NISCAIR Online Periodicals Repository Collection: IJEB Vol.47(10) [October 2009]

Impact of in vivo electrical stimulation during denervation dis-use muscle atrophy

Mon, 28 Sep 2009 22:58:59 GMT

Title: Impact of in vivo electrical stimulation during denervation dis-use muscle atrophy

Authors: Sendhilvadivu, M

Abstract: Male albino rats were sciatectomized and kept for 30 days to assess the induced oxidative damage due to dis-use gastrocnemius muscle atrophy. An enhanced lipid peroxidation was recorded with elevated activity levels of conjugated diens, malondialdehyde and other thiobarbituric acid reactive substances in denervated muscle. The activity levels of antioxidant defense enzymes, viz. superoxide dismutase, catalase, glutathioneperoxidase (selenium, non-selenium), glutathione reductase, glutathione-s-transferase were depleted in the denervated muscle. The denervated muscle was subjected to a programme of in vivo electrical stimulations, revealed a depleted lipid peroxidation and increased activity levels of antioxidant defense enzymes. The results, suggest that the programme of in vivo electrical stimulation could prevent the oxidative damage in gastrocnemius muscle despite denervation.

Page(s): 839-842

Hypersensitive response of Sesamum prostratum Retz. elicitated by Fusarium oxysporum f. sesame (Schelt) Jacz Butler.

Mon, 28 Sep 2009 22:58:59 GMT

Title: Hypersensitive response of Sesamum prostratum Retz. elicitated by Fusarium oxysporum f. sesame (Schelt) Jacz Butler.

Authors: Rajab, Reeja; Rajan, S Sajitha; Satheesh, L Shilpa; Harish, S R; Sunukumar, S S; Sandeep, B S; Mohan, T C Kishor; Murugan, K

Abstract: Aim of this study was to investigate the intensity and timing of the ROS formation, lipid peroxidation and expression of antioxidant enzymes as initial responses of calli of Sesamum prostratum (SP) against Fusarium oxysporum f. sesame crude toxin metabolite of varying concentrations. 2,4 dichlorophenoxy acetic acid (2,4-D) / coconut milk combinations were found to be more efficient among different hormonal regimes (2,4 -D, 2,4-D/casein hydrosylate and 2,4-D/ coconut milk). The concentration of hydrogen peroxide and lipid peroxidation were higher (13.2 and 5.7-folds, respectively) after 6 h in the treated callus confirmed the oxidative stress. An increase in total phenolics was also detected in inoculated callus. Increased activity of antioxidative enzymes viz., NADPH oxidase and superoxide dismutase (SOD) corroborate with the high level of ROSs, such as O₂^.-and H₂O₂. The poor activity of catalase confirmed the oxidative burst in the callus leading to necrosis. Activity of peroxidase was at par with total phenolics. Similarly, phenylalanine ammonia lyase (PAL) also showed high activity revealing the active phase in the synthesis of secondary metabolites in the plant. The oxidative burst generated in the interaction between Sesamum and F. oxysporum f. sesame toxin might be the first line of defense by the host mounted against the invading necrotrophic pathogen. The results suggested that the rapid production of reactive oxygen species in the callus in response to fungal toxin had been proposed to orchestrate the establishment of different defensive barriers against the pathogens.

Page(s): 834-838

Comparative expression of two abscisic acid-inducible genes and proteins in seeds of aromatic indica rice cultivar with that of non-aromatic indica rice cultivars

Mon, 28 Sep 2009 22:58:59 GMT

Title: Comparative expression of two abscisic acid-inducible genes and proteins in seeds of aromatic indica rice cultivar with that of non-aromatic indica rice cultivars

Authors: Roychoudhury, Aryadeep; Basu, Supratim; Sengupta, Dibyendu N

Abstract: As an integral part of stress signal transduction, the phytohormone abscisic acid (ABA) regulates important cellular reactions, including up-regulation of stress-associated genes, the products of which are involved directly or indirectly in plant protection. Being accompanied by an increased endogenous ABA level, the matured seeds, embryo and aleurone tissues of cereals accumulate several genes and proteins, associated with desiccation. The present study was aimed at investigating how the contrasting rice genotypes, varying in their salt-stress sensitivity, differ with respect to the expression pattern of two abiotic stress-inducible genes, Rab16A and SamDC, and corresponding proteins, in the seeds, at the background level (dry or water-imbibed state) and ABA-imbibed conditions, which could be related to the varietal differences in tolerance. The rice genotypes selected were M-1-48 (salt-sensitive), Nonabokra (salt-tolerant) and Gobindobhog (aromatic). An extremely low abundance of Rab16A or practically undetectable SamDC transcripts were observed in M-1-48 and Gobindobhog seeds under control conditions, induced only after exogenous ABA treatment, whereas they were expressed at a much higher level even in dry and water-imbibed seeds of Nonabokra, and lesser induced by ABA. The RAB16A (= dehydrin) and SAMDC protein expression in the three varieties were also identical to the gene expression patterns. Thus, the expression was stress-inducible in M-1-48 and Gobindobhog, while constitutive in Nonabokra. Our study reflected the similarity of the molecular responses to exogenous ABA of the seeds of the aromatic rice Gobindobhog to that of the salt-sensitive M-1-48, in exhibiting lower expression of stress-tolerant proteins only after stress. This work also proved that variation in gene/protein expression in seeds could be highly correlated with the variation in the tolerance mechanism of rice varieties.

Page(s): 827-833

Aqueous extract of Ficus religiosa Linn. reduces oxidative stress in experimentally induced type 2 diabetic rats

Mon, 28 Sep 2009 22:58:59 GMT

Title: Aqueous extract of Ficus religiosa Linn. reduces oxidative stress in experimentally induced type 2 diabetic rats

Authors: Kirana, H; Agrawal, S S; Srinivasan, B P

Abstract: One of the major etiologies in pathogenesis of type 2 diabetes especially complications is oxidative stress. Aqueous extract of Ficus religiosa at a dose of 100 and 200 mg/kg orally decreased the fasting blood glucose in streptozotocin induced type 2 diabetic rats. The drug had enzyme induction effect with respect to catalase (CAT) and glutathione peroxidase (GSH-Px) activity, however decreased the exaggerated activity of superoxide dismutase (SOD) in type 2 diabetic rats. F. religiosa modulated the enzymes of antioxidant defence system to combat oxidative stress. As a result, glutathione (GSH-reduced form) was restored and inhibited the formation of malondialdehyde. Drug at higher dose (200 mg/kg) had more pronounced effect. F. religiosa, a rasayana group of plant drug having anti-diabetic activity along with antioxidant potential was beneficial in treatment of type 2 diabetes.

Page(s): 822-826