HCl release profiles of the sustained-release pellets were scarcely influenced by the pH of the dissolution medium. Release from the 12-h sustained-release tablets was markedly quicker than that from the 24-h sustained-release pellets, the cumulative release up to 12-h was 99.9% vs68.7%. From a pharmacokinetic standpoint, the 24-h SM.HCI sustainedrelease pellets had longer tmax and lower Cmax compared to the 12-h sustained-release tablets, the tmax being 2.67±0.52 h vs 9.83±0.98 h and the Cmax being 1334.45±368.76 ng/mL vs 893.12±292.55 ng/mL, respectively. However, the AUC0-tn of two SM·HCl dosage forms was comparable and both preparations were statistically bioequivalent. Furthermore, the two preparations had good correlations between SM·HCl percentage absorption in vivoand the cumulative percentage release in vitro. CONCLUSION： The in vitro release properties of the dosage forms strongly affect their pharmacokinetic behavior in vivo. Therefore, managing the in vitro release behavior of dosage forms is a promising strategy for obtaining the optimal in vivo pharmacokinetic characteristics and safe therapeutic drug concentration-time curves.

Anti-ulcer effects of Lycium barbarum polysaccharide in rats

Objective: To investigate the effects of Lycium barbarum polysaccharide (LBP) on experimental gastric ulcers in rats.Methods: The ulcers were induced by water-immersion restraint stress, acetic acid and pylorus-ligation in rats. In each model, animals were divided randomly into 4 groups and administrated with LBP of 100 mg/kg and 300 mg/kg, ranitidine 100 mg/kg (as a reference standard) and saline respectively. Mucosal lesions were scored as ulcer index. In the pylorus-ligation model, we also compared the gastric juice volume, total acidity, acid output and pepsin activity among groups.Results: Oral administration of LBP inhibited the formation of the acute gastric lesions induced by physical stress such as water-immersion restraint (P<0.05), and accelerated the healing of chronic gastric ulcer model induced by acetic acid (P<0.05 to P<0.01). In the pylorus-ligated rats, significant decrease was also seen in ulcer index (P<0.05 to P<0.01), total acidity (P<0.05), acid output (P<0.05 to P<0.01). LBP 300 mg/kg even showed marked reduction of the volume (P<0.05) and pepsin activity (P<0.05) in the gastric juice. These effects were in a dose-dependent manner. Conclusion: LBP has protective effects on treating gastric ulcer and this action may relate to the reduction of acid output and pepsin activity in the gastric juice.

EXPERIMENTAL STUDY ON THE EFFECT OF ACUPOINT-CATGUT-EMBEDDING ON EEG OF EPILEPSY RATS

Aim: To observe the therapeutic effect of acupoint catgut embedding in the treatment of epilepsy rats. Methods: 40 Wistar rats were randomly and evenly divided into normal control, model, medication (Natrii Valproas syrup), and catgut embedding groups. Epilepsy model was established by intraperitoneal injection of sodium penicillin (0.4 mu/100 g), twice every week, continuously for 4 weeks. Electroencephalograph (EEG) was used as the index for assessing the effect of catgut embedding on epilepsy. Results: In epilepsy rats of model group, the amplitude and frequency of EEG increased significantly in comparison with control group (P<0.05). While the amplitude and frequency of EEG of catgut embedding group and medication group were all significantly lower than those of model group (P<0.05, 0.01). The frequency of EEG of catgut embedding group was significantly lower than that of medication group (P<0.05). These findings show that both acupoint catgut embedding and medication can apparently improve epileptic electrical activities of the brain in the rat, and the effect of catgut embedding is better than that of medication in lowering the frequency of EEG.

NEUTROPHIL INFILTRATION IS INVOLVED IN 5-FLUOROURACIL INDUCED LIPID PEROXIDATIVE DAMAGE OF THE SMALL INTESTINE

This study evaluated the mechanisms of 5-fluorouracil (5-FU) induced intestinal damage by investi-gating the lipid peroxide (LPO) level, myeloperoxidase (MPO) activity and disaccharidase activity in rats.Group Ⅰ animals (n=6) were sacrificed and served as a normal control group. Group Ⅱ animaIes (n= 24 )were given a single intraperitoneal injection of 5-FU (150 mg/kg) and every 8 rats were sacrificed on day1,3 and 5 after injection respectively. Results: LPO concentration in blood and intestinal mucosa was sig-nificantly higher in the group Ⅱ than in the group Ⅰ on day 1 and 3 (P<0. 05) MPO activity was signif-icantly higher in the group I than in the group Ⅰ at different times (P<0. 01 ). Lactase activity on day 5(P<0. 01); sucrase activity (P<0. 01 and P<0. 05 respectiviely) and maltase activity (P<0. 01 ) on day3 and 5, were significantly lower in the group than in the group l. Conclusion: The results indicatethat neutrophil infiltration may be involved in 5-FU-induced lipid peroxidative damage of the small intes-tine which was reflected by the decreased disaccharidases activities.

近交系小鼠C57BL/6和C57BL/10的转录组差异研究

目的:对近交系小鼠C57BL/6和C57BL/10进行转录组测序,对比其转录组差异,发现免疫反应相关差异基因,为药物体内活性评价动物选择提供参考。方法:采用Illumina Hiseq 2000测序平台进行测序,通过短序列分析获取转录本,通过基因功能分类(GO)和京都基因与基因组百科全书(KEGG)数据库进行测序结果分析。结果:获得38 553 614个C57BL/6小鼠的原始序列和37 721 318个C57BL/10小鼠的原始序列。获得118 002个转录本,注释了46 193个差异基因。38 106个转录本注释到2 196个GO分类中,GO分类主要分为3类:细胞成分,分子功能和生物过程。1 600个转录本注释到254个KEGG通路中。另外,发现了4 651个单核苷酸(SNP)位点。结论:通过二代测序方法发现近交系小鼠C57BL/6和C57BL/10转录组存在显著差异基因。在KEGG通路分析中筛选了一系列与小鼠免疫应答相关的差异基因,为建立小鼠免疫评价模型积累了数据,对药物实验动物体内活性检测分析具有参考意义,为生物制品评价用实验动物的标准化提供技术支撑。

Common parameters of acupuncture for the treatment of hypertension used in animal models

Hypertension is associated with at least 7.6 million annual deaths worldwide.While pharmacotherapy may provide good control for blood pressure,it sometimes induces adverse effects.Meanwhile,acupuncture has been used for the treatment of cardiovascular diseases,such as hypertension,coronary artery disease,and stroke,but its mechanisms of actions remain poorly understood.The efficacy of acupuncture depends on multiple constituent elements including acupoints,manipulation skills,and implementation programs,which are termed as acupuncture prescription.This review summarized the previous information of experimental use of acupuncture on animals including species,hypertension models,acupoints selection,acupoint location,stimulation protocols,and evaluation of effectiveness to provide useful guidance for researchers when performing acupuncture in animal experiments.

Therapeutic effect of cisapride on gastric injury following hemorrhagic shock resuscitation in rats

Objective: To investigate the therapeutic effect of cisapride on gastric injury following hemorrhagic shock resuscitation. Methods: 108 Wistar rats weighing (200 g±30 g) were randomly divided into a sham shock (SS) group (n=36), a hemorrhagic shock resuscitation (HS) group (n=36) and a hemorrhagic shock cisapride treated (HSC) group (n=36). Sampling at 1, 2 and 4 hours after resuscitation was done and 6 samples for each observation item were taken. The gastric blood flow volume was measured by isotope label biological microglobulin. Gastric pHi, gastric emptying, MDA and Na+-K+-ATPase of gastric mucosa were measured. Results: In the HSC group, the relative residual rate of gastric pigment decreased significantly, the gastric blood flow volume elevated; gastric pHi increased significantly at 2 hours; the level of mucosal MDA decreased at 4 hours, the activity of Na+-K+-ATPase increased and the lactic acid level in the portal vein decreased significantly compared to the HS group. Conclusions: After hemorrhagic shock resuscitation, cisapride contained the following functions,1) promoting gastric emptying, 2) increasing the blood flow of gastric blood flow volume and gastric pHi, 3) depressing the lactic acid concentration of the portal vein and improving MDA volume and Na+-K+ -ATPase activity of gastric mucosa. It suggests that after comple menting effective circulating blood volume for hemorrhagic shock resuscitation, early use of cisapride for gastric motility is helpful for an improvement of lasting ischemia and hypoxia in stomach.