麦糟蛋白的胃肠酶水解液的体外抗氧化活性分析

采用胃肠消化酶对麦糟提取蛋白进行胃肠消化模拟实验,研究发现其胃蛋白酶水解液、胰蛋白酶和胰凝乳蛋白酶复合酶水解液以及胰酶水解液均具有较强的抗氧化活性。其中,胰酶水解液的总还原能力、DPPH·清除率和脂质过氧化抑制率最高,分别为2.33、39.7%、30.1%;胰蛋白酶和胰凝乳蛋白酶复合酶水解液的超氧阴离子清除率、羟自由基清除率最高,分别为42.0%、53.0%。研究结果表明麦糟蛋白的胃肠酶水解液适合用于抗氧化肽的制备。

连梅提取液对湿热泻痢仔猪的血清抗氧化指标、胃肠调节酶及十二指肠凋亡基因表达的影响

为了探索连梅提取液对湿热泻痢仔猪的抗氧化功能、胃肠调节酶及十二指肠凋亡基因表达的影响,试验采用了人工模拟高湿高热的环境,给仔猪灌服大肠杆菌辅助致使泻痢,选择泻痢仔猪分为模型组、阳性药物组和连梅提取液高、中、低剂量组,以正常环境下正常饲喂的仔猪作为对照,通过检测仔猪血清抗氧化酶、胃肠调节酶、肝ATP酶以及十二指肠凋亡基因Caspase-3、-8、-9 mRNA转录变化以分析连梅提取液治疗泻痢仔猪的作用机制。结果显示,湿热泻痢仔猪经连梅提取液进行治疗后,血清T-SOD、GSH-Px活力升高,LDH、MDA含量减少,与模型组相比较差异极显著(P<0.01);乙酰胆碱酯酶、淀粉酶、肝Na+-K+-ATPase和Ca2+-Mg2+-ATPase活力较模型组显著增强(P<0.05);T3、T4和GH分泌量显著升高(P<0.05),GC分泌量显著降低(P<0.05);同时各药物组仔猪十二指肠凋亡基因得到了不同程度的恢复,Caspase-8 mRNA表达量只有中剂量组较模型组极显著降低至2.62倍(P<0.01);Caspase-3mRNA表达中,高、中剂量组分别降至正常组的5.82、3.29倍,较模型组差异显著(P<0.05)或极显著(P<0.01);Caspase-9mRNA表达量均显著降低(P<0.05),且降低量与药物浓度成正比。由此可知,连梅提取液可以通过增强湿热泻痢仔猪抗氧化损伤能力,改善胃肠道的消化吸收,促进生长激素的分泌和降低凋亡基因的表达而达到治疗仔猪湿热泻痢。

三化汤对脑缺血-再灌注老龄大鼠胃肠组织Na^＋-K^＋-ATP酶活性及Ca^2＋-ATP酶活性的影响

目的观察三化汤对脑缺血-再灌注老龄大鼠胃肠组织Na^＋-K^＋-ATP酶活性、Ca^2＋-ATP酶活性的影响。方法将大鼠随机分为正常对照组（空白组）、模型组、三化汤组、西药对照组（尼莫地平）、中成药对照组（血栓心脉宁）。采用双侧颈总动脉结扎方法制备脑缺血模型，脑缺血1 h后，再灌注30 min。取出各组大鼠胃组织和小肠组织各5-20 mg制成匀浆，测定ATP酶（Na^＋-K^＋-ATP酶、Ca^2＋-ATP酶）活性。结果与空白组比，模型组胃肠组织Na^＋-K^＋-ATP酶活性、Ca^2＋-ATP酶活性明显降低（P〈0.01）；与模型组比，用药各组胃肠组织Na^＋-K^＋-ATP酶活性、Ca^2＋-ATP酶活性均明显升高（P〈0.05）；其中三化汤组胃肠组织Na^＋-K^＋-ATP酶活性明显高于尼莫地平组（P〈0.05），Ca^2＋-ATP酶活性明显高于血栓心脉宁组（P〈0.05）。结论三化汤能明显升高脑缺血-再灌注老龄大鼠胃肠组织Na^＋-K^＋-ATP酶活性、Ca^2＋-ATP酶活性，对脑缺血-再灌注老龄大鼠胃肠损伤有一定保护作用。

Expression of COX-2 in Different Subtypes of Gastric Intestinal Metaplasia and Gastric Carcinoma by Tissue Microarray

Objective: To study the expression of cyclooxygenase-2 (COX-2) protein in different subtypes of intestinal metaplasia (IM) and gastric carcinoma, evaluate the possibility of COX-2 forecasting the risk of malignant potential of IM, and the relationship between COX-2 expression and gastric carcinogenesis. Methods: Forty cases of chronic atrophic gastritis (CAG) with IM, 40 cases of gastric carcinoma and corresponding paracancerous tissues were selected to construct a tissue microarray. High iron diamine/alcian blue (HID/AB) staining and Hematoxylin and Eosin (HE) staining was used to classify IM and gastric carcinoma, and the expression of COX-2 protein detected in different subtypes of IM and gastric cancer by using immunohistochemistry. Results: The positive expression rate of COX-2 was 45.65%, 59.38% and 77.27% in IM foci in CAG, IM foci in paracancerous tissues, and intestinal-type gastric carcinoma, respectively, significantly higher than in diffuse-type gastric cancer (16.67%)(P<0.05, 0.005 and 0.005, respectively), and the expression intensity of COX-2 protein showed a increased tendency gradually in the sequence of IM foci in CAG→IM foci in paracancerous tissues→intestinal-type gastric carcinoma (P<0.005). The positive expression rate of COX-2 protein in type Ⅲ IM was significantly higher than in type Ⅰ and type Ⅱ IM (P<0.005 and 0.05, respectively), and the expression intensity also showed a increased tendency gradually from type Ⅰ to type Ⅲ IM (P<0.005). Conclusion: The expression level of COX-2 was increased gradually along with the increase of the risk of malignancy of IM, and its expression level may be a useful index to forecast the risk of malignant potential of IM. COX-2 expression was associated with intestinal-type gastric carcinoma, but it might also have some role in the carcinogenesis of diffuse-type gastric carcinoma.

Small gastrointestinal stromal tumor concomitant with early gastric cancer:A case report

The term gastrointestinal stromal tumors （GISTs） is defined diagnostically as the main group of mesenchymal tumors with spindle or epithelioid cells arising from the wall of the gastrointestinal tract with immunohistochemical reactivity for CD117 antibody. Previous studies revealed that cells in GISTs express a growth factor receptor with tyrosine kinase activity （termed c-kit）, which is the product of the c-kit protooncogene. The most specific and practical diagnostic criteria for GISTs are： immunohistochemically determined c-kit （CD117） expression; mitotic score; and tumor size. A small GIST concomitant with early gastric cancer is rarely encountered clinically. Herein we have reported a case of a 1.1-cm GIST detected by esophagogastroduo denoscopy concomitant with a IIc type of early gastric cancer （signet ring cell type）. It was detected during a routine physical health examination. To our knowledge, this is the first report of a small GIST concomitant with a signet ring cell type of early gastric cancer.

胃肠道脂肪酶抑制剂治疗肥胖的药理药效研究进展——以奥利司他为例

肥胖症是一种由于机体能量过剩导致的慢性代谢性疾病,有可能引起Ⅱ型糖尿病、心血管病、高血压、中风和多种肿瘤等疾病。目前有多种药物可用于肥胖症治疗,胃肠道脂肪酶抑制剂是当前治疗肥胖症的有效药物。现就胃肠道酶抑制剂及其代表药物奥利司他治疗肥胖的研究进展予以综述,旨在为肥胖症研究及其治疗药物的开发提供参考。

Carbonic anhydrases in normal gastrointestinal tract and gastrointestinal tumours

Carbonic anhydrases (CAs) catalyse the hydration of C02 to bicarbonate at physiological pH. This chemical interconversion is crucial since HCO3- is the substrate for several biosynthetic reactions. This review is focused on the distribution and role of CA isoenzymes in both normal and pathological gastrointestinal (GI) tract tissues. It has been known for many years that CAs are widely present in the GI tract and play important roles in several physiological functions such as production of saliva, gastric acid, bile, and pancreatic juice as well as in absorption of salt and water in intestine. New information suggests that these enzymes participate in several processes that were not envisioned earlier. Especially, the recent reports on plasma membrane-bound isoenzymes IX and XII have raised considerable interest since they were reported to participate in cancer invasion and spread. They are induced by tumour hypoxia and may also play a role in von Hippel-Lindau (VHL)-mediated carcinogenesis.

Heme oxygenase-1 system and gastrointestinal inflammation:A short review

Heme oxygenase-1(HO-1) system catalyzes heme to biologically active products:carbon monoxide,biliverdin/bilirubin and free iron.It is involved in maintaining cellular homeostasis and many physiological and pathophysiological processes.A growing body of evidence indicates that HO-1 activation may play an important protective role in acute and chronic inflammation of gastrointestinal tract.This review focuses on the current understanding of the physiological significance of HO-1 induction and its possible roles in the gastrointestinal inflammation studied to date.The ability to upregulate HO-1 by pharmacological means or using gene therapy may offer therapeutic strategies for gastrointestinal inflammation in the future.

Progress in researches about focal adhesion kinase in gastrointestinal tract

Focal adhesion kinase(FAK)is a 125-kDa non-receptor protein tyrosine.Growth factors or the clustering of integrins facilitate the rapid phosphorylation of FAK at Tyr-397 and this in turn recruits Src-family protein tyrosine kinases,resulting in the phosphorylation of Tyr-576 and Tyr-577 in the FAK activation loop and full catalytic FAK activation.FAK plays a critical role in the biological processes of normal and cancer cells including the gastrointestinal tract.FAK also plays an important role in the restitution,cell survival and apoptosis and carcinogenesis of the gastrointestinal tract.FAK is over-expressed in cancer cells and its over-expression and elevated activities are associated with motility and invasion of cancer cells.FAK has been proposed as a potential target in cancer therapy.Small molecule inhibitors effectively inhibit the kinase activity of FAK and show a potent inhibitory effect for the proliferation and migration of tumor cells,indicating a high potential for application in cancer therapy.

Presence of CCK-A, B receptors and effect of gastrin and cholecystokinin on growth of pancreatobiliary cancer cell lines

AIM: To investigate the effects of gastrin and cholecystokinin (CCK) and their specific antagonists on the growth of pancreatic and biliary tract cancer cell lines. METHODS: Five pancreatic and 6 biliary cancer cell lines with 2 conrtol cells were used in this study. Cell proliferation study was done using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) test and direct cell count method. Reverse transcription-polymerase chain reaction (RT-PCR) and slot blot hybridization were performed to examine and quantify the expression of hormonal receptors in these cell lines. RESULTS: SNU-308 showed a growth stimulating effect by gastrin-17, as did SNU-478 by both gastrin-17 and CCK-8. The trophic effect of these two hormones was completely blocked by specific antagonists (L-365, 260 for gastrin and L-364, 718 for CCK). Other cell lines did not respond to gastrin or CCK. In RT-PCR, the presence of CCK-A receptor and CCK-B/gastrin receptor mRNA was detected in all biliary and pancreatic cancer cell lines. In slot blot hybridization, compared to the cell lines which did not respond to hormones, those that responded to hormones showed high expression of receptor mRNA. CONCLUSION: Gastrin and CCK exert a trophic action on some of the biliary tract cancers.

Study of the expressions of p53 and bcl-2 genes, the telomerase activity and apoptosis in GIST patients

AIM： To explore the relationship between clinicobiological behavior and the expression levels of telomerase activity, apoptosis, p53 gene and bcl-2 gene in gastrointestinal stromal tumors （GISTs）. METHODS： The intensity of telomerase activity, apoptosis, p53 and bcl-2 expression in GISTs were detected by telomeric repeat amplification protocol, in situ end-labeling technique, and immunohistochemistry, respectively. RESULTS： The positive rates of telomerase activity of malignant GIST, potential malignant GIST and benign GIST were 85% （17/20）, 22.8% （2/9） and 0 （0/9）, respectively. The apoptosis indices of malignant GIST, potential malignant GIST, and benign GIST were 11.7±5.4, 30.2±5.6 and 45.2 ±7.2, respectively. The intensity of telomerase activity and apoptosis were related to the biological characteristics of GISTs （85% vs 22.8%, 0, 0; P 〈 0.01 or 11.7±5.4 vs 30.2±5.6, 45.2±7.2, 72.1±9.3; P 〈 0.05）. The intensity of telomerase activity was negatively correlated with cellular apoptosis （22.9±8.4 vs 9.5±5.7, P 〈 0.01）. The intensity of telomerase activity was positively correlated with/753, bcl-2 expression （40.0% vs 78.9%, 40.0% vs 84.2%; P 〈 0.05）. CONCLUSION： The detection of telomerase activity, apoptosis and its control genes in GIST will be helpful for the discrimination of the malignant and benign GIST and evaluation of the prognosis.

Effects of gastrin 17 on β-catenin/Tcf-4 pathway in Colo320WT colon cancer cells

AIM： To explore the effect of gastrin 17 （G17） on β-catenin/T cell factor-4 （Tcf-4） signaling in colonic cancer cell line Colo320WT. METHODS： The pCR3.1/GR plasmid, which expresses gastrin receptor, cholecystokinin-2 receptor （CCK-2R）, was transfected into a colonic cancer cell line Colo320 by Lipofectamine ^TM 2000 and the stably expressing CCK-2R clones were screened by G418. The expression levels of gastrin receptor in the Colo320 and the transfected Colo320WT cell line were assayed by RTPCR. Colo320WT cells were treated with G17 in a time-dependent manner （0, 1, 6, 12, 24 and 48 h）, then with L365,260 （Gastrin17 receptor blocker） for 30 rain, and with G17 again for 12 h or L365,260 for 12 h. Expression levels of β-catenin in a TX-100 soluble fraction and TX-100 insoluble fraction of Colo320WT cells treated with G17 were detected by co-immuniprecipation and Western blot. Immunocytochemistry was used to examine the distribution of β-catenin in CoLoWT320 cells. Expression levels of c-myc and cyclin D1 in Colo320WT cells treated with G17 were assayed by Western blot. RESULTS： Expression levels of β-catenin in the TX-100 solution fraction decreased apparently in a time- dependent fashion and reached the highest level after G17 treatment for 12 h, while expression levels of β-catenin in the TX-100 insoluble fraction were just on the contrary. Immunocytochemistry showed that β-catenin was translocated from the cell membranes into the cytoplasm and nucleus under G17 treatment. Expression levels of c-myc and cyclin D1 in the G17- treated Colo320WT cells were markedly higher compared to the untreated Colo320WT cells. In addition, the aforementioned G17-stimulated responses were blocked by L365,260.CONCLUSION： Gastrin17 activates β-catenin/Tcf-4 signaling in Colo320WT cells, thereby leading to over- expression of c-myc and cyclin D1.

Bromophenacyl bromide,a phospholipase A_2 inhibitor attenuates chemically induced gastroduodenal ulcers in rats

AIM: To study the effect of bromophenacyl bromide (BPB), a phospholipase A2 inhibitor on gastric secretion and to protect chemically induced gastric and duodenal ulcers in rats. METHODS: Acid secretion studies were undertaken in pylorus-ligated rats with BPB treatment (0, 5, 15 and 45 mg/kg). Gastric and duodenal lesions in the rats were induced by ethanol and cysteamine respectively. The levels of gastric wall mucus, nonprotein sulfhydryls (NP- SH) and myeloperoxidase (MPO) were also measured in the glandular stomach of rats following ethanol induced gastric lesions. RESULTS: BPB produced a dose-dependent inhibition of gastric acid secretion and acidity in rats. Pretreatment with BPB significantly attenuated the formation of etha- nol induced gastric lesion. BPB also protected intestinal mucosa against cysteamine-induced duodenal ulcers. The antiulcer activity of BPB was associated with signifi- cant inhibition of ethanol-induced depletion of gastric wall mucus, NP-SH and MPO. These findings pointed towards the mediation of sulfhydryls in BPB induced gas- trointestinal cytoprotection. CONCLUSION: BPB possesses significant antiulcer and cytoprotective activity against experimentally induced gastroduodenal lesions.

Effect of Gastrointestinal Protease Digestion on Bioactivity of Marine Peptides

Focus in nutritional science has turned towards components in, or added to, foods that may possess health beneficial activities beyond the classical nutritional value, namely functional food. Bioactive peptides are examples of such components. In vitro studies on bioactivities have mainly been executed without concerning subsequent digestion after intake and the aim of this work was hence to investigate how the in vitro antioxidative, antihypertensive and caspase activating activities of peptides are affected by digestion with gastrointestinal （GI） proteases. Five different fish protein hydrolysates were chosen to study the effect of in vitro digestion on bioactivity. The protein concentration decreased in all samples during digestion and the molecular weight distribution of the peptides shifted towards lower values. Thus, in vitro digestion with GI proteases resulted in a further degradation of the peptides obtained by hydrolysis. The antihypertensive effect increased in all samples after digestion with GI proteases whereas the antioxidative capacity decreased. The effect on the caspase activity depended on the proteases used in the preparation of hydrolysates. In conclusion, the caspase activity and antihypertensive activity are maintained during digestion with GI proteases, while the antioxidative capacity seems to be reduced.

Enhanced Free Radical Scavenging and Inhibition of DPP-4 and ACE Activities by Compounds from Salmon Tissues Digested in Vitro with Gastrointestinal Proteases

Research on marine bioactive peptides has mainly focused on characterization of peptides in hydrolysates prepared with commercial industrial enzymes and the usefulness of such hydrolysates in health and functional foods. However, a relevant question is whether digestion of fish proteins with gastrointestinal proteases per se generates peptides that also can have health promoting properties and can reduce, e.g., diabetes 2, inflammation and hypertension either in relation to gastrointestinal digestion or as alternative to industrial proteases. The aim of the study was to investigate hydrolysates obtained from in vitro sequential digestion of salmon muscle and skin with gastrointestinal proteases including pepsin, pancreatic and pancreatic ＋ mucosal proteases for their ability to scavenge ABTS^＋ radicals and inhibit activity of angiotensin I-converting enzyme （ACE） and dipeptidyl peptidase 4 （DPP-4）. Furthermore, it was the aim to study the inhibitory mechanism and stability towards ACE and DPP-4 activity. Analysis of〈 10 kDa hydrolysates showed that gastrointestinal proteases generated peptides with clear radical scavenging activity and DPP-4 and ACE inhibiting activity as well. Hydrolysates from pepsin digestion exhibited the lowest ECso values for radical scavenging activity and ACE inhibition, whereas ECso increased in hydrolysates after subsequent digestion with pancreatic and mucosal proteases. Interestingly, ECso values for the DPP-4 inhibition were hardly affected by sequential digestion. Inhibition modes for the muscle hydrolysates were both competitive and non-competitive, but prolonged incubation showed that the inhibitory properties were unstable and therefore they were probably digested as competitive substrates by gastrointestinal proteases.

Modern treatment of gastric gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GIST) are rare mesenchymal smooth muscle sarcomas that can arise anywhere within the gastrointestinal tract. Sporadic mutations within the tyrosine kinase receptors of the interstitial cells of Cajal have been identified as the key molecular step in GIST carcinogenesis. Although many patients are asymptomatic, the most common associated symptoms include: abdominal pain, dyspepsia, gastric outlet obstruction, and anorexia. Rarely, GIST can perforate causing life-threatening hemoperitoneum. Most are ultimately diagnosed on cross-sectional imaging studies (i.e., computed tomography and/or magnetic resonance imaging in combination with upper endoscopy. Endoscopic ultrasonographic localization of these tumors within the smooth muscle layer and acquisition of neoplastic spindle cells harboring mutations in the c-KIT gene is pathognomonic. Curative treatment requires a complete gross resection of the tumor. Both open and minimally invasive operations have been shown to reduce recurrence rates and improve long-term survival. While there is considerable debate over whether GIST can be benign neoplasms, we believe that all GIST have malignant potential, but vary in their propensity to recur after resection and metastasize to distant organ sites. Prognostic factors include location, size (i.e., > 5 cm), grade (> 5-10 mitoses per 50 high power fields and specific mutational events that are still being defined. Adjuvant therapy with tyrosine kinase inhibitors, such as imatinib mesylate, has been shown to reduce the risk of recurrence after one year of therapy. Treatment of locally-advanced or borderline resectable gastric GIST with neoadjuvant imatinib has been shown to induce regression in a minority of patients and stabilization in the majority of cases. This treatment strategy potentially reduces the need for more extensive surgical resections and increases the number of patients eligible for curative therapy. The modern surgical treatment of gastric GIST combines the novel use of targeted therapy and aggressive minimally invasive surgical procedures to provide effective treatment for this lethal, but rare gastrointestinal malignancy.

Glutathione-S-transferase (GSTM1,GSTT1) and the risk of gastrointestinal cancer in a Korean population

AIM： To evaluate the association of glutathione S-trans-ferase mu （GSTM1） and glutathione S-transferase theta （GSTT1） null genotypes with the risk of gastric cancer （GC） and colorectal cancer （CRC） in a South Korean population. METHODS： We conducted a population-based, large- scale case-control study including 2213 GCs, 1829 CRCs, and 1699 controls. Null and non-null genotypes of GSTM1 and GSI-F1 were determined using realtime PCR. RESULTS： The null genotypes of GSTM1 and GSTT1 were not significantly associated with elevated risk of gastric （OR = 1.070, 95% CI = 0.935-1.224; OR = 1.101, 95% CI = 0.963-1.259, respectively） or colorectal cancer （OR = 1.065, 95% CI = 0.923-1.228; OR = 1.041, 95% CI = 0.903-1.200, respectively）. The frequency of the combined null GST genotype was not different between the two cancer groups and controls. Moreover, smoking, drinking, and age did not modify the association between these genotypes and the risk of gastric or colorectal cancer. CONCLUSION： GSTM1 and GSCI-1 null genotypes were not associated with increased risk of GC or CRC in Koreans.

Pingwei capsules improve gastrointestinal motility in rats with functional dyspepsia

OBJECTIVE: To investigate the mechanism of Ping-wei capsules(PWC) in improving gastrointestinal m otility in rats with functional dyspepsia(FD).METHODS: We established an FD model by stimu-lating semi-starvation rats via tail damping, provo-cation, and forced exercise fatigue. The FD model group was further divided into five groups accord-ing to the treatment received: normal saline, dom-peridone, low-dose PWC, mid-dose PWC, or highdose PWC. The effect of PWC on FD was evaluated by measuring gastrointestinal motility. Changes in leptin and cholecystokinin(CCK) were detected through enzyme-linked immunosorbent assay, re-verse transcription-polymerase chain reaction, and immunohistochemistry.RESULTS: PWC significantly increased gastrointesti-nal m otility in FD rats. Furthermore, PWC signifi-cantly increased CCK m RNA and protein concentra-tions in the duodenum and antrum, decreased leptin protein concentrations in the duodenum, an-trum, and hypothalamus, and decreased CCK pro-tein concentration in the hypothalamus.CONCLUSION: PWC improves gastrointestinal mo-tor function in FD rats by decreasing the leptin con-centration in serum and the brain-gut axis, and by increasing the CCK concentration in gastrointesti-nal tissue. Our findings help to elucidate the mech-anism of FD and provide further insight into the pharmacokinetics of PWC.