Effects of some anti-neoplastic drugs on sheep liver sorbitol dehydrogenase

Naringenin, Hesperidin and Quercetin Ameliorate Radiation-Induced Damage In Rats: In Vivo And In Silico Evaluations

In this study, we sought to determine how well naringenin, hesperidin, and quercetin prevented damage brought on by radiotherapy. During the investigation, 48 adult female Sprague Dawley rats were used. Eight groups of eight rats each were formed by randomly assigning the rats to the groups. The normal control group was represented by Group 1. Group 2 rats were those that received a dose of 15 Gray (Gy) of radiotherapy. The rats assigned to Group 3 received only Naringenin, whereas those assigned to Group 4 received only quercetine, and those assigned to Group 5 received only hesperidin. Rats in Group 6, 7 and 8 were received naringenin, quarcetin and hesperidin at a dose of 50 mg/kg daily for one week prior to radiotheraphy exposition. After radiotheraphy and phenolic compounds rats were sacrificed and some metabolic enzyme (aldose reductase (AR), sorbitol dehydrogenase (SDH), paraoxonase-1 (PON1), butyrylcholinesterase (BChE) and glutathione S-transferase (GST)) activity was determined in eye and brain tissues. It was found that phenolic compounds have protective effect against radiation-induced damage because of their anti-diabetic antioxidant and anti-inflammatory properties. In addition, hesperidin was found to be superior to quercetin and naringenin in terms of enzyme activity efficacy. Furthermore, hesperidin exhibited favorable binding affinity for BChE in silico compared to other enzymes.

Molecular docking and inhibition studies of vulpinic, carnosic and usnic acids on polyol pathway enzymes

Aldose reductase (AR) and sorbitol dehydrogenase (SDH) are important enzymes of the polyol pathway. In the current study, inhibitory effects of vulpinic acid (VA) carnosic acid (CA) and usnic acid (UA) on purified AR and SDH enzymes were determined. These enzymes inhibition could be essential to prevent diabetic complications. AR and SDH enzymes were purified from sheep kidney. Then, VA, CA and UA were tested in various concentrations against these enzymes activity in vitro. K_I values were found to be as 1.46 ± 0.04, 5.13 ± 0.25 and 11.71 ± 0.27 μΜ for VA, CA and UA, respectively, for AR. K_I constants were found to be as 15.32 ± 0.34, 145.60 ± 2.17 and 213.40 ± 2.64 μΜ VA, CA and UA, respectively, for SDH. These findings indicate that VA, CA and UA could be useful in the treatment of diabetic complications.Communicated by Ramaswamy H. Sarma.

Negative Effects of Chronic High Intake of Fructose on Lung Diseases

In the modern diet, excessive fructose intake (>50 g/day) had been driven by the increase, in recent decades, of the consumption of sugar-sweetened beverages. This phenomenon has dramatically increased within the Caribbean and Latin American regions. Epidemiological studies show that chronic high intake of fructose related to sugar-sweetened beverages increases the risk of developing several non-communicable diseases, such as chronic obstructive pulmonary disease and asthma, and may also contribute to the exacerbation of lung diseases, such as COVID-19. Evidence supports several mechanisms—such as dysregulation of the renin−angiotensin system, increased uric acid production, induction of aldose reductase activity, production of advanced glycation end-products, and activation of the mTORC1 pathway—that can be implicated in lung damage. This review addresses how these pathophysiologic and molecular mechanisms may explain the lung damage resulting from high intake of fructose.

Neuroprotective effects of oleuropein on retina photoreceptors cells primary culture and olive leaf extract and oleuropein inhibitory effects on aldose reductase in a diabetic model: Meriones shawi

Aldose reductase (AR) is an enzyme implicated in the development of diabetes complications among them diabetic retinopathy. Erythrocyte AR activity was measured in control and diabetic Meriones shawi, a type-2 diabetic model. We noticed an increase of AR activity in diabetic Meriones by comparison to controls. Olive leaf aqueous extract and oleuropein were tested for their inhibitory potential on AR activity. Both exerted a partial in-vitro inhibition effect which was higher with the olive leaf extract. The ex-vivo protective effect of oleuropein was tested in photoreceptors rod and Mcône retinal cells of Meriones shawi in hyperglycaemic conditions. Mixed retinal cells were cultured at 25 mM glucose for 5 days and treated with oleuropein. Cell viability was assessed using MTT test and trypan blue exclusion dye. Rod and Mcône Photoreceptors were characterised by immuno-cytochemistry. Oleuropein protected retinal cells against the toxic effect of glucose by improving the viability of photoreceptors.

Metabolic status of the coral Mussismilia harttii in field conditions and the effects of copper exposure in vitro

It is widely known that metals can alter enzyme functioning, however, little is known about the mechanisms of metal toxicity in energy metabolism enzymes of corals. Thus, the present study had two objectives: firstly, we evaluated the activity of eight metabolic enzymes of the coral Mussismilia harttii to clarify metabolic functioning under field conditions. After that, we investigated the in vitro effect of copper (Cu) exposure in the activity of an enzyme representative of each metabolism stage. We evaluated enzymes involved in glycolysis (hexokinase, HK; phosphofructokinase, PFK; pyruvate kinase, PK and lactate dehydrogenase, LDH), Krebs cycle (citrate synthase, CS and isocitrate dehydrogenase, IDH), electron transport chain (electron transport system activity, ETS) and pentose phosphate pathway (glucose-6-phosphate dehydrogenase, G6PDH). The in vitro tests were performed through contamination of the reaction medium using Cu concentrations of 0, 1.4, 3.7 and 14.2 μg L^-1. The results showed that M. harttii has elevated activity of HK, PK and CS in field conditions compared to the activity of other energy metabolism enzymes evaluated. Moreover, lower activities of LDH and ETS in exposed samples were observed. In conclusion, in field conditions this species has elevated aerobic metabolism and glucose may be an important energetic fuel. Also, exposure to Cu in vitro caused inhibition of LDH and ETS by direct binding.

Determination of the inhibition profiles of pyrazolyl-thiazole derivatives against aldose reductase and α-glycosidase and molecular docking studies

Aldose reductase (AR) is the first and rate-limiting enzyme of the polyol pathway, which converts glucose to sorbitol in an NADPH-dependent reaction. α-Glycosidase breaks down starch and disaccharides to glucose. Hence, inhibition of these enzymes can be regarded a considerable approach in the treatment of diabetic complications. AR was purified from sheep liver using simple chromatographic methods. The inhibitory effects of pyrazolyl-thiazoles ((3aR,4S,7R,7aS)-2-(4-{1-[4-(4-bromophenyl)thiazol-2-yl]-5-(aryl)-4,5-dihydro-1H-pyrazol-3-yl}phenyl)-3a,4,7,7a-tetrahydro-1H-4,7-methanoisoindole-1,3(2H)-dione derivatives; 3a-i) on AR and α-glycosidase enzymes were investigated. All compounds showed a good inhibitory action against AR and α-glycosidase. Among these compounds, compound 3d exhibited the best inhibition profiles against AR, with a K_i value of 7.09 ± 0.19 µM, whereas compound 3e showed the lowest inhibition effects, with a K_i value of 21.89 ± 1.87 µM. Also, all compounds showed efficient inhibition profiles against α-glycosidase, with K_i values in the range of 0.43 ± 0.06 to 2.30 ± 0.48 µM, whereas the K_i value of acarbose was 12.60 ± 0.78 µM. Lastly, molecular modeling approaches were implemented to predict the binding affinities of compounds against AR and α-glycosidase. In addition, the ADME analysis of the molecules was performed.

A potential risk factor for paraoxonase 1: in silico and in-vitro analysis of the biological activity of proton-pump inhibitors†

Objectives

Proton-pump inhibitors (PPIs) are drugs commonly utilized by about 7% of adults in the world. Recent researches have shown that there are countless and severe side effects of these drugs. This situation has raised concern among clinicians and patients alike. The purpose of this study is to contribute the novel drug discovery and development technology and toxicology field by researching interactions of PPIs on paraoxonase 1.

Methods

In this study, the paraoxonase 1 enzyme was purified from human serum by using rapid and straightforward chromatographic techniques. Subsequently, the inhibition effects of pantoprazole, omeprazole, and esomeprazole, PPIs, were investigated on paraoxonase 1. Besides, molecular docking studies were performed to unravel the binding mechanism between the enzyme and drugs.

Key findings

All drugs showed potent inhibitory activities. IC50 of the drugs values were 54.780 ± 0.524, 86.470 ± 0.818 and 93.390 ± 0.885 mm and Ki constants were found as 39.895 ± 0.005 mm, 70.112 ± 0.010 mm and 78.868 ± 0.008 mm, respectively. The binding scores observed in silico studies were found to agree with the obtained from in-vitro experimental results.

Conclusions

We observed that the drugs decreased PON1 activity at low concentrations. The results show that adjusting the dosages of these medications is a crucial case for each patient. The physicians should more carefully interpret whether there is an essential indication before prescribing PPIs and, if there is, to approve the proper dosing for the situation.

The effects of some cephalosporins on acetylcholinesterase and glutathione S-transferase: an in vivo and in vitro study

BACKGROUND

Glutathione S-transferase (GST) and acetylcholinesterase (AChE) are important enzymes in the metabolism. GSTs are primarily available in phase II metabolism. AChE is vital for neurodegenerative disorders.

SUBJECTS AND METHODS

The in vitro and in vivo effects of cefoperazone sodium (CFP), cefuroxime (CXM), and cefazolin (CZO) were investigated on GST and AChE activity in the present study. GST was purified using Glutathione-Agarose affinity chromatography.

RESULTS

K_i constants of CFP, CXM, and CZO were 0.1392 ± 0.02, 1.5179 ± 0.33, and 1.006 ± 0.11 mM for GST and 0.3010 ± 0.07, 0.3561 ± 0.09, and 0.3844 ± 0.04 mM, for AChE, respectively. The most effective inhibitor was CFP for both enzymes in in vitro. CZO (50 mg/kg), CXM (25 mg/kg), and CFP (100 mg/kg) inhibit in vivo GST and AChE activities. CXM had the most effective in vivo inhibition on AChE and GST.

CONCLUSIONS

CZO, CXM, and CFP are effective AChE and GST inhibitors in both in vitro and in vivo.

The interactions of cephalosporins on polyol pathway enzymes from sheep kidney

CONTEXT

Cephalosporins are derived from the fungus Acremonium. Due to their strong bactericidal ability, these drugs have to a wide usage in medicine.

OBJECTIVE

An investigation of the effects on sheep renal aldose reductase (AR) and sorbitol dehydrogenase (SDH) of cefoperazone, cefazolin, cefuroxime, ceftazidime and ceftriaxone as cephalosporin drugs was carried out in the present study.

METHODS

AR and SDH were purified from sheep kidney by ion exchange, gel filtration and affinity methods with approximately 219- and 484-fold, respectively. Some kinetic properties of the enzymes were determined such as optimal pH, optimal ionic strength, optimal temperature, stable pH, K_m and V_max. IC₅₀ values of the drugs were found for each enzyme.

RESULTS

While the AR was inhibited by all drugs, SDH enzyme was inhibited by only CXM (IC₅₀ 8.10 mM). Interestingly, CZO activated SDH enzyme. This result was evaluated as important for the flow of the polyol reactions. K_i values and inhibition types were determined for AR. However, these values could not have determined for SDH, due to insufficient inhibition.

CONCLUSIONS

From these results, it was concluded that cephalosporins may have an important effect on flow of the polyol metabolism.

Inhibition behaviours of some phenolic acids on rat kidney aldose reductase enzyme: an in vitro study

Aldose reductase (AR) inhibitors have vital importance in the treatment and prevention of diabetic complications. In this study, rat kidney AR was purified 19.34-fold with a yield of 3.49% and a specific activity of 0.88 U/mg using DE-52 Cellulose anion exchange chromatography, gel filtration chromatography and 2'5' ADP Sepharose-4B affinity chromatography, respectively. After purification, the in vitro inhibition effects of some phenolic acids (tannic acid, chlorogenic acid, sinapic acid, protocatechuic acid, 4-hydroxybenzoic acid, p-coumaric acid, ferulic acid, vanillic acid, syringic acid, α-resorcylic acid, 3-hydroxybenzoic acid and gallic acid) were investigated on purified enzyme. We determined IC50, Ki values and inhibition types of these phenolic acids. As a result, tannic and chlorogenic acid had a strong inhibition effect. On the other hand, gallic acid had a weak inhibition effect. In this study, all phenolic acids except for chlorogenic acid and p-coumaric acid showed non-competitive inhibition effects on rat kidney AR.

Antipsychotic agents screened as human carbonic anhydrase I and II inhibitors

The antipsychotic drugs currently used to treat schizophrenia can be divided into two distinct classes, typical and atypical antipsychotics. Many drug molecules are enzyme inhibitors that bind reversibly or irreversibly to their target through intermolecular interactions. That's why enzyme inhibition studies are an important issue for drug design and biochemical applications. In this study, in vitro inhibition effect of some antipsychotic drugs on the purified carbonic anhydrase (CA) I and II isoenzymes were investigated by using CO2 as a substrate. CA I and II were purified from human erythrocytes by a simple one step procedure using Sepharose 4B-L-tyrosine-sulfonamide affinity column. The results showed that all the drugs inhibited the cytosolic carbonic anhydrases enzyme activity in a concentration-dependent fashion. Among the studied drugs, aripiprazole and pramipexole were found to be the most active one for hCA I (IC50: 3.64 and 5.37 μM) and hCA II (IC50: 4.16 and 4.81 μM) activity, respectively.

Carbonic anhydrase activity from the gilthead sea bream (Sparus aurata) liver: the toxicological effects of heavy metals

Many studies have shown that metal ions may lead to oxidative stress in biological systems. Accordingly, DNA damage, protein modification, enzyme inhibition and activation, lipid peroxidation and many other effects may occur in living organisms. Many different formations of metal ions may enter human cells along with water, air, and various foods, and humans are negatively affected by these conditions, either directly or indirectly. These effects may cause irreversible damage to human metabolism. In this study, the toxicological effects of heavy metals on carbonic anhydrase enzyme activity from the gilthead sea bream liver were investigated. The carbonic anhydrase enzyme was purified via affinity chromatography and had a specific activity of 6775.5EUmg(-1). The kinetics and characteristic properties, such as optimum pH, stable pH, optimum temperature, activation energy (Ea), activation enthalpy (ΔH), Q10, Km, and Vmax, were determined for the purified enzyme SDS-polyacrylamide gel electrophoresis showed a single band and molecular weight of the subunit was approximately 25kDa. Cd(II), Cu(II), Ni(II) and Ag(I) inhibited the enzyme activity in vitro. The type of inhibition and Ki values for these metals were calculated from Lineweaver-Burk plots as 17.74mM, 36.20mM, 12.85mM and 0.025mM for Cd(II), Cu(II), Ni(II) and Ag(I), respectively. All the metals were noncompetitive inhibitors.