EGCG synergizes the therapeutic effect of irinotecan through enhanced DNA damage in human colorectal cancer cells

Irinotecan is a kind of alkaloid with antitumour activity, but its low solubility and high toxicity limit its application. Epigallocatechin-3-gallate (EGCG) is one of the main bioactive components in tea. The epidemiological investigation and animal and cell experiments show that EGCG has a preventive and therapeutic effect on many kinds of tumours. Here, colorectal cancer cells RKO and HCT116 were employed, and the CCK8 proliferation test was used to screen the appropriate concentration of EGCG and irinotecan, and the effects of single and/or combined drugs on migration, invasion, DNA damage, cell cycle and autophagy of tumour cells were investigated. The results showed that EGCG combined with irinotecan (0.5 μmol L⁻) not only had a stronger inhibitory effect on tumour cells than EGCG or irinotecan alone but also prevented tumour cell migration and invasion. EGCG alone did not cause DNA damage in colorectal cancer cells, but its combination with irinotecan could induce S or G2 phase arrest by inhibiting topoisomerase I to cause more extensive DNA damage. EGCG also induced apoptosis by promoting autophagy with irinotecan synergistically. These results indicated that EGCG in combination with irinotecan could be a promising strategy for colorectal cancer.     

Interleukin 1 protects against the lethal effects of irradiation of mice but has no effect on tumors in the same animals

Interleukin 1 (IL-1) is a radioprotector of bone marrow and is cytotoxic to some tumor cells. This investigation examines these two properties in the same host animals and gives evidence of radioprotection against localized x-irradiation of the head and neck region. By LD50 analyses, recombinant human IL-1 (100 ng/mouse, approximately 3 micrograms/kg) was found to be radioprotective against whole-body irradiation for both C3H/Km and C57BL/Ka mice. The combined potency ratio for the two strains was 1.07 (95% confidence limit: 1.02-1.12). It was also radioprotective against the injury leading to acute lethality resulting from localized head and neck irradiation of C3H/Km mice; 100 ng of IL-1/mouse produced a potency ratio of 1.05 (95 confidence limit: 1.03-1.07). However, two tumors that originated in C3H/Km mice, RIF-1 and SCCVII, showed neither in vitro nor in vivo response to IL-1. Also, there was no IL-1-induced reduction in in vivo growth of the RL 12NP lymphoma in C57BL/Ka mice.     

The effect of a single injection of irinotecan on the development of enamel in the Wistar rats

Cancer is the second most frequent cause of death in children. Because the prognosis for childhood malignancies has improved, attention has now focused on long‐term consequences of cancer treatment. The immediate effects of chemotherapy on soft tissues have been well described; however, there is less information about long‐term effects of chemotherapy on the development of dental tissues. To test the association between the effect of chemotherapy on enamel development, we examined two groups of rats: one that had received an intraperitoneal dose of 200 mg/kg of irinotecan, whereas the other (control) group had received vehicle only. Rats were killed at 6, 48 and 96 hr post‐injection; the mandibles dissected out, fixed for histological evaluation and scanned for mineralization defects by Micro‐CT. Our results showed structural changes in the ameloblast layer along with a significant reduction in mineralization and thickness of enamel at 96 hr after chemotherapy. These data demonstrate that irinotecan induces structural changes in forming enamel that become apparent after anticancer chemotherapy treatment.     

Resveratrol protects against atherosclerosis,but does not add to the antiatherogenic effect of atorvastatin,in APOE*3-Leiden.CETP mice

Resveratrol is a major constituent of traditional Asian medicinal herbs and red wine and is suggested to be a potential antiatherosclerotic drug due to its proposed hypolipidemic, anti-inflammatory and antioxidative properties. The aim of this study was to evaluate whether resveratrol protects against atherosclerosis development in APOE*3-Leiden.CETP (E3L.CETP) mice and adds to the antiatherogenic effect of mild statin treatment, currently the most widely used antiatherogenic therapy. E3L.CETP mice were fed a cholesterol-rich diet without (control) or with resveratrol (0.01% w/w), atorvastatin (0.0027% w/w) or both for 14 weeks. During the study plasma lipid, inflammatory and oxidative stress parameters were determined. Resveratrol reduced atherosclerotic lesion area (?52%) in the aortic root, comparable to atorvastatin (?40%) and the combination of both drugs (?47%). The collagen/macrophage ratio in the atherosclerotic lesion, a marker of plaque stability, was increased by resveratrol (+108%), atorvastatin (+124%) and the combination (+154%). Resveratrol decreased plasma cholesterol levels (?19%) comparable to atorvastatin (?19%) and the combination (?22%), which was completely confined to (very)low-density lipoprotein cholesterol levels in all groups. Post hoc analyses showed that the antiatherogenic effect of atorvastatin could be explained by cholesterol lowering, while the antiatherosclerotic effect of resveratrol could be attributed to factors additional to cholesterol lowering. Markers of inflammation and oxidative stress were not different, but resveratrol improved macrophage function. We conclude that resveratrol potently reduces atherosclerosis development and induces a more stable lesion phenotype in E3L.CETP mice. However, under the experimental conditions tested, resveratrol does not add to the antiatherogenic effect of atorvastatin.     

The role of AKT1 and autophagy in the protective effect of hydrogen sulphide against hepatic ischemia/reperfusion injury in mice

Hydrogen sulphide (H₂S) exerts a protective effect in hepatic ischemia-reperfusion (I/R) injury. However, the exact mechanism of H₂S action remains largely unknown. This study was designed to investigate the role of the PtdIns3K-AKT1 pathways and autophagy in the protective effect of H₂S against hepatic I/R injury. Primary cultured mouse hepatocytes and livers with or without NaHS (a donor of H₂S) preconditioning were exposed to anoxia/reoxygenation (A/R) and I/R, respectively. In certain groups, they were also pretreated with LY294002 (AKT1-specific inhibitor), 3-methyladenine (3MA, autophagy inhibitor) or rapamycin (autophagy enhancer), alone or simultaneously. Cell viability, expression of P-AKT1, T-AKT1, LC3 and BECN1 were examined. The severity of liver injury was measured by the levels of serum aminotransferase and inflammatory cytokine, apoptosis and histological examination. GFP-LC3 redistribution and transmission electron microscopy were used to test the activity of autophagy. H₂S preconditioning activated PtdIns3K-AKT1 signaling in hepatocytes. LY294002 could abolish the AKT1 activation and attenuate the protective effect of H₂S on hepatocytes A/R and hepatic I/R injuries. H₂S suppressed hepatic autophagy in vitro and in vivo. Further reducing autophagy by 3MA also diminished the protective effect of H₂S, while rapamycin could reverse the autophagy inhibitory effect and enhance the protective effect of H₂S against hepatocytes A/R and hepatic I/R injuries, consequently. Taken together, H₂S protects against hepatocytic A/R and hepatic I/R injuries, at least in part, through AKT1 activation but not autophagy. An autophagy agonist could be applied to potentiate this hepatoprotective effect by reversing the autophagy inhibition of H₂S.     

The role of AKT1 and autophagy in the protective effect of hydrogen sulphide against hepatic ischemia/reperfusion injury in mice

Hydrogen sulphide (H 2S) exerts a protective effect in hepatic ischemia-reperfusion (I/R) injury. However, the exact mechanism of H 2S action remains largely unknown. This study was designed to investigate the role of the PtdIns3K-AKT1 pathways and autophagy in the protective effect of H 2S against hepatic I/R injury. Primary cultured mouse hepatocytes and livers with or without NaHS (a donor of H 2S) preconditioning were exposed to anoxia/reoxygenation (A/R) and I/R, respectively. In certain groups, they were also pretreated with LY294002 (AKT1-specific inhibitor), 3-methyladenine (3MA, autophagy inhibitor) or rapamycin (autophagy enhancer), alone or simultaneously. Cell viability, expression of P-AKT1, T-AKT1, LC3 and BECN1 were examined. The severity of liver injury was measured by the levels of serum aminotransferase and inflammatory cytokine, apoptosis and histological examination. GFP-LC3 redistribution and transmission electron microscopy were used to test the activity of autophagy. H 2S preconditioning activated PtdIns3K-AKT1 signaling in hepatocytes. LY294002 could abolish the AKT1 activation and attenuate the protective effect of H 2S on hepatocytes A/R and hepatic I/R injuries. H 2S suppressed hepatic autophagy in vitro and in vivo. Further reducing autophagy by 3MA also diminished the protective effect of H 2S, while rapamycin could reverse the autophagy inhibitory effect and enhance the protective effect of H 2S against hepatocytes A/R and hepatic I/R injuries, consequently. Taken together, H 2S protects against hepatocytic A/R and hepatic I/R injuries, at least in part, through AKT1 activation but not autophagy. An autophagy agonist could be applied to potentiate this hepatoprotective effect by reversing the autophagy inhibition of H 2S.     

Involvement of PI3K/Akt pathway in the protective effect of hesperidin against a chemically induced liver cancer in rats

Hesperidin is a flavanone glycoside that is found in the Citrus species and showed antioxidant, hepatoprotective as well as anticancer activity. This study investigated the effect of hesperidin on the PI3K/Akt pathway as a possible mechanism for its protective effect against diethylnitrosamine (DEN)‐induced hepatocellular carcinoma (HCC). Adult Wistar rats were divided into Control group (received drug vehicle); DEN group (received 100 mg/L of DEN solution for 8 weeks), and hesperidin + DEN group (received 200 mg/kg body weight of hesperidin/day orally for 16 weeks + DEN solution as DEN group). Our findings showed that the administration of hesperidin significantly decreased the elevation in liver function enzymes, serum AFP level, and oxidative stress markers. Moreover, hesperidin administration suppressed DEN‐induced upregulation of PI3K, Akt, CDK‐2 protein expression, and preserved the integrity of the liver tissues from HCC formation. In conclusion, the hepatoprotective activity of hesperidin is mediated via its antioxidation and downregulation of the PI3K/Akt pathway.     

香菇C91-3菌丝发酵液提取蛋白抗小鼠宫颈癌U14的初步探讨

目的 探讨香菇C91-3菌丝发酵液提取蛋白对小鼠宫颈癌的作用.方法 观察香菇C91-3菌丝发酵液提取蛋白对小鼠宫颈癌U14荷瘤小鼠生存期的影响和对体外培养的小鼠宫颈癌U14细胞的抑杀作用.结果 香菇C91-3菌丝发酵液提取蛋白能明显延长小鼠宫颈癌U14荷瘤小鼠的生存期并能对体外培养的小鼠宫颈癌U14细胞有直接抑杀作用.结论 香菇C91-3菌丝发酵液提取蛋白对机体有调节、增强机体免疫系统功能的作用.     

纳米中药对S180荷瘤小鼠肠道菌群影响的研究及其防治作用

目的研究纳米中药对S180荷瘤小鼠肠道菌群的影响及其抑制作用。方法将S180荷瘤瘤株以2×105/(0.2 m l.鼠)用注射器接种于小鼠右前肢腋下,建立实体瘤模型,肿瘤发生率为100%。观察小鼠的一般状态,用梯度稀释法和培养法测定小鼠4种肠道正常菌群,即乳酸杆菌、双歧杆菌、肠球菌、肠杆菌。用电子天平称瘤重并计算瘤抑制率。病理行HE(苏木精-伊红)染色,在光学显微镜下观察。结果与模型组比较,纳米中药组双歧杆菌和乳酸杆菌数量明显升高,肠球菌和肠杆菌数量明显减少,肿瘤坏死因子数量增加,抑瘤率达64%,病理显示肿瘤组织间坏死灶明显,有大量的炎性细胞浸润。结论纳米中药提高机体免疫屏障功能,增强药物的靶向性,扶植机体正常菌群的生长,实现抗肿瘤的目的。     

Tetramethylcyclopropyl analogue of the leading antiepileptic drug, valproic acid: evaluation of the teratogenic effects of its amide derivatives in NMRI mice

BACKGROUND: Although valproic acid (VPA) is used extensively for treating various kinds of epilepsy, it causes hepatotoxicity and teratogenicity. In an attempt to develop a more potent and safer second generation to VPA drug, the amide derivatives of the tetramethylcyclopropyl VPA analogue, 2,2,3,3‐tetramethylcyclopropanecarboxamide (TMCD), N‐methyl‐TMCD (MTMCD), 4‐(2,2,3,3‐tetramethylcyclopropanecarboxamide)‐benzenesulfonamide (TMCD‐benzenesulfonamide), and 5‐(TMCD)‐1,3,4‐thiadiazole‐2‐sulfonamide (TMCD‐thiadiazolesulfonamide) were synthesized and shown to have more potent anticonvulsant activity than VPA. Teratogenic effects of these CNS‐active compounds were evaluated in Naval Medical Research Institute (NMRI) mice susceptible to VPA‐induced teratogenicity by comparing them to those of VPA. METHODS: Pregnant NMRI mice were given a single sc injection of either VPA or TMC‐amide derivatives on gestation day 8.5, and then the live fetuses were examined to detect any external malformations on gestation day 18. After double‐staining for bone and cartilage, their skeletons were examined. RESULTS: In contrast to VPA, which induced NTDs in a high number of fetuses at 2.4–4.8 mmol/kg, TMCD, TMCD‐benzenesulfonamide, and TMCD‐thiadiazolesulfonamide at 4.8 mmol/kg and MTMCD at 3.6 mmol/kg did not induce a significant number of NTDs. TMCD‐thiadiazolesulfonamide exhibited a potential to induce limb defects in fetuses. Skeletal examination also revealed that fetuses exposed to all four of the tetramethylcyclopropanecarboxamide derivatives developed vertebral and rib abnormalities less frequently than those exposed to VPA. Our results established that TMCD, MTMCD, and TMCD‐benzenesulfonamide are distinctly less teratogenic than VPA in NMRI mice. CONCLUSIONS: The CNS‐active amides containing a tetramethylcyclopropanecarbonyl moiety demonstrated better anticonvulsant potency compared to VPA and a lack of teratogenicity, which makes these compounds good second‐generation VPA antiepileptic drug candidates. Birth Defects Research (Part A), 2008. © 2008 Wiley‐Liss, Inc.     

Expression of cholera toxin B subunit–lumbrokinase in edible sunflower seeds–the use of transmucosal carrier to enhance its fusion protein's effect on protection of rats and mice against thrombosis

Lumbrokinase (LK) is a group of serine proteases with strong fibrinolytic and thrombolytic activities and is useful for treating diseases caused by thrombus. Cholera toxin B subunit (CTB) has been widely used to facilitate antigen delivery by serving as an effective mucosal carrier molecule for the induction of oral tolerance. We investigate here the application of CTB as a transmucosal carrier in enhancing its fusion protein‐LKs effect to protect rats against thrombosis. Thus, in this study, CTB‐LK fusion gene separated by a furin cleavage site was expressed in seeds of Helianthus annuus L. The activity of recombinant protein in seeds of transgenic sunflower was confirmed by Western blot analysis, fibrin plate assays and G_M1‐ganglioside ELISA. The thrombosis model of rats and mice revealed that the oral administration of peeled seeds of sunflower expressing CTB‐LK had a more significant anti‐thrombotic effect on animals compared with that administration of peeled seeds of sunflower expressing LK. It is possible to conclude that CTB can successfully enhance its fusion protein to be absorbed in rats or mice thrombosis model. The use of CTB as a transmucosal carrier in the delivery of transgenic plant‐derived oral therapeutic proteins was supported. In addition, for the purpose of that recombinant CTB‐LK was designed for oral administration, thus the expression of CTB‐LK in edible sunflower seeds eliminated the need for downstream processing of proteins. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:1029–1039, 2014