Nejib Guizani - Academia.edu (original) (raw)
Papers by Nejib Guizani
Canadian Journal of Clinical Nutrition
Bioactive Components, Diet and Medical Treatment in Cancer Prevention
Nutrition and cancer, Jan 29, 2018
Folate and vitamin B12 deficiency is associated with depletion of the major intracellular antioxi... more Folate and vitamin B12 deficiency is associated with depletion of the major intracellular antioxidant glutathione, and oxidative stress is emerging as an etiological mechanism for colon cancer. Azoxymethane (AOM), a potent carcinogen, induces colon cancer in rats by causing pathophysiological changes and oxidative stress. We investigated the synergistic effect of folate and vitamin B12 supplementation against AOM-induced carcinogenesis and oxidative stress in rat colon. Adult male rats were distributed into four groups: 1) Basal diet only; 2) AOM injection (15 mg/kg once per week in weeks 5 and 6); 3) Folate and vitamin B12 supplemented diet; 4) Folate and B12 diet with AOM injection. After 16 weeks, rats were sacrificed, colon tissue dissected, indicators of oxidative stress were measured, and immunohistochemical and ultrastructural changes were evaluated. AOM-injected rats showed oxidative stress, evident by glutathione depletion, oxidation of cellular proteins, and DNA oxidative ...
Frontiers in bioscience (Scholar edition), Mar 1, 2018
Oxidative stress and mitochondrial dysfunction mediated neuro apoptosis is reported to play a maj... more Oxidative stress and mitochondrial dysfunction mediated neuro apoptosis is reported to play a major role in the pathology of Parkinson's disease. Zizyphus spina-christi fruits (ZSCF) are used as traditional medicines that are well-known for their high antioxidant properties. In the present study, we investigated the protective effects of ZSCF extract against 1-methyl-4-phenylpyridinium (MPP+) induced neurotoxicity in SH-SY5Y cell lines. The effect of ZCSF on MPP+ induced cell viability (MTT - 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay), membrane damage - (lactate dehydrogenase (LDH), oxidative stress (levels of ROS, nitric oxide and GSH and activities of SOD and catalase), mitochondrial membrane potential and apoptosis (activity of caspase 3 and protein expressions of cyto c, Bax and Bcl-2) were measured. Our results showed that ZSCF could be able to reduce the neurotoxicity of MPP+ and offer neuroprotection in vitro. This protective effect of ZCF might...
Preventive nutrition and food science, 2017
Oxidative stress plays a pivotal role in the development of diabetes and hyperglycaemia. The prot... more Oxidative stress plays a pivotal role in the development of diabetes and hyperglycaemia. The protective effects of natural extracts against diabetes are mainly dependent on their antioxidant and hypoglycaemic properties. Broccoli (Brassica oleracea) exerts beneficial health effects in several diseases including diabetes; however, the mechanism has not been elucidated yet. The present study was carried out to evaluate the potential hypoglycaemic and antioxidant properties of aqueous broccoli extracts (BEs) in diabetic rats. Streptozotocin (STZ) drug was used as a diabetogenic agent in a single intraperitoneal injection dose of 50 mg/kg body weight. The blood glucose level for each rat was measured twice a week. After 8 weeks, all animals were fasted overnight and sacrificed; pancreatic tissues were homogenized and used for measuring oxidative DNA damage, biochemical assessment of glutathione (GSH), and total antioxidant capacity (TAC) as well as histopathological examination for panc...
Comparative Biochemistry and Physiology Part B: Comparative Biochemistry
Beni-Suef University Journal of Basic and Applied Sciences, 2016
Http Dx Doi Org 10 1080 07373930802046294, May 12, 2008
The effect of drying method and pretreatment with salt on the properties of shark meat was invest... more The effect of drying method and pretreatment with salt on the properties of shark meat was investigated. Water loss during the salting step was faster with dry salting than with brine salting; however, both methods led to the same final water content at the end of the drying process. Moisture desorption isotherms showed that addition of salt prior to sun or air drying resulted in lower equilibrium moisture contents at the same water activity levels. Salting and method of drying had significant effects on the microbial load. Osmo-air-dried samples showed better microbial quality than samples treated by other methods. Molds grew on all samples after two months of storage at room temperature. Color and rehydration ratio were affected by the drying method. Higher dehydration ratios were obtained with air drying.
Food Science and Technology Research, Jul 1, 2013
International Journal of Food Properties
Journal of Food Biochemistry
Phenoloxidase (PO) is a key factor in insect immunity. On invasion of microorganisms and pathogen... more Phenoloxidase (PO) is a key factor in insect immunity. On invasion of microorganisms and pathogens, prophenoloxidase changes to its active form to PO. This study investigated purification biochemical properties of PO from the hemolymph of 5 th instar larvae of Hyphantria cunea (Lepidoptera). The purification fold was determined as 9.67 with a recovery of 0.12 and a specific activity of 23.28 U/mg protein identified. Kinetic parameters of purified PO from the insect H. cunea were determined. The Michaelis constant (K m) and the maximal velocity (V max) were 4.08 and 12.98 µmol/min/mg protein, respectively. The optimal pH and temperature of the enzyme for oxidation of L-DOPA were 10.0 and 35 º C, respectively. The ions Zn 2+ , Cu 2+ , K + and Na + significantly increased the enzyme activity and synthetic inhibitors such as diethyldithiocarbamate (DETC) significantly decreased it. Finally, it was found that purified PO had a molecular mass of 33 kDa. This study demonstrated some PO properties and its inhibitory effects demonstrating that it can be employed as useful methods for developing novel insecticides to replace traditionally used ones.
Gelatin extraction yield increased with the increase of acetic acid concentration and temperature... more Gelatin extraction yield increased with the increase of acetic acid concentration and temperature. Gelatin extracted from shaari skin using 0.1 N acid solutions and temperatures of 323 and 353 K gave highest protein content comparable to that of commercial bovine and porcine gelatins. In general, gelatin extracted from shaari gelatin showed lower onset of glass transition temperature than mammalian gelatins. For shaari skin gelatin, the onset of glass transition temperature decreased with the increase of extraction temperature up to 323 K and then remained nearly constant. The decrease in glass transition was more pronounced for gelatin extracted at 0.01 N compared to the 0.1 and 1.0 N samples. Unfolding temperature decreased exponentially with the increase of extraction temperature. The unfolding temperature shifted to lower temperature, and the decrease was more pronounced in the case of higher (1.0 N) concentrated samples. The extraction concentration and temperature did not show significant effect on the onset solids-melting temperature. Keywords Fish skin gelatin Á Glass transition Á Solidsmelting Á Shaari Á Amino acid List of symbols T gi Onset temperature of glass transition (K) T gp Peak temperature of glass transition (K) T ge End temperature of glass transition (K) T mi Onset temperature of solids-melting (K) T mm Maximum slope temperature of solids-melting (K) T mp Peak temperature of solids-melting (K) T me End temperature of solids-melting (K) T ui Onset unfolding temperature (K) T um Maximum slope of unfolding temperature (K) T up Peak of unfolding temperature (K) X w Moisture content (g/100 g sample) DC p Change of specific heat (J/kg K) DH u Enthalpy change for unfolding (kJ/kg) DH m Enthalpy change for solids-melting (kJ/kg)
Pakistan Journal of Biological Sciences
ABSTRACT
Food Research International
ABSTRACT
Canadian Journal of Clinical Nutrition
Bioactive Components, Diet and Medical Treatment in Cancer Prevention
Nutrition and cancer, Jan 29, 2018
Folate and vitamin B12 deficiency is associated with depletion of the major intracellular antioxi... more Folate and vitamin B12 deficiency is associated with depletion of the major intracellular antioxidant glutathione, and oxidative stress is emerging as an etiological mechanism for colon cancer. Azoxymethane (AOM), a potent carcinogen, induces colon cancer in rats by causing pathophysiological changes and oxidative stress. We investigated the synergistic effect of folate and vitamin B12 supplementation against AOM-induced carcinogenesis and oxidative stress in rat colon. Adult male rats were distributed into four groups: 1) Basal diet only; 2) AOM injection (15 mg/kg once per week in weeks 5 and 6); 3) Folate and vitamin B12 supplemented diet; 4) Folate and B12 diet with AOM injection. After 16 weeks, rats were sacrificed, colon tissue dissected, indicators of oxidative stress were measured, and immunohistochemical and ultrastructural changes were evaluated. AOM-injected rats showed oxidative stress, evident by glutathione depletion, oxidation of cellular proteins, and DNA oxidative ...
Frontiers in bioscience (Scholar edition), Mar 1, 2018
Oxidative stress and mitochondrial dysfunction mediated neuro apoptosis is reported to play a maj... more Oxidative stress and mitochondrial dysfunction mediated neuro apoptosis is reported to play a major role in the pathology of Parkinson's disease. Zizyphus spina-christi fruits (ZSCF) are used as traditional medicines that are well-known for their high antioxidant properties. In the present study, we investigated the protective effects of ZSCF extract against 1-methyl-4-phenylpyridinium (MPP+) induced neurotoxicity in SH-SY5Y cell lines. The effect of ZCSF on MPP+ induced cell viability (MTT - 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay), membrane damage - (lactate dehydrogenase (LDH), oxidative stress (levels of ROS, nitric oxide and GSH and activities of SOD and catalase), mitochondrial membrane potential and apoptosis (activity of caspase 3 and protein expressions of cyto c, Bax and Bcl-2) were measured. Our results showed that ZSCF could be able to reduce the neurotoxicity of MPP+ and offer neuroprotection in vitro. This protective effect of ZCF might...
Preventive nutrition and food science, 2017
Oxidative stress plays a pivotal role in the development of diabetes and hyperglycaemia. The prot... more Oxidative stress plays a pivotal role in the development of diabetes and hyperglycaemia. The protective effects of natural extracts against diabetes are mainly dependent on their antioxidant and hypoglycaemic properties. Broccoli (Brassica oleracea) exerts beneficial health effects in several diseases including diabetes; however, the mechanism has not been elucidated yet. The present study was carried out to evaluate the potential hypoglycaemic and antioxidant properties of aqueous broccoli extracts (BEs) in diabetic rats. Streptozotocin (STZ) drug was used as a diabetogenic agent in a single intraperitoneal injection dose of 50 mg/kg body weight. The blood glucose level for each rat was measured twice a week. After 8 weeks, all animals were fasted overnight and sacrificed; pancreatic tissues were homogenized and used for measuring oxidative DNA damage, biochemical assessment of glutathione (GSH), and total antioxidant capacity (TAC) as well as histopathological examination for panc...
Comparative Biochemistry and Physiology Part B: Comparative Biochemistry
Beni-Suef University Journal of Basic and Applied Sciences, 2016
Http Dx Doi Org 10 1080 07373930802046294, May 12, 2008
The effect of drying method and pretreatment with salt on the properties of shark meat was invest... more The effect of drying method and pretreatment with salt on the properties of shark meat was investigated. Water loss during the salting step was faster with dry salting than with brine salting; however, both methods led to the same final water content at the end of the drying process. Moisture desorption isotherms showed that addition of salt prior to sun or air drying resulted in lower equilibrium moisture contents at the same water activity levels. Salting and method of drying had significant effects on the microbial load. Osmo-air-dried samples showed better microbial quality than samples treated by other methods. Molds grew on all samples after two months of storage at room temperature. Color and rehydration ratio were affected by the drying method. Higher dehydration ratios were obtained with air drying.
Food Science and Technology Research, Jul 1, 2013
International Journal of Food Properties
Journal of Food Biochemistry
Phenoloxidase (PO) is a key factor in insect immunity. On invasion of microorganisms and pathogen... more Phenoloxidase (PO) is a key factor in insect immunity. On invasion of microorganisms and pathogens, prophenoloxidase changes to its active form to PO. This study investigated purification biochemical properties of PO from the hemolymph of 5 th instar larvae of Hyphantria cunea (Lepidoptera). The purification fold was determined as 9.67 with a recovery of 0.12 and a specific activity of 23.28 U/mg protein identified. Kinetic parameters of purified PO from the insect H. cunea were determined. The Michaelis constant (K m) and the maximal velocity (V max) were 4.08 and 12.98 µmol/min/mg protein, respectively. The optimal pH and temperature of the enzyme for oxidation of L-DOPA were 10.0 and 35 º C, respectively. The ions Zn 2+ , Cu 2+ , K + and Na + significantly increased the enzyme activity and synthetic inhibitors such as diethyldithiocarbamate (DETC) significantly decreased it. Finally, it was found that purified PO had a molecular mass of 33 kDa. This study demonstrated some PO properties and its inhibitory effects demonstrating that it can be employed as useful methods for developing novel insecticides to replace traditionally used ones.
Gelatin extraction yield increased with the increase of acetic acid concentration and temperature... more Gelatin extraction yield increased with the increase of acetic acid concentration and temperature. Gelatin extracted from shaari skin using 0.1 N acid solutions and temperatures of 323 and 353 K gave highest protein content comparable to that of commercial bovine and porcine gelatins. In general, gelatin extracted from shaari gelatin showed lower onset of glass transition temperature than mammalian gelatins. For shaari skin gelatin, the onset of glass transition temperature decreased with the increase of extraction temperature up to 323 K and then remained nearly constant. The decrease in glass transition was more pronounced for gelatin extracted at 0.01 N compared to the 0.1 and 1.0 N samples. Unfolding temperature decreased exponentially with the increase of extraction temperature. The unfolding temperature shifted to lower temperature, and the decrease was more pronounced in the case of higher (1.0 N) concentrated samples. The extraction concentration and temperature did not show significant effect on the onset solids-melting temperature. Keywords Fish skin gelatin Á Glass transition Á Solidsmelting Á Shaari Á Amino acid List of symbols T gi Onset temperature of glass transition (K) T gp Peak temperature of glass transition (K) T ge End temperature of glass transition (K) T mi Onset temperature of solids-melting (K) T mm Maximum slope temperature of solids-melting (K) T mp Peak temperature of solids-melting (K) T me End temperature of solids-melting (K) T ui Onset unfolding temperature (K) T um Maximum slope of unfolding temperature (K) T up Peak of unfolding temperature (K) X w Moisture content (g/100 g sample) DC p Change of specific heat (J/kg K) DH u Enthalpy change for unfolding (kJ/kg) DH m Enthalpy change for solids-melting (kJ/kg)
Pakistan Journal of Biological Sciences
ABSTRACT
Food Research International
ABSTRACT