Sleep deprivation increase the expression of inducible heat shock protein 70 in rat gastric mucosa

Aim: To investigate if sleep deprivation is able to increase the expression of inducible heat shock protein 70 in gastric mucosa and its possible role in mucosal defense. Methods: Rats for sleep disruption were placed inside a computerized rotating drum, gastric mucosa was taken from rats with 1, 3 and 7 d sleep deprivation. RT-PCR, immunohistochemistry and Western blotting were used to determine the expression of heat shock protein 70. Ethanol (500 mL.L-1, i.g.) was used to induce gastric mucosa damage. Results: RT-PCR, Western blotting and immunostaining confirmed that the sleep deprivation as a stress resulted in significantly greater expression of inducible heat shock protein 70 in gastric mucosa of rats. After the 500mL.L-1 ethanol challenge, the ulcer area found in the rats with 7 d sleep deprivation (19.15 ± 4.2) mm2 was significantly lower (P<0.01) than the corresponding control (53.7 ± 8.1) mm2. Conclusion: Sleep deprivation as a stress, in addition to lowering the gastric mucosal barrier, is able to stimulate the expression of inducible heat shock protein 70 in gastric mucosa of rats, the heat shock protein 70 may play an important role in gastric mucosal protection.published_or_final_versio

Gene expression profiles in gastric mucosa of sleep deprivation rats

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Expression and activities of three inducible enzymes in the healing of gastric ulcers in rats

Aim: To explore the roles of nitric oxide synthase (NOS), heme oxygenase (HO) and cyclooxygenase (COX) in gastric ulceration and to investigate the relationships of the expression and activities of these enzymes at different stages of gastric ulceration. Methods: Gastric ulcers (kissing ulcers) were induced by luminal application of acetic acid. Gastric tissue samples were obtained from the ulcer base, ulcer margin, and non-ulcerated area around the ulcer margin at different time intervals after ulcer induction. The mRNA expression and protein levels of inducible and constitutive isoforms of NOS, HO and COX were analyzed with RT-PCR and Western blotting methods. The activities of the total NOS, inducible NOS (iNOS), HO, and COX were also determined. Results: Differential expression of inducible iNOS, HO-1 and COX-2 and enzyme activities of NOS, HO and COX were found in the gastric ulcer base. High iNOS expression and activity were observed on day 1 to day 3 in severely inflamed ulcer tissues. Maximum expressions of HO-1 and COX-2 and enzyme activities of HO and COX lagged behind that of iNOS, and remained at high levels during the healing phase. Conclusion: The expression and activities of inducible NOS, HO-1 and COX-2 are found to be correlated to different stages of gastric ulceration. Inducible NOS may contribute to ulcer formation while HO-1 and COX-2 may promote ulcer healing.published_or_final_versio

Chinese green tea ameliorates lung injury in cigarette smoke-exposed rats

Background: Epigallocatechin-3-gallate (EGCG), which has been shown to have potent antioxidant effect, comprises 80% of catechins in Chinese green tea. This study was to investigate whether cigarette smoke (CS) exposure would induce lung morphological changes and oxidative stress in the CS-exposed rat model, and whether Chinese green tea (Lung Chen tea with EGCG as its main active ingredient) consumption would alter oxidative stress in sera and lung leading to protection of CS-induced lung damage. Methods: Sprague-Dawley rats were randomly divided into four groups, i.e. sham air (SA), 4% CS, 2% Lung Chen tea plus SA or 4% CS. Exposure to SA or 4% CS was performed for 1 h/day for 56 days in ventilated smoking chambers. Sera and lung tissues were collected 24 h after last CS exposure for histology and all biochemical assays. Results: Airspace enlargement and goblet cell hyperplasia were observed after 56-day CS exposure alone, which were abolished in the presence of green tea consumption. Serum 8-isoprostane level was significantly elevated (p < 0.01) as well as lung superoxide dismutase (SOD) and catalase activities in CS-exposed rats compared to SA-exposed rats (p < 0.05), which returned to the levels of SA-exposed rats after Chinese green tea consumption. Conclusion: These results indicate that increased levels of systemic oxidative stress after CS exposure play an important role in the induction of lung damage. Chinese green tea may have the ability to suppress CS-induced oxidative stress that leads to protection of lung injury. © 2009 Elsevier Ltd. All rights reserved.postprin

Memory enhancing effects of tea

Conference Theme: A New Golden AgeSymposium 5: Pharmacotherapy in the Elderl

Aloe vera: Antiulcer and antidiabetic effects

A health product containing aloe vera gel was examined for its effects on gastric mucosal lesions induced by cold-restraint or by oral administration of 70% v/v ethanol (2 mL/kg), and on plasma glucose levels in alloxan-induced diabetic rats. Pretreatment with the preparation orally did not protect against lesion formation. There was no beneficial effect on the healing of ethanol-induced gastric mucosal damage when the preparation was given twice daily for 3 days. The plasma glucose level of alloxan-injected rats (120 mg/kg, s.c.) was about twice as high as that of their controls. It was further elevated by a single oral dose of the preparation. Chronic treatment with the preparation, given twice daily for 10 days, produced a sustained increase in the plasma glucose levels. The findings do not support the claimed efficacy of the preparation in treating gastric ulceration and diabetes mellitus.link_to_subscribed_fulltex

Effects of ginseng on ethanol induced sedation in mice

The effects of ginseng, ginsenosides, coffee, and caffeine on 75% ethanol induced sleeping in mice were examined. Mice treated with ethanol lost their fighting reflex within 30 min and this lasted for about 4 h. The onset time of lose of righting reflex (LR) in mice pre-treated with ginseng, ginsenosides, coffee or caffeine 10 min before ethanol was significantly delayed; whereas the duration of sleep was not affected by all treatments. Administration of these agents 10 min alter ethanol was ineffective in counteracting the LR effect of ethanol. Coffee and caffeine produced central stimulation and increased locomotor activity. Ginseng and ginsenosides were found to enhance exercise endurance and reduced the plasma level of ethanol. Gastric emptying was slowed by ginseng, ginsenosides or ethanol administration. An additive effect was observed when the mice were pre- treated with ginseng or ginsenosides 10 rain before ethanol administration. It is suggested that ginseng decreased plasma ethanol concentration by delaying gastric emptying and this may be partly due to the effect of the ginsenosides.link_to_subscribed_fulltex

Anti-Helicobacter pylori activity of Chinese tea: In vitro study

Background: Chinese tea has an antibacterial activity against a wide range of bacteria. However, its activity against Helicobacter pylori has not been reported. Method: In this study the anti-Helicobacter pylori effects of a Chinese tea (Lung Chen tea), and two tea catechins, epigallocatechin gallate and epicatechin and their minimum inhibitory concentrations (MICs) were examined. The effect of Lung Chen on metronidazole resistance was also studied using the E-test. Results: Lung Chen, epigallocatechin gallate and epicatechin all inhibited the growth of H. pylori. The MIC90 for Lung Chen was 0.25-0.5% (w/w) and that of epigallocatechin gallate and epicatechin were 50-100 and 800-1600 μg/mL, respectively. Epigallocatechin gallate is probably the active ingredient responsible for most of the anti-H. pylori activity of Chinese tea. Lung Chen did not reverse metronidazole resistance. Conclusions: Chinese tea has anti-H. pylori activity in a daily consumed concentration, and epigallocatechin gallate is probably the active ingredient responsible for the action.link_to_OA_fulltex