Oxidative hemolysis, or "what made the red cell break"?

Ameliorative Effect of Gallic Acid on Methotrexate-Induced Hepatotoxicity and Nephrotoxicity in Rat

We investigated the protective effect of gallic acid (GA) against methotrexate (MTX)-induced hepatotoxicity and nephrotoxicity. Male Wistar rats were randomized into five groups (n = 6/group): I, control; II, MTX-treated for seven days; III, pre-treated with GA for seven days, followed by MTX for seven days; IV, co-treated with MTX and GA for seven days and V, GA for seven days. MTX caused a significant increase (P<0.05) in plasma biomarkers of nephrotoxicity (urea, creatinine) and hepatotoxicity (Bilirubin, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, gamma glutamyl transferase) when compared with control. Furthermore, MTX caused a significant decrease in the activities of hepatic enzymic antioxidants (superoxide dismutase, catalase, glutathione S-transferase) and nonenzymic antioxidants (Vitamin C and glutathione), followed by a significant increase in hepatic malondialdehyde content. However, pre-treatment and co-treatment with gallic acid ameliorated the MTX-induced biochemical changes observed. Taken together, GA protected against MTX-induced hepatotoxicity and nephrotoxicity in rats, by reducing the impact of oxidative damage to tissues.

Fluazifop-p-butyl, an aryloxyphenoxypropionate herbicide, diminishes renal and hepatic functions and triggers testicular oxidative stress in orally exposed rats

Fluazifop- p-butyl (FPB) is a selective aryloxyphenoxypropionate herbicide. Its phytotoxicity mechanism involves inhibition of lipid biosynthesis, free-radical generation, and oxidative stress in vulnerable plants. This study evaluates the impact of orally administered FPB on selected tissues in non-target animal model. Twenty-four male wistar rats (160–180g) were randomized into groups (I–IV). Group-I served as control, while animals in groups II, III, and IV received FPB at 18.75, 37.5, and 75 mg/kg body weight/day p.o., respectively, for 21 days. FPB caused significant ( p < 0.05) increase in plasma biomarkers of renal and hepatic function (urea, creatinine, bilirubin, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase) when compared to control. Significant reductions in testicular ascorbic acid, glutathione, and activities of glutathione-S transferase, superoxide dismutase, and catalase were observed in FPB-treated animals when compared to control, in a dose-dependent manner. This was accompanied by increased testicular lipid peroxidation in the treated groups. Furthermore, a significant decrease in testicular acid phosphatase and γ-glutamyl transferase activities was also observed in the FPB-treated groups in a dose-dependent manner compared to control. However, testicular lactate dehydrogenase activity was significantly increased in the FPB-treated rats when compared to control. Additionally, histopathological studies revealed severe interstitial oedema and congestion of testicular blood vessels in the FPB-treated groups. Overall, data from this study suggest that FPB induced hepatotoxicity, nephrotoxicity, and oxidative stress-mediated alteration of testicular functions in rat.

Hepatotoxicity, Nephrotoxicity and Oxidative Stress in Rat Testis Following Exposure to Haloxyfop-p-methyl Ester, an Aryloxyphenoxypropionate Herbicide

Haloxyfop-p-methyl ester (HPME) ((R)-2-{4-[3-chloro-5-(trifluoromethyl)-2-pyridyloxy]phenoxy}propionic acid), is a selective aryloxyphenoxypropionate (AOPP) herbicide. It exerts phytotoxicity through inhibition of lipid metabolism and induction of oxidative stress in susceptible plants. This study investigated the toxicological potentials of HPME in rats. Twenty-four male Wistar rats (170–210 g) were randomized into four groups (I–IV). Group I (control) received 1 mL of distilled water, while animals in Groups II, III and IV received 6.75, 13.5 and 27 mg/kg body weight HPME, respectively, for 21 days. There was a significant (p < 0.05) increase in renal and hepatic function biomarkers (urea, creatinine, total bilirubin, ALP, ALT, AST) in the plasma of treated animals compared to control. Levels of testicular antioxidants, ascorbic acid and glutathione, and activities of glutathione-S-transferase, superoxide dismutase and catalase were reduced significantly after 21 days of HPME administration in a dose-dependent manner. The testicular malondialdehyde level increased significantly in the HPME-treated rats relative to the control. A significant decrease in testicular lactate dehydrogenase, acid phosphatase and γ-glutamyl transferase was also observed in HPME-treated animals. Testicular histology revealed severe interstitial edema and sections of seminiferous tubules with necrotic and eroded germinal epithelium in the HPME-treated rats. Overall, data from this study suggest that HPME altered hepatic and renal function and induced oxidative stress and morphological changes in the testis of rats.

Influence of Moxifloxacin on Hepatic Redox Status and Plasma Biomarkers of Hepatotoxicity and Nephrotoxicity in Rat

Moxifloxacin is a broad spectrum fluoroquinolone antibacterial agent. We examined the hepatic redox status and plasma biomarkers of nephrotoxicity and hepatotoxicity in rat following administration of moxifloxacin (MXF). Twenty-four Wistar rats, 180–200 g, were randomized into four groups (I–IV). Animals in group I (control) received 1 mL of distilled water, while animals in groups II, III, and IV received 1 mL each of MXF equivalent to 4 mg/kg b.w., 8 mg/kg b.w., and 16 mg/kg b.w., respectively. After seven days, plasma urea, bilirubin, and creatinine were significantly (P < 0.05) elevated in the MXF-treated animals. Activities of alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase were significantly increased in the plasma of MXF-treated animals compared to control. Also plasma total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides increased significantly in the MXF-treated groups relative to control. Moreover, MXF triggered a significant decrease in hepatic catalase, superoxide dismutase, and glutathione-S transferase activities. Likewise, MXF caused a decrease in the hepatic levels of glutathione and vitamin C. A significant increase in hepatic MDA content was also observed in the MXF-treated animals relative to control. Overall, our data suggest that the half-therapeutic, therapeutic, and twice the therapeutic dose of MXF induced nephrotoxicity, hepatotoxicity, and altered hepatic redox balance in rats.

Ameliorative Effect of Gallic Acid on Cyclophosphamide-Induced Oxidative Injury and Hepatic Dysfunction in Rats

Cyclophosphamide (CP), a bifunctional alkylating agent used in chemotherapy has been reported to induce organ toxicity mediated by generation of reactive oxygen species and oxidative stress. Gallic acid (GA), a phenolic substance, is a natural antioxidant with proven free radical scavenging activity and offers protection against oxidative damage. This research study was designed to investigate the ameliorative effect of GA against CP-induced toxicity in rats. Twenty-five male Wistar rats (180-200 g) were randomized into five treatment groups: (A) control, (B) CP, 2 mg/kg body weight (b.w.), (C) pre-treatment with GA (20 mg/kg b.w.) for seven days followed by CP (2 mg/kg b.w.) for seven days, (D) co-treatment with GA (20 mg/kg b.w) and CP (2 mg/kg b.w.) for seven days, and (E) GA (20 mg/kg b.w.) for seven days. CP induced marked renal and hepatic damages as plasma levels of urea, creatinine, bilirubin and activities of AST, ALT, ALP and GGT were significantly elevated (p < 0.05) in the CP-treated group relative to control. In addition, hepatic levels of GSH, vitamin C and activities of SOD, catalase and GST significantly reduced in the CP-treated group when compared with control. This was accompanied with a significant increase in hepatic lipid peroxidation. The restoration of the markers of renal and hepatic damages as well as antioxidant indices and lipid peroxidation by pre- and co-treatment with GA clearly shows that GA offers ameliorative effect by scavenging the reactive oxygen species generated by CP. This protective effect may be attributed to the antioxidant property of gllic acid.

Quercetin, a Flavonoid Antioxidant, Ameliorated Procarbazine-Induced Oxidative Damage to Murine Tissues

Procarbazine (PCZ) (indicated in Hodgkin's disease), is an alkylating agent known to generate free radicals in vivo, while Quercetin (QCT) is a flavonoid antioxidant with proven free radical scavenging capacity. This study investigated the protective effects of QCT on PCZ-induced oxidative damage in the rat. Male Wistar rats (160-180 g) were randomized into five groups (n = 5/group): I (control), II PCZ-treated (2 mg/kg body weight (bw) for seven days); III pre-treated with QCT (20 mg/kg bw) for seven days, followed by PCZ for seven days; IV co-treated with PCZ and QCT for seven days and V administered QCT alone for seven days. PCZ caused a significant increase in plasma total bilirubin, urea, and creatinine when compared with control (P < 0.05). Similarly, plasma activities of alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and γ-glutamyl transferase (γ-GT) were significantly increased in the PCZ-treated group relative to control. Furthermore, PCZ caused a significant decrease in the activities of hepatic superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) as well as levels of ascorbic acid (AA) and glutathione (GSH). This was followed by a significant increase in hepatic malondialdehyde (MDA) content. However, QCT pre-treatment and co-treatment ameliorated the PCZ-induced changes in plasma levels of urea, creatinine, and bilirubin as well as the activities of ALP, AST, ALT, and GGT. QCT also ameliorated hepatic AA and GSH levels and the activities of SOD, CAT, and GST. This all suggests that QCT protected against PCZ-induced oxidative damage in rats.

Influence of Different Doses of Levofloxacin on Antioxidant Defense Systems and Markers of Renal and Hepatic Dysfunctions in Rats

Levofloxacin (LFX) is a broad spectrum fluoroquinolone antibiotic used in the treatment of infections such as pneumonia, chronic bronchitis, and sinusitis. The present study assessed the likely toxic effect of LFX on hepatic and renal tissues in rats. Twenty male Wistar rats were randomly divided into four treatment groups: A: control, B: 5 mg/kg bw LFX (half therapeutic dose), C: 10 mg/kg bw LFX (therapeutic dose), and D: 20 mg/kg bw LFX (double therapeutic dose). After seven days of administration, result indicated significant (P<0.05) increase in plasma ALT, AST, and ALP activities in the treated groups compared to control. Also, there was a significant increase in plasma creatinine, urea, and total bilirubin in the treated groups relative to control. Plasma total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides also increased significantly in the treated groups relative to control. Also, hepatic MDA level increased significantly in all the treated groups. However, hepatic SOD, catalase, and GST activities were significantly reduced in the LFX-treated animals. Moreover, GSH and ascorbic acid levels were significantly decreased in the LFX-treated groups relative to control. In conclusion, three doses of levofloxacin depleted antioxidant defense system and induced oxidative stress and hepatic and renal dysfunctions in rats.

Protective effect of quercetin on melphalan-induced oxidative stress and impaired renal and hepatic functions in rat

One major challenge with the use of anticancer agents is the phenomenon of drug-induced toxicity. Melphalan (MPLN) is an alkylating anticancer agent, while quercetin (QCT) is an antioxidant. We investigated the protective role of quercetin against MPLN-induced toxicity. Twenty-five male Wistar rats (160-170 g) were randomized into five treatment groups; (I) control, (II) MPLN (0.2 mg/kg b.w.), (III) pre-treated with QCT (20 mg/kg b.w.) for 7 days followed by MPLN (0.2 mg/kg b.w.) for 7 days, (IV) cotreated with QCT (20 mg/kg b.w.) and MPLN (0.2 mg/kg b.w.) for 7 days, and (V) QCT (20 mg/kg b.w.) alone. MPLN caused a significant increase in plasma bilirubin, urea, and creatinine by 122.2%, 102.3%, and 188%, respectively (P < 0.05). Similarly, plasma ALP, ALT, AST, and γ-GT activities increased significantly by 57.9%, 144.3%, 71.3%, and 307.2%, respectively, relative to control. However, pre or cotreatment with QCT ameliorated the levels of renal and hepatic function indices. Hepatic ascorbic acid and GSH and activities of glutathione-S-transferase, SOD, and catalase decreased significantly by 36.2%, 188%, 46.5%, 34.4%, and 55.2%, respectively, followed by increase in MDA content by 46.5% relative to control. Pre- and cotreatment with QCT reestablished the hepatic antioxidant status and lipid peroxidation. Overall, quercetin protected against MPLN-induced renal and hepatic toxicity in rats.

Toxicological implications of polymorphic drug metabolism

The occurrence of genetic polymorphisms of drug metabolism means that populations contain subgroups (phenotypes) that differ sharply in their abilities to effect a number of metabolic reactions. Because of this, major interphenotype differences occur in responsiveness to drugs and toxic substances. The well established genetic polymorphisms of acetylation and hydrolysis illustrate the important association that exists between phenotype and propensity to develop toxic and exaggerated responses to some substances. Recently, for metabolic oxidation, a new genetic polymorphism of drug metabolism has been described and it promises to provide a better understanding of inter-individual variability in the metabolic handling of, and responsiveness to, drugs and toxic substances. The following effects of the polymorphism are described here: (a) its influence in determining variable presystemic metabolism and hence systemic drug availability; (b) its role in determining alternative toxic pathways of metabolism in individuals who have a genetically determined impairment of oxidative capacity and (c) its influence on the development of agranulocytosis associated with metiamide administration.

[Bone marrow morphology and various hemolytic markers in growing rats with alimentary lead deficiency]

The effects of an alimentary lead deficiency on bone marrow morphology and several laboratory parameters of hemolysis were examined in two growth- and one generation-experiments with female Sprague Dawley rats. The animals were fed a semisynthetic casein-based diet supplemented with 0 ppb up to 800 ppb lead as Pb-II-acetat-3-hydrate. The evaluation of bone marrow did not show differences among the groups with different lead supply in the diet. Concerning the laboratory parameters of hemolysis it has been shown that the hemoglobin concentration of plasma and the lactate-dehydrogenase activity of serum were increased and the haptoglobin concentration of serum was decreased in the groups fed the diets poor in lead relative to lead-adequate animals. The activity of glutathione peroxidase and the glutathione concentration in red blood cells were increased in the groups fed the lead-deficient diet compared to lead-adequate groups. In conclusion, the study shows that the pancytopenia observed recently in lead-deficient rats is not caused by disturbed hematopoesis, whereas some parameters measured suggest that there exists increased hemolysis in lead-deficient rats.

The contribution of genetically determined oxidation status to inter-individual variation in phenacetin disposition

The oxidative O-de-ethylation and aromatic 2-hydroxylation of phenacetin have been investigated in panels of extensive (EM, n = 13) and poor (PM, n = 10) metabolizers of debrisoquine. The EM group excreted in the urine significantly more paracetamol (EM: 40.8 +/- 14.9% dose/0-8 h; PM: 29.2 +/- 8.7% dose/0-8 h, 2P less than 0.05) and significantly less 2-hydroxylated metabolites (EM: 4.7 +/- 2.3% dose/0-8 h; PM: 9.7 +/- 3.5% dose/0-8 h, 2P less than 0.005) than the PM group. Apparent first-order rate constants, calculated from pooled phenotype data, for overall elimination of phenacetin (k) and formation of paracetamol (kml) were higher in the EM group (EM: k = 0.191 +/- 0.151 h-1; kml = 0.091 +/- 0.025 h-1; PM: k = 0.098 +/- 0.035 h-1, 2P less than 0.05, kml = 0.052 +/- 0.019 h-1, 2P less than 0.05) than the PM group. The apparent first-order rate constant for 2-hydroxylation displayed no significant inter-phenotype differences. Correlation analysis demonstrated that genetically determined oxidation status accounted for approximately 50% of the inter-individual variability in phenacetin disposition encountered in this study.

Decrease of red blood cell filterability seen in intensive care I. The correlation of low erythrocyte filterability with mortality and its return to normal values in critically ill patients under parenteral nutrition

Damage to the internal viscosity of red cell is correlated with changes in the surface area to volume ratio and to prelytic phenomena. Considerable changes in shape were noticed in red cells from shocked dogs and some critically ill patients in blood smear or fresh preparation, or after in vitro treatment with colloidal plasma substitutes or glucose, and so erythrocyte filterability was investigated in critically ill patients, given or not given parenteral nutrition. The results revealed an increase of the erythrocyte filtration time (EFT 1/2) in more than 50% of the critically ill patients and less alteration in critically ill patients given total parenteral nutrition, the mortality being half as great. The return of increased EFT 1/2 to normal values occurred after 3-12 days of total parenteral nutrition in 6 patients investigated. A death rate twice as great was seen in patients with high EFT 1/2 as compared to the 27.7% mortality in patients with normal EFT 1/2, its correlation with increased filtration time being significant, r = 0.81 greater than 3 Sr, y = 1.291x + 27.44, n = 47.

Red-cell-membrane polypeptide aggregates in glucose-6-phosphate dehydrogenase mutants with chronic hemolytic disease. A clue to the mechanism of hemolysis

Red-cell membranes from patients with glucose-6-phosphate dehydrogenase deficiency were studied with polyacrylamide gel electrophoresis and gel filtration chromatography in sodium dodecyl sulfate. Membranes from each of five such patients who also had chronic hemolytic disease contained polypeptide aggregates within two molecular-weight ranges (4.4 X 10(5) and greater than 50 X 10(6) daltons). The 4.4 X 10(5) dalton aggregates were not detectable in red-cell membranes of patients with the enzyme deficiency without chronic hemolysis or in membranes from normal subjects, and the greater than 50 X 10(6) dalton aggregates were not found in appreciable amounts in these cells. The aggregates were dissociated by mercaptoethanol or dithiothreitol -- indicating that they were formed by intermolecular disulfide bonds. The polypeptide aggregates contained spectrin but not globin. Red-cell deformability was decreased in aggregate-containing cells. We postulate that the polypeptide aggregates are indicators of oxidant damage to the red-cell membrane, which results in decreased deformability and chronic hemolysis.

Haemolytic effect of two sulphonamides evaluated by a new method

A technique to investigate drugs which could cause haemolysis in subjects deficient in glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate: NADP oxidoreductase; G6PD) has been developed. The method is based on the technique of 14CO2 evolution during the incubation of normal erythrocytes in the presence of [I-14C]glucose and their own serum, the latter containing the active metabolites of the drugs received by normal subjects. By this method agents causing a stimulation of the hexosemonophosphate pathway of normal erythrocytes should be regarded as potentially haemolytic for G6PD-deficient subjects. Two sulphonamides, sulphormethoxine and sulphalene, of which until now no haemolytic effects have been reported, together with chloroquine, have been investigated. While chloroquine does not affect the hexosemonophosphate shunt of normal erythrocytes, the two sulphonamides stimulate this pathway. THE RESULTS ARE CONFIrmed by the reduction of the half-life of 51Cr-labelled G6PD-deficient red cells (Mediterranean variant), after administration of the two sulphonamides.

Serum hemopexin in patients with dermatitis herpetiformis on dapsone (di(4-aminophenyl)sulphone)

Twenty patients with dermatitis herpetiformis treated with di(4-aminophenyl)-sulphone (Dapsone) were analyzed with respect to serum hemopexin concentration as well as some other haematological parameters. With one exception, there were normal concentrations of serum hemopexin when the haptoglobin and methaemoglobin concentrations were normal. Ten out of 11 patients with haptoglobin below 0.3 g/l, which is the lower limit of reference interval at this laboratory, had their hemopexin concentrations reduced to various extents. There was an inverse relationship between the concentration of serum hemopexin and blood methaemoglobin. There was no correlation between amount of Heinz bodies and the concentrations of blood methaemoglobin, serum haptoglobin or serum hemopexin. It is concluded that serum hemopexin measurement should be of value in the assessment of the severity of the haemolysis caused by the drug treatment in those cases who have a low serum haptoglobin concentration.

Malaria, favism and glucose-6-phosphate dehydrogenase deficiency

Although glucose-6-phosphate dehydrogenase deficient individuals may suffer (sometimes fatally) from favism, a high incidence of this trait occurs in many Mediterranean populations. This apparent paradox is explained on the basis of a synergistic interaction between favism and G-6-PD deficiency that provides increased protection against malaria compared to that of the G-6-PD deficiency alone. This relationship is analogous to that between various hemoglobins and malaria in that there is selection for a more severe trait if it provides more protection against malaria.