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This paper reports the use of a GIS based Probabilistic Certainty Factor method to assess the geo-environmental factors that contribute to landslide susceptibility in Tevankarai Ar sub-watershed, Kodaikkanal. Landslide occurrences are a common phenomenon in the Tevankarai Ar sub-watershed, Kodaikkanal owing to rugged terrain at high altitude, high frequency of intense rainfall and rapidly expanding urban growth. The spatial database of the factors influencing landslides are compiled primarily from topographical maps, aerial photographs and satellite images. They are relief, slope, aspect, curvature, weathering, soil, land use, proximity to road and proximity to drainage. Certainty Factor Approach is used to study the interaction between the factors and the landslide, highlighting the importance of each factor in causing landslide. The results show that slope, aspect, soil and proximity to roads play important role in landslide susceptibility. The landslide susceptibility map is classified into five susceptible classes-low, very low, uncertain, high and very high − 93.32% of the study area falls under the stable category and 6.34% falls under the highly and very highly unstable category. The relative landslide density index (R index) is used to validate the landslide susceptibility map. R index increases with the increase in the susceptibility class. This shows that the factors selected for the study and susceptibility mapping using certainty factor are appropriate for the study area. Highly unstable zones show intense anthropogenic activities like high density settlement areas, and busy roads connecting the hill town and the plains.

Altered membrane integrity has been suggested as a major factor in the development of cellular injury during myocardial necrosis. The present study was designed to investigate the effect of diosgenin on lysosomal hydrolases, membrane-bound enzymes, and electrolytes during isoproterenol (ISO)-induced myocardial necrosis in rats. Animals were pretreated with DIOS (80 mg/kg) for a period of 35 days. Myocardial infarction was experimentally induced with ISO (85 mg/kg) twice at 24 h interval. Experimental myocardial infarction was evidenced with marked elevation of creatine kinase-MB (CK-MB) in serum with concomitant increase in lipid peroxidation (plasma thiobarbituric acid reactive substances (TBARS) and hydroperoxides (HP)). Activity of lysosomal hydrolases (beta-glucuronidase, beta-N-acetyl glucosaminidase, beta-D-galactosidase, cathepsin D, and acid phosphatase) was found to be increased in serum and heart tissue of ISO-alone treated animals. DIOS (80 mg/kg) pretreated groups showed significant decrease in CK-MB, lipid peroxidation, and lysosomal hydrolases activity. The membrane-bound enzymes such as Ca2+-ATPase and Mg2+-ATPase activity was increased and Na+/K+-ATPase activity was decreased in the heart tissues of ISO-alone treated animals. These enzyme alterations lead to the change in the electrolytes content such as sodium, potassium, and calcium in the heart tissue. However, DIOS (80 mg/kg) pretreatment reversed the membrane-bound enzymes activity and thereby maintained the normal electrolyte concentration. These results suggest the protective action of diosgenin in ISO-induced myocardial infarction. The salubrious effect observed in this study might be due to the antioxidant and membrane stabilizing potential of diosgenin.

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Diabetes exacerbates neuronal injury induced by hyperglycemia mediated oxidative damage and mitochondrial dysfunction. The aim of the present study is to investigate the effects of curcuminoids, polyphenols of Curcuma longa (L.) on oxidative stress and mitochondrial impairment in the brain of streptozotocin (STZ)-induced diabetic rats. A marked increase in lipid peroxidation and nitrite levels with simultaneous decrease in endogenous antioxidant marker enzymes was observed in the diabetic rat brain, which was restored to normal levels on curcuminoids treatment. Down-regulation of mitochondrial complex I and IV activity caused by STZ induction was also up-regulated on oral administration of curcuminoids. Moreover, curcuminoids administration profoundly elevated the ATP level, which was earlier reduced in the diabetic brain. These results suggest that curcuminoids exhibit a protective effect by accelerating antioxidant defense mechanisms and attenuating mitochondrial dysfunction in the brain of diabetic rats. Curcuminoids thus may be used as a promising therapeutic agent in preventing and/or delaying the progression of diabetic complications in the brain.

Isoproterenol is a synthetic catecholamine found to cause toxicity leading to severe stress in the myocardium of experimental animals. The aim of the present study is to evaluate the cardioprotective effect of Cymbopogon citratus, which is used as a culinary item and commonly known as lemon grass (LG), in isoproterenol-induced cardiotoxicity. Male Wistar albino rats were segregated into five different groups as follows. Groups I and II rats were treated with vehicle. Groups III and IV rats were treated with 100 and 200 mg/kg b.wt. of LG. Group V with 100 mg/kg b.wt. of vitamin E. Myocardial necrosis was induced in Groups II, III, IV and V on 58th and 59th day using isoproterenol at a dose of 85 mg/kg twice at 24-hour interval. Animals were sacrificed on the 60 th day. LG pretreatment exhibited cardioprotective activity as evidenced by decreased activity of cardiac markers in serum and increased the same in heart homogenate (p < 0.05). LG administration decreased the toxic events of lipid peroxidation (TBARS) in both serum and heart tissue, by increasing the level of enzymatic antioxidants and non-enzymatic antioxidants significantly in both heart homogenate and serum sample (p < 0.05). The histopathological observations also revealed that the cardioprotective effect of LG extract was observed at a dose of 200 mg/kg b.wt. The results of the present study reveal that LG is cardioprotective and antilipid peroxidative by increasing various antioxidants at a dose of 200 mg/kg b.wt., which is comparable with that of vitamin E.

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