Determination of Plasma Concentration of Cinnamic Acid by High-Performance Liquid Chromatography and Its Pharmacokinetics in Rats after Oral Administration of Zi-Shen Pill

Aim To develop a simple and sensitive high-performance liquid chromatographicmethod for determination of plasma concentration of cinnamic acid and pharmacokinetic study in ratsafter a single oral dose of traditional Chinese medicinal preparation Zi-Shen pill. Method Plasmasamples were acidified with hydrochloric acid and extracted with ethyl acetate . Cinnamic acid wasdetermined by HPLC using a G_(18) column. A mobile phase ofmethanbl-acetonitrile-water-triethyl-amine (7:22:73 = 0.2, V/V), with the pH adjusted to 4.0 withphosphoric acid, and with a UV detector set at 340 nm. Results The standard curve was linear overthe range of 1.92- 192.0 μg·mL^(-1). The LLOQ was 1.92 μg·mL^(-1) . The RSDs of within-day andbetween-day precision were < 8%. The mean recovery was 82.0% . Conclusion After validation, themethpd has been used to investigate the pharmacokinetic profiles of the traditional Chinesemedicinal preparation Zi-Shen pill.

Protective Effect of Ascorbate-Lysine on Carbon Tetrachloride and Alcohol-Induced Liver Injury in Mice

As an essential amino acid, lysine boosts protein synthesis (Nestor et al1997). Yao et al demonstrated that, lysine also exerts protective effect against the isch-emiclesion of brain. Meanwhile, vitamin C is a natural antioxidant, which has undisputable protectiveaction against free radical damages. In order to ascertain whether their combination could affordbetter effect, we have investigated the prophylactic effect of the couplant ascorbate-lysine inliver injuries.

Pharmacokinetics of Recombinant E. coli L-asparaginase in Rats

The distribution of ^(125)I recombinant E. coli L-asparaginase in tissues ororgans and the excretion in urine, feces and bile were studied with in vivo radioactive tracertechnique. The amount of radioactivity excreted in urine, feces and bile within 24 h afterintravenous administration of ^(125)I recombinant E. col L-asparaginase to rats was 68.95% ,4.44%and 5.36% of the dose respectively. ^(125)I recombinant E. coli L-asparaginase in plasma samples wasdetermined. The levels of structural intact molecule in plasma samples were evaluated by SDS-PAGEand bio-imaging analyzer system. Pharmacokinetic parameters were assessed with a model-dependentmethod. The concentration-time curves of recombinant E. coli L-asparaginase after intravenousinjection at 1 250 IU·kg^(-1), 2 500, IU·kg^(-1), 5 000 IU·kg^(-1) to rats were consistent withthe two-compartment model. The first and terminal elimination t_(1/2) were 0.52 ~ 0.63 h and 2.39 ~2.76 h respectively. AUC was linearly related to the doses. The results of distribution in tissuesor organs and excretion in urine suggested that the metabolites of the enzyme were cleared bymechanisms of urinary excretion. Pharmacokinetics parameters of recombinant E. coli L- asparaginasein rats are warranted for the design of future clinical trials.

Establishment of a mdr1 Multidrug Resistant Model of Orthotopic Transplantation of Liver Carcinoma on Nude Mice

To develop a new method of inducing mdrl multidrug resistance by establishinga nude mice model of orthotopic transplantation of liver carcinoma by sporadic abdominalchemotherapy at intervals. Methods: Hepatocellular carcinoma HepG2 cell was cultured and injectedsubcutaneously to form the tumor-supplying mice. The tumor bits from the tumor-supplying mice wereimplanted under the envelope of the mice liver and induced by abdominal chemotherapy withPharmorubicin. Physical examination, ultrasonography, spiral CT and operative inspection were usedto examine tumor progression. RT-PCR and immunohistochemistry were adopted to detect the expressionof mdr1-mRNA and its encoded protein P-gp protein (P-gp). Results: There was no operative dead, therate of implanting tumor successfully was 88% (22/25), the rate of implanting secondly successfullywas 100% (3/3), and the rate of inducing successfully was 80% (16/20). The expression of mdrl-mRNAand the P-gp in the inducing group was 23 folds and 13 folds in the control group respectively.Conclusion: We have established an in vivo model of mdr using nude mice transplanted with orthotopicliver neoplasm coupled to chemotherapy.

幽默

让座 一次坐公交，有位美女上车，掏出公交卡来刷，只听刷卡机回复：“滴……老人卡……!”全车人冻住了，目光一起瞅向她。她一脸黑线说：“看什么，天山童姥，没见过啊？”一大爷起身，说：“来，大娘。您坐这。”

Pharmacokinetics and Bioavailability of 2-Amino-6-Cyclopropylamino-9-(2,3 -Dideoxy-β-D-glyceropent-2-enofuranosyl) Purine (Cyclo-D4G) in Rats

AimTo characterize the pharmacokinetics of 2 -amino-6-cyclopropylamino-9-(2,3-dideoxy-β-D-glyceropent-2-enofuran osyl) purine (Cyclo-D4G) following intravenous administration and oral administ ration to rats. MethodsThe concentrations of Cyclo-D4G in rat (Sprague-Dawley male rats) plasma and urine were analyzed by high performance liquid chromatography (HPLC). ResultsFollowing intravenous adm inistration to rats, concentrations of Cyclo-D4G in plasma declined with a term inal phase half-life of 0 78±0 14 h (±s). Total clearance was 0 90±0 21 L·h -1 ·kg -1 . Renal excretion of unchanged Cyclo-D4G accounted for approximately 20% of total clearance. Steady state volume of distr ibution was 0 91±0 07 L·kg -1 . After oral administration to rats, conce ntrations of Cyclo-D4G in plasma declined with a terminal phase half-life of 0 83±0 13 h (±s). Total clearance was 3 81±2 03 L·h -1 ·kg -1 . Renal excretion of unchanged Cyclo-D4G accounted for approximat ely 9% of total clearance. Oral bioavailability of Cyclo-D4G in rat was 26 9%. ConclusionThe favorable pharmacokinetic profiles and lower to xicity provide support for further development of Cyclo-D4G clinical trials.

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.

Effects of Chinese herbs on salivary fluid secretion by isolated and perfused rat submandibular glands

AIM： TO determine whether Chinese herbs （CHs） relieve xerostomia （dry mouth） by increasing salivary secretion. METHODS： The submandibular glands of Wistar rats were surgically isolated and perfused arterially with buffered salt solution. After control perfusion, recording started 5 min prior to the start of stimulation. After fluid secretion was induced by 0.2 μmol/L carbamylcholine （CCh） in the perfusate for 10 min, Chinese herb （CH） was added in the perfusion for 5 min. CCh was then overloaded at 0.2 μmol/L in the perfusion for 20 min. The volume of salivary fluid secretion was recorded by a computer-controlled balance system. RESULTS： Saliva secretion formed an initial ephemeral peak at 30 s followed by a gradual increase to a sustained level. CH alone induced no or little saliva in all types of CH selected. During perfusion with CH,overloading of CCh promoted fluid secretion in 1S of 20 CHs. This promotion was classified into four patterns, which were eventually related to the categories of CH： Overall sustained phase was continuously raised （Yin-nourishing, fluid production-promoting and heatclearing agents）; The sustained secretion rose to reach a maximum then decreased （Qi-enhancing agent）; Sustained secretion rose to reach the highest maximum and was then sustained with a slight decline （swelling-reducing, phlegm-resolving and pus-expelling agents）; Stimulation of salivary secretion without any added stimulants. Addition of CCh raised the fluid secretion to reach the highest maximum then sharply decreased to a lower sustained level （blood activating agent）. CONCLUSION： The present findings lead to the conclusion that various CHs have different promotional effects directly on the salivary gland.

Chronic morphine drinking establishes morphine tolerance, but not addiction in Wistar rats

Objective： Some animal models apply morphine in the drinking water to generate addiction, but related reports are not free of conflicting results. Accordingly, this study aimed to figure out if chronic consumption of morphine in the drinking water can induce morphine addiction in Wistar rats. Methods： For 3 weeks, the animals received a daily morphine dose of 35 mg/kg by offering a calculated volume of sugar water （5% sucrose） with morphine （0. l mg/ml） to each rat; animals receiving just sugar water served as controls. Immediately after the treatment phase, the tail immersion test was used to check for morphine tolerance, and all animals were then kept on tap water for one week （withdrawal phase）. Afterwards, all rats were allowed to choose their drinking source by offering two bottles, containing sugar water without and with morphine, simultaneously for two days （preference phase）. Results： While the chronic consumption of morphine led to a reduction in body weight and to morphine tolerance, the morphine-treated Wistar rats did not show any preference for the opiate-containing sugar water. Conclusion： Body weight loss and tolerance do not reveal a condition of drug craving, and current animal models should be re-evaluated regarding their potential to establish morphine addicted animals.

Effects of atorvastatin on vascular remodeling in spontaneously hypertensive rats

Objective: To investigate the structural changes of aorta, and evaluate the effects of atorvastatinon the remodeling of thoracic aorta in spontaneously hypertensive rats(SHR) . Methods : Twelve eight-week-old SHR were randomized into atorvastatin treated group( ATV group, n = 6) and distilled water group( DW group, n = 6) ; Wistar-Kyoto rats(WKY) were used as normal controls. Atorvastatin was administered to ATV group for 10 weeks by gavage in mixture with distilled water( 1ml) ; the latter two groups were given the same amount of distilled water by gavage for 10 weeks. Systolic blood pressure of caudal artery was examined before and after treatment, and serum concentrations of total cholesterol, triglycerides and HDL-C were measured.Wall thickness, media thickness, medial cross-sectional area and lumen diameter of thoracic aorta were assessed with computed video processing. Results: Systolic blood pressure in ATV group was markedly lower than that in DW group( P < 0.01). Compared with DW group and WKY group, serum concentrations of total cholesterol, triglycerides and HDL-C in ATV group were significantly lower( P < 0.01, P < 0.05). Wall thickness, media thickness, and medial cross-sectional area to lumen ratio in DW group were significantly higher than those in WKY group and ATV group( P < 0.01, P < 0.05), but no such difference was found between WKY group and ATV group( P > 0.05 ). Conclusion : Vascular structural changes of aorta are due to the alteration of the vessel wall in early stage of SHR. Atorvastatin can markedly improve vascular remodeling.

Ca^(2+) cytochemical changes of hepatotoxicity caused by halothane and sevoflurane in enzyme-induced hypoxic rats

AIM： To investigat the relation between hepatotoxicity of halothane and sevoflurane and altered hepatic calcium homeostasis in enzyme-induced hypoxic rats. METHODS： Forty-eight rats were pretreated with phenobarbital and randomly divided into six groups （eight in each group） and exposed to O2/N2/1.2 MAC anesthetics for 1 h： normal control （NC）, 21% O2/79% N2; hypoxic control （HC）, 14% O2/86% N2; normal sevoflurane （NS）, 21% O2/ N2/1.2MAC sevoflurane; hypoxic sevoflurane （HS）, 14% O2/N2/1.2MAC sevoflurane; normal halothane （NH）21%O2/79%N2/1.2MAC halothane; hypoxic halothane （HH）, 14%O2/N2/1.2MAC halothane. Liver specimens and blood were taken 24 h after exposure to calcium and determined by EDX microanalysis. RESULTS： The liver of all rats given halothane （14% O2） had extensive centrilobular necrosis and denaturation. Morphologic damage was accompanied with an increase in serum glutarnic pyruvic transminase. In groups NH and HH, more calcium was precipitated in cytoplasm and mitochondria. CONCLUSION： These results suggest that halothane increases cytosolic Ca^2＋ concentration in hepatocytes. Elevation in Ca^2＋ concentration is implicated in the mechanism of halothane-induced hepatotoxicity. sevoflurane is less effective in affecting hepatic calcium homeostasis than halothane.

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.

A pharmacodynamic model of portal hypertension in isolated perfused rat liver

AIM： To develop a pharmacodynamic model of porta hypertension from chronic hepatitis. METHODS： Pathological changes and collagen depositions were analyzed using morphometry to confirm CCI4-induced chronic hepatitis. At do, d28, ds6 and d84 of the process, the portal perfused velocities （μL/min） in isolated rat livers were exactly controlled with a quanti-fied pump. The pressure （mmHg） was monitored with a Physiological System. The geometric concentrations of phenylephrine or acetylcholine were added to a fixed volume （300 mL） of the circulating perfusate. The equation, the median effective concentration and its 95% confidence intervals of phenylephrine or acetyl- choline were regressed with Prism-4 software in non-linear fit and various slopes. In the isolated perfused rat livers with chronic hepatitis, both median effective concentrations were defined as the pharmacodynamic model of portal hypertension.CONCLUSION： A pharmacodynamic model of portal hypertension in isolated perfused rat livers with chronic hepatitis was defined as the median effective concen- trations of phenylephrine and acetylcholine.

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 Sinai San decoction on the development of non-alcoholic steatohepatitis in rats

AIM: To explore the effect of Sinai san decoction on the development of non-alcoholic steatohepatitis induced by CCL4 combined with a fat-rich diet in rats.METHODS: Twenty-seven Sprague-Dawley rats were divided into three groups randomly: control group (n = 9),model group (n = 9) and treatment group (n = 9). The rats of model group and treatment group were given small dosage of CCL4 combined with a fat-rich diet, andthose of control group were given normal diet. After four weeks of fat-rich diet feeding, the rats of treatment group were given Sinai san decoction. The serum levels of aminotransferase and lipid were measured, and the pathology of livers was observed by HE staining after the rats were sacrificed at eight weeks.RESULTS: The rats' livers presented the pathology of steatosis and inflammation with higher serum levels of ALT and AST in the model group. In the treatment group the serum ALT and AST levels decreased significantly and were close to the control group. The hepatic inflammation scores also decreased markedly, but were still higher than those of control group. And the degree of hepatocyte steatosis was similar to that of model group.CONCLUSION: Sinai san decoction may ameliorate the hepatic inflammation of rats with steatohepatitis induced by small dosage of CCL4 combined with a fat-rich diet,but does not prevent the development of hepatocyte steatosis.

Gastric mucosal injury due to hemorrhagic reperfusion and efficacy of Salvia miltiorrhizae extract F and cimetidine

AIM: To observe the gastric mucosal injury caused by hemorrhagic shock and reperfusion and to compare the effect between Salvia miltiorrhizae extract F (SEF) and cimetidine (CI) on it. METHODS: A model of hemorrhage/reperfusion injury was produced by Itoh method. Wistar rats were randomly divided into three groups: 0.9% sodium chloride treatment group (NS group), SEF treatment group (SEF group), and CI treatment group (CI group). Saline, SEF and CI were injected respectively. The index of gastric mucosal lesions (IGML) was expressed as the percentage of lesion area in the gastric mucosa. The degree of gastric mucosal lesions was categorized into grades 0, 1, 2, 3. Atom absorption method was used to measure the intracellular calcium content. Radioimmunoassay was used to measure the concentrations of prostaglandins. RESULTS: IGML (%) and grade 3 (%) were 23.18±6.82, 58.44±9.07 in NS group, 4.42±1.39, 20.32±6.95 in SEF group and 3.74±1.56, 23.12±5.09 in CI group, and the above parameters in SEF group and CI group decreased significantly (IGML: SEF vs NS, t=6.712, P=0.000<0.01; CI vs NS, t=6.943, P=0.000<0.01; grade 3: SEF vs HS, t=8.386, P=0.000; CI vs HS, t=8.411, P= 0.000), but the grade 0 and grade 1 damage in SEF group (22.05±5.96, 34.12±8.12) and CI group (18.54±4.82, 30.15±7.12) were markedly higher than those in NS group (3.01±1.01, 8.35±1.95; grade 0: SEF vs HS, t=8.434, P=0.000<0.01; CI vs NS, t=7.950, P=0.000<0.01; grade 1: SEF vs NS, t =8.422, P=0.000<0.01; CI vs NS, t=8.448, P=0.000<0.01). The intracellular calcium content (μg/mg) in SEF group (0.104±0.015) and CI group (0.102±0.010) was markedly lower than that in NS group (0.131±0.019, SEF vs NS, t=2.463, P=0.038<0.05; CI vs HS, t=3.056, P=0.017<0.05). The levels (pg/mg) of PGE_2, 6-keto-PGF_(1α) and 6-keto-PGF_(1α)/TXB_2 were 540±183, 714±124,17.38±5.93 in NS group and 581±168, 737±102, 19.04±8.03 in CI group, 760±192,1 248±158, 33.42±9.24 in SEF group, and the above parameters in SEF group markedly raised (PGE_2: SEF vs NS, t=2.282, P=0.046<0.05; SEF vs CI, t=2.265, P=0.047<0.05; 6-keto-PGF_(1α): SEF vs NS, t=6.583, P=0.000<0.000; SEF vs CI, t=6.708, P=0.000<0.01; 6-keto-PGF_(1α)/TXB_2: SEF vs NS, t=3.963, P=0.003<0.001; SEF vs Cl, t=3.243, P=0.009<0.01), whereas TXB_2 level in SEF group (45.37±7.54) was obviously lower than that in NS group (58.28±6.74, t=3.086, P=0.014<0.05) and CI group (54.32±6.89, t=2.265, P=0.047<0.05). No significant difference was shown between NS group and CI group (PGE_2: t=0.414, P=0.688>0.05; 6-keto-PGF_(1α): t=0.310, P=0.763>0.05; TXB_2: t=1.099, P=0.298>0.05; 6-keto-PGF_(1α)/TXB_2: t=0.372, P=0.718>0.05). CONCLUSION: Both SEF and CI could inhibit reperfusioninduced injury in gastric mucosa, but with different mechanisms. SEF could not only enhance the protective effect of gastric mucosa, but also abate the injury factors, while CI can only abate the injury factors.

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.

Antitumor effect and mechanism of Gecko on human esophageal carcinoma cell lines in vitro and xenografted sarcoma 180 in Kunming mice

AIM: To investigate the anti-tumor effect of Chinese medicine Gecko on human esophageal carcinoma cell lines and xenografted sarcoma 180 in Kunming mice and its mechanism. METHODS: The serum pharmacological method was used in vitro . The growth rates of the human esophageal carcinoma cells (EC9706 or EC1) were measured by a modifi ed 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The transplanted tumor model of the mouse S180 sarcoma was established. Fifty mice were randomly divided into fi ve groups (n = 10). Three Gecko groups were treated respectively with oral administration of Gecko powder at a daily dose of 13.5 g/kg, 9 g/kg, and 4.5 g/kg. The negative group (NS group) was treated with oral administration of an equal volume of saline and the positive group (CTX group) was treated with 100 mg/kg Cytoxan by intraperitoneal injection at the fi rst day. After 2 wk of treatment, the anti-tumor activity was evaluated by tumor tissue weighing. The impact on immune organ was detected based on the thymus index, spleen index, phagocytic rate and phagocytic index. The protein expression of vascular endothelingrowth factor (VEGF) and basic fibroblast growth factor (bFGF) were detected by immunohistochemistry. The cell apoptotic rate was detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay. RESULTS: The A value in each group treated with Gecko after 72 h was reduced signif icantly in EC9706 and in EC1. The tumor weight in each group of Gecko was decreased signifi cantly (1.087 ± 0.249 vs 2.167 ± 0.592; 1.021 ± 0.288 vs 2.167 ± 0.592; 1.234 ± 0.331 vs 2.167 ± 0.592; P < 0.01, respectively). However, the thymus index and Spleen index of mice in Gecko groups had no significant difference compared with the NS group. The immunoreactive score of VEGF and bFGF protein expression of each Gecko group by immunohistochemical staining were lowered signifi cantly. The apoptosis index (AI) of each group was increased progressively with increase of dose of Gecko by TUNEL. CONCLUSION: Gecko has anti-tumor effects in vitro and in vivo; induction of tumor cell apoptosis and the down-regulation of protein expression of VEGF and bFGF may be contributed to anti-tumor effects of Gecko.

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.