NISCAIR Online Periodicals Repository Collection: IJBB Vol.46(1) [February 2009]

Induction of oxidative stress by restraint stress and corticosterone treatments in rats

Thu, 29 Jan 2009 22:58:59 GMT

Title: Induction of oxidative stress by restraint stress and corticosterone treatments in rats

Authors: Zafir, Ayesha; Banu, Naheed

Abstract: Chronic exposure to psychological stress in humans and restraint stress in experimental animals results in increased oxidative stress and resultant tissue damage. To study the contribution of stress hormones towards stress-induced oxidative processes in the brain, we investigated the response of important free-radical scavenging enzymes toward chronic administration of two doses of corticosterone (low dose: 10 mg/kg/day, high dose: 40 mg/kg/day) in rodents. After a 21-day experimental period, a significant decline in both superoxide dismutase and catalase was observed in both stressed and stress hormone-treated animals. The brain levels of glutathione as well as the activities of glutathione-S-transferase and glutathione reductase were also significantly decreased, while lipid peroxidation levels were significantly increased in comparison to controls. A direct pro-oxidant effect of stress hormones in the brain during physical and psychological stress was observed, indicating important implications for oxidative stress as a major pathological mechanism during chronic stress and a consequent target option for anti-stress therapeutic interventions.

Page(s): 53-58

Effect of Bacillus subtilis PB6, a natural probiotic on colon mucosal inflammation and plasma cytokines levels in inflammatory bowel disease

Thu, 29 Jan 2009 22:58:59 GMT

Title: Effect of Bacillus subtilis PB6, a natural probiotic on colon mucosal inflammation and plasma cytokines levels in inflammatory bowel disease

Authors: Selvam, R; Maheswari, P; Kavitha, P; Ravichandran, M; Sas, Benedikt; Ramchand, C N

Abstract: The pathophysiology of inflammatory bowel disease (IBD) involves the production of diverse lipid mediators, namely eicosanoid, lysophospholipids, and platelet-activating factor, in which phospholipase A₂ (PLA₂) is the key enzyme. Thus, it has been postulated that control of lipid mediators production by inhibition of PLA₂ would be useful for the treatment of IBD. This hypothesis has been tested in the present study by examining the therapeutic effect of a novel natural probitic Bacillus subtilis PB6 (ATCC- PTA 6737). B. subtilis PB6 is found to secrete surfactins (cyclic lipopeptides) which have anti-bacterial potential. These surfactins inhibit PLA₂, a rate-limiting enzyme involved in the arachidonic acid associated inflammatory pathway and could downregulate the inflammatory response by regulating the eicosanoid and cytokine pathways. With this concept, an experimental animal trial has been conducted in a rat model of 2, 4, 6-trinitrobenzene sulfonic acid (TNBS)-induced colitis. The oral administration of PB6 suppresses the colitis as measured by mortality rate, changes in the weight gain, colon morphology and the levels of plasma cytokines. The animals treated orally with PB6 at 1.5 × 10⁸ CFU/kg thrice daily from day 4 to 10 significantly improve gross pathology of the colon and regain the colon weight to normal (p< 0.05), compared to TNBS-induced positive control. The plasma levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6 and IFN-γ) are also significantly lowered (p<0.05) and anti-inflammatory cytokine (IL-10 and TGF-β) significantly (p<0.05) increased after the oral administration of PB6 on day 11. The present study supports the concept that PB6 inhibits PLA₂ by the secreting surfactins. In a clinical investigation, it is found to be well tolerated by all the healthy volunteers.

Page(s): 79-85

Future Perspectives of Nutrigenomics Foods: Benefits vs. Risks

Thu, 29 Jan 2009 22:58:59 GMT

Title: Future Perspectives of Nutrigenomics Foods: Benefits vs. Risks

Authors: Ghosh, Dilip

Abstract: Nutrigenomics, defined as the application of high-throughput genomics tools in nutrition research is now past its incubation phase. The poorly understood associations of diet and disease prevention in particular will likely be the single most important catalyst to its accelerated and continued growth. Whether the goal of matching foods to individual genotypes to improve the health of those individuals can be attained, and personalised nutrigenomic foods enter the world's food markets, depends on numerous hurdles being overcome: some scientific in nature, some technical and others related to consumer, market or ethical issues. Public adoption of new technologies is an important determinant for their success. Many of the drivers behind the trend in personalisation of food are now known, particularly ethical, legal, and social issues (ELSI) are the major drivers. Future development in the field of nutrigenomics undoubtedly will place its seemingly huge potential in better perspective. From the scientific responsibility point of view, one hopes that the new perspectives to be gained and progress to be made in this field will be so managed as to take the public at large on board, if we are to avoid another nutrition education disaster of the genetically modified organism type and dimension.

Page(s): 31-36

Role of bilirubin as antioxidant in neonatal jaundice and effect of ethanolic extract of sweet lime peel on experimentally induced jaundice in rat

Thu, 29 Jan 2009 22:58:59 GMT

Title: Role of bilirubin as antioxidant in neonatal jaundice and effect of ethanolic extract of sweet lime peel on experimentally induced jaundice in rat

Authors: Nag, N; Halder, S; Chaudhuri, R; Adhikary, S; Mazumder, S

Abstract: Bilirubin above a threshold level is toxic to human system and is excreted in urinary and through gastrointestinal tract. The role of bilirubin as antioxidant is debatable. This paper aims at elucidating the role of bilirubin as an antioxidant in neonatal jaundice patients. It is observed that bilirubin up to 6 mg/dl in blood acts as an antioxidant and above 12.5 mg/dl is strongly prooxidant. Phototherapy is the accepted therapeutic management of neonatal jaundice and has been shown to enhance the oxidative stress. Approaches have been taken to formulate a herbal medication which will reduce bilirubin level in the neonates without inducing additional damages. The ethanolic extract of sweet lime peel, administered orally at a dose of 72 µg is found to reduce the oxidative stress in erythrocytes of phenylhydrazine-induced jaundiced rats treated with phototherapy.

Page(s): 73-78