Effect of host portal and peripheral sera fractions on cell proliferation of Schistosoma mansoni schistosomules

Schistosomules of Schistosoma mansoni were incubated in medium containing hamster (highly susceptible host) portal or peripheral venous serum, or rat (poorly susceptible host) portal or peripheral venous serum or their fractions in the presence of bromodeoxyuridine (BrdU) in order to determine effects of host sera on cell proliferation. BrdU labeling indices (BLIs) were significantly increased in the presence of portal (33.05±0.70, p<0.05), but not in peripheral serum (19.1±0.85, p>0.05) of hamsters, compared to schistosomules cultured in presence of control medium (18.96±0.66). This stimulatory effect was substantially reproduced by fraction 4 (31.03±0.69, p>0.05) separated from hamster portal serum. In contrast, no significant differences were observed in the BLIs in rat portal or peripheral sera as well as their fractions when compared to control medium. Taken together, it was concluded that portal serum of hamster and its fraction which includes a low molecular weight protein (20 kDa) enhanced cell proliferation of S. mansoni schistosomules. This could explain the localization and preference of S. mansoni schistosomules and worms to portal-mesenteric venous system.

Effect of cadmium and aluminum intake on the antioxidant status and lipid peroxidation in rat tissues

This work aimed to study the relationship between the accumulation of cadmium (Cd) or aluminum (Al) in certain tissues and the levels of lipid peroxides as well as tissue antioxidants. To carry out such investigations, CdCl2 was given to rats in two dose levels; 0.5 or 2.0 mg/kg i.p for 1 day or daily repeated doses for 2 weeks. Al was given as AlCl3 either in a single dose of 100 mg/kg or daily repeated doses of 20 mg/kg for 2 and 4 weeks. The measured parameters were tissue malondialdehyde (MDA, index of lipid peroxidation) and reduced glutathione (GSH) levels as well as the activities of glutathione peroxidase (GSH-PX), glutathione reductase (GSSG-R), and glucose-6-phosphate dehydrogenase (G-6-PDH) enzymes. Liver and kidney functions were assessed by measuring serum alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities as well as serum urea and creatinine concentrations. Cd and Al concentrations in the studied tissues were also measured. Results indicated that tissue Cd was significantly increased after administration of either Cd doses. After a single dose of 0.5 or 2.0 mg/kg CdCl2, the increase in tissue Cd levels were accompanied by an increase in MDA and a decrease in GSH levels. On the other hand, after repeated administration of Cd, tissue Cd accumulation was accompanied by increased hepatic and renal GSH levels with decrease in MDA content and a decrease in GSH-PX activity in liver. Liver function was affected at all dose regimens, whereas kidney function was affected only after 2 weeks administration of the higher dose. In Al treated rats, Al concentration was shown to be increased in liver much more than in brain. This was accompanied by a slight decrease in hepatic GSH level after 2 weeks and a decrease in GSH-PX activity after 4 weeks. Liver function was affected only after repeated injection of Al for 2 or 4 weeks. In general, Al administration exhibited safer pattern than Cd.

Study of the hypolipidemic properties of pectin, garlic and ginseng in hypercholesterolemic rabbits

Experimental hypercholesterolemia and its modulation by some natural dietary supplements (pectin, garlic and ginseng) and by the drug gemfibrozil were studied. Experimental hypercholesterolemia was induced by feeding rabbits a 2% cholesterol-enriched diet for 28 days. Hypercholesterolemic rabbits were classified into five groups. One group did not receive treatments and served as a control hypercholesterolemic group. The other four groups were fed the cholesterol-enriched diet in conjunction with either 10% pectin, 2% garlic, 2% ginseng or 135 mg g-1 b.w gemfibrozil in a daily oral dose. A normal group of rabbits fed a plain chow diet was also included in the study. The hypolipidemic effect of the above treatments was examined by estimating serum triglycerides (TG), total-, LDL- and HDL-cholesterol. Post-heparin total and hepatic lipase activities were estimated in post-heparin plasma obtained 10 min after an intravenous injection of heparin (200 IU kg-1 b.w). In order to evaluate the antioxidant status of the rabbits, plasma malondialdehyde (MDA) level and erythrocyte superoxide dismutase (SOD) activity were measured. After killing, aorta from all rabbits were subjected to histopathological examination. Results of the study demonstrated that feeding the cholesterol-enriched diet caused a significant increase in total-, LDL-, and HDL-cholesterol, plasma MDA and post-heparin total and hepatic lipase activities. On the other hand, serum TG and erythrocyte SOD were not changed. Histopathological examination revealed marked alteration in the aortic wall with the appearance of large multiple atheromatous plaques. Both garlic and pectin were successful in a significant reduction of the hypercholesterolemia in a way comparable to gemfibrozil. Garlic was the only treatment that has antilipid peroxidative property. Erythrocyte SOD activity was not affected by hypercholesterolemia or by any of the treatments. Also, none of the treatments were able to modify the significant elevation of post-heparin lipolytic activities associated with the hypercholesterolemia or to significantly affect the serum triglycerides level. Finally, among the hypercholesterolemic groups that received treatments, the least changes in the aortic wall were shown in the animals of the gemfibrozil group. Slight degeneration was observed in the aorta of animals treated with pectin or garlic. Ginseng administration failed to exert any significant protection from the remarkable hypercholesterolemia or atherosclerosis associated with the cholesterol- enriched diet.

Biochemical evaluation of acetyl salicylic acid in relation to different diets

Effect of aspirin on some biochemical and nutritional parameters was studied in rats fed with high fat, low fat, high protein or low protein diets. Two doses of aspirin (50 and 150 mg/kg rat body weight) were tested. The experiment continued for 10 days. Results showed that, when rats fed high fat diet, high dose of aspirin significantly decreased body weight gain, food efficiency ratio, plasma high density lipoproteins-cholesterol and its ratio to total cholesterol. Low dose of aspirin significantly reduced plasma total lipids. Low aspirin dose significantly increased plasma glucose level, when low fat diet was fed. Feeding high protein diet during administration of both doses of aspirin significantly reduced plasma total lipids and albumin/globulin ratio, while both doses significantly elevated plasma globulins. Low aspirin dose reduced plasma HDL-ch and significantly elevated plasma total proteins. In rats fed low protein diet, both aspirin doses significantly increased plasma triglycerides. The high dose significantly increased albumin/globulin ratio.

Effect of pretreatment with vitamin E or diazepam on brain metabolism of stressed rats

The effect of vitamin E (VE) or diazepam (DZ) pretreatment on some carbohydrate metabolic aspects in the brains of stressed rats was studied. DZ and VE were given i.p. at doses of 5 mg/kg body wt for 6 days prior to subjecting the animals to single swimming stress (SSS). Pretreatment of the rats with DZ or VE diminished the stress-induced increases in plasma corticosterone and glucose levels and reversed the decrease due to stress on brain ATP, glucose, glycogen and pyruvate contents. The increase in brain ADP and lactate was brought back to levels which approached the pre-stressed values. Moreover, DZ and VE pretreatments helped in attenuating the stress-induced alteration in brain mitochondrial and cytosolic hexokinase as well as sodium, potassium adenosine triphosphatase (Na+,K(+)-ATPase) activities. The change in these metabolic parameters produced by VE pre-treatment was less than that exhibited by DZ. The effects of VE were explained in light of its antioxidant property in preventing the free radical production and lipid peroxide formation which are important factors in the pathogenesis of stress.

Effect of vitamin C administration in modulating some biochemical changes in arthritic rats

Two phases of arthritis, acute phase (four days after adjuvant inoculation) and chronic phase (21 or 29 days after adjuvant inoculation) were studied in male rats. The effect of administration of vitamin C in a daily oral dose of 50 mg/kg body wt for four and 21 days starting on the day of adjuvant inoculation and for 7 days starting 21 days after adjuvant inoculation against these phases of arthritis was demonstrated. Results showed that prolonged administration of vitamin C (21 days) increased the lowered serum sulphydryl (SH-groups) to prearthritic values while it decreased the elevated level of blood glutathione (GSH) of arthritic rats. However, neither (four-day) nor seven-day treatment with vitamin C exerted any significant changes in these parameters. The results showed also a slight significant increase in the level of erythrocyte superoxide dismutase activity (SOD) [1.15.1.1] upon seven-day treatment with vitamin C. Meanwhile, four-, 21- or seven-day treatment with vitamin C produced no significant change in the elevated levels of serum ceruloplasmin (Cp) and alpha 2-macroglobulin (alpha 2-M) of arthritic rats. However, 21-day and 7-day administration of vitamin C has improved the lowered A/G ratio in these animals. The improvement in these parameters after prolonged administration of vitamin C was explained in the light of the antioxidant property of this vitamin and suggests a beneficial role for it in the treatment of arthritis.

Biochemical changes in arthritic rats under the influence of vitamin E

Two phases of adjuvant arthritis, acute phase (4 days after adjuvant inoculation) and chronic phase (21 and 29 days after adjuvant inoculation) were studied in male rats. The effect of administration of vitamin E in a daily oral dose of 147 mg/kg body wt. for one week against these phases of arthritis were demonstrated before and after adjuvant inoculation. Results showed that administration of the vitamin before and after adjuvant inoculation increased the lowered serum-SH group in arthritic rats so that their level was restored to pre-arthritic values especially in chronic treated group. Meanwhile, these treatments produced no change in the increased level of blood GSH or erythrocyte SOD activity of arthritic rats. The results showed also that administration of vitamin E before adjuvant inoculation increased significantly the level of alpha 2-M while it did not alter the increased serum Cp in acute phase. However, administration of the vitamin after adjuvant inoculation failed to exert any change in these parameters. In the meantime, these treatments tended to increase the lowered A/G of arthritic rats in different phases especially in acute one. These observations suggest that antioxidants such as vitamin E may be beneficial for arthritis.

Effect of chronic administration of DL-amphetamine and fenfluramine on adrenocortical functions and on certain aspects of carbohydrate and fat metabolism

Chronic treatment of rats with amphetamine (4 mg/kg body mass) or fenfluramine (10 mg/kg body mass) might have stimulating effects on adrenocortical function. This was indicated by the significant decrease in adrenal cholesterol, ascorbic acid, glycogen, and the increase in adrenal phosphorylase activity. Both 17-oxo (17-OS) and 17-hydroxy-corticosteroids (17-OHS) were also increased by fenfuramine, while only 17-OHS was increased by amphetamine. Amphetamine did not affect plasma glucose, liver glycogen and phosphorylase activity, while fenfluramine increased liver glycogen but did not affect plasma glucose or liver phosphorylase activity. The drugs markedly increased plasma free fatty acids (FFA) which might indicate increased lipolysis.

Effect of ascorbic acid on oxygen consumption, glycolysis and lipid metabolism of diabetic rat testis. Ascorbic acid and diabetes, I

Alloxan diabetes caused a marked stimulation of endogenous oxygen uptake by rat testis tissues. However, the oxygen uptake in the presence of added glucose or pyruvate as substrate was significantly reduced. The ability of the testis tissues to utilize these substrates and to produce lactate was significantly inhibited in the diabetic animals. Alloxan diabetes also increased the levels of cholesterol, cholesterol esters, non-esterified fatty acids, triglycerides and phospholipids in rat testis tissues. Treatment of the diabetic rats with ascorbic acid caused more or less a normalization of all the parameters tested.