Pseudomonas putida Metallothionein: Structural Analysis and Implications of Sustainable Heavy Metal Detoxification in Madinah.

Heavy metals, specifically cadmium (Cd) and lead (Pb), contaminating water bodies of Madinah (Saudi Arabia), is a significant environmental concern that necessitates prompt action. Madinah is exposed to toxic metals from multiple sources, such as tobacco, fresh and canned foods, and industrial activities. This influx of toxic metals presents potential hazards to both human health and the surrounding environment. The aim of this study is to explore the viability of utilizing metallothionein from Pseudomonas putida (P. putida) as a method of bioremediation to mitigate the deleterious effects of pollution attributable to Pb and Cd. The use of various computational approaches, such as physicochemical assessments, structural modeling, molecular docking, and protein-protein interaction investigations, has enabled us to successfully identify the exceptional metal-binding properties that metallothionein displays in P. putida. The identification of specific amino acid residues, namely GLU30 and GLN21, is crucial in understanding their pivotal role in facilitating the coordination of lead and cadmium. In addition, post-translational modifications present opportunities for augmenting the capacity to bind metals, thereby creating possibilities for focused engineering. The intricate web of interactions among proteins serves to emphasize the protein's participation in essential cellular mechanisms, thereby emphasizing its potential contributions to detoxification pathways. The present study establishes a strong basis for forthcoming experimental inquiries, offering potential novel approaches in bioremediation to tackle the issue of heavy metal contamination. Metallothionein from P. putida presents a highly encouraging potential as a viable remedy for environmental remediation, as it is capable of proficiently alleviating the detrimental consequences related to heavy metal pollution.

An In Silico Bioremediation Study to Identify Essential Residues of Metallothionein Enhancing the Bioaccumulation of Heavy Metals in Pseudomonas aeruginosa.

Microorganisms are ubiquitously present in the environment and exert significant influence on numerous natural phenomena. The soil and groundwater systems, precipitation, and effluent outfalls from factories, refineries, and waste treatment facilities are all sources of heavy metal contamination. For example, Madinah, Saudi Arabia, has alarmingly high levels of lead and cadmium. The non-essential minerals cadmium (Cd) and lead (Pb) have been linked to damage to vital organs. Bioremediation is an essential component in the process of cleaning up polluted soil and water where biological agents such as bacteria are used to remove the contaminants. It is demonstrated that Pseudomonas aeruginosa (P. aeruginosa) isolated from activated sludge was able to remove Cd and Pb from water. The protein sequence of metallothionein from P. aeruginosa was retrieved to explore it for physicoparameters, orthologs, domain, family, motifs, and conserved residues. The homology structure was generated, and models were validated. Docking of the best model with the heavy metals was carried out to inspect the intramolecular interactions. The target protein was found to belong to the "metallothionein_pro" family, containing six motifs, and showed a close orthologous relationship with other heavy metal-resistant bacteria. The best model was generated by Phyre2. In this study, three key residues of metallothionein were identified that participate in heavy metal (Pb and Cd) binding, viz., Ala33, Ser34, and Glu59. In addition, the study provides an essential basis to explore protein engineering for the optimum use of metallothionein protein to reduce/remove heavy metals from the environment.

Prospective Protective Effects of Arthrospira platensis Against Acetaminophen Induced Hepato-Renal Toxicity in Rats / Efectos Protectores Prospectivos de Arthrospira platnesis Contra la Toxicidad Hepatorrenal Inducida por Paracetamol en Ratas

SUMMARY: The toxic effects of acetaminophen appear primarily in the liver and kidney. The protective effect of blue green alga Arthrospira platensis on hepato-renal toxicity caused by acetaminophen was evaluated in male rats. The obtained results showed that subcutaneous injection of acetaminophen at a dose 120 &240 սl acetaminophen/kg by weight resulted in an observed elevation in the enzyme activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and Alkaline phosphatase (ALP), serum total lipids, total cholesterol, creatinine, total bilirubin, urea, nitric oxide (NO), L- malondialdehyde (MDA) and interleukins (IL-2 &IL-6). However, there is a decrease in the serum total protein, albumin and loss in antioxidant enzyme activities in liver including; superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GSH). This effect was found to be dose and time dependent. In spite of, pre- oral administration of Arthrospira platensis 1000 mg/kg .b. wt. prior acetaminophen injection succeeded to modulate the effect of the observed abnormalities caused by acetaminophen. Moreover, there were no remarkable changes in serum biomarkers of rats received Arthrospira platensis only at a dose of 1000 mg/kg by weight (group 2). The histopathological findings confirm the biochemical results that indicates the safety use of Arthrospira platensis at the selected dose in this study. Therefore, the present results clarified the protective effect of blue green alga Arthrospira platensis on oxidative stress, hepatic and nephrotoxicity induced by acetaminophen in male Wister rats.

Los efectos tóxicos del paracetamol aparecen principalmente en el hígado y el riñón. Se evaluó en ratas macho Wistar el efecto protector del alga verde azulada Arthrospira platensis sobre la toxicidad hepatorrenal causada por paracetamol. Los resultados obtenidos mostraron que la inyección subcutánea de paracetamol a dosis de 120 y 240 µl de paracetamol/kg, resultó en una elevación en las actividades enzimáticas de la aspartato aminotransferasa (AST), alanina aminotransferasa (ALT) y fosfatasa alcalina (ALP), lípidos séricos totales, colesterol total, creatinina, bilirrubina total, urea, óxido nítrico (NO), L- malondialdehído (MDA) e interleucinas (IL-2 e IL-6). Sin embargo, hay una disminución en la proteína sérica total, albúmina y pérdida en las actividades de las enzimas antioxidantes en el hígado, incluyendo; superóxido dismutasa (SOD), catalasa (CAT) y glutatión reductasa (GSH). Se encontró que este efecto era dependiente de la dosis y el tiempo. A pesar de la administración preoral de Arthrospira platensis 1000 mg/kg, la inyección previa de acetaminofeno logró modular el efecto de las anormalidades observadas causadas por el acetaminofeno. Además, no hubo cambios notables en los biomarcadores séricos de ratas que recibieron Arthrospira platensis solo a una dosis de 1000 mg/kg (Grupo 2). Los hallazgos histopatológicos confirman los resultados bioquímicos que indican la seguridad del uso de Arthrospira platensis a la dosis seleccionada en este estudio. Por lo tanto, los presentes resultados aclararon el efecto protector del alga verde azulada Arthrospira platensis sobre el estrés oxidativo, la toxicidad hepática y la nefrotoxicidad inducida por paracetamol en ratas Wistar macho.

Design and Synthesis of Benzene Homologues Tethered with 1,2,4-Triazole and 1,3,4-Thiadiazole Motifs Revealing Dual MCF-7/HepG2 Cytotoxic Activity with Prominent Selectivity via Histone Demethylase LSD1 Inhibitory Effect.

In this study, an efficient multistep synthesis of novel aromatic tricyclic hybrids incorporating different biological active moieties, such as 1,3,4-thiadiazole and 1,2,4-triazole, was reported. These target scaffolds are characterized by having terminal lipophilic or hydrophilic parts, and their structures are confirmed by different spectroscopic methods. Further, the cytotoxic activities of the newly synthesized compounds were evaluated using in vitro MTT cytotoxicity screening assay against three different cell lines, including HepG-2, MCF-7, and HCT-116, compared with the reference drug Taxol. The results showed variable performance against cancer cell lines, exhibiting MCF-7 and HepG-2 selectivities by active analogs. Among these derivatives, 1,2,4-triazoles 11 and 13 and 1,3,4-thiadiazole 18 were found to be the most potent compounds against MCF-7 and HepG-2 cancer cells. Moreover, structure-activity relationship (SAR) studies led to the identification of some potent LSD1 inhibitors. The tested compounds showed good LSD1 inhibitory activities, with an IC50 range of 0.04-1.5 µM. Compounds 27, 23, and 22 were found to be the most active analogs with IC50 values of 0.046, 0.065, and 0.074 µM, respectively. In addition, they exhibited prominent selectivity against a MAO target with apparent cancer cell apoptosis, resulting in DNA fragmentation. This research provides some new aromatic-centered 1,2,4-triazole-3-thione and 1,3,4-thiadiazole analogs as highly effective anticancer agents with good LSD1 target selectivity.

Spectroscopic and structural studies of the Schiff base 3-methoxy-N-salicylidene-o-amino phenol complexes with some transition metal ions and their antibacterial, antifungal activities.

Spectroscopic (IR, Raman, NMR, UV-visible, and ESR), and structural studies of the ligand 3-methoxy-N-salicylidene-o-amino phenol (H2L) and its synthesized complexes with some transition metal ions (Mn(II), Co(II), Ni(II)), Cu(II) and Zn(II)) were recorded and analyzed. The magnetic properties and thermal gravimetric analysis (TGA and DTA) were also measured for the complexes. The metal complexes were found to have The structural formula ML⋅H2O and the metal ions Mn(II), Co(II), Ni(II)) and Zn(II) were found to form tetrahedral complexes with the ligand whereas Cu(II) formed a square planar one. Antimicrobial activity of the ligand and its complexes were also investigated and discussed.

Effects of aminoguanidine and desferrioxamine on some vascular and biochemical changes associated with streptozotocin-induced hyperglycaemia in rats.

The effects of aminoguanidine (AG; 100 mg x kg(-1)) and desferrioxamine (DFO; 50 mg x kg(-1)) on some vascular and biochemical changes associated with streptozotocin (STZ; 65 mg x kg(-1); i.p.)-induced hyperglycaemia were investigated in rats. Both AG and DFO were administered i.p., once daily, for 14 consecutive days to normal and hyperglycaemic animals. The responsiveness of the isolated aortic rings to phenylephrine (PE) was tested. In addition, biochemical markers for oxidative stress such as plasma levels of lipid peroxides and total thiols, as well as the activities of erythrocytic superoxide dismutase (SOD) and whole blood glutathione peroxidase (GSH-Px) were assessed. Results of the present study indicated that induction of hyperglycaemia was associated with increased aortic ring responsiveness to PE, loss in body weight, increase in urine volume, elevation of plasma total thiols and lipid peroxide levels and elevated SOD and GSH-Px enzymatic activities. Treatment of normal rats with AG reduced the response of their aortae to PE. Furthermore, a profound increase in body weight without any significant change in the measured biochemical parameters was observed. In hyperglycaemic animals, AG tended to normalize the enhanced aortic response to PE and modulated STZ-induced biochemical changes without affecting the elevated plasma glucose level. Treatment of normal rats with DFO reduced the response of their aortae to PE and decreased their body weight without altering any of the chosen biochemical parameters. In hyperglycaemic animals, DFO attenuated the responsiveness of their aortae to PE and at the same time, did not affect the loss in body weight and the elevation of plasma glucose level observed in the hyperglycaemic group. Additionally, DFO normalized the elevated plasma level of total thiols and exerted a modulatory influence on the enhanced activities of SOD and GSH-Px as well as on the increased levels of lipid peroxides. Our data lend further credence for the contribution of oxidative stress in the vascular and biochemical changes associated with STZ-induced hyperglycaemia. It is also apparent that advanced glycosylation end products and nitric oxide might be involved. Until clinical studies prove the efficacy and safety of these drugs, specific agents which could scavenge free radicals and block protein glycosylation seem beneficial as a helpful adjunct to the therapy of diabetes.

Ginkgo biloba extract (EGb 761) modulates bleomycin-induced acute lung injury in rats.

The effect of Ginkgo biloba extract (EGb 761) on bleomycin (BLM)-induced acute lung injury was studied in rats. The responsiveness of isolated pulmonary arterial rings to 5-hydroxytryptamine (5-HT) as well as the levels of some relevant biochemical markers in the lung tissue were taken as evidence for the acute lung injury. BLM was given intraperitoneally at a dose of 15 mg/kg/day for five consecutive days. It was found that BLM treatment attenuated the vasoconstrictor effect of 5-HT on the isolated pulmonary arteries. In lung tissues BLM also elevated the level of lipid peroxides and enhanced the activity of glutathione peroxidase. On the other hand, the level of glutathione and the activity of alkaline phosphatase were reduced. Body weight, lung weight and tissue glutathione-S-transferase activity were, however, not altered. Oral administration of EGb 761 at a dose of 100 mg/kg/day for five consecutive days did not alter any of the chosen biochemical parameters in the lung tissue except for a slight reduction in alkaline phosphatase activity. However, treatment with EGb 761 reduced the responsiveness of the pulmonary artery to 5-HT. Administration of EGb 761 (100 mg/kg/day; po) two hours prior to BLM (15 mg/kg/day; ip), for five consecutive days blunted the occurrence of further reduction in the vasoconstrictor response of the pulmonary artery to 5-HT. Furthermore, EGb 761 tended to normalize BLM-induced alterations in the measured biochemical markers in the lung tissue. The apparent modulatory influence of EGb 761 on BLM-induced acute lung injury stems, at least in part, from its beneficial free radical scavenging properties that provide the extract with antioxidant activity.

Modulatory effects of melatonin and vitamin E on doxorubicin-induced cardiotoxicity in Ehrlich ascites carcinoma-bearing mice.

Doxorubicin (Dox), an anthracycline antibiotic, has a wide spectrum of antitumor activity with dose-limiting cardiotoxicity. The drug's toxicity is known to be closely related to the generation of active oxygen free radicals. In our study the normal cardiac tissue contents of total protein, glutathione (GSH) and malondialdehyde (MDA) were significantly decreased, by 25%, 33% and 92%, respectively, in the group of mice bearing Ehrlich ascites carcinoma (EAC) and treated with Dox (4 mg/kg/week x 2, ip). Administration of melatonin (5 mg/kg/day x 15, po) starting 24 hours prior to Dox treatment significantly increased the cardiac contents of total protein and GSH as well as the superoxide dismutase (SOD) activity, by 31%, 36% and 39%, respectively, compared to treatment with Dox only, while the content of MDA was decreased by 26%. Similarly, administration of vitamin E (250 mg/kg/day x 15, po) starting 24 hours prior to Dox treatment significantly increased the cardiac contents of total protein, GSH and SOD, by 23%, 26% and 42%, respectively, while the cardiac content of MDA was decreased by 35% compared with the Dox-only-treated group. As to the oncolytic activity of Dox, pretreatment of EAC-bearing mice with melatonin (5 mg/kg/day x 30, po) or vitamin E (250 mg/kg/day x 30, po) 24 hours prior to Dox administration (4 mg/kg/week x 4, ip) improved the antitumor activity of Dox as indicated by the increase in the average life span of the animals and the number of long-term survivors as well as the decrease in body weight loss induced by Dox treatment. It is clear from these results that administration of melatonin not only protects against the cardiotoxicity induced by Dox treatment but also enhances its antitumor activity to a more significant extent than does vitamin E.

Adverse testicular effects of some quinolone members in rats.

In the last few years, a marked decrease in male fertility has been reported. Environmental factors were recently suspected for this effect. Among those factors is the misuse of drugs and in particular antibiotics. Quinolones are a group of antibacterial agents with broad-spectrum activity. Testicular impairment of some quinolone members is controversial; a matter which stimulated our attention to investigate the adverse testicular effects of the most familiar quinolone members, namely: ofloxacin, ciprofloxacin and pefloxacin. They were given to rats in doses of 72, 135 and 72 mg kg(-1) day(-1) p.o., respectively, for 15 consecutive days. Ofloxacin was also used to establish a dose-response relationship in doses of 36, 72 and 360 mg kg(-1) day(-1) p.o. for 15 consecutive days. Results revealed that ofloxacin, ciprofloxacin and pefloxacin reduced testicular LDH-X activity by 39.8%, 62.7% and 60.7%, respectively. Moreover, sperm count, motility and daily sperm production were markedly decreased. Ofloxacin induced a dose-dependent decrease in testicular LDH-X activity, sperm count and motility. Furthermore, daily sperm production showed a marked reduction which amounted to 26.1% and 40. 0% following administration of ofloxacin (72, 360 mg kg(-1) day(-1) x 15 days), respectively. Moreover, administration of ofloxacin resulted in marked testicular histopathological changes. It is concluded that, ofloxacin, ciprofloxacin and pefloxacin significantly impaired both testicular function and structure in rats.

Effect of glutathione modulation of the distribution and transplacental uptake of 2-[14C]-chloroacetonitrile (CAN) quantitative whole-body autoradiographic study in pregnant mice.

Chloroacetonitrile (CAN), a drinking water disinfectant by-product, has mutagenic and carcinogenic properties. CAN is known to deplete glutathione (GSH), and previous studies reported an enhanced molecular interaction of CAN after GSH depletion in the uterine and fetal tissues of mice. The present report may help to understand the potential mechanisms involved in such molecular interactions by examining the disposition, transplacental uptake and covalent interaction of the chemical in normal and GSH depleted pregnant mice (at 13th day of gestation). Both normal and GSH depleted (by administration of Diethylmaleate (DEM), 0.6 mL/kg, i.p.) pregnant mice were given an equitoxic i.v. dose of 2-[14C]-CAN(333 microCi/kg equivalent to 77 mg/kg). Animals were processed for whole-body autoradiography (WBA) at 1, 8 and 24 hr after treatment. Tissue distribution of radioactivity in the autoradiographs was quantitated using computer aided image analysis. With few exceptions, a rapid high uptake (at 1 hr) of radioactivity was observed in all major maternal (liver, lung, urinary bladder, gastrointestinal mucosa, cerebellum, uterine luminal fluid) and fetal (liver, brain) organs of both normal and GSH depleted mice. This pattern of distribution was observed, with lesser intensity, at 8 hr following treatment. At a later time period (24 hr), there was a significant higher retention and covalent interaction of radioactivity in GSH depleted mouse tissues especially in the liver as compared to normal mouse. This study suggests that 2-[14C]-CAN and/or its metabolites are capable of crossing the placental barrier. The observed higher uptake and retention of the radioactivity in the maternal liver, kidney, cerebellum, nasal turbinates and fetal liver may pose toxicity of the chemical to these organs. The increased covalent interaction of radioactivty in GSH depleted mice liver may indicate the potential utilization of GSH pathway by this organ in the detoxication of CAN derived metabolites and thus exerting hepatotoxicity.

The effect of thiola, piroxicam and diltiazem on the uterine contractility of gamma-irradiated rats.

Accidental radiation exposure raises concern for functional modifications in the uterine physiology. In the current work, total body gamma-irradiation (0.7, 1.4 and 2.1 Gy) of non-pregnant adult female albino rats increased significantly the frequency and amplitude of uterine contractions in vivo. Administration of Thiola (a sulfhydryl containing agent) in doses of 100 or 250 mg kg-1, pre-irradiation or Piroxicam (a potent prostaglandin inhibitor) in a dose of 2 mg kg-1, pre- or post-irradiation failed to normalize the changes induced by gamma-irradiation. However, administration of Diltiazem (a Ca2+ channel blocker, 8 mg kg-1) pre- or post-irradiation caused a significant decrease in the frequency of uterine contractions (21% and 24% respectively) in comparison to the uterotonic pattern of gamma-irradiation alone. The results indicate a promising tocolytic activity of Diltiazem against the uterotonic effect of gamma-radiation.

Effect of glutathione modulation on molecular interaction of [14C]-chloroacetonitrile with maternal and fetal DNA in mice.

Binding of haloacetonitriles or their reactive metabolites to macromolecules of fetal tissue may be responsible for reproductive toxicity. To investigate the role of glutathione (GSH) in the metabolism and reproductive toxicity of haloacetonitriles, irreversible interaction of chloroacetonitrile (CAN) with maternal uterine and fetal DNA was assessed in a time course study among normal and among glutathione-depleted mice treated with [2-14C]-CAN. GSH was depleted in maternal and fetal tissues by treating of animals with diethylmaleate (DEM) 1 h before [2-14C]-CAN administration. Maternal urinary excretion of thiocyanate was 5 times higher in glutathione-depleted mice than in controls. At 8 and 24 h following [2-14C]-CAN administration, total radioactivity uptake in maternal uterine tissue, amniotic fluid, and fetal tissue was higher in glutathione-depleted mice than in control. Also the interaction of CAN or its reactive metabolites with maternal uterine DNA was enhanced following glutathione depletion. At 24 h after treatment, the covalent binding to DNA in fetal tissue was significantly increased in glutathione depleted mice (205% of control). The magnitude of interaction of CAN in fetal DNA was about 4 times higher than that in uterine DNA. The time course study in either maternal uterine or fetal DNA revealed elevated and persistent levels of covalent binding of [ C]-CAN to DNA at 72 h after treatment. Enhancement of the molecular interaction of CAN in maternal and fetal DNA following GSH depletion indicates an important role for GSH in CAN metabolism.

Immuno and histochemical study of endometrium in women using copper IUCD.

PIP: This study dealt with the possible local tissue reaction induced by IUDs and its possible antifertility role. Premenstrual endometrial biopsies were taken from 50 women using the copper IUD for periods ranging from 5 months to 3 years, together with a control group of 10 nonusers. The immunohistochemical localization of the total immunoglobulins and the immunoglobulin G (IgG) concentrations in the endometrial tissue revealed a significant increase in copper IUD users when compared with the controls. Histochemically, there was a decrease in alkaline phosphatase activity, RNA, DNA, and the acid mucopolysaccharide reactions in the endometrial biopsies from women with copper IUDs. These changes were more apparent in specimens taken less than 1 year after copper IUD insertion, especially in the surface epithelium. The reaction showed progressive increase in the 2nd and 3rd year after copper IUD insertion. It can be claimed that, early after insertion, copper ions, when released in reasonable amounts, lead to metabolic changes in the endometrium, rendering it unfavorable for implantation. It is very likely that, through time, the oxidative changes occurring on the copper wire surface interfered with the release of ions, thus predisposing it to gradually act as an inert foreign body.^ieng