Purification and characterization of the carbonic anhydrase enzyme from horse mackerel (Trachurus trachurus) muscle and the impact of some metal ions and pesticides on enzyme activity

Multiple forms of carbonic anhydrase in Tetragonia tetragonioides leaves and the impact of heavy metal ions on enzyme activity

Tetragonia tetragonioides (Aizoaceae; Caryophyllales), an annual herbaceous plant, a halophyte native to the marine coasts of New Zealand is now cultivated worldwide as a minor salt-tolerant crop. The aim of this study was to evaluate the activity of carbonic anhydrase (CA, EC 4.2.1.1) and identify the CA isoforms in a fraction of total soluble proteins from T. tetragonioides leaves and to determine CA sensitivity to specific sulfonamide inhibitors and heavy metal (HM) ions. In higher plants, CA is one of the most abundant leaf enzymes catalyzing CO2 and HCO3- interconversions that maintain the balance between dissolved forms of inorganic carbon. Catalytically active CA isoforms in the soluble protein fraction isolated from T. tetragonioides leaves were identified by a protonography method which involves the detection of CA activity in the gel following SDS-PAGE and subsequent removal of SDS (De Luca et al., 2015). This approach enabled the detection of active oligomeric forms of CA in the gel, allowing for the separate assessment of their activity. The protonogram revealed the presence of five sources of CA activity, which correspond to isoforms with approximate molecular masses of 26, 35, 41, 52, and 166 kDa. The total CA activity of T. tetragonioides leaf proteins was found to be inhibited by specific CA inhibitors, acetazolamide (AZ) and ethoxyzolamide (EZ), within the same concentration range as CAs from other plants. The half-maximal inhibition of hydratase activity was estimated to be 16 μM AZ and 2 μM EZ. The in vitro impact of selected heavy metal ions (Cu2⁺, Cd2⁺, Zn2⁺, Pb2⁺, Hg2⁺, and Ag⁺) on the hydratase activity of the soluble T. tetragonioides protein fraction was examined. High sensitivity of CA activity to inhibition by silver (I50-0.5 μM) and mercury ions (I50 ∼ 2 μM) was shown. Copper and cadmium ions inhibited CA activity with I50 ∼ 40 and ∼12 μM, respectively. Zinc ions (I50 ∼ 200 μM) were weaker inhibitors, and lead ions in the concentration range of 50-500 μM insignificantly stimulated the hydratase activity of soluble proteins of T. tetragonioides. The high sensitivity of T. tetragonioides CA to Ag⁺ and Hg2⁺ ions, which are known to act as sulfhydryl poisons, can be attributed to the presence of SH-containing cysteines within the active site of the plant CAs.

Protective Effects of Carvacrol on Mercuric Chloride-Induced Lung Toxicity Through Modulating Oxidative Stress, Apoptosis, Inflammation, and Autophagy

Mercuric chloride (HgCl2) is extremely toxic to both humans and animals. It could be absorbed via ingestion, inhalation, and skin contact. Exposure to HgCl2 can cause severe health effects, including damages to the gastrointestinal, respiratory, and central nervous systems. The purpose of this work was to explore if carvacrol (CRV) could protect rats lungs from damage caused by HgCl2. Intraperitoneal injections of HgCl2 at a dose of 1.23 mg/kg body weight were given either alone or in conjunction with oral CRV administration at doses of 25 and 50 mg/kg body weight for 7 days. The study included biochemical and histological techniques to examine the lung tissue's oxidative stress, apoptosis, inflammation, and autophagy processes. HgCl2-induced reductions in GSH levels and antioxidant enzymes (SOD, CAT, and GPx) activity were enhanced by CRV co-administration. Furthermore, MDA levels were lowered by CRV. The inflammatory mediators NF-κB, IκB, NLRP3, TNF-α, IL-1β, IL6, COX-2, and iNOS were all reduced by CRV. When exposed to HgCl2, the levels of apoptotic Bax, caspase-3, Apaf1, p53, caspase-6, and caspase-9 increased, but the levels of antiapoptotic Bcl-2 reduced after CRV treatment. CRV decreased levels of Beclin-1, LC3A, and LC3B, which in turn decreased HgCl2-induced autophagy damage. After HgCl2 treatment, higher pathological damage was observed in terms of alveolar septal thickening, congestion, edema, and inflammatory cell infiltration compared to the control group while CRV ameliorated these effects. Consequently, by preventing HgCl2-induced increases in oxidative stress and the corresponding inflammation, autophagy, apoptosis, and disturbance of tissue integrity in lung tissues, CRV might be seen as a useful therapeutic alternative.

Isolation, Identification, and Carbonate Mineralization Characteristics of a Newly Carbonic Anhydrase-Producing Strain

Carbonic anhydrase-producing microorganisms can rely on their metabolism for carbon sequestration and carbonate precipitation, which is a relatively effective mode among the known microbially induced carbonate precipitation (MICP) methods. A newly carbonic anhydrase-producing strain was isolated from soil samples. 16S rDNA gene sequencing showed this strain had 99.18% sequence identity to Chryseobacterium gambrini. Various culture parameters (temperature, pH, rotational speed, inoculum size, and metal ions) were optimized for optimal microbial growth and CA activities. Optimal culture conditions were as follows: temperature of 30 °C, pH 6-7, rotational speed 150 rpm, and inoculum size 1%. It was observed that Co2+ and Mn2+ can improve CA activity with optimal concentrations of 0.02 mM and 0.01 mM, respectively. Furthermore, the introduction of CO2 for 15 min daily leads to a 36% increase in the final production of biotic CaCO3, reaching 2.884 g/L. Characterization of the mineralization precipitates was conducted to reveal the mechanism of the carbonic anhydrase-producing bacterium. Lastly, an analysis of the crystalline species and content of the biogenic CaCO3 was performed to lay the groundwork for future crystalline adjustments and to offer technical support for the application of the calcium method.

Peripheral (E)-2-[(4-hydroxybenzylidene)-3,4-dihydronaphthalen-1(2H)-one)]-coordinated phthalocyanines with improved enzyme inhibition properties and photophysicochemical behaviors

In this study, (E)-4-{4-[(1-oxo-3,4-dihydronaphthalen-2(1H)-ylidene)methyl]phenoxy}phthalonitrile (4) and its phthalocyanine derivatives (5-8) were synthesized for the first time. Aggregation behaviors of the novel soluble phthalocyanines in organic solvents were investigated. In addition, the efficiency of 1O2 production of (5) and ZnPc (6) was investigated. The singlet oxygen quantum yields (ΦΔ) for 2HPc (5) and ZnPc (6) were found to be 0.58 and 0.83, respectively. Additionally, novel phthalocyanines (5-8) were investigated for their ability to inhibit enzymes. They exhibited a highly potent inhibition effect on human carbonic anhydrase I and II (hCA I and II) and α-glycosidase (α-Gly) enzymes. Ki values are in the range of 2.60 ± 9.87 to 11.53 ± 6.92 µM, 3.35 ± 0.53 to 15.47 ± 1.20 µM, and 28.60 ± 4.82 to 40.58 ± 7.37 nM, respectively. The calculations of the studied molecule at the B3LYP, HF, and M062X levels in the 6-31G basis sets were made using the Gaussian package program. Afterward, the interactions occurring in the docking calculation against a protein that is the crystal structure of hCA I (PDB ID: 2CAB), the crystal structure of hCA II (PDB ID: 5AML), and the crystal structure of α-Gly (PDB ID: 1R47), were examined. Following that, Protein-Ligand Interaction Profiler (PLIP) analysis was used to look at the interactions that occurred during the docking calculation in further detail.

Liposomal silymarin anti-oxidative and anti-apoptotic features in lung cells: An implication in cadmium toxicity

BACKGROUND

Several metallic elements with high atomic weight and density are serious systemic toxicants, and their wide environmental distribution increase the risk of their exposure to human. Silymarin (SL), a polyphenol from milk thistle (Silybum marianum) plant has shown protective role against heavy metal toxicity. However, its low aqueous solubility and rapid metabolism limits its therapeutic potential in clinic.

METHODS

We compared the role of silymarin nanoliposomes (SL-L) against cadmium (Cd) toxicity in normal MRC-5 and A 549 cancer cells. MRC-5 and A 549 cells exposed to Cd at 25 and 0.25 µM respectively, were treated with various non-toxic SL-L concentrations (2.5, 5, 10 µM) and cells viability, reactive oxygen species (ROS) generation, apoptosis and levels of cleaved PARP and caspase-3 proteins were determined following incubation.

RESULTS

Results indicated that Cd exposure significantly increased apoptosis due to ROS generation, and showed greater toxicity on cancer cells compared to normal cells. While SL-L at higher concentrations (25 µM and higher) exhibits pro-apoptotic features, lower concentrations (10 and 2.5 µM for MRC-5 and A 549 cancer cells, respectively) played a protective and anti-oxidant role in Cd induced toxicity in both cells. Further, lower SL-L was required to protect cancer cells against Cd toxicity. In general, treatment with SL-L significantly improved cell survival by decreasing ROS levels, cleaved PARP and caspase-3 in both MRC-5 and A 549 cells compared to free silymarin.

CONCLUSION

Results demonstrated that SL-L potential in protecting against Cd-induced toxicity depends on concentration-dependent antioxidant and anti-apoptotic balance.

Sub-acute toxicity of the herbicide glufosinate-ammonium exposure in adult red swamp crayfish (Procambarus clarkii)

Glufosinateammonium (GLA) is one of the most widely used agricultural herbicides. It is frequently detected in surface waters near farmland and may pose a risk to non-target aquatic species. This study aimed to explore the toxicity of subacute GLA exposure in crayfish. Adult red swamp crayfish were exposed to GLA (0, 1, 10, and 100 mg/L) for 21 days. Bioaccumulation, oxidative stress, nonspecific immunity, and the expression of genes encoding xenobiotic detoxification-related enzymes were examined. The results showed GLA accumulation and hepatopancreatic histopathological changes (dilation of hepatic tubules and vacuolation of hepatocytes) in the exposed crayfish. GLA exposure induced ROS production, inhibited glutathione expression, and catalase activity in the crayfish hepatopancreas, as well as inhibited immunoenzyme expression (acid phosphatase, alkaline phosphatase, and lysozyme) in the hemolymph. In addition, the total hemocyte number decreased, and the proportion of hemocyte subsets changed significantly. Superoxide dismutase first increased and then decreased with increasing GLA dosage. GLA promoted the expression of biotransformation enzymes (cypb5, gst) in the hepatopancreas. Our results suggest that subacute GLA exposure caused structural damage to the hepatopancreatic tissue and decreased antioxidant capacity and non-specific immunity in crayfish. These findings provide insight into the toxicity of herbicides on non-target organisms.

Design, synthesis and biological activity determination of novel phenylpyrazole protoporphyrinogen oxidase inhibitor herbicides

Protoporphyrinogen oxidase (PPO, EC 1.3.3.4) is the last common enzyme in the biosynthetic pathway in the synthesis of heme and chlorophyll. The high-frequency use of PPO inhibitor herbicides has led to the gradual exposure of pesticide damage and resistance problems. In order to solve this kind of problem, there is an urgent need to develop new PPO inhibitor herbicides. In this paper, 16 phenylpyrazole derivatives were designed by the principle of active substructure splicing through the electron isosterism of five-membered heterocycles. Greenhouse herbicidal activity experiments and in vitro PPO activity experiments showed that the inhibitory effect of compound 9 on weed growth was comparable to that of pyraflufen-ethyl. Crop safety experiments and cumulative concentration experiments in crops showed that when the spraying concentration was 300 g ai/ha, wheat, corn, rice and other cereal crops were more tolerant to compound 9, among which wheat showed high tolerance, which was comparable to the crop safety of pyraflufen-ethyl. Herbicidal spectrum experiments showed that compound 9 had inhibitory activity against most weeds. Molecular docking results showed that compound 9 formed one hydrogen bond interaction with amino acid residue ARG-98 and two π-π stacking interactions with amino acid residue PHE-392, indicating that compound 9 had better herbicidal activity than pyraflufen-ethyl. It shows that compound 9 is expected to be a lead compound of phenylpyrazole PPO inhibitor herbicide and used as a herbicide in wheat field.

Investigation of the effects of some pesticides on carbonic anhydrase isoenzymes

The aim of this study was to investigate the inhibitory effects of some pesticides known to have harmful effects on human health on carbonic anhydrase isoenzymes. Therefore, carbonic anhydrase isoenzymes (hCA I and II) were purified from human erythrocytes. The isoenzymes were purified from human erythrocytes by using an affinity column that has the chemical structure of Sepharose-4B-4-(6-amino-hexyloxy)-benzenesulfonamide. The purity of the isoenzymes was checked by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDSPAGE). It was determined that the pesticides used in this study inhibit hCA I and hCA II isoenzymes at different levels in vitro. It was determined that the strongest inhibitor for the hCA I enzyme was Carbofuran (IC50 :6.52 μM; Ki : 3.58 μM) and the weakest one was 1-Naphtol (IC50 :16.55 μM; Ki : 14.4 μM) among these pesticides. It was also found that the strongest inhibitor for the hCA II enzyme was coumatetralil (IC50 :5.06 μM; Ki : 1.62 μM) and the weakest one was Dimethachlor (IC50 14.6 μM; Ki : 8.44 μM).

Benzimidazolium Salts Containing Trifluoromethoxybenzyl: Synthesis, Characterization, Crystal Structure, Molecular Docking Studies and Enzymes Inhibitory Properties

The method for producing 4-trifluoromethoxybenzyl substituted benzimidazolium salts is described in this article. The method is based on the reaction of 4-trifluoromethoxybenzyl substituent alkylating agent with 1-alkylbenzimidazole. This method yielded 1-(4-trifluoromethoxybenzyl)-3-alkylbenzimidazolium bromide salts. These benzimidazolium salts were characterized by using ¹ H-NMR, ¹³ C-NMR, FT-IR spectroscopy, and elemental analysis techniques. The crystal structure of 1f was enlightened by single crystal X-ray diffraction studies. Also, the enzyme inhibition effects of the synthesised compounds were investigated. They demonstrated highly potent inhibition effect on acetylcholinesterase (AChE) and carbonic anhydrases (hCAs) (K_i values are in the range of 7.24±0.99 to 39.12±5.66 nM, 5.57±0.96 to 43.07±11.76 nM, and 4.38±0.43 to 18.68±3.60 nM for AChE, hCA I, and hCA II, respectively). In molecular docking study, the interactions of active compounds showing activity against AChE and hCAs enzymes were examined. The most active compound 1f has -10.90 kcal/mol binding energy value against AChE enzyme, and the potential structure compound 1e, which has activity against hCA I and hCA II enzymes, was -7.51 and -8.93 kcal/mol, respectively.

Evaluation of protective effects of quercetin against cypermethrin-induced lung toxicity in rats via oxidative stress, inflammation, apoptosis, autophagy, and endoplasmic reticulum stress pathway

Cypermethrin (CYP), a type II synthetic pyrethroid, is the most widely used insecticide worldwide. Inhalation of it may cause side effects. This study is aimed to examine potential protection of quercetin (QUE) which is a well-known antioxidant in CYP-induced lung toxicity. Accordingly, 35 Spraque Dawley male rats were divided into five equal groups as follows: I-Control group, II-QUE group (50 mg/kg/b.w. QUE), III-CYP group (25 mg/kg/b.w. CYP), IV-CYP + QUE 25 (25 mg/kg/b.w. CYP + 25 mg/kg/b.w. QUE), V-CYP + QUE (25 mg/kg/b.w. CYP + 50 mg/kg/b.w. QUE) were treated with oral gavage throughout 28 days. CYP intoxication was associated with increased malondialdehyde level while glutathione concentration, activities of glutathione peroxidase, superoxide dismutase, and catalase reduced. CYP adminisitration caused of apoptosis in the lung by up-regulating caspase-3 and Bax levels and down-regulating Bcl-2. CYP also caused of endoplasmic reticulum (ER) stress by increasing mRNA transcript levels of PERK, IRE1, ATF6, and GRP78. Additionally, it was observed that CYP administration activated IL-6/JAK2/STAT3/MAPK14 signaling pathway and levels of IL-1β, NF-κB, TNF-α, and iNOS in the lung tissue. Therefore, it was determined that CYP administration triggered autophagy by upregulating LC3A and LC3B mRNA transcript levels. Moreover, the protein levels of NF-κB, caspase-3, Bax, Bcl-2, and cytochorme-c were examined by Western blot analysis. However, co-treatment with QUE at a dose of 25 and 50 mg/kg considerably protective oxidative stress, inflammation, apoptosis, ER stress, autophagy, and IL-6/JAK2/STAT3/MAPK14 signaling pathway in lung tissue. Overall, the findings of this study suggest that lung damage associated with CYP toxicity could be protected by QUE administration.

Properties of a neutral, thermally stable and surfactant-tolerant pullulanase from worker termite gut-dwelling Bacillus safensis as potential for industrial applications

The gut of termite has been observed to host communities of bacteria which exhibited pullulan-degrading ability. Bacillus safensis displayed maximum pullulanase (a debranching enzyme) activity and it was therefore selected for production, purification and characterization of pullulanase which was the aim of the study. The crude enzyme obtained from the pullulanase production medium was subjected to ammonium sulphate precipitation, ion exchange and gel-filtration chromatography and the physicochemical properties of the purified was thereafter characterized. A purified pullulanase with the yield of 13% and 24-fold purification was obtained and its homogeneity was established by molecular weight of 42 kDa. The optimum pH 7 and 60 °C were obtained while the enzyme was stable between 40-60 °C and pH 4–5 and 7–8 respectively with significant amount of residual activities recorded. The purified pullulanase was stimulated in the presence of Ca²⁺, urea and SDS while Al³⁺, Fe²⁺, Co²⁺, Cu²⁺, Mg²⁺ and chelating agent, EDTA mildly inhibited the activity of the enzyme in a concentration-dependent manner. The K_m and V_max were found to be 0.324 μmol/ml/min and 6.85 mg/ml respectively. The exceptional physicochemical properties of B. safensis pullulanase could find application in several industrial processes.

Enzyme mediated transformation of CO2 into calcium carbonate using purified microbial carbonic anhydrase

In this study, a bacterial carbonic anhydrase (CA) was purified from Corynebacterium flavescens for the CO₂ conversion into CaCO₃. The synthesized CaCO₃ can be utilized in the papermaking industry as filler material, construction material and in steel industry. Herein, the CA was purified by using a Sephadex G-100 column chromatography having 29.00 kDa molecular mass in SDS-PAGE analysis. The purified CA showed an optimal temperature of 35 °C and pH 7.5. In addition, a kinetic study of CA using p-NPA as substrate showed V_max (166.66 μmoL/mL/min), K_m (5.12 mM), and K_cat (80.56 sec^-1) using Lineweaver Burk plot. The major inhibitors of CA activity were Na²⁺, K⁺, Mn²⁺, and Al³⁺, whereas Zn²⁺ and Fe²⁺ slightly enhanced it. The purified CA showed a good efficacy to convert the CO₂ into CaCO₃ with a total conversion rate of 65.05 mg CaCO₃/mg of protein. In silico analysis suggested that the purified CA has conserved Zn²⁺ coordinating residues such as His 111, His 113, and His 130 in the active site center. Further analysis of the CO₂ binding site showed conserved residues such as Val 132, Val 142, Leu 196, Thr 197, and Val 205. However, a substitution has been observed where Trp 208 of its closest structural homolog T. ammonificans CA is replaced with Arg 207 of C. flavescens. The presence of a hydrophilic mutation in the CO₂ binding hydrophobic region is a further subject of investigation.

The palladium-based complexes bearing 1,3-dibenzylbenzimidazolium with morpholine, triphenylphosphine, and pyridine derivate ligands: synthesis, characterization, structure and enzyme inhibitions

The palladium-based complexes bearing N-heterocyclic carbene (NHC) ligand have long attracted attention as active catalysts for many catalytic reactions. Recently, the biological activities of these complexes, which are stable to air and moisture, have also been wondered. With the aim, we report the synthesis of a series of (NHC)Pd(Br2)(L) complexes (NHC: 1,3-dibenzylbenzimidazolium, L: morpholine, triphenylphosphine, pyridine, 3-chloropyridine, and 2-aminopyridine). All complexes were characterized by NMR (1H and 13C), FTIR spectroscopic and elemental analysis techniques. In addition, the single crystal structures of the complex 3, 4, and 6 were determined through single crystal x-ray crystallographic method. Furthermore, the carbonic anhydrase I and II isoenzymes (hCAs) and acetylcholinesterase (AChE) inhibition effects of these palladium-based complexes bearing NHC ligand were investigated. They showed highly potent inhibition effect with Ki values are between 10.06 ± 1.49-68.56 ± 11.53 nM for hCA I isoenzyme, 7.74 ± 0.66 to 49.39 ± 6.50 nM for hCA II isoenzyme and 22.83 ± 3.21 to 64.09 ± 9.05 nM for AChE enzyme.

Physiological and Transcriptomic Analysis provide Molecular Insight into 24-Epibrassinolide mediated Cr(VI)-Toxicity Tolerance in Pepper Plants

The ever-increasing industrial activities over the decades have generated high toxic metals such as chromium (Cr) that hampers plant growth and development. To counter Cr-toxicity, plants have evolved complex defensive systems including hormonal crosstalk with various signaling pathways. 24-epibrassinolide (24-EBR) lowers oxidative stress and alleviates Cr(VI)-toxicity in plants. In this study, the concealed BR-mediated influences on Cr(VI)-stress tolerance were explored by transcriptome analysis in the Capsicum annuum. Results revealed a linkage between plant development under Cr(VI)-stress and the mitigating effect of 24-epibrassinolide and brassinazole. Growth inhibition, chlorophyll degradation, and a significant rise of malondialdehyde (MDA) were observed after 40 mg/L Cr(VI) treatment in Brz supplemented seedlings, whereas 24-EBR supplemented seedlings exhibited commendatory effect. Comparative transcriptome analysis showed that the expression levels of 6687 genes changed (3846 up-regulated and 2841 downregulated) under Cr(VI)-stress with Brz supplementation. Whereas the expression levels of only 1872 genes changed under Cr(VI)-stress with 24-EBR supplementation (1223 up-regulated and 649 downregulated). The functional categories of the differentially expressed genes (DEGs) by gene ontology (GO) revealed that drug transport, defense responses, and drug catabolic process were the considerable enrichments between 24-EBR and Brz supplemented seedlings under Cr(VI)-stress. Furthermore, auxin signaling, glutathione metabolism, ABC transporters, MAPK pathway, and 36 heavy metal-related genes were significantly differentially expressed components between Cr(VI)-stress, 24-EBR, and Brz supplemented seedlings. Overall, our data demonstrate that employing 24-EBR can commendably act as a growth stimulant in plants subjected to Cr(VI)-stress by modulating the physiological and defense regulatory system.

Investigation of the effects of hesperidin administration on abamectin-induced testicular toxicity in rats through oxidative stress, endoplasmic reticulum stress, inflammation, apoptosis, autophagy, and JAK2/STAT3 pathways

In this study, the potential effects of hesperidin (HES) on chronic toxicity caused by abamectin (ABM) in the testicular tissue were investigated through oxidative stress, inflammation, endoplasmic reticulum stress (ERS), apoptosis, and autophagy pathways. Male Sprague Dawley rats were used in the study. Animals in the ABM group were orally administered 1 mg/kg ABM every other day for 28 days, while HES used against ABM was given at 100 or 200 mg/kg 30 min after ABM administration for 28 days. Markers of oxidative stress, inflammation, ERS, apoptosis, and autophagy in the testicular tissues removed after the animals are sacrificed were analyzed using biochemical, real-time polymerase chain reaction (RT-PCR), or western blot techniques. The results obtained showed that ABM caused oxidative stress, and triggered ERS, inflammation, apoptosis, and autophagy. On the other hand, HES showed antioxidant effect by increasing superoxide dismutase, catalase, glutathione peroxidase enzyme activities, and glutathione levels in testis tissue and attenuated lipid peroxidation. Accordingly, MAPK14 reduced the NF-κB, IL-1β, TNF-α, and IL-6 expression levels, presenting an anti-inflammatory effect. In addition, Bax protected against apoptosis and autophagy by reducing the caspase-3, beclin-1, LC3A, and LC3B expressions, and increasing Bcl-2 expression. It was observed that HES also interrupted the JAK2/STAT3 signaling pathway by suppressing IL-6 expression. Taken into consideration together, HES provided significant protection against the destruction caused by ABM in testicular tissue with antioxidant, anti-inflammatory, antiapoptotic, and anti-autophagic effects. Thus, it was revealed that HES has the potential to serve as an alternative treatment option in ABM toxicity.

Biochemical characterization of a novel azo reductase named BVU5 from the bacterial flora DDMZ1: application for decolorization of azo dyes

One of the main mechanisms of bacterial decolorization and degradation of azo dyes is the use of biological enzymes to catalyze the breaking of azo bonds. This paper shows the expression and properties of a novel azo reductase (hybrid-cluster NAD(P)-dependent oxidoreductase, accession no. A0A1S1BVU5, named BVU5) from the bacterial flora DDMZ1 for degradation of azo dyes. The molecular weight of BVU5 is about 40.1 kDa, and it contains the prosthetic group flavin mononucleotide (FMN). It has the decolorization ability of 80.1 ± 2.5% within 3 min for a dye concentration of 20 mg L⁻¹, and 53.5 ± 1.8% even for a dye concentration of 200 mg L⁻¹ after 30 min. The optimum temperature of enzyme BVU5 is 30 °C and the optimum pH is 6. It is insensitive to salt concentration up to a salinity level of 10%. Furthermore, enzyme BVU5 has good tolerance toward some metal ions (2 mM) such as Mn²⁺, Ca²⁺, Mg²⁺ and Cu²⁺ and some organic solvents (20%) such as DMSO, methanol, isopentyl, ethylene glycol and N-hexane. However, the enzyme BVU5 has a low tolerance to high concentrations of denaturants. In particular, it is sensitive to the denaturants guanidine hydrochloride (GdmCl) (2 M) and urea (2 M). Analysis of the dye substrate specificity shows that enzyme BVU5 decolorizes most azo dyes, which is indicating that the enzyme is not strictly substrate specific, it is a functional enzyme for breaking the azo structure. Liquid chromatography/time-of-flight/mass spectrometry (LC-TOF-MS) revealed after the action of enzyme BVU5 that some intermediate products with relatively large molecular weights were produced; this illustrates a symmetric or an asymmetric rapid cleavage of the azo bonds by this enzyme. The potential degradation pathways and the enzyme-catalyzed degradation mechanism are deduced in the end of this paper. The results give insight into the potential of a rapid bio-pretreatment by enzyme BVU5 for processing azo dye wastewater.

The combination of BVU5 enzyme and coenzyme NADH can quickly degrade the azo dye RB5.

Metal Ions, Metal Chelators and Metal Chelating Assay as Antioxidant Method

Heavy metals are essential for a wide range of biological processes, including the growth and reproduction of cells, synthesis of biomolecules, many enzymatic reactions, and the body’s immunity, but their excessive intake is harmful. Specifically, they cause oxidative stress (OS) and generate free radicals and reactive oxygen species (ROS) in metabolism. In addition, the accumulation of heavy metals in humans can cause serious damage to different organs, especially respiratory, nervous and reproductive and digestive systems. Biologically, metal chelation therapy is often used to treat metal toxicity. This process occurs through the interaction between the ligand and a central metal atom, forming a complex ring-like structure. After metals are chelated with appropriate chelating agents, their damage in metabolism can be prevented and efficiently removed from the body. On the other hand, heavy metals, including Zn, Fe and Cu, are necessary for the suitable functioning of different proteins including enzymes in metabolism. However, when the same metals accumulate at levels higher than the optimum level, they can easily become toxic and have harmful effects toward biomolecules. In this case, it induces the formation of ROS and nitrogen species (RNS) resulting in peroxidation of biological molecules such as lipids in the plasma membrane. Antioxidants have an increasing interest in many fields due to their protective effects, especially in food and pharmaceutical products. Screening of antioxidant properties of compounds needs appropriate methods including metal chelating assay. In this study, a general approach to the bonding and chelating properties of metals is described. For this purpose, the basic principles and chemical principles of metal chelation methods, both in vivo and in vitro, are outlined and discussed. Hence, in the main sections of this review, the descriptions related to metal ions, metal chelating, antioxidants, importance of metal chelating in biological system and definitions of metal chelating assays as widely used methods to determine antioxidant ability of compounds are provided. In addition, some chemical properties, technical and critical details of the used chelation methods are given.

Evaluation of oxidative stress, inflammation, apoptosis, oxidative DNA damage and metalloproteinases in the lungs of rats treated with cadmium and carvacrol

BACKGROUND

The potential protective properties of carvacrol (CRV), which possesses various biological and pharmacological properties, against lung toxicity caused by cadmium (Cd), a major environmental pollutant, were investigated in the present study.

METHODS AND RESULTS

In the study, rats were given 25 or 50 mg/kg CRV orally 30 min after administrating 25 mg/kg cadmium chloride for seven days. Subsequently, the levels of 8-OHdG, MMP-2, and MMP-9, as well as markers of oxidative stress, inflammation, and apoptosis, were analyzed in the lung tissue of the animals. The results revealed that CRV exhibited antioxidant characteristics and raised SOD, CAT, GPx, and CAT levels and decreased the MDA levels induced by Cd. It also suppressed proinflammatory cytokines by lowering the levels of CRV NF-κB and p38 MAPK, thus exerting an anti-inflammatory effect against Cd. It was found that the levels of Bax, Caspase-3, and cytochrome c increased by Cd were decreased by the application of CRV. CRV also showed an anti-apoptotic effect by increasing Bcl-2 levels. The levels of 8-OHdG, MMP2, and MMP9, which increased with Cd administration, were observed to reduce after treatment with CRV.

CONCLUSIONS

The results indicate that CRV has protective properties against Cd-induced lung toxicity.

Some indazoles as alternative inhibitors for potato polyphenol oxidase

Fresh-cut vegetables and fruits have gained attention among consumers because of their fresh appearance, lack of pollution, nutrition, and convenience. However, in fresh-cut foods, enzymatic browning is the main problem. Polyphenol oxidase (PPO) is a vital enzyme involved in the process of enzymatic browning. In this study, PPO was purified from potato using Sepharose 4B-l-tyrosine-p-aminobenzoic acid affinity chromatography and the effect of some indazoles on the enzyme was determined. The enzyme was purified with a specific activity of 52,857.14 EU/mg protein and 21.26-purification fold. Indazoles exhibited inhibitor properties for PPO with IC₅₀ values in the range of 0.11-1.12 mM and K_i values in the range of 0.15 ± 0.04-3.55 ± 0.88 mM. Among these compounds, 7-chloro-1H-indazole was shown as the most potent PPO inhibitor (K_i : 0.15 ± 0.04 mM). Determination of the enzyme's inhibition kinetics will simplify the testing of candidate PPO inhibitors.

Protective effects of rutin against deltamethrin-induced hepatotoxicity and nephrotoxicity in rats via regulation of oxidative stress, inflammation, and apoptosis

Deltamethrin is a type-II pyrethroid synthetic insecticide that is extensively used for controlling mosquitoes, flies, pests, and insects worldwide. This study was carried out to evaluate the likelihood protective effects of rutin, a natural antioxidant, against deltamethrin-induced liver and kidney toxicities in rats. Hepatotoxicity and nephrotoxicity were evaluated after the rats were treated orally with deltamethrin (1.28 mg/kg b.w.) alone or with rutin (25 and 50 mg/kg b.w.) for 30 days. Deltamethrin administration caused an increase in lipid peroxidation level and a decrease in activities of SOD, CAT, GPx, and GSH levels in the both tissues. Deltamethrin also increased serum ALT, AST, ALP, urea, and creatinine levels, while reduced nephrine levels in rats. In addition, deltamethrin increased the activation of inflammatory and apoptotic pathways by decreasing Bcl-2 and increasing TNF-α, NF-κB, IL-1β, p38α MAPK, COX-2, iNOS, beclin-1, Bax, and caspase-3 protein levels and/or activities. Furthermore, deltamethrin increased mRNA expression levels of PARP-1, VEGF, and immunohistochemical expressions of c-fos in the tissues. Rutin treatment significantly improved all examined parameters and restored the liver and kidney histopathological and immunohistochemical alterations. These findings demonstrate that rutin could be used to ameliorate hepatotoxicity and nephrotoxicity associated with oxidative stress, inflammation, and apoptosis in deltamethrin-induced rats.

Inhibition Profiles of Some Symmetric Sulfamides Derived from Phenethylamines on Human Carbonic Anhydrase I, and II Isoenzymes

In this work, the inhibitory effect of some symmetric sulfamides derived from phenethylamines were determined against human carbonic anhydrase (hCA) I, and II isoenzymes, and compared with standard compound acetazolamide. IC₅₀ values were obtained from the Enzyme activity (%)-[Symmetric sulfamides] graphs. Also, K_i values were calculated from the Lineweaver-Burk graphs. Some symmetric sulfamides compounds (11-18) demonstrated excellent inhibition effects against hCA I, and II isoenzymes. These compounds demonstrated effective inhibitory profiles with IC₅₀ values in ranging from 21.66-28.88 nM against hCA I, 14.44-30.13 nM against hCA II. Among these compounds, the best K_i value for hCA I (K_i : 8.34±1.60 nM) and hCA II (K_i : 16.40±1.00 nM) is compound number 11. Besides, the IC₅₀ value of acetazolamide used as a standard was determined as hCA I, hCA II 57.75 nM, 49.50 nM, respectively. Moreover, in silico ADME-Tox study showed that all synthesized compounds (11-18) had good oral bioavailability in light of Jorgensen's rule of three, and of Lipinski's rule of five.

Synthesis of N-alkylated pyrazolo[3,4-d]pyrimidine analogs and evaluation of acetylcholinesterase and carbonic anhydrase inhibition properties

Fused pyrimidines, especially pyrazolo[3,4-d]pyrimidines, are among the most preferred building blocks for pharmacology studies, as they exhibit a broad spectrum of biological activity. In this study, new derivatives of pyrazolo[3,4-d]pyrimidine were synthesized by alkylation of the N1 nitrogen atom. We synthesized 3-iodo-1H-pyrazolo[3,4-d]pyrimidin-4-amine 2 from commercially available aminopyrazolopyrimidine 1 using N-iodosuccinimide as an iodinating agent. The synthesis of compound 2 started with nucleophilic substitution of 3-iodo-1H-pyrazolo[3,4-d]pyrimidin-4-amine with R-X (X: -OMs, -Br, -Cl), affording N-alkylated pyrazolo[3,4-d]pyrimidine. We performed this synthesis using a weak inorganic base and the mild temperature was also used for a two-step procedure to generate N-alkylated pyrazolo[3,4-d]pyrimidine derivatives. Also, all compounds were tested for their ability to inhibit acetylcholinesterase (AChE) and the human carbonic anhydrase (hCA) isoforms I and II, with K_i values in the range of 15.41 ± 1.39-63.03 ± 10.68 nM for AChE, 17.68 ± 1.92-66.27 ± 5.43 nM for hCA I, and 8.41 ± 2.03-28.60 ± 7.32 nM for hCA II. Notably, compound 10 was the most selective and potent CA I inhibitor with a significant selectivity ratio of 26.90.

Production, purification and applications of raw starch degrading and calcium-independent α-amylase from soil rich in extremophile

Calcium independent, raw starch hydrolyzing, acidic α-amylase (66 kDa) was synthesized by Bacillus subtilis S113 that is an aerobic, rod-shaped and Gram +ve bacteria. Purification of the enzyme was performed by HiTrap Capto Q (Ion-exchange chromatography; 19.28 fold; 22.41% yield). The purified enzyme was found stable at broad acidic pH (4-6.5) and high-temperature range (40-80 °C), that fulfilled the necessary criteria and laid the foundation to be utilized in starch saccharification industry. Kinetic studies of the enzyme revealed that K_m and V_max of the enzyme was 0.22% and 357.14 U/mg respectively. Scanning electron microscopy studies showed that the enzyme was capable of completely hydrolyzing raw wheat and potato starch, further confirming its role in the starch industry. It was found that only 7.93% of the activity was loss at 4 °C when kept for one year.

Molecular docking and inhibition profiles of some antibiotics on lactoperoxidase enzyme purified from bovine milk

Antibiotics are generally used for human and veterinary applications to preserve and to control microbial diseases. Milk has a biologically significant enzyme known as lactoperoxidase (LPO) that is a member of peroxidase family. In metabolism, LPO has ability to catalyze the transformation of thiocyanate (SCN^-) to hypothiocyanite (OSCN^-) that is an antibacterial agent and the reaction occurs with hydrogen peroxide. In this work, LPO inhibition effects of some antibiotics including cefazolin, oxytetracycline, flunixin meglumine, cefuroxime, tylosin, vancomycin, chloramphenicol and lincomycin were tested. Among the antibiotics cefazolin was indicated the strongest inhibitory efficacy. The half maximal inhibitory concentration (IC₅₀) and the inhibition constant (K_i) values of cefazolin were found as 8.19 and 34.66 µM, respectively. It was shown competitive inhibition. 5-Methyl-1,3,4-thiadiazol-2-yl moiety activity plays a key role in the inhibition mechanism of cefazolin.Communicated by Ramaswamy H. Sarma.

Molecular Docking Studies and Inhibition Properties of Some Antineoplastic Agents against Paraoxonase-I

Background:

Currently, most of the drugs used in clinical applications show their pharmacological influences by inhibiting or activating enzymes. Therefore, enzyme inhibitors have an essential place in the drug design for many diseases.

Objective:

The current study aimed to contribute to this growing drug design field (i.e., medicine discovery and development) by analyzing enzyme-drug interactions.

Methods:

For this reason, Paraoxonase-I (PON1) enzyme was purified from fresh human serum by using rapid chromatographic techniques. Additionally, the inhibition effects of some antineoplastic agents were researched on the PON1.

Results:

The enzyme was obtained with a specific activity of 2603.57 EU/mg protein. IC50 values for pemetrexed disodium, irinotecan hydrochloride, dacarbazine, and azacitidine were determined to be 9.63μM, 30.13μM, 53.31μM, and 21.00mM, respectively. These agents found to strongly inhibit PON1, with Ki constants ranging from 8.29±1.47μM to 23.34±2.71mM. Dacarbazine and azacitidine showed non-competitive inhibition, while other drugs showed competitive inhibition. Furthermore, molecular docking was performed using maestro for these agents. Among these, irinotecan hydrochloride and pemetrexed disodium possess the binding energy of -5.46 and -8.43 kcal/mol, respectively.

Conclusion:

The interaction studies indicated that these agents with the PON1 possess binding affinity.

Impact Assessment of heavy metal cations to the characteristics of photosynthetic phycocyanin

This work has assessed the impact of typical heavy metal cations on C-phycocyanin in vitro and in silico. At low concentrations (<2×10^-6 mol/L), the influence of Pb²⁺ is the highest on the light absorption of C-phycocyanin trimer. At higher concentrations, however, a new order of influence on the light absorption has been observed with Cd²⁺ < Cu²⁺ < Pb²⁺ < Zn²⁺. The fluorescence polarization has changed from the order of Cd²⁺ < Pb²⁺≈Cu²⁺ < Zn²⁺ to Cd²⁺ < Cu²⁺ < Pb²⁺ < Zn²⁺, when the metal concentrations reaches 2×10^-6 mol/L. The mechanisms for these findings have been studied using FTIR, hydrophobic probe, isothermal titration calorimetry and molecular docking for the analysis of structure disorder of C-phycocyanin. It has been suggested that the secondary structure of C-phycocyanin affects more to the light absorbance while the fluorescence characteristics relies more on the tertiary structure. The interaction between Pb²⁺ and C-phycocyanin is both enthalpically and entropically favoured, whereas the interactions for Cd²⁺, Cu²⁺ and Zn²⁺ are entropically driven. The ion-molecular docking suggests that the structure disorder of C-phycocyanin relies on the molecular interactions with metal ions. The in silico study also showed that the binding cites of Zn²⁺ are closer to chromophores.

Carbonic Anhydrase Sensitivity to Pesticides: Perspectives for Biomarker Development

Carbonic anhydrase (CA) is a widespread metalloenzyme playing a pivotal role in several physiological processes. Many studies have demonstrated the in vitro and in vivo sensitivity of CA to the exposure to several classes of pesticides in both humans and wildlife. This review aims to analyze and to discuss the literature available in this field, providing a comprehensive view useful to foresee perspectives for the development of novel CA-based pesticide biomarkers. The analysis of the available data highlighted the ability of several pesticide molecules to interact directly with the enzyme in humans and wildlife and to inhibit CA activity in vitro and in vivo, with possible alterations of key physiological functions. The analysis disclosed key areas of further research and, at the same time, identified some perspectives for the development of novel CA-based sensitive biomarkers to pesticide exposure, suitable to be used in several fields from human biomonitoring in occupational and environmental medicine to environmental monitoring on non-target species.

A Novel Ag-N-Heterocyclic Carbene Complex Bearing the Hydroxyethyl Ligand: Synthesis, Characterization, Crystal and Spectral Structures and Bioactivity Properties

In this study, a novel silver N-heterocyclic carbene (Ag-NHC) complex bearing hydroxyethyl substituent has been synthesized from the hydroxyethyl-substituted benzimidazolium salt and silver oxide by using in-situ deprotonation method. A structure of the Ag-NHC complex was characterized by using UV-Vis, FTIR, 1H-NMR and 13C-NMR spectroscopies and elemental analysis techniques. Also, the crystal structure of the novel complex was determined by single-crystal X-ray diffraction method. In this paper, compound 1 showed excellent inhibitory effects against some metabolic enzymes. This complex had Ki of 1.14 0.26 µM against human carbonic anhydrase I (hCA I), 1.88±0.20 µM against human carbonic anhydrase II (hCA I), and 10.75±2.47 µM against α-glycosidase, respectively. On the other hand, the Ki value was found as 25.32±3.76 µM against acetylcholinesterase (AChE) and 41.31±7.42 µM against butyrylcholinesterase (BChE), respectively. These results showed that the complex had drug potency against some diseases related to using metabolic enzymes.

Protective effect of rutin on mercuric chloride-induced reproductive damage in male rats

This study investigated the effects of rutin against reproductive damage caused by toxic mercury in male rats. Thirty-five Sprague Dawley rats were used. Control group was injected with saline for 7 days. The rutin-100 group received 100 mg/kg/b.w. rutin for 7 days. Mercuric chloride (HgCl₂ ) group received 1.23 mg/kg/b.w. of HgCl₂ for 7 days. Mercury chloride + rutin-50 group received 50 mg/kg/b.w. rutin and HgCl₂ 1.23 mg/kg/b.w. for 7 days. HgCl₂  + rutin-100 group received 100 mg/kg/b.w. rutin and HgCl₂ 1.23 mg/kg/b.w. for 7 days. It was detected that HgCl₂ treatment increased malondialdehyde (MDA) levels, tumour necrosis factor-α (TNF-α) and cyclooxygenase-2 (COX-2) expressions, necrosis and degeneration of spermatogonium, dead and abnormal sperm percentages; tubular walls thinning; and decreased antioxidant enzyme activities and sperm motility. It was determined that rutin application reduced testicular damage caused by HgCl₂ . In conclusion, rutin administration may treat HgCl₂ toxicity in testes.

Morin attenuates ifosfamide-induced neurotoxicity in rats via suppression of oxidative stress, neuroinflammation and neuronal apoptosis

Ifosfamide (IFA), a commonly used chemotherapeutic drug, has been frequently associated with encephalopathy and central nervous system toxicity. The present study aims to investigate whether morin could protect against acute IFA-induced neurotoxicity. Morin was administered to male rats once daily for 2 consecutive days at doses of 100 and 200 mg/kg body weight (BW) orally. IFA (500 mg/kg BW; i.p.) was administered on second day. The results showed that morin markedly inhibited the production of acetylcholinesterase (AChE), butrylcholinesterase (BChE), carbonic anhydrase (CA), glial fibrillary acidic protein (GFAP), brain-derived neurotrophic factor (BDNF) and nuclear factor erythroid 2-related factor 2 (Nrf-2) induced by IFA. Morin ameliorated IFA-induced lipid peroxidation, glutathione (GSH) depletion, and decrease antioxidant enzyme activities, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx). Histopathological changes and immunohistochemical expressions of c-Jun N-terminal kinase (JNK) and c-Fos in the IFA-induced brain tissues were decreased after administration of morin. Furthermore, morin was able to down regulate the levels of inflammatory and apoptotic markers such as nuclear factor kappa B (NF-κB), neuronal nitric oxide synthase (nNOS), tumor necrosis factor-α (TNF-α), p53, cysteine aspartate specific protease-3 (caspase-3) and B-cell lymphoma-2 (Bcl-2). Taken together, our results demonstrated that morin elicited a typical chemoprotective effect on IFA-induced acute neurotoxicity.