A Novel Chinese Medicine Formula Inhibits Non-small Cell Lung Cancer by Triggering Oxidative Stress Dependent on Pentose Phosphate Pathway / 中国肺癌杂志

BACKGROUND@#Non-small cell lung cancer (NSCLC) is one of the most lethal malignancies worldwide. A novel Chinese medicine formula-01 (NCHF-01) has shown significant clinical efficacy in the treatment of NSCLC, but the mechanism of this formula in the treatment of NSCLC is not fully understood. The aim of this study is to investigate the molecular mechanism of NCHF-01 in inhibiting NSCLC.@*METHODS@#Lewis lung cells (LLC) tumor bearing mice were established to detect the tumor inhibitory effect of NCHF-01. The morphological changes of tissues and organs in LLC tumor-bearing mice were detected by hematoxylin-eosin (HE) staining. NSCLC cells were treated by NCHF-01. The effects of cell viability and proliferation were detected by MTT and crystal violet staining experiment. Flow cytometry was used to detect cell cycle, apoptosis and reactive oxygen species (ROS). Network pharmacology was used to predict the mechanism of its inhibitory effect of NSCLC. Western blot and immunohistochemistry (IHC) were used to detect the expression of related proteins.@*RESULTS@#NCHF-01 can inhibit tumor growth in LLC tumor-bearing mice, and has no obvious side effects on other tissues and organs. NCHF-01 could inhibit cell viability and proliferation, induce G2/M phase arrest and apoptosis, and promote the increase of ROS level. Network pharmacological analysis showed that NCHF-01 exerts anti-NSCLC effects through various biological processes such as oxidative stress and central carbon metabolism. NCHF-01 can reduce the protein expression and enzyme activity of the key enzymes 6-phosphate glucose dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) in the pentose phosphate pathway (PPP).@*CONCLUSIONS@#NCHF-01 can inhibit NSCLC through oxidative stress dependent on the PPP.

Betaine supplementation improved L-threonine fermentation of Escherichia coli THRD by upregulating zwf (glucose-6-phosphate dehydrogenase) expression

BACKGROUND: The supplementation of betaine, an osmoprotective compatible solute, in the cultivation media has been widely used to protect bacterial cells. To explore the effects of betaine addition on industrial fermentation, Escherichia coli THRD, an L-threonine producer, was used to examine the production of L-threonine with betaine supplementation and the underlying mechanism through which betaine functions was investigated. RESULTS: Betaine supplementation in the medium of E. coli THRD significantly improved L-threonine fermentation parameters. The transcription of zwf and corresponding enzyme activity of glucose-6-phosphate dehydrogenase were significantly promoted by betaine addition, which contributed to an enhanced expression of zwf that provided more nicotinamide adenine dinucleotide phosphate (NADPH) for L-threonine synthesis. In addition, as a result of the betaine addition, the betaine-stimulated expression of enhanced green fluorescent protein (eGFP) under the zwf promoter within a plasmid-based cassette proved to be a transcription-level response of zwf. Finally, the promoter of the phosphoenolpyruvate carboxylase gene ppc in THRD was replaced with that of zwf, while L-threonine fermentation of the new strain was promoted by betaine addition. Conclusions: We reveal a novel mode of betaine that facilitates the microbial production of useful compounds. Betaine supplementation upregulates the expression of zwf and increases the NADPH synthesis, which may be beneficial for the cell growth and thereby promote the production of L-threonine. This finding might be useful for the production of NADPH-dependent amino acids and derivatives in E. coli THRD or other E. coli strains.

Obesity-Associated Metabolic Signatures Correlate to Clinical and Inflammatory Profiles of Asthma: A Pilot Study

PURPOSE: Obesity is associated with metabolic dysregulation, but the underlying metabolic signatures involving clinical and inflammatory profiles of obese asthma are largely unexplored. We aimed at identifying the metabolic signatures of obese asthma. METHODS: Eligible subjects with obese (n = 11) and lean (n = 22) asthma underwent body composition and clinical assessment, sputum induction, and blood sampling. Sputum supernatant was assessed for interleukin (IL)-1β, -4, -5, -6, -13, and tumor necrosis factor (TNF)-α, and serum was detected for leptin, adiponectin and C-reactive protein. Untargeted gas chromatography time-of-flight mass spectrometry (GC-TOF-MS)-based metabolic profiles in sputum, serum and peripheral blood monocular cells (PBMCs) were analyzed by orthogonal projections to latent structures-discriminate analysis (OPLS-DA) and pathway topology enrichment analysis. The differential metabolites were further validated by correlation analysis with body composition, and clinical and inflammatory profiles. RESULTS: Body composition, asthma control, and the levels of IL-1β, -4, -13, leptin and adiponectin in obese asthmatics were significantly different from those in lean asthmatics. OPLS-DA analysis revealed 28 differential metabolites that distinguished obese from lean asthmatic subjects. The validation analysis identified 18 potential metabolic signatures (11 in sputum, 4 in serum and 2 in PBMCs) of obese asthmatics. Pathway topology enrichment analysis revealed that cyanoamino acid metabolism, caffeine metabolism, alanine, aspartate and glutamate metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, pentose phosphate pathway in sputum, and glyoxylate and dicarboxylate metabolism, glycerolipid metabolism and pentose phosphate pathway in serum are suggested to be significant pathways related to obese asthma. CONCLUSIONS: GC-TOF-MS-based metabolomics indicates obese asthma is characterized by a metabolic profile different from lean asthma. The potential metabolic signatures indicated novel immune-metabolic mechanisms in obese asthma with providing more phenotypic and therapeutic implications, which needs further replication and validation.

The Pentose Phosphate Pathway as a Potential Target for Cancer Therapy

During cancer progression, cancer cells are repeatedly exposed to metabolic stress conditions in a resource-limited environment which they must escape. Increasing evidence indicates the importance of nicotinamide adenine dinucleotide phosphate (NADPH) homeostasis in the survival of cancer cells under metabolic stress conditions, such as metabolic resource limitation and therapeutic intervention. NADPH is essential for scavenging of reactive oxygen species (ROS) mainly derived from oxidative phosphorylation required for ATP generation. Thus, metabolic reprogramming of NADPH homeostasis is an important step in cancer progression as well as in combinational therapeutic approaches. In mammalian, the pentose phosphate pathway (PPP) and one-carbon metabolism are major sources of NADPH production. In this review, we focus on the importance of glucose flux control towards PPP regulated by oncogenic pathways and the potential therein for metabolic targeting as a cancer therapy. We also summarize the role of Snail (Snai1), an important regulator of the epithelial mesenchymal transition (EMT), in controlling glucose flux towards PPP and thus potentiating cancer cell survival under oxidative and metabolic stress.

My Sweetheart Is Broken: Role of Glucose in Diabetic Cardiomyopathy

Despite overall reductions in heart disease prevalence, the risk of developing heart failure has remained 2-fold greater among people with diabetes. Growing evidence has supported that fluctuations in glucose level and uptake contribute to cardiovascular disease (CVD) by modifying proteins, DNA, and gene expression. In the case of glucose, clinical studies have shown that increased dietary sugars for healthy individuals or poor glycemic control in diabetic patients further increased CVD risk. Furthermore, even after decades of maintaining tight glycemic control, susceptibility to disease progression can persist following a period of poor glycemic control through a process termed "glycemic memory." In response to chronically elevated glucose levels, a number of studies have identified molecular targets of the glucose-mediated protein posttranslational modification by the addition of an O-linked N-acetylglucosamine to impair contractility, calcium sensitivity, and mitochondrial protein function. Additionally, elevated glucose contributes to dysfunction in coupling glycolysis to glucose oxidation, pentose phosphate pathway, and polyol pathway. Therefore, in the "sweetened" environment associated with hyperglycemia, there are a number of pathways contributing to increased susceptibly to "breaking" the heart of diabetics. In this review we will discuss the unique contribution of glucose to heart disease and recent advances in defining mechanisms of action.

Glucose-6-phosphate dehydrogenase deficiency does not increase the susceptibility of sperm to oxidative stress induced by H₂O₂ / 대한생식의학회지

OBJECTIVE: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzyme defect. G6PD plays a key role in the pentose phosphate pathway, which is a major source of nicotinamide adenine dinucleotide phosphate (NADPH). NADPH provides the reducing equivalents for oxidation-reduction reductions involved in protecting against the toxicity of reactive oxygen species such as H₂O₂. We hypothesized that G6PD deficiency may reduce the amount of NADPH in sperms, thereby inhibiting the detoxification of H₂O₂, which could potentially affect their motility and viability, resulting in an increased susceptibility to infertility. METHODS: Semen samples were obtained from four males with G6PD deficiency and eight healthy males as a control. In both groups, motile sperms were isolated from the seminal fluid and incubated with 0, 10, 20, 40, 60, 80, and 120 µM concentrations of H2O2. After 1 hour incubation at 37℃, sperms were evaluated for motility and viability. RESULTS: Incubation of sperms with 10 and 20 µM H₂O₂ led to very little decrease in motility and viability, but motility decreased notably in both groups in 40, 60, and 80 µM H₂O₂, and viability decreased in both groups in 40, 60, 80, and 120 µM H₂O₂. However, no statistically significant differences were found between the G6PD-deficient group and controls. CONCLUSION: G6PD deficiency does not increase the susceptibility of sperm to oxidative stress induced by H₂O₂, and the reducing equivalents necessary for protection against H₂O₂ are most likely produced by other pathways. Therefore, G6PD deficiency cannot be considered as major risk factor for male infertility.

Regulation of the pentose phosphate pathway in cancer

Energy metabolism is significantly reprogrammed in many human cancers, and these alterations confer many advantages to cancer cells, including the promotion of biosynthesis, ATP generation, detoxification and support of rapid proliferation. The pentose phosphate pathway (PPP) is a major pathway for glucose catabolism. The PPP directs glucose flux to its oxidative branch and produces a reduced form of nicotinamide adenine dinucleotide phosphate (NADPH), an essential reductant in anabolic processes. It has become clear that the PPP plays a critical role in regulating cancer cell growth by supplying cells with not only ribose-5-phosphate but also NADPH for detoxification of intracellular reactive oxygen species, reductive biosynthesis and ribose biogenesis. Thus, alteration of the PPP contributes directly to cell proliferation, survival and senescence. Furthermore, recent studies have shown that the PPP is regulated oncogenically and/or metabolically by numerous factors, including tumor suppressors, oncoproteins and intracellular metabolites. Dysregulation of PPP flux dramatically impacts cancer growth and survival. Therefore, a better understanding of how the PPP is reprogrammed and the mechanism underlying the balance between glycolysis and PPP flux in cancer will be valuable in developing therapeutic strategies targeting this pathway.

Effects of glucose variation on hexose monophosphate shunt and leucocyte respiratory burst in patients with type 2 diabetes / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of blood glucose instability on respiratory burst of leukocytes in patients with type 2 diabetes (T2DM).</p><p><b>METHODS</b>Forty-five patients with T2DM were divided into 3 groups after continuous glucose monitoring for 72 h with glucose wavy coefficient <1.5 (n=11), between 1.5 and 3.0 (n=19), and >3.0 (n=15). Peripheral blood neutrophils were isolated from the diabetic patients and normal control subjects for assay of glucose 6-phosphate dehydrogenase (G6PD) with a spectrophotometric method, detecting G6PD mRNA expression by real-time PCR, and determining reactive oxygen species level using the fluorescent probe DCFH-DA.</p><p><b>RESULTS</b>Compared with the normal control group, the diabetic patients showed significantly lowered G6PD activity (F=78.739, P<0.05) and ROS level (F=384.962, P<0.05) but significantly increased G6PD mRNA expression (F=269.612, P<0.01). These changes were significantly correlated with the blood glucose wavy coefficients.</p><p><b>CONCLUSION</b>The fluctuation of blood glucose in T2DM patients can decrease G6PD activity and lead to functional decline of the respiratory burst.</p>

Repressing malic enzyme 1 redirects glucose metabolism, unbalances the redox state, and attenuates migratory and invasive abilities in nasopharyngeal carcinoma cell lines / 癌症

A large amount of nicotinamide adenine dinucleotide phosphate (NADPH) is required for fatty acid synthesis and maintenance of the redox state in cancer cells. Malic enzyme 1(ME1)-dependent NADPH production is one of the three pathways that contribute to the formation of the cytosolic NADPH pool. ME1 is generally considered to be overexpressed in cancer cells to meet the high demand for increased de novo fatty acid synthesis. In the present study, we found that glucose induced higher ME1 activity and that repressing ME1 had a profound impact on glucose metabolism of nasopharyngeal carcinoma(NPC) cells. High incorporation of glucose and an enhancement of the pentose phosphate pathway were observed in ME1-repressed cells. However, there were no obvious changes in the other two pathways for glucose metabolism: glycolysis and oxidative phosphorylation. Interestingly, NADPH was decreased under low-glucose condition in ME1-repressed cells relative to wild-type cells, whereas no significant difference was observed under high-glucose condition. ME1-repressed cells had significantly decreased tolerance to low-glucose condition. Moreover, NADPH produced by ME1 was not only important for fatty acid synthesis but also essential for maintenance of the intracellular redox state and the protection of cells from oxidative stress. Furthermore, diminished migration and invasion were observed in ME1-repressed cells due to a reduced level of Snail protein. Collectively, these results suggest an essential role for ME1 in the production of cytosolic NADPH and maintenance of migratory and invasive abilities of NPC cells.

Function of the pentose phosphate pathway and its key enzyme, transketolase, in the regulation of the meiotic cell cycle in oocytes / 대한생식의학회지

OBJECTIVE: Previously, we identified that transketolase (Tkt), an important enzyme in the pentose phosphate pathway, is highly expressed at 2 hours of spontaneous maturation in oocytes. Therefore, this study was performed to determine the function of Tkt in meiotic cell cycle regulation, especially at the point of germinal vesicle breakdown (GVBD). METHODS: We evaluated the loss-of-function of Tkt by microinjecting Tkt double-stranded RNAs (dsRNAs) into germinal vesicle-stage oocytes, and the oocytes were cultured in vitro to evaluate phenotypic changes during oocyte maturation. In addition to maturation rates, meiotic spindle and chromosome rearrangements, and changes in expression of other enzymes in the pentose phosphate pathway were determined after Tkt RNA interference (RNAi). RESULTS: Despite the complete and specific knockdown of Tkt expression, GVBD occurred and meiosis was arrested at the metaphase I (MI) stage. The arrested oocytes exhibited spindle loss, chromosomal aggregation, and declined maturation promoting factor and mitogen-activated protein kinase activities. The modified expression of two enzymes in the pentose phosphate pathway, Prps1 and Rbks, after Tkt RNAi and decreased maturation rates were amended when ribose-5-phosphate was supplemented in the culture medium, suggesting that the Tkt and pentose phosphate pathway are important for the maturation process. CONCLUSION: We concluded that Tkt and its associated pentose phosphate pathway play an important role in the MI-MII transition of the oocytes' meiotic cell cycle, but not in the process of GVBD.

Research progress in glucose-6-phosphate dehydrogenase in higher plants / 生物工程学报

Glucose-6-phosphate dehydrogenase (G6PDH) catalyzes the first and rate-limiting step of the oxidative pentose phosphate pathway, existing in both cytosolic and plastidic compartments of higher plants. Its main function is to provide reducing power (NADPH) and pentose phosphates for reductive biosynthesis and maintenance of the redox state of the cell. In addition, the expression of this enzyme is related to different biotic and abiotic stresses. In this review, we analyzed the isoenzyme, regulation and biological function of G6PDH. Meanwhile, we summarized the progress work of G6PDH involved in stress resistance, gene cloning, enzyme-deficiency and cluster analysis. Problems should be solved were also discussed.

Metabolism and brain cancer

Cellular energy metabolism is one of the main processes affected during the transition from normal to cancer cells, and it is a crucial determinant of cell proliferation or cell death. As a support for rapid proliferation, cancer cells choose to use glycolysis even in the presence of oxygen (Warburg effect) to fuel macromolecules for the synthesis of nucleotides, fatty acids, and amino acids for the accelerated mitosis, rather than fuel the tricarboxylic acid cycle and oxidative phosphorylation. Mitochondria biogenesis is also reprogrammed in cancer cells, and the destiny of those cells is determined by the balance between energy and macromolecule supplies, and the efficiency of buffering of the cumulative radical oxygen species. In glioblastoma, the most frequent and malignant adult brain tumor, a metabolic shift toward aerobic glycolysis is observed, with regulation by well known genes as integrants of oncogenic pathways such as phosphoinositide 3-kinase/protein kinase, MYC, and hypoxia regulated gene as hypoxia induced factor 1. The expression profile of a set of genes coding for glycolysis and the tricarboxylic acid cycle in glioblastoma cases confirms this metabolic switch. An understanding of how the main metabolic pathways are modified by cancer cells and the interactions between oncogenes and tumor suppressor genes with these pathways may enlighten new strategies in cancer therapy. In the present review, the main metabolic pathways are compared in normal and cancer cells, and key regulations by the main oncogenes and tumor suppressor genes are discussed. Potential therapeutic targets of the cancer energetic metabolism are enumerated, highlighting the astrocytomas, the most common brain cancer.

The pentose phosphate pathway in Trypanosoma cruzi: a potential target for the chemotherapy of Chagas disease

Trypanosoma cruzi is highly sensitive to oxidative stress caused by reactive oxygen species. Trypanothione, the parasite's major protection against oxidative stress, is kept reduced by trypanothione reductase, using NADPH; the major source of the reduced coenzyme seems to be the pentose phosphate pathway. Its seven enzymes are present in the four major stages in the parasite's biological cycle; we have cloned and expressed them in Escherichia coli as active proteins. Glucose 6-phosphate dehydrogenase, which controls glucose flux through the pathway by its response to the NADP/NADPH ratio, is encoded by a number of genes per haploid genome, and is induced up to 46-fold by hydrogen peroxide in metacyclic trypomastigotes. The genes encoding 6-phosphogluconolactonase, 6-phosphogluconate dehydrogenase, transaldolase and transketolase are present in the CL Brener clone as a single copy per haploid genome. 6-phosphogluconate dehydrogenase is very unstable, but was stabilized introducing two salt bridges by site-directed mutagenesis. Ribose-5-phosphate isomerase belongs to Type B; genes encoding Type A enzymes, present in mammals, are absent. Ribulose-5-phosphate epimerase is encoded by two genes. The enzymes of the pathway have a major cytosolic component, although several of them have a secondary glycosomal localization, and also minor localizations in other organelles.

Trypanosoma cruzi é altamente sensível ao estresse oxidativo causado por espécies reativas do oxigênio. Tripanotiona, o principal protetor do parasita contra o estresse oxidativo, é mantido reduzido pela tripanotiona redutase, pela presença deNADPH; a principal fonte da coenzima reduzida parece ser a via da pentose fosfato. As sete enzimas dessa via estão presentes nos quatro principais estágios do ciclo biológico do parasita; nós clonamos e expressamos as enzimas em Escherichia coli como proteínas ativas. Glucose 6-fosfato desidrogenase, que controla o fluxo da glucose da via em resposta à relação NADP/NADPH, é codificada por um número de genes por genoma haplóide e é induzida até 46-vezes por peróxido de hidrogênio em trypomastigotas metacíclicos. Os genes que codificam 6-fosfogluconolactonase, 6-fosfogluconato desidrogenase, transaldolase e transcetolase estão presentes no clone CL Brener como cópia única por genoma haplóide. 6-fosfogluconato desidrogenase é muito instável, mas foi estabilizada introduzindo duas pontes salinas por mutagênese sítio-dirigida. A Ribose-5-fosfato isomerase pertence ao Tipo B; genes que codificam enzimas Tipo A, presentes em mamíferos estão ausentes. A Ribulose-5-fosfato epimerase é codificada por dois genes. As enzimas da via têm um componente citosólico principal, embora várias delas tenham uma localização glicosomal secundária e também, localizações em menor número em outras organelas.

Studies on glucose-metabolizing enzymes in cytosolic and bacteroidal fractions of mungbean (Vigna radiata L.) and lentil (Lens culinaris L.) nodules.

Nitrogen is exported in the form of ureides or amides from the nodules in pulse crops. In order to understand the carbon metabolism in ureide and amide exporting nodules, activities of enzymes involved in glucose metabolism were compared in cytosolic and bacteroidal fractions of mungbean (ureide exporter) and lentil (amide exporter) nodules during development. Activities of hexokinase, fructokinase, phosphoglucomutase, fructose-1,6-bisphosphatase, phosphohexose isomerase and UDP-glucose pyrophosphorylase were detected in cytosolic fraction of nodules of both the crops during development. Out of these enzymes, specific activity of phosphohexose isomerase was the highest in nodules of both the crops, in comparison with other enzymes. In comparison with mungbean, activities of various enzymes were less in cytosolic fraction of lentil. Activities of hexokinase, fructokinase, phosphoglucomutase were present only in cytosolic fraction of mungbean (Vigna radiata L.), however, low activity of these enzymes was also observed in lentil (Lens culinaris L.) bacteroids. Activities of phosphohexose isomerase and fructose-1,6-bisphosphatase were higher in bacteroids of lentil, as compared to mungbean during early nodule development, but this pattern was reversed with progress of crop development. Higher activities of phosphoglucomutase and fructose-1,6-phosphatase in mungbean cytosolic fraction could lead to increased flow of carbon towards pentose phosphate pathway.

Molecular characterization of glucose-6-phosphate dehydrogenase deficiency in patients from the southern Brazilian city of Porto Alegre, RS

Glucose-6-phosphate dehydrogenase (G6PDH; EC 1.1.1.49) deficiency is one of the most common human enzymopathies throughout the world. Although most affected individuals are asymptomatic, there is a risk of neonatal jaundice and acute hemolytic anemia which can be triggered by infection, some pharmaceuticals and, in older individuals, eating fava beans. We characterized the molecular basis of G6PDH deficiency in a sample of 348 adults from Porto Alegre (population about 1.5 million), the capital of the southernmost Brazilian state of Rio Grande do Sul. Genomic DNA was extracted from peripheral blood leukocytes. We studied the three G6PDH mutations that appear to be the most frequent in Southern Brazil, the G202A and A376G A minus (A-) variants and the C563T Mediterranean (Med) variant. From July 2004 to October 2005, 348 patients (162 Females plus 186 males, age range 0 to 82 years) from Porto Alegre were referred to our laboratory for G6PDH analysis, 36 (9.7 percent) of which showed deficient G6PDH activity. These 36 patients and 34 randomly-selected non-deficient control individuals were submitted to molecular analysis which revealed a predominance of G6PDH A- allele among the deficient patients. The prevalence of the G6PDH A- variant agrees with its distribution among the ethnic groups that colonized RS, especially those of African, Portuguese, Spanish, and Italian origin.

In Silico Identification of 6-Phosphogluconolactonase Genes that are Frequently Missing from Completely Sequenced Bacterial Genomes

6-Phosphogluconolactonase (6PGL) is one of the key enzymes in the ubiquitous pathways of central carbon metabolism, but bacterial 6PGL had been long known as a missing enzyme even after complete bacterial genome sequence information became available. Although recent experimental characterization suggests that there are two types of 6PGLs (DevB and YbhE), their phylogenetic distribution is severely biased. Here we present that proteins in COG group previously described as 3-carboxymuconate cyclase (COG2706) are actually the YbhE-type 6PGLs, which are widely distributed in Proteobacteria and Firmicutes. This case exemplifies how erroneous functional description of a member in the reference database commonly used in transitive genome annotation cause systematic problem in the prediction of genes even with universal cellular functions.

The secondary alcohol and aglycone metabolites of doxorubicin alter metabolism of human erythrocytes

Anthracyclines, a class of antitumor drugs widely used for the treatment of solid and hematological malignancies, cause a cumulative dose-dependent cardiac toxicity whose biochemical basis is unclear. Recent studies of the role of the metabolites of anthracyclines, i.e., the alcohol metabolite doxorubicinol and aglycone metabolites, have suggested new hypotheses about the mechanisms of anthracycline cardiotoxicity. In the present study, human red blood cells were used as a cell model. Exposure (1 h at 37ºC) of intact human red blood cells to doxorubicinol (40 µM) and to aglycone derivatives of doxorubicin (40 µM) induced, compared with untreated red cells...

Changes in glutathione, glutathione-linked enzymes and hexose monophosphate shunt enzymes in senile cataract.

Changes in glucose-6-phosphate dehydrogenase (G-6-PD), glutathione reductase (GSH-R), reduced glutathione (GSH), glutathione peroxidase (GSH-PO), transketolase (TK) and transaldolase (TA) were studied in lens and red blood cells (RBCs) to understand the possible biochemical mechanisms responsible for the development of senile cataract. The activity of G-6-PD was increased in lens, though not so in erythrocytes during cataractogenesis. A marked decrease was observed in GSH level and GSH-R activity in the lens and RBCs of the cataractous group. The activity of GSH-PO was remarkably high in lens but not in the erythrocytes during the maturity of cataract. The activity of TK decreased gradually in both the lens and erythrocytes. The activity of TA decreased in erythrocytes but increased in the lens with maturation of cataract.

Toxoplasmosis in a group of glucose-6-phosphate dehydrogenase deficient patients

This was a retrospective study that aimed at evaluating the relative risk of Toxoplasma infection in patients with glucose-6-phosphate dehydrogenase deficiency as compared to a control group with no glucose-6-phosphate dehydrogenase deficiency. Ninety-one blood donor volunteers had serology testing from Toxoplasma gondii and were screened for glucose-6-phosphate dehydrogenase deficiency by a qualitative method using fluorescent spot test. They were all males and their ages ranged from 17 to 52 years. Fifty-three persons [58%] were glucose-6-phosphate dehydrogenase deficient and 38 [42%] were glucose-6-phosphate dehydrogenase normal. In the glucose-6-phosphate dehydrogenase deficient group, 31 [58.5%] had positive titers for Toxoplasma; while in the glucose-6-phosphate dehydrogenase normal group 9 persons [24%] had positive titers for Toxoplasma. The relative risk of infection was 2.5 times more in the glucose-6-phosphate dehydrogenase deficient group, a statistically significant difference with a p value of 0.002. Glucose-6-phosphate dehydrogenase deficiency seems to increase the risk for Toxoplasma infection by 2.5 fold probably due to decreased killing effect, of phagocytic cells