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Howarth G.S.,University of Adelaide | Howarth G.S.,Center for Paediatric and Adolescent Gastroenterology | Wang H.,University of Adelaide

Although gut diseases such as inflammatory bowel disease, mucositis and the alimentary cancers share similar pathogenetic features, further investigation is required into new treatment modalities. An imbalance in the gut microbiota, breached gut integrity, bacterial invasion, increased cell apoptosis to proliferation ratio, inflammation and impaired immunity may all contribute to their pathogenesis. Probiotics are defined as live bacteria, which when administered in sufficient amounts, exert beneficial effects to the gastrointestinal tract. More recently, probiotic-derived factors including proteins and other molecules released from living probiotics, have also been shown to exert beneficial properties. In this review we address the potential for probiotics, with an emphasis on probiotic-derived factors, to reduce the severity of digestive diseases and further discuss the known mechanisms by which probiotics and probiotic-derived factors exert their physiological effects. © 2013 by the authors; licensee MDPI, Basel, Switzerland. Source

Lange B.,University of Adelaide | Currie K.-L.,Flinders University | Howarth G.S.,University of Adelaide | Howarth G.S.,Center for Paediatric and Adolescent Gastroenterology | And 3 more authors.

Summer mortality (SM) in greenlip abalone (Haliotis laevigata Donovan) heavily affects productivity of land-based abalone farms in Southern Australia. It has been associated with conditions of high water temperature (>. 23. °C), low dissolved oxygen levels, and a range of other stressful factors in the culture water during summer months. This study aimed to alleviate mortality experienced by abalone at high water temperatures (26. °C), by dietary intervention using grape seed extract (GSE) and dried Ulva lactuca Linnaeus, two products which contain antioxidative and bioactive compounds. These products were formulated into a commercial abalone diet at levels of 5 and 30%. The diets were fed to 3-year-old greenlip abalone (26.8. g; 57.9. mm) at a water temperature of 22 or 26. °C for 38. days. No mortalities were observed at 22. °C. Compared to the unaltered commercial diet, both GSE and dried U. lactuca additive diets significantly increased the survival of abalone at the 26. °C water temperature (P<. 0.05). GSE addition also significantly increased serum superoxide dismutase activity, feed intake, and meal acceptance of the abalone (P<. 0.05). These results demonstrate the potential for GSE or dried U. lactuca to act as dietary additives to reduce mortality and improve productivity on abalone farms subjected to high summer water temperatures. © 2014. Source

Whittaker A.L.,University of Adelaide | Howarth G.S.,University of Adelaide | Howarth G.S.,Center for Paediatric and Adolescent Gastroenterology
Applied Animal Behaviour Science

The understanding and recognition of pain in laboratory rats and mice has advanced considerably in recent times. However, there is evidence that despite these advances, analgesics are still relatively underutilised in these species. One possible contributing influence to this is the difficulty in assessing pain reliably and objectively in these prey species. This review presents the current scientific knowledge on behavioural methods of pain assessment in laboratory rats and mice. The focus is on measures of spontaneous behaviour, since these will find greatest utility in clinical pain management.A range of behavioural pain assessment tools are discussed and difficulties in study interpretation are highlighted. Such methods include locomotor activity, pain specific behaviour identification and the novel facial pain recognition methods developed more recently. Practical problems associated with the techniques are discussed and gaps in the scientific knowledge are identified. A substantial body of information on behavioural signs of acute pain has been collected. Developing awareness and attention to this amongst research workers would improve its application to practice. However, use of techniques for objective measurement can be laborious, subject to variability and confounded by experimental procedures. The increased availability of automated behavioural monitoring systems will reduce these concerns, but it still remains imperative that researchers perform behavioural pilot studies to elucidate behaviours of interest specific to their animal model.Few murine studies of behavioural pain assessment have been performed and this is an area that needs further investigation. Additionally, whilst acute post-operative pain scales in rats have been fairly well-characterised, these should be tested in different acute pain models to determine their reproducibility. Few tools for assessment of chronic pain, such as that arising from inflammatory or neoplastic disease, exist in both of the species examined. Pain-specific behavioural identification is the more widely tested method in the face of chronic pain. However, studies to date have yielded few reliable and consistent behaviours indicative of this category of pain. This is an area in which future studies and funding should be directed, given the significant number of laboratory animals that are likely to experience such pain states. Greater collaboration between ethologists and scientists using animal models should be established in order to improve animal welfare and advance scientific knowledge in this area. © 2013 Elsevier B.V. Source

Yazbeck R.,Flinders University | Yazbeck R.,Center for Paediatric and Adolescent Gastroenterology | Yazbeck R.,University of South Australia | Howarth G.S.,Flinders University | And 6 more authors.
Journal of Cellular Physiology

The dextran sulfate sodium (DSS) model of colitis has been commonly utilized in mice to assess novel treatments for ulcerative colitis. Recent studies have indicated that morphological and biochemical changes extend to the small intestine (SI). This study aimed to characterize histological and biochemical changes in the SI during DSS colitis in wild-type (WT) and DPIV knock-out (DPIV -/-) mice treated with saline or the DPIV inhibitors, Ile-Pyrr-(2-CN)*TFA or Ile-Thia. Groups (n=10) of DPIV -/- and WT mice were orally gavaged twice daily with saline, Ile-Pyrr-(2-CN)*TFA or Ile-Thia. Mice consumed 2% DSS in drinking water for 6 days to induce colitis. Small intestinal tissue was assessed for histological changes, sucrase, and DPIV activity and neutrophil infiltration. Jejunal villus length was increased in all groups after 6 days DSS consumption (P<0.05). Jejunal DPIV activity was significantly lower by 35% in WT mice receiving Ile-Pyrr-(2-CN)*TFA compared to saline controls. Jejunal MPO activity was significantly increased in the WT+saline and DPIV -/-+saline groups following DSS consumption, compared to WT and DPIV -/- controls at day 0. Increased sucrase activity was apparent at day 0 in DPIV -/- compared to WT mice (P<0.05). We conclude that DSS-induced damage is not restricted to the colon, but also extends to the small intestine. Furthermore, reduced or absent DPIV activity resulted in functional adaptations to brush border enzyme activity. DPIV inhibitors are now a recognized therapy for type-II diabetes. The work presented here highlights the need to delineate any long-term effects of DPIV inhibitors on SI function, to further validate their safety and tolerability. © 2011 Wiley-Liss, Inc. Source

Lindsay R.J.,University of Adelaide | Geier M.S.,South Australian Research And Development Institute | Yazbeck R.,Flinders University | Yazbeck R.,Center for Paediatric and Adolescent Gastroenterology | And 3 more authors.
British Journal of Nutrition

Mucositis resulting from cancer chemotherapy is a serious disorder of the alimentary tract. Emu oil has demonstrated anti-inflammatory properties in animal models of arthritis and wound healing; however, its effects on the intestine remain unknown. We investigated emu oil for its potential to decrease the severity of mucositis in a rat model. Female Dark Agouti rats (110-150g) were orogastrically gavaged with emu oil (05 or 1ml) or water (1ml) for 5d before intraperitoneal injection of 5-fluorouracil (5-FU, 150mg/kg) or saline (control), and this was continued up to the day of sacrifice (48, 72 and 96h post 5-FU administration). Histological (villus height, crypt depth (CD) and disease severity score) and biochemical (myeloperoxidase (MPO) activity) parameters were determined in intestinal tissues collected at sacrifice. Sucrase activity in vivo was quantified by the sucrose breath test. Activated neutrophil activity (MPO) in the ileum was significantly decreased by emu oil (05ml, 451 (sem 168)U/g and 1ml, 503 (sem 213)U/g) compared with 5-FU-treated controls (1724 (sem 431)U/g) 96h post 5-FU administration. There were also significant increases in CD (152 (sem 8)m) in the ileum of rats that receivied 1ml emu oil at 96h compared with 5-FU-treated controls (CD (106 (sem 12)m)). Emu oil did not affect sucrase activity. Emu oil decreased acute ileal inflammation, and improved mucosal architecture in the intestine during recovery from chemotherapy in rats. Further studies investigating the potential benefits of emu oil as a nutritional supplement for the treatment of intestinal disorders are indicated. Copyright © The Authors 2010. Source

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