In vitro effects of some antibiotics on glucose-6-phosphate dehydrogenase from rat (Rattus norvegicus) erythrocyte

The effects of morin and methotrexate on pentose phosphate pathway enzymes and GR/GST/TrxR enzyme activities: An in vivo and in silico study

In this study, the mechanisms by which the enzymes glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), glutathione reductase (GR), glutathione-S-transferase (GST), and thioredoxin reductase (TrxR) are inhibited by methotrexate (MTX) were investigated, as well as whether the antioxidant morin can mitigate or prevent these adverse effects in vivo and in silico. For 10 days, rats received oral doses of morin (50 and 100 mg/kg body weight). On the fifth day, a single intraperitoneal injection of MTX (20 mg/kg body weight) was administered to generate toxicity. Decreased activities of G6PD, 6PGD, GR, GST, and TrxR were associated with MTX-related toxicity while morin treatment increased the activity of the enzymes. The docking analysis indicated that H-bonds, pi-pi stacking, and pi-cation interactions were the dominant interactions in these enzyme-binding pockets. Furthermore, the docked poses of morin and MTX against GST were subjected to molecular dynamic simulations for 200 ns, to assess the stability of both complexes and also to predict key amino acid residues in the binding pockets throughout the simulation. The results of this study suggest that morin may be a viable means of alleviating the enzyme activities of important regulatory enzymes against MTX-induced toxicity.

The Effects of Sodium Tetraborate against Lead Toxicity in Rats: The Behavior of Some Metabolic Enzymes

This study was planned to research the in vivo effects of lead (Pb) ions and sodium tetraborate (Na₂B₄O₇) on G6PD and 6PGD, which are some of the enzymes of the pentose phosphate pathway, which carries vital importance for metabolism, and GR and GST, which are glutathione metabolism enzymes, and the in vitro effects of the same agents on the 6PGD enzyme. According to the in vivo analysis results, in comparison to the control group, the rat liver G6PD (p < 0.05), and 6PGD (p < 0.01) enzyme activities in the Na₂B₄O₇ group were significantly lower. In addition, GR and GST enzyme activities were insignificantly lower in the Na₂B₄O₇ group compared to the control group (p > 0.05). The Pb group had lower G6PD and 6PGD enzyme activity levels and higher GR and GST enzyme activity levels compared to the control group, while these changes did not reach statistical significance (p > 0.05). In the in vitro analyses of the effects of Pb ions on the 6PGD enzyme that was purified out of rat liver with the 2',5'-ADP-Sepharose 4B affinity chromatography method, it was determined that Pb ions (200-1200 μM) increased the rat liver 6PGD enzyme activity levels by 33%. On the other hand Na₂B₄O₇ was not significantly effective on 6PGD activity. These results will also contribute to future studies in understanding the physiopathology of the states triggered by Pb ions and sodium tetraborate (Na₂B₄O₇).

Screening of in vitro and in silico effect of Fluorophenylthiourea compounds on glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase enzymes

Inhibition studies of enzymes in the pentose phosphate pathway (PPP) have recently emerged as a promising technique for pharmacological intervention in several illnesses. Glucose 6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) are the most important enzymes of the PPP. For this purpose, in the current study, we examined the effect of some fluorophenylthiourea on G6PD and 6PGD enzyme activity. These compounds exhibited moderate inhibitory activity against G6PD and 6PGD with K_I values ranging from 21.60 ± 8.42 to 39.70 ± 11.26 μM, and 15.82 ± 1.54 to 29.97 ± 5.72 μM, respectively. 2,6-difluorophenylthiourea displayed the most potent inhibitory effect for G6PD, and 2-fluorophenylthiourea demonstrated the most substantial inhibitory effect for 6PGD. Furthermore, the molecular docking analyses of the fluorophenylthioureas, competitive inhibitors, were performed to understand the binding interactions at the enzymes' binding site.

The effects of chrysin and naringin on cyclophosphamide-induced erythrocyte damage in rats: biochemical evaluation of some enzyme activities in vivo and in vitro

In recent years, there have been efforts to develop therapeutic agents that target metabolic enzyme systems in addition to existing treatment in possible cancer treatments. Cyclophosphamide (CYP) is an anticancer drug commonly used in various cancer treatments. Chrysin (CH) and naringin (NR) are natural flavonoids that possess many medicinal and pharmacological properties. In the present study, we aimed to investigate the effect of CH and NR against CYP-induced toxicity on some metabolic enzyme activities. For this purpose, 56 male rats were randomly divided into 8 groups in our in vivo study. The rats were pretreated with CH (25 and 50 mg/kg bw) and NR (50 and 100 mg/kg bw) for 7 days before administering a single dose of CYP (200 mg/kg bw) on the seventh day. According to the in vivo results of our study, it was observed that CH and NR regulated abnormal changes in CYP-induced enzyme activities. In addition, our in vitro study, G6PD enzyme was purified from rat erythrocyte using affinity chromatography. The effects of CH, NR, and CYP were investigated on the purified enzyme. It was determined that CH increased the enzyme activity, CYP ineffective on the enzyme activity, whereas NR inhibited the enzyme activity noncompetitively. Graphical abstract.

Characterization of glutathione S-transferase enzyme from brown meagre (Sciaena umbra) and inhibitory effects of heavy metals

Glutathione S-transferase (GST) detoxifies a broad spectrum of xenobiotics, especially in chemotherapeutic drugs, endogenous molecules, and environmental pollutants. Since the enzyme metabolizes toxic compounds, it has been extensively studied in many living things including aquatic organisms. In the current study, the GST enzyme was purified from brown meagre (Sciaena umbra) muscle tissue for the first time. Then, kinetic parameters of the enzyme were determined as optimum ionic strength: 20 mM Tris/HCl, optimum pH: 7.0 (Tris/HCl), and optimum substrate concentration: 3.125 mM. Eventually, inhibitory effects of the heavy metals were evaluated. IC₅₀ values of the tested metal ions were calculated to be 0.1112, 0.6113, 0.727, and 0.7774 mM for Cd²⁺ , Fe³⁺ , Ag⁺ , and Cu²⁺ , respectively. Our results show that these heavy metals inhibit GST at very low concentrations which could cause dangerous results for aquatic systems.

The effects of cardiac drugs on human erythrocyte carbonic anhydrase I and II isozymes

Cardiovascular diseases are the leading cause of mortality worldwide. In recent years, the relationship between carbonic anhydrase inhibitors and atherosclerosis has attracted attention. In this study, we aimed to determine the in vitro effects of 35 frequently used cardiac drugs on human carbonic anhydrase I (hCA I) and II (hCA II). The inhibitory effects of the drugs on hCA I and hCA II were determined with both the hydratase and esterase methods. The most potent inhibitors observed were propafenone (hCA I: 2.8 µM and hCA II: 3.02 µM) and captopril (hCA I: 1.58 µM and hCA II: 6.25 µM). Isosorbide mononitrate, propranolol, furosemide, and atorvastatin were also potent inhibitors. The inhibitor constant, Ki, value from the Lineweaver-Burk plot for propafenone was 2.38 µM for hCA I and 2.97 µM for hCA II. The tested cardiac drugs showed potent in vitro inhibition of the hCA I and II isozymes. Especially, in patients with atherosclerotic heart disease, these drugs may be preferred primarily due to the beneficial effects of carbonic anhydrase inhibition on atherosclerosis.

Possible inhibition mechanism of dobutamine hydrochloride as potent inhibitor for human glucose-6-phosphate dehydrogenase enzyme

Glucose-6-phosphate dehydrogenase (G6PD) is the first rate-limiting enzyme in the pentose phosphate pathway. One of the enzyme's most important functions is the production of a reducing agent that is essential for preserving the level of reduced glutathione (GSH). However, some chemicals, such as industrial waste and the active ingredients of several drugs, can cause reduction or blockage in this enzyme's activity. This case causes the occurrence of anemia by damaging erythrocytes. In this study, the G6PD enzyme was purified 21,981 fold with affinity chromatography and the effects of the active ingredients of some antiarrhythmic drugs on enzyme activity were investigated with in vitro and in silico methods. We found that dobutamine hydrochloride significantly decreased enzyme activity and its inhibitory constant (K_i) value was calculated as 19.02 ± 4.83 mM. The in vitro study results also show that dobutamine hydrochloride is a potent inhibitor of enzyme activity. We also found that dobutamine hydrochloride inhibits the hG6PD enzyme's activity by causing structural alterations in substrate and coenzyme binding sites.Communicated by Ramaswamy H. Sarma.

The Effects of Amoxicillin, Cefazolin, and Gentamicin Antibiotics on the Antioxidant System in Mouse Heart Tissues

BACKGROUND

Free radicals lead to destruction in various organs of the organism. The improper use of antibiotics increases the formation of free radicals and causes oxidative stress.

OBJECTIVE

In this study, it was aimed to determine the effects of gentamicin, amoxicillin, and cefazolin antibiotics on the mouse heart.

METHODS

20 male mice were divided into 4 groups (1st control, 2nd amoxicillin, 3rd cefazolin, and 4th gentamicin groups). The mice in the experimental groups were administered antibiotics intraperitoneally at a dose of 100 mg / kg for 6 days. The control group received normal saline in the same way. The gene expression levels and enzyme activities of SOD, CAT, GPx, GR, GST, and G6PD antioxidant enzymes were investigated.

RESULTS

GSH levels decreased in both the amoxicillin and cefazolin groups, while GR, CAT, and SOD enzyme activities increased. In the amoxicillin group, Gr, Gst, Cat, and Sod gene expression levels increased.

CONCLUSION

As a result, it was concluded that amoxicillin and cefazolin caused oxidative stress in the heart, however, gentamicin did not cause any effects.

Inhibition effects of some antidepressant drugs on pentose phosphate pathway enzymes

The glucose metabolism in the pentose cycle is essential to the source of NADPH. Deficiency of these enzymes have been linked to depression and psychotic disorders. Depression is an increasingly prevalent mental disorder which may cause loss of labor. Antidepressant drugs are commonly employed in treatments of mood disorders and anxiety treatment. The purpose of this study is to investigate the effects of aripiprazole, mirtazapine, risperidone, escitalopram and haloperidol on the activity of 6-phosphogluconate dehydrogenase (6PGD) and glucose-6-phosphate dehydrogenase (G6PD) enzymes purified from human erythrocytes. It was found that aripiprazole, mirtazapine, risperidone, escitalopram and haloperidol show effective inhibitor properties on purified G6PD and 6PGD enzymes. The IC₅₀ values of these drugs were found in the range of 26.34 μM-5.78 mM for 6PGD and 16.26 μM-3.85 mM for G6PD. The K_i values of the drugs were found in the range of 30.21 ± 4.31 μM-4.51 ± 1.83 mM for 6PGD and 14.12 ± 3.48 μM-4.98 ± 1.14 mM for G6PD. Usage of drugs with significant biological effects may be a hazard in some conditions.

The Effect of Mercury Chloride and Boric Acid on Rat Erythrocyte Enzymes

The aim of this study was to investigate the effects of mercury chloride and boric acid on rat (Wistar albino) erythrocyte: glucose 6-phosphate dehydrogenase (G6PD), 6-phosphoglucona-te dehydrogenase (6PGD), thioredoxin reductase (TrxR), glutathione reductase (GR) and glutathione S-transferase (GST) enzymes in vivo, and the rat erythrocyte G6PD enzyme in vitro. In the in vivo study, 24 male rats were divated into three different groups: control (C), mercury chloride (M), and mercury chloride + boric acid (M + BA). At the completion of this study, a significant degree of inhibition for both G6PD and GST enzyme activity was observed in the M groups when compared to the C group (p < 0.05), and no significant effect was observed in the 6PGD enzyme. However, there was significantly increased TrxR and GR enzyme activity of both the M and M + BA groups (p < 0.05). In the in vitro study, the G6PD enzyme from rat erythrocytes was purified with 2',5'-ADP Sepharose-4B affinity chromatography, and the effect of both mercury chloride and boric acid on the enzyme activity was investigated. The results showed that boric acid increased the G6PD enzyme activity while the mercury ions that inhibited the enzyme activity (IC₅₀ values of 346 μM and K_i values of 387 μM) were noncompetitive.