Amelioration of galactosamine-induced nephrotoxicity by a protein isolated from the leaves of the herb, Cajanus indicus L

<p>Abstract</p> <p>Background</p> <p>Galactosamine (GalN), an established experimental toxin, mainly causes liver injury via the generation of free radicals and depletion of UTP nucleotides. Renal failure is often associated with end stage liver damage. GalN intoxication also induces renal dysfunction in connection with hepatic disorders. Present study was designed to find out the effect of a protein isolated from the leaves of the herb <it>Cajanus indicus </it>against GalN induced renal damage.</p> <p>Methods</p> <p>Both preventive as well as curative effect of the protein was investigated in the study. GalN was administered intraperitoneally at a dose of 800 mg/kg body weight for 3 days pre and post to protein treatment at an intraperitoneal dose of 2 mg/kg body weight for 4 days. The activities of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) and glutathione-S-transferase (GST), levels of cellular metabolites, reduced glutathione (GSH), total thiols, oxidized glutathione (GSSG) and lipid peroxidation end products were determined to estimate the status of the antioxidative defense system. In addition, serum creatinine and urea nitrogen (UN) levels were also measured as a marker of nephrotoxicity.</p> <p>Results</p> <p>Results showed that GalN treatment significantly increased the serum creatinine and UN levels compared to the normal group of mice. The extent of lipid peroxidation and the level of GSSG were also enhanced by the GalN intoxication whereas the activities of antioxidant enzymes SOD, CAT, GR and GST as well as the levels of total thiols and GSH were decreased in the kidney tissue homogenates. Protein treatment both prior and post to the toxin administration successfully altered the effects in the experimental mice.</p> <p>Conclusion</p> <p>Our study revealed that GalN caused a severe oxidative insult in the kidney. Protein treatment both pre and post to the GalN intoxication could protect the kidney tissue against GalN induced oxidative stress. As GalN induced severe hepatotoxicity followed by renal failure, the protective role of the protein against GalN induced renal damages is likely to be an indirect effect. Since the protein possess hepatoprotective activity, it may first ameliorate GalN-induced liver damage and consequently the renal disorders are reduced. To the best of our knowledge, this is probably the first report describing GalN-induced oxidative stress in renal damages and the protective role of a plant protein molecule against it.</p

The Solar Dynamo and Emerging Flux (Invited Review)

Abstract. The largest concentrations of magnetic flux on the Sun occur in active regions. In this paper, the properties of active regions are investigated in terms of the dynamics of magnetic flux tubes which emerge from the base of the solar convection zone, where the solar cycle dynamo is believed to operate, to the photosphere. Flux tube dynamics are computed using the ‘thin flux tube ’ approxi-mation, and by using MHD simulation. Simulations of active region emergence and evolution, when compared with the known observed properties of active regions, have yielded the following results: (1) The magnetic field at the base of the convection zone is confined to an approximately toroidal geometry with a field strength in the range.3–10 / 104 G. The latitude distribution of the toroidal field at the base of the convection zone is more or less mirrored by the observed active latitudes; there is not a large poleward drift of active regions as they emerge. The time scale for emergence of an active region from the base of the convection zone to the surface is typically 2–4 months. The equatorial gap in the distribution of active regions has two possible origins; if the toroidal field strength is close to 105 G, it is due to the lack of equilibrium solutions at low latitude; if it is closer to 3 104 G, it may be due to modest poleward drift during emergence. (2) The tilt of active regions is due primarily to the Coriolis force acting to twist the diverging flows of the rising flux loops