ANN-GA based biosorption of As(III) from water through chemo-tailored and iron impregnated fungal biofilter system.

The iron impregnated fungal bio-filter (IIFB) discs of luffa sponge containing Phanerochaete chrysosporium mycelia have been used for the removal of As(III) from water. Two different forms of same biomass viz. free fungal biomass (FFB) and modified free fungal biomass (chemically modified and iron impregnated; CFB and IIFB) have been simultaneously investigated to compare the performance of immobilization, chemo-tailoring and iron impregnation for remediation of As(III). IIFB showed highest uptake capacity and percentage removal of As(III), 1.32 mg/g and 92.4% respectively among FFB, CFB and IIFB. Further, the application of RSM and ANN-GA based mathematical model showed a substantial increase in removal i.e. 99.2% of As(III) was filtered out from water at optimised conditions i.e. biomass dose 0.72 g/L, pH 7.31, temperature 42 °C, and initial As(III) concentration 1.1 mg/L. Isotherm, kinetic and thermodynamic studies proved that the process followed monolayer sorption pattern in spontaneous and endothermic way through pseudo-second order kinetic pathway. Continuous mode of As(III) removal in IIFB packed bed bioreactor, revealed increased removal of As(III) from 76.40 to 88.23% with increased column height from 5 to 25 cm whereas the removal decreased from 88.23 to 69.45% while increasing flow rate from 1.66 to 8.30 mL/min. Moreover, the IIFB discs was regenerated by using 10% NaOH as eluting agent and evaluated for As(III) removal for four sorption-desorption cycles, showing slight decrease of their efficiency by 1-2%. SEM-EDX, pHzpc, and FTIR analysis, revealed the involvement of hydroxyl and amino surface groups following a non-electrostatic legend exchange sorption mechanism during removal of As(III).

Protective antioxidant effect of vitamins C and E in streptozotocin induced diabetic rats.

We have investigated the protective effect of vitamin C and E together supplementation on oxidative stress and antioxidant enzyme activities in the liver of streptozotocin-induced diabetic rats, unsupplemented diabetic and control rats. We also determined the levels of both the vitamins and oxidative stress in plasma. Vitamin supplementation in diabetic rats lowered plasma and liver lipid peroxidation, normalised plasma vitamin C levels and raised vitamin E above normal levels. In liver, the activity of glutathione peroxidase was raised significantly and that of glutathione-S-transferase was normalised by vitamin supplementation in diabetic rats. The levels of lipid peroxidation products in plasma and liver of vitamin-supplemented diabetic rats and activities of antioxidant enzymes in liver suggest that these vitamins reduce lipid peroxidation by quenching free radicals.

Effect of vitamin C supplementation on oxidative stress in experimental diabetes.

Alloxan diabetic rats supplemented with vitamin C (ascorbic acid) orally in drinking water had increased plasma and liver ascorbic acid as compared to unsupplemented diabetic rats. The levels of liver reduced glutathione also increased in vitamin C supplemented diabetic rats as compared to non-supplemented diabetic rats. Vitamin C supplementation did not have any effect in reducing increased liver lipid peroxidation in diabetic rats. The results of the present study suggest that diabetes results in decreased levels of protective antioxidant species and vitamin C is effective to some extent in maintaining levels of plasma and liver ascorbic acid and liver reduced glutathione.

Antioxidant status of streptozotocin diabetic rats.

Free radicals may play an important role in causation and complications of diabetes mellitus. Antioxidant status of blood was determined in rats made diabetic in intraperitoneal injection of streptozotocin (75 mg/kg body weight). The product of lipid peroxidation malondialdehyde in erythrocytes (RBC) was increased in diabetic rats as compared to normal controls after 6 weeks of induction of diabetes. The levels of major natural protective antioxidants, viz. glutathione and alphatocopherol (vitamin E) were lower in RBC and plasma respectively of diabetic rats as compared to normal controls. The results indicate that increased oxidative stress and accompanying decrease in antioxidants may be related to the causation of diabetes mellitus.