Expression of hepatic antioxidant genes in l-thyroxine-induced hyperthyroid rats: Regulation by vitamin E and curcumin

Concomitant Effects of Metformin and Vitamin C on Indomethacin-Induced Gastric Ulcer in Rats: Biochemical and Histopathological Approach

INTRODUCTION

Gastric ulcer is one of the most common and serious conditions in the gastrointestinal tract. One of the main causes of gastric ulcers is using of non-steroidal anti-inflammatory drugs (NSAIDs) which have limited their use in clinical practice. Several studies have revealed that metformin and Vitamin C (Vit C) exhibit protective effects against gastric mucosal damage in different animal models. However, no studies indicate their combination's effect on gastric ulcer models. Therefore, this study aims to investigate the protective effects of metformin and Vit C combination on indomethacin-induced gastric ulcers.

MATERIAL AND METHODS

In total, thirty rats were divided into six groups, including the control group, rats received indomethacin (50 mg/kg, i.p.), rats received indomethacin and pretreated with ranitidine (100 mg/kg), metformin (100 mg/kg, i.p.), Vit C (100 mg/kg), or metformin combined with Vit C. Four hours after indomethacin administration, rats were euthanized, and gastric tissues were removed for macroscopic, histopathologic, and biochemical examinations.

RESULTS

All therapeutics used in this study were found to alleviate gastric mucosal injury caused by indomethacin, as observed in histopathologic and macroscopic evaluations. Both Vit C and metformin were observed to significantly decrease lipid peroxidation and enhance the activity of anti-oxidative enzymes, SOD, GPx, and catalase. However, a more significant effectiveness was observed in catalase and GPx activities when Vit C was co-administered with metformin.

CONCLUSIONS

In conclusion, the present study revealed that metformin and Vit C combination therapy could potentially treat gastric ulcers associated with indomethacin.

Biochemical and biophysical interaction of rare earth elements with biomacromolecules: A comprehensive review

The growing utilization of rare earth elements (REEs) in industrial and technological applications has captured global interest, leading to the development of high-performance technologies in medical diagnosis, agriculture, and other electronic industries. This accelerated utilization has also raised human exposure levels, resulting in both favourable and unfavourable impacts. However, the effects of REEs are dependent on their concentration and molecular species. Therefore, scientific interest has increased in investigating the molecular interactions of REEs with biomolecules. In this current review, particular attention was paid to the molecular mechanism of interactions of Lanthanum (La), Cerium (Ce), and Gadolinium (Gd) with biomolecules, and the biological consequences were broadly interpreted. The review involved gathering and evaluating a vast scientific collection which primarily focused on the impact associated with REEs, ranging from earlier reports to recent discoveries, including studies in human and animal models. Thus, understanding the molecular interactions of each element with biomolecules will be highly beneficial in elucidating the consequences of REEs accumulation in the living organisms.

Effective substances and molecular mechanisms guided by network pharmacology: An example study of Scrophulariae Radix treatment of hyperthyroidism and thyroid hormone-induced liver and kidney injuries

ETHNOPHARMACOLOGICAL RELEVANCE

Scrophulariae Radix (Xuanshen [XS]) has been used for several years to treat hyperthyroidism. However, its effective substances and pharmacological mechanisms in the treatment of hyperthyroidism and thyroid hormone-induced liver and kidney injuries have not yet been elucidated.

AIM OF THE STUDY

This study aimed to explore the pharmacological material basis and potential mechanism of XS therapy for hyperthyroidism and thyroid hormone-induced liver and kidney injuries based on network pharmacology prediction and experimental validation.

MATERIALS AND METHODS

Based on 31 in vivo XS compounds identified using ultra-performance liquid chromatography tandem quadruple exactive orbitrap high-resolution accurate-mass spectrometry (UPLC-QE-HRMS), a network pharmacology approach was used for mechanism prediction. Systematic networks were constructed to identify the potential molecular targets, biological processes (BP), and signaling pathways. A component-target-pathway network was established. Mice were administered levothyroxine sodium through gavage for 30 d and then treated with different doses of XS extract with or without propylthiouracil (PTU) for 30 d. Blood, liver, and kidney samples were analyzed using an enzyme-linked immunosorbent assay (ELISA) and western blotting.

RESULTS

A total of 31 prototypes, 60 Phase I metabolites, and 23 Phase II metabolites were tentatively identified in the plasma of rats following the oral administration of XS extract. Ninety-six potential common targets between the 31 in vivo compounds and the diseases were identified. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that Bcl-2, BAD, JNK, p38, and ERK1/2 were the top targets. XS extract with or without PTU had the following effects: inhibition of T3/T4/fT3/fT4 caused by levothyroxine; increase of TSH levels in serum; restoration of thyroid structure; improvement of liver and kidney structure and function by elevating the activities of anti-oxidant enzymes catalase (CAT),superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px); activation anti-apoptotic proteins Bcl-2; inhibition the apoptotic protein p-BAD; downregulation inflammation-related proteins p-ERK1/2, p-JNK, and p-p38; and inhibition of the aggregation of pro-inflammatory cytokines TNF-α, IL-1β, and IL-6, as well as immune cells in the liver.

CONCLUSION

XS can be used to treat hyperthyroidism and liver and kidney injuries caused by thyroid hormones through its anti-oxidant, anti-inflammatory, and anti-apoptotic properties. In addition, serum pharmacochemical analysis revealed that five active compounds, namely 4-methylcatechol, sugiol, eugenol, acetovanillone, and oleic acid, have diverse metabolic pathways in vivo and exhibit potential as effective therapeutic agents.

Evidence of microplastics release from polythene and paper cups exposed to hot and cold: A case study on the compromised kinetics of catalase

Microplastics (MPs) have become widespread in the modern world posing a hidden threat to the global environment. However, growing accumulation and devastating impact of MPs on human health and the environment have received least attention. In the current investigation, for the first time MPs have been identified which are released from the daily usable materials like polythene bags (PB) and paper cups (PC) in response to hot and cold water exposure at different time intervals. The impact of these MPs has been assessed on the major antioxidant enzyme, bovine liver catalase (BLC). The binding of MPs caused conformational changes in BLC by decreasing the α-helical content, which results in reduction of the enzymatic activity. Kinetics study revealed nearly ∼1.4-fold compromised catalytic efficiency of catalase in response to MPs. Nevertheless, hepatic catalase activity was also significantly decreased in presence of MPs. Further, materials like glass, porcelain, stainless steel, and high-grade plastics are discovered as greener alternatives to PB and PC.

Enhanced enzymatic activity and conformational stability of catalase in presence of tetrahedral DNA nanostructures: A biophysical and kinetic study

The emergence of DNA nanotechnology has shown enormous potential in a vast array of applications, particularly in the medicinal and theranostics fields. Nevertheless, the knowledge of the compatibility between DNA nanostructures and cellular proteins is largely unknown. Herein, we report the biophysical interaction between proteins (circulatory protein bovine serum albumin, BSA, and the cellular enzyme bovine liver catalase, BLC) and tetrahedral DNA (tDNAs), which are well-known nanocarriers for therapeutics. Interestingly, the secondary conformation of BSA or BLC was unaltered in the presence of tDNAs which supports the biocompatible property of tDNA. In addition, thermodynamic studies showed that the binding of tDNAs with BLC has a stable non-covalent interaction via hydrogen bond and van der Waals contact, which is indicative of a spontaneous reaction. Furthermore, the catalytic activity of BLC was increased in the presence of tDNAs during 24 h of incubation. These findings indicate that the presence of tDNA nanostructures not only ensures a steady secondary conformation of proteins, but also stabilize the intracellular proteins like BLC. Surprisingly, our investigation discovered that tDNAs have no effect on albumin proteins, either by interfering or by adhering to the extracellular proteins. These findings will aid in the design of future DNA nanostructures for biomedical applications by increasing the knowledge on the biocompatible interaction of tDNAs with biomacromolecules.

Compromised conformation and kinetics of catalase in the presence of propylthiouracil: A biophysical study and alleviation by curcumin

In the present study, the inhibitory effect of propylthiouracil (PTU) on bovine liver catalase (BLC) activity was studied in the presence of curcumin (CUR). The results suggest that the PTU-induced decrease in BLC activity was caused by a change in conformation of BLC with reduced α-helical content and decrease in zeta potential. Nevertheless, temperature-dependent activation of CUR protects the activity of BLC by restoring the secondary conformation and zeta potential of BLC. CUR inhibited the time-induced reduction in BLC activity and the protection was increased with increasing concentrations of CUR and found to be significant even from 1:0.1 molar ratios. The enzyme kinetics confirmed the high catalytic efficiency of BLC in presence of CUR than PTU. The protective role of CUR was due to the formation of a more stabilized complex as demonstrated by molecular docking, and fourier-transform infrared study. Isothermal titration calorimetric study supports for a favourable reaction between BLC and PTU or CUR due to the negative ΔH, and positive TΔS. Although the number of binding sites for PTU and CUR was found to be 10 and 7, respectively, the binding affinity between CUR and BLC is approximately 3.72 fold stronger than BLC-PTU complex. The increased melting temperature of BLC was noticed in presence of CUR suggesting the protective potential of CUR towards biomolecules. Indeed, this is the first biophysical study to describe the molecular mechanism of PTU-induced reduction in BLC activity and alleviation by CUR with detail kinetics. Thus, CUR can be further extended to other antioxidant enzymes or compromised biomolecules for therapeutic interventions.

Hormone-linked redox status and its modulation by antioxidants

Hormones have been considered as key factors involved in the maintenance of the redox status of the body. We are making considerable progress in understanding interactions between the endocrine system, redox status, and oxidative stress with the dynamics of life, which encompasses fertilization, development, growth, aging, and various pathophysiological states. One of the reasons for changes in redox states of vertebrates leading to oxidative stress scenario is the disruption of the endocrine system. Comprehending the dynamics of hormonal status to redox state and oxidative stress in living systems is challenging. It is more difficult to come to a unifying conclusion when some hormones exhibit oxidant properties while others have antioxidant features. There is a very limited approach to correlate alteration in titers of hormones with redox status and oxidative stress with growth, development, aging, and pathophysiological stress. The situation is further complicated when considering various tissues and sexes in vertebrates. This chapter discusses the beneficial impacts of hormones with antioxidative properties, such as melatonin, glucagon, insulin, estrogens, and progesterone, which protect cells from oxidative damage and reduce pathophysiological effects. Additionally, we discuss the protective effects of antioxidants like vitamins A, E, and C, curcumin, tempol, N-acetyl cysteine, α-lipoic acid, date palm pollen extract, resveratrol, and flavonoids on oxidative stress triggered by hormones such as aldosterone, glucocorticoids, thyroid hormones, and catecholamines. Inflammation, pathophysiology, and the aging process can all be controlled by understanding how antioxidants and hormones operate together to maintain cellular redox status. Identifying the hormonal changes and the action of antioxidants may help in developing new therapeutic strategies for hormonal imbalance-related disorders.

Protective effects of butylated hydroxytoluene on the initiation of N-nitrosodiethylamine-induced hepatocellular carcinoma in albino rats

Diethylnitrosamine (DEN), a hepatocarcinogen, is found in a variety of smoked and fried foods and was reported to be hepatotoxic in mice. Butylated hydroxytoluene (BHT) is a potent antioxidant used in cosmetic formulations and as a food additive and preservative. As a result, BHT was studied as a potential inhibitor in the early stages of diethylnitrosamine (DEN)-induced HCC. Male Wistar albino rats (n = 24) were equally subdivided. Group 1 was the negative control; Group 2 and 3 administered BHT and DEN, respectively; Group 4 received BHT followed by DEN. Blood samples and rat livers were taken for biochemical and histological investigation. Hepatotoxicity was assessed by increased liver enzymes and HCC indicators, along with reduced antioxidant and pro-apoptotic factors. AFP, AFPL3, GPC3, GSH, SOD, MDA, CASP3 and BAX expression increased significantly after DEN treatment. DEN also reduced GPx, CAT, and CYP2E1 activity, and BCl-2 expression. Moreover, in the hepatic parenchyma, the DEN caused histological alterations. Pretreatment with BHT enhanced antioxidant status while preventing histopathological and most biochemical alterations. BHT pretreatment suppresses DEN-initiated HCC by decreasing oxidative stress, triggering intrinsic mitotic apoptosis, and preventing histopathological changes in liver tissue.

Management of Feline Hyperthyroidism and the Need to Prevent Oxidative Stress: What Can We Learn from Human Research?

Feline hyperthyroidism is a clinical syndrome related to an excessive production of thyroid hormones, and it is considered as a spontaneous animal model for human thyrotoxicosis. Many shared features between the feline and the human disease have been identified so far, including pathogenesis, clinical signs, and treatment options. Although methimazole is considered the first-choice drug in both species, several side effects have been described. Furthermore, methimazole could interfere with the oxidative status, already perturbated by the disease. It has been reported in humans that dietary management, mainly through antioxidant supplementation, could mitigate this oxidative burden. The purpose of the review is to describe current therapeutic options in the course of feline hyperthyroidism and to summarize the state of the art relationship between dietary antioxidants administration and the reduction of methimazole side-effects in humans to support the use of this approach also in cats.

Perspective on the application of medicinal plants and natural products in wound healing: A mechanistic review

Wound is defined as any injury to the body such as damage to the epidermis of the skin and disturbance to its normal anatomy and function. Since ancient times, the importance of wound healing has been recognized, and many efforts have been made to develop novel wound dressings made of the best material for rapid and effective wound healing. Medicinal plants play a great role in the wound healing process. In recent decades, many studies have focused on the development of novel wound dressings that incorporate medicinal plant extracts or their purified active compounds, which are potential alternatives to conventional wound dressings. Several studies have also investigated the mechanism of action of various herbal medicines in wound healing process. This paper attempts to highlight and review the mechanistic perspective of wound healing mediated by plant-based natural products. The findings showed that herbal medicines act through multiple mechanisms and are involved in various stages of wound healing. Some herbal medicines increase the expression of vascular endothelial growth factor (VEGF) and transforming growth factor-β (TGF-β) which play important role in stimulation of re-epithelialization, angiogenesis, formation of granulation tissue, and collagen fiber deposition. Some other wound dressing containing herbal medicines act as inhibitor of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and inducible nitric oxide synthase (iNOS) protein expression thereby inducing antioxidant and anti-inflammatory properties in various phases of the wound healing process. Besides the growing public interest in traditional and alternative medicine, the use of herbal medicine and natural products for wound healing has many advantages over conventional medicines, including greater effectiveness due to diverse mechanisms of action, antibacterial activity, and safety in long-term wound dressing usage.

Role of Oxidative Stress and the Identification of Biomarkers Associated With Thyroid Dysfunction in Schizophrenics

Background: Schizophrenia is associated with a deficiency of dietary antioxidants like vitamin B6, B9, and B12 resulting in defective methylation leading to hyperhomocysteinemia. Hyperhomocysteinemia causes mitochondrial DNA damage, oxidative stress, vascular damage, and lipid peroxidation. Oxidative stress and increase in reactive oxygen species result in 8-oxodG production which induces apoptosis of both astrocytes and thyrocytes thus predisposing them to thyroid dysfunction and neurodegeneration. Furthermore, the presence of excessive free radicals increases thyroid thermogenesis causing hyperthyroidism or its excess may cause hypothyroidism by inhibiting iodide uptake. In the present study, we evaluated the various biomarkers associated with thyroid dysfunction in schizophrenics. Materials and Methods: 288 patients suffering from schizophrenia and 100 control subjects were screened for liver function tests (LFTs) such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and total bilirubin (TB). Also, the stress markers, namely malondialdehyde (MDA), homocysteine, cysteine, methionine, the thyroid profile including triiodothyronine (T3), thyroxine (T4), thyroid-stimulating hormone (TSH), thyroxine peroxide antibody (TPO-Ab); TSH receptor-Ab (TSHr-Ab), dietary antioxidants, lipids, cytokines, aminoacids and hormones, vitamins and trace elements, and other biochemical parameters. Results: The LFTs showed elevated levels of ALT (45.57 ± 4.87 Vs. 26.41 ± 3.76 U/L), AST (40.55 ± 1.34 Vs. 21.92 ± 3.65 U/L), ALP (121.54 ± 4.87 Vs. 83.76 ± 5.87 U/L), and total bilirubin (2.63 ± 0.987 Vs. 1.10 ± 0.056 mg/dl), in schizophrenics than controls. Increased levels of MDA (3.71 ± 0.967 Vs. 1.68 ± 0.099) and homocysteine (17.56 ± 2.612 Vs. 6.96 ± 1.987 μmol/L were observed in schizophrenics compared to the controls, indicating increased stress. Levels of cysteine and methionine were decreased in schizophrenics than the controls (1.08 ± 0.089 Vs. 4.87 ± .924 μmol/L and 17.87 ± 1.23 Vs. 99.20 ± 5.36 μmol/L). The levels of TPO-Ab (IU/ml), Tg-Ab (pmol/L), and TSHr-Ab (IU/L) were observed to be higher in the patients' group as compared to control subjects (9.84 ± 2.56 Vs. 5.81 ± 1.98, 55.50 ± 2.98 Vs. 32.95 ± 2.87 and 2.95 ± 0.0045 Vs. 1.44 ± 0.0023 respectively). Levels of Vitamin B6, B9, and B12 were also significantly decreased in the patients compared to the healthy controls. Conclusion: The schizophrenics, demonstrated altered liver function, increased stress markers, and decreased dietary antioxidants. Reduced primary and secondary antioxidant levels, may result in hyperhomocysteinemia and cause further DNA and mitochondrial damage. Therefore, homocysteine and/or prolactin levels may serve as candidate prognostic markers for schizophrenia. Also, both neurological symptoms and the susceptibility to thyroid disorders may be prevented in the initial stages of this debilitating disorder by appropriate dietary supplementation of antioxidants which can rectify a reduction in primary and secondary antioxidants, and disturbed prolactin-serotonin-dopamine interactions in schizophrenics.

Biophysical interaction between self-assembled branched DNA nanostructures with bovine serum albumin and bovine liver catalase

Branched DNA (bDNA) nanostructures have emerged as self-assembled biomaterials and are being considered for biomedical applications. Herein, we report the biophysical interaction between self-assembled bDNA nanostructure with circulating protein bovine serum albumin (BSA) and cellular enzyme bovine liver catalase (BLC). The binding between bDNA and BSA or BLC was confirmed through the decrease in fluorescence spectra. The Stern-Volmer data supports for non-covalent bonding with ~1 binding site in case of BSA and BLC thus advocating a static binding. Furthermore, FTIR and ITC study confirmed the binding of bDNAs with proteins through hydrogen bonding and van der Waals interaction. The negative free energy observed in ITC represent spontaneous reaction for BLC-bDNA interaction. The biophysical interaction between bDNA nanostructures and proteins was also supported by DLS and zeta potential measurement. With an increase in bDNA concentrations up to 100 nM, no significant change in absorbance and CD spectra was observed for both BLC and BSA which suggests structural stability and unaffected secondary conformation of proteins in presence of bDNA. Furthermore, the catalytic activity of BLC was unaltered in presence of bDNAscr even with increasing the incubation period from 1 h to 24 h. Interestingly, the time-dependent decrease in activity of BLC was protected by bDNAmix. The thermal melting study suggests a higher Tm value for proteins in presence of bDNAmix which demonstrates that interaction with bDNAmix increases the thermal stability of proteins. Collectively these data suggest that self-assembled DNA nanostructure may bind to BSA for facilitating circulation in plasma or binding to intracellular proteins like BLC for stabilization, however the secondary conformation of protein or catalytic activity of enzyme is unaltered in presence of bDNA nanostructure. Thus, the newly established genomic sequence-driven self-assembled DNA nanostructure can be explored for in vitro or in vivo experimental work in recent future.

Interaction of artemisinin protects the activity of antioxidant enzyme catalase: A biophysical study

The major antioxidant enzyme catalase is downregulated and the enzyme activity is compromised in various disease conditions such as malarial and cancer. Hence, the restoration and protection of catalase is a promising therapeutic strategy in disease management. In the present study, for the first time we have demonstrated the protective role of well-known anti-malarial drug Artemisinin (ART) on the time and temperature-induced degradation of bovine liver catalase (BLC) activity. The findings at different time intervals and at higher temperature showed the protective role of ART on BLC activity. Molecular docking studies suggested specific binding of ART on BLC through heme group interface which was further supported by cyclic voltammetry and dynamic light scattering study. The stabilization of BLC in presence of ART was mediated through forming a BLC-ART complex with reduced and shifted electrochemical peak and increased hydrodynamic diameter. ART substantially prevents the temperature-induced reduction in α-helical content with simultaneous increment in other secondary structures like antiparallel, parallel, β-turn and random coils. Nevertheless, the protective role of ART was accepted from the enhanced thermal stability and increased T_m value of BLC in presence of ART at higher temperatures. Our results uncover the mechanism of interaction between ART with BLC and suggest the protective role of ART towards spatiotemporal alteration of BLC by preventing the structural and molecular change in BLC. Thus, the findings advocate ART as a potential therapeutic drug for diseases associated with reduced catalase activity.

Agnucastoside C, isolated from Moringa oleifera ameliorates thyrotoxicosis and liver abnormalities in female mice

Background

In the present investigation an attempt was made to evaluate the potential of agnucastoside C (ACC), isolated from the leaves of Moringa oleifera in ameliorating thyrotoxicosis, hepatic lipid peroxidation (LPO) and hyperglycemia in female mice.

Methods

L-thyroxine (L-T4) at 0.5 mg/kg/d was administered through intra-peritoneal route for 15 consecutive days to induce thyrotoxicosis and then the effects of three different doses (10, 20 and 30 mg/kg body weight) of the isolated ACC for 21 days were investigated on the changes in serum thyroid hormones, insulin, glucose, different lipids; hepatic lipid peroxidation, enzymatic antioxidants such as superoxide dismutase, catalase and glutathione peroxidase, advanced oxidation protein products, reduced glutathione and in lipid peroxides.

Results

Following the administration of L-T4, serum T3, T4, insulin, glucose levels and the tissue LPO were increased with a decrease in serum thyroid stimulating hormone and antioxidative enzymes. However, administration of the test compound to hyperthyroid animals significantly decreased the levels of thyroid hormones, glucose and lipid peroxidation and normalized the concentration of insulin and tissue antioxidants, suggesting its antithyroid, antihyperglycemic and antiperoxidative potential. The T4-induced adverse effects on liver histology were also abolished. These findings suggest the possible use of the test compound in ameliorating thyrotoxicosis.

Conclusion

ACC exhibited antithyroidic, antihypoglycemic, antioxidative and insulin normalizing activities.

Prospective role of thyroid disorders in monitoring COVID-19 pandemic

COVID-19 pandemic has affected more than 200 countries and 1.3 million individuals have deceased within eleven months. Intense research on COVID-19 occurrence and prevalence enable us to understand that comorbidities play a crucial role in spread and severity of SARS-CoV-2 infection. Chronic kidney disease, diabetes, respiratory diseases and hypertension are among the various morbidities that are prevalent in symptomatic COVID-19 patients. However, the effect of altered thyroid-driven disorders cannot be ignored. Since thyroid hormone critically coordinate and regulate the major metabolism and biochemical pathways, this review is on the potential role of prevailing thyroid disorders in SARS-CoV-2 infection. Direct link of thyroid hormone with several disorders such as diabetes, vitamin D deficiency, obesity, kidney and liver disorders etc. suggests that the prevailing thyroid conditions may affect SARS-CoV-2 infection. Further, we discuss the oxidative stress-induced aging is associated with the degree of SARS-CoV-2 infection. Importantly, ACE2 protein which facilitates the host-cell entry of SARS-CoV-2 using the spike protein, are highly expressed in individuals with abnormal level of thyroid hormone. Altogether, we report that the malfunction of thyroid hormone synthesis may aggravate SARS-CoV-2 infection and thus monitoring the thyroid hormone may help in understanding the pathogenesis of COVID-19.

The benzene metabolite p-benzoquinone inhibits the catalytic activity of bovine liver catalase: A biophysical study

The current communication reports the inhibitory effect of para-benzoquinone (p-BQ) on the structure and function of bovine liver catalase (BLC), a vital antioxidant enzyme. Both BLC and p-BQ were dissolved in respective buffers and the biophysical interaction was studied at physiological concentrations. For the first time our data reveals an enthalpy-driven interaction between BLC and p-BQ which is due to hydrogen bonding and van der Waals interactions. The binding affinity of p-BQ with BLC is nearly 2.5 folds stronger in MOPS buffer than Phosphate buffer. Importantly, the binding affinity between BLC and p-BQ was weak in HEPES buffer as compared to other buffers being the strongest in Tris buffer. Molecular docking studies reveal that binding affinity of p-BQ with BLC differ depending upon the nature of buffers rather than on the participating amino acid residues of BLC. This is further supported by the differential changes in secondary structures of BLC. The p-BQ-induced conformational change in BLC was evident from the reduced BLC activity in presence of different buffers in the following order, Phosphate>MOPS>Tris>HEPES. The absorbance peak of BLC was gradually increased and fluorescence spectra of BLC were drastically decreased when BLC to p-BQ molar ratio was incrementally enhanced from 0 to 10,000 times in presence of all buffers. Nevertheless, the declined activity of BLC was positively correlated with the reduced fluorescence and negatively correlated with the enhanced absorbance. Electrochemical study with cyclic voltammeter also suggests a direct binding of p-BQ with BLC in presence of different buffers. Thus, p-BQ-mediated altered secondary structure in BLC results into compromised activity of BLC.

The Keap1/Nrf2 Signaling Pathway in the Thyroid-2020 Update

The thyroid gland has a special relationship with oxidative stress. On the one hand, like all other tissues, it must defend itself against reactive oxygen species (ROS). On the other hand, unlike most other tissues, it must also produce reactive oxygen species in order to synthesize its hormones that contribute to the homeostasis of other tissues. The thyroid must therefore also rely on antioxidant defense systems to maintain its own homeostasis in the face of continuous self-exposure to ROS. One of the main endogenous antioxidant systems is the pathway centered on the transcription factor Nuclear factor erythroid 2-related factor 2 (Nrf2) and its cytoplasmic inhibitor Kelch-like ECH-associated protein 1 (Keap1). Over the last few years, multiple links have emerged between the Keap1/Nrf2 pathway and thyroid physiology, as well as various thyroid pathologies, including autoimmunity, goiter, hypothyroidism, hyperthyroidism, and cancer. In the present mini-review, we summarize recent studies shedding new light into the roles of Keap1/Nrf2 signaling in the thyroid.

Hypothyroidism-Induced Nonalcoholic Fatty Liver Disease (HIN): Mechanisms and Emerging Therapeutic Options

Nonalcoholic fatty liver disease (NAFLD) is an emerging worldwide problem and its association with other metabolic pathologies has been one of the main research topics in the last decade. The aim of this review article is to provide an up-to-date correlation between hypothyroidism and NAFLD. We followed evidence regarding epidemiological impact, immunopathogenesis, thyroid hormone-liver axis, lipid and cholesterol metabolism, insulin resistance, oxidative stress, and inflammation. After evaluating the influence of thyroid hormone imbalance on liver structure and function, the latest studies have focused on developing new therapeutic strategies. Thyroid hormones (THs) along with their metabolites and thyroid hormone receptor β (THR-β) agonist are the main therapeutic targets. Other liver specific analogs and alternative treatments have been tested in the last few years as potential NAFLD therapy. Finally, we concluded that further research is necessary as well as the need for an extensive evaluation of thyroid function in NAFLD/NASH patients, aiming for better management and outcome.

Evidence-Based Perioperative Nutrition Recommendations: Optimizing Results and Minimizing Risks

Plastic surgery patients span the nutritional spectrum from generally healthy, nutritionally competent patients to inherently catabolic, nutritionally deficient, and chronic wound patients. Therefore, plastic and reconstructive surgery affords the opportunity to investigate the impact of nutrition across a heterogeneous patient population following a wide variety of procedures. Although patients may be nutritionally deficient in certain vitamins warranting perioperative repletion, other supplements have the potential to benefit all patients, regardless of nutritional status. Despite these putative benefits, there is a dearth of information regarding nutritional optimization, with the limited, available literature focusing mostly on herbal supplements and their potential side effects. A significant barrier to supplement use is the lack of education and available supporting information regarding the indications, contraindications, and physiology of these adjuncts. The goal of this article is to provide a comprehensive, evidence-based review of available nutritional supplements that can be considered for the plastic surgery patient in the perioperative period to optimize surgical outcomes while minimizing risk. Prospective, well-designed studies using validated, high-quality supplements will be critical in determining the significance that perioperative supplementation can have for surgical outcomes. Until well-done prospective studies are performed, the supplement, dose, and duration should be determined on an individual, patient-per-patient basis at the discretion of the operating surgeon.

Evaluating Hyperthyroidism-Induced Liver Injury Based on In Situ Fluorescence Imaging of Glutathione and Phosphate via Nano-MOFs Sensor

Hyperthyroidism-induced liver injury is quite common in clinical settings. Therefore, developing rapid and simple methods for the assessment of hyperthyroid liver injury is of great significance. Considering phosphorus metabolism is disordered because of hyperthyroidism, and the hyperthyroid liver injury is closely related to the abnormal level of glutathione (GSH). Thus, development of a new method that can simultaneously detect changes in blood phosphorus and GSH levels of serum, liver, kidney, and other organs to assess the degree of hyperthyroid liver injury is necessary for clinical medical research. Herein, a novel fluorescent metal-organic frameworks (MOFs) nanoprobe using the UiO-66(OH)₂ as core and Cu-MOFs as shell was designed and synthesized. Through the specific action between Zr (IV) and phosphate, and the combine interaction of MOFs active center Cu (II) and GSH, high sensitivity and specific fluorescence detection of phosphate and GSH were achieved, respectively. Finally, the nanosensor was applied for evaluating different degrees of hyperthyroid liver injury in mice models and realized the monitoring of serum, liver, kidney, and other organs' blood phosphorus and GSH levels, and found that the levels of phosphate and GSH in serum were negatively correlated with the degree of hyperthyroid liver injury, while the changes of phosphate and GSH levels in the liver and kidney organs were positively correlated with the degree of hyperthyroid liver injury. In general, the present works provide a new way to effectively evaluate liver injury induced by hyperthyroidism in the early clinical stage.

Differential interaction of cerium chloride with bovine liver catalase: A computational and biophysical study

In this study, Cerium chloride-induced conformational changes of Bovine Liver Catalase (BLC) has been investigated by molecular docking and further supported by various biophysical techniques. The temporal change of catalytic activity of BLC has also been studied in presence of Ce(III) with different buffer solution in vitro at 25 °C. The differential binding of Ce(III) to BLC observed by simulation study was well supported by the differential regulation of BLC activity in different buffers. After 1 h of incubation with CeCl₃, the reduction in activity of BLC was maximum in MOPS, HEPES and Tris buffer, whereas no change in activity was noticed in phosphate buffer. Isothermal Titration Calorimetric (ITC) study also supports the differential binding of Ce(III) to BLC in different buffers. Ce(III)-induced conformational transition in BLC was followed as a function of concentration. Nevertheless, with 24 h incubation of CeCl₃ the activity of BLC was highest with higher molar concentration of CeCl₃ suggesting the conformational stability of BLC in presence of Ce(III). The compromised activity of BLC in response to Ce(III) is due to the induced conformational change and the degree of change in secondary conformation of BLC was maximum in MOPS, HEPES and Tris and least in phosphate buffer. Therefore, the reduced activity of BLC is controlled by the direct interaction of Ce(III) in the active site of BLC in Tris buffer or indirect interaction of Ce(III) in the non-active site of BLC in MOPS and HEPES buffer.

Hormones and oxidative stress: an overview

In aerobes, oxygen is essential for maintenance of life. However, incomplete reduction of oxygen leads to generation of reactive oxygen species. These oxidants oxidise biological macromolecules present in their vicinity and thereby impair cellular functions causing oxidative stress (OS). Aerobes have evolved both enzymatic and nonenzymatic antioxidant defences to protect themselves from OS. Although hormones as means of biological coordination involve in regulation of physiological activities of tissues by regulating metabolism, any change in their normal titre leads to pathophysiological states. While, hormones such as melatonin, insulin, oestrogen, progesterone display antioxidant features, thyroid hormone, corticosteroids and catecholamines elicit free radical generation and OS, and the role of testosterone in inducing OS is debateable. This review is an attempt to understand the impact of free radical generation and cross talk between the hormones modulating antioxidant defence system under various pathophysiological conditions.

Challenges in early identification of causes and treatment of cholestasis in patients with hyperthyroidism: a case report and literature review

Early identification of the causes of cholestasis is important for appropriate management of patients with hyperthyroidism. We report a patient who had hyperthyroidism and severe cholestasis after methimazole (MMI) treatment. The patient was diagnosed as having MMI-induced cholestatic hepatitis. Treatment with MMI was stopped at admission to hospital. However, his serum total bilirubin (TBil) level rose from 410.5 µmol/L to 519.9 µmol/L and prothrombin time activity (PTA) dropped from 81.0% to 52.2% in 10 days. To prevent further deterioration of his liver function, plasma exchange was performed three times, and dexamethasone (10 mg, intravenously) was used each time. His PTA rose to 101% and his TBil continued to increase to 669.8 µmol/L after plasma exchange. He was subsequently diagnosed as having thyrotoxicosis-induced cholestasis and treated with radioactive iodine (380 MBq) 2 weeks after admission. His hyperthyroidism was significantly relieved, but the TBil level further increased to 776.8 µmol/L. Three weeks after admission, oral prednisone (30 mg/day) was used in this patient. Subsequently, his TBil levels gradually decreased and his liver function almost normalized within 3 months. We discuss the literature on cholestasis in the context of hyperthyroidism.

Potential of Curcumin in Skin Disorders

Curcumin is a compound isolated from turmeric, a plant known for its medicinal use. Recently, there is a growing interest in the medical community in identifying novel, low-cost, safe molecules that may be used in the treatment of inflammatory and neoplastic diseases. An increasing amount of evidence suggests that curcumin may represent an effective agent in the treatment of several skin conditions. We examined the most relevant in vitro and in vivo studies published to date regarding the use of curcumin in inflammatory, neoplastic, and infectious skin diseases, providing information on its bioavailability and safety profile. Moreover, we performed a computational analysis about curcumin's interaction towards the major enzymatic targets identified in the literature. Our results suggest that curcumin may represent a low-cost, well-tolerated, effective agent in the treatment of skin diseases. However, bypass of limitations of its in vivo use (low oral bioavailability, metabolism) is essential in order to conduct larger clinical trials that could confirm these observations. The possible use of curcumin in combination with traditional drugs and the formulations of novel delivery systems represent a very promising field for future applicative research.

Oxidative Stress Produced by Hyperthyroidism Status Induces the Antioxidant Enzyme Transcription through the Activation of the Nrf-2 Factor in Lymphoid Tissues of Balb/c Mice

Hyperthyroidism is an endocrine disorder characterized by excessive secretion of thyroid hormones T3 and T4. Thyroid hormones exert pleiotropic actions on numerous tissues and induce an overall increase in metabolism, with an increase in energy demand and oxygen consumption. Therefore, the purpose of this study was to investigate the effects of hyperthyroidism on the production of reactive oxygen species (ROS) in lymph node and spleen cells of euthyroid and hyperthyroid mice, analyzing antioxidant mechanisms involved in the restitution of the cellular redox state. For this, thirty female Balb/c (H-2d) mice were randomly divided into two groups: euthyroid (by treatment with placebo) and hyperthyroid (by treatment with 12 mg/l of T4 in drinking water for 30 days). We found a significant increase in ROS and an increase in the genomic and protein expression of the antioxidant enzymes catalase (CAT) and glutathione peroxidase-1 (GPx-1) in lymph node and spleen cells of hyperthyroid mice. In vitro treatment with H₂O₂ (250 μM) of the lymphoid cells of euthyroid mice increased the expression levels of CAT and GPx-1. The hyperthyroidism increased the phosphorylation levels of Nrf2 (nuclear factor erythroid 2-related factor) and the kinase activity of protein kinase C (PKC) and extracellular signal-regulated kinase (ERK). Additionally, we found an increase in the expression of the classic isoenzymes of PKCα, β and γ. In conclusion, these results indicated that the increase in ROS found in the hyperthyroid state induces the antioxidant enzyme transcription through the activation of the Nrf-2 factor in lymphoid tissues. This shows the influence of hyperthyroidism on the regulation of the cellular antioxidant system.

Possible activation of NRF2 by Vitamin E/Curcumin against altered thyroid hormone induced oxidative stress via NFĸB/AKT/mTOR/KEAP1 signalling in rat heart

Oxidative stress is implicated in both hypo- and hyper-thyroid conditions. In the present study an attempt has been made to elucidate possible interaction between vitamin E or/and curcumin (two established antioxidants) with active portion (redox signaling intervening region) of nuclear factor erythroid 2-related factor 2 (NRF2) as a mechanism to alleviate oxidative stress in rat heart under altered thyroid states. Fifty Wistar strain rats were divided into two clusters (Cluster A: hypothyroidism; Cluster B: hyperthyroidism). The hypo- (0.05% (w/v) propylthiouracil in drinking water) and hyper- (0.0012% (w/v) T4 in drinking water) thyroid rats in both clusters were supplemented orally with antioxidants (vitamin E or/and curcumin) for 30 days. Interactive least count difference and principal component analyses indicated increase in lipid peroxidation, reduced glutathione level, alteration in the activities and protein expression of antioxidant enzymes like superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase under altered thyroid states. However, the expression of stress survival molecules; nuclear factor κB (NFκB) and the serine-threonine kinase B (Akt), in hyper-thyroidism only points towards different mechanisms responsible for either condition. Co-administration of vitamin E and curcumin showed better result in attenuating expression of mammalian target for rapamycin (mTOR), restoration of total protein content and biological activity of Ca²⁺ ATPase in hyperthyroid rats, whereas, their individual treatment showed partial restoration. Since NRF2 is responsible for activation of antioxidant response element and subsequent expression of antioxidant enzymes, possible interactions of both vitamin E or/and curcumin with the antioxidant enzymes, NRF2 and its regulator Kelch ECH associating protein (KEAP1) were studied in silico. For the first time, a modeled active portion of the zipped protein NRF2 indicated its interaction with both vitamin E and curcumin. Further, curcumin and vitamin E complex showed in silico interaction with KEAP1. Reduction of oxidative stress by curcumin and/or vitamin E may be due to modulation of NRF2 and KEAP1 function in rat heart under altered thyroid states.

Nutrition and Wound Healing: An Overview Focusing on the Beneficial Effects of Curcumin

Wound healing implicates several biological and molecular events, such as coagulation, inflammation, migration-proliferation, and remodeling. Here, we provide an overview of the effects of malnutrition and specific nutrients on this process, focusing on the beneficial effects of curcumin. We have summarized that protein loss may negatively affect the whole immune process, while adequate intake of carbohydrates is necessary for fibroblast migration during the proliferative phase. Beyond micronutrients, arginine and glutamine, vitamin A, B, C, and D, zinc, and iron are essential for inflammatory process and synthesis of collagen. Notably, anti-inflammatory and antioxidant properties of curcumin might reduce the expression of tumor necrosis factor alpha (TNF-α) and interleukin-1 (IL-1) and restore the imbalance between reactive oxygen species (ROS) production and antioxidant activity. Since curcumin induces apoptosis of inflammatory cells during the early phase of wound healing, it could also accelerate the healing process by shortening the inflammatory phase. Moreover, curcumin might facilitate collagen synthesis, fibroblasts migration, and differentiation. Although curcumin could be considered as a wound healing agent, especially if topically administered, further research in wound patients is recommended to achieve appropriate nutritional approaches for wound management.

Cellular and molecular mechanisms of curcumin in prevention and treatment of disease

Curcumin is a naturally occurring polyphenolic compound present in rhizome of Curcuma longa belonging to the family zingiberaceae. Growing experimental evidence revealed that curcumin exhibit multitarget biological implications signifying its crucial role in health and disease. The current review highlights the recent progress and mechanisms underlying the wide range of pharmacological effects of curcumin against numerous diseases like neuronal, cardiovascular, metabolic, kidney, endocrine, skin, respiratory, infectious, gastrointestinal diseases and cancer. The ability of curcumin to modulate the functions of multiple signal transductions are linked with attenuation of acute and chronic diseases. Numerous preclinical and clinical studies have revealed that curcumin modulates several molecules in cell signal transduction pathway including PI3K, Akt, mTOR, ERK5, AP-1, TGF-β, Wnt, β-catenin, Shh, PAK1, Rac1, STAT3, PPARγ, EBPα, NLRP3 inflammasome, p38MAPK, Nrf2, Notch-1, AMPK, TLR-4 and MyD-88. Curcumin has a potential to prevent and/or manage various diseases due to its anti-inflammatory, anti-oxidant and anti-apoptotic properties with an excellent safety profile. In contrast, the anti-cancer effects of curcumin are reflected due to induction of growth arrest and apoptosis in various premalignant and malignant cells. This review also carefully emphasized the pharmacokinetics of curcumin and its interaction with other drugs. Clinical studies have shown that curcumin is safe at the doses of 12 g/day but exhibits poor systemic bioavailability. The use of adjuvant like piperine, liposomal curcumin, curcumin nanoparticles and curcumin phospholipid complex has shown enhanced bioavailability and therapeutic potential. Further studies are warranted to prove the potential of curcumin against various ailments.

Aliskiren, Fosinopril, and Their Outcome on Renin-Angiotensin-Aldosterone System (RAAS) in Rats with Thyroid Dysfunction

BACKGROUND AND OBJECTIVES

Thyroid hormones have an important role in the growth and development of various tissues including the kidney, which is the major site of renin release and the consequent angiotensin and aldosterone formation. Therefore any derangement in thyroid function can result in abnormal functioning in the renin-angiotensin-aldosterone system. The current study was undertaken to find the impact of using a direct renin inhibitor (Aliskiren) and an angiotensin-converting enzyme inhibitor (Fosinopril) on the components of the renin-angiotensin-aldosterone system (RAAS) in rats with thyroid dysfunctions.

METHOD

Forty-two male albino rats were divided into three subgroups. First group (6 rats) served as control. Second group (18 rats) served as hyperthyroid group (6 rats positive control, 6 rats given Aliskiren, and 6 rats given Fosinopril). Third group (18 rats) served as hypothyroid group (6 rats positive control, 6 rats given Aliskiren, and 6 rats given Fosinopril). Induction of hyperthyroidism and hypothyroidism was done through daily oral administration of L-Thyroxine and Propylthiouracil, respectively. On day 40 of the study, the rats were sacrificed and blood was collected for estimation of renin, angiotensin I, angiotensin II, aldosterone, TSH, T₃, and T₄. The collected blood samples were also used for estimation of levels blood urea, serum creatinine, liver enzymes, and serum electrolytes. Blood pressure and urine collection were done on days 1 and 40. The collected urine was used for estimation of urine flow, sodium excretion, and potassium excretion rates.

RESULTS

In hypothyroid induced rats, serum renin level dropped as expected, while the use of Aliskiren and Fosinopril on these hypothyroid rats raised renin level due to the feedback mechanism. Both angiotensin I and II were significantly (P <0.05) lower than normal levels in the hypothyroid rats, unlike the level of aldosterone, which was higher than normal level. There was nonsignificant lowering in BP (systolic, diastolic, and mean BP) in the hypothyroid rats. Treatment of these rats with Aliskiren and Fosinopril did not lower the blood pressure more than normal when compared to the hypothyroid group. The hypothyroid rats also showed a decrease in level of serum creatinine. In hyperthyroid rats, there was a rise in levels of serum renin, angiotensin II, and aldosterone; nevertheless, the increase in angiotensin I level was significant. The use of Aliskiren and Fosinopril increased the level of renin nonsignificantly (decreased angiotensin I significantly). Hyperthyroid rats showed a significant increase in systolic, diastolic, and mean blood pressure. Both Aliskiren and Fosinopril increased urine flow, Na⁺ excretion, and K⁺ excretion rates. Aliskiren was better at reducing the high blood pressure.

CONCLUSION

Aliskiren and Fosinopril in hyperthyroid rats decreased serum angiotensin I, angiotensin II, and aldosterone. Blockade of renin and inhibition of angiotensin-converting enzyme both resulted in a rebound increase in level of renin in hypothyroid rats. Aliskiren is better at controlling blood pressure in hyperthyroid rats. Urine flow, sodium excretion, and potassium excretion rates were improved by the use of Aliskiren and Fosinopril in hyperthyroid rats.

Neonatal Exposure to 6-n-Propyl-Thiouracil, an Anti-Thyroid Drug, Alters Expression of Hepatic DNA Methyltransferases, Methyl CpG-Binding Proteins, Gadd45a, p53, and PCNA in Adult Male Rats

BACKGROUND

Neonatal 6-n-propyl-2-thiouracil (PTU) exposure to male rats is reported to impair liver function in adulthood. However, the mechanism by which the drug impairs liver function is not well known.

OBJECTIVES

The objectives of the study were to investigate the effects of neonatal exposure of PTU on the expression of DNA methyltransferases (DNMTs), methyl-DNA binding proteins (MBDs), Gadd45a, p53, and proliferating cell nuclear antigen (PCNA) in adult rat liver.

METHODS

The effects of neonatal transient (from birth to 30 days of age) and persistent (from birth to 90 days of age) treatment of PTU on DNA damage and on the expression of p53, PCNA, DNMTs, and MBDs were investigated at transcriptional and translational levels in male adult liver.

RESULTS

Persistent exposure to PTU from birth caused significant downregulation of expression of DNMT1 and DNMT3a and upregulation of DNMT3b, MBD4, and Gadd45a without any damage to DNA. Although MeCp2 transcripts were significantly low in the liver of adult rats after persistent exposure to PTU compared to controls, its translated products were significantly higher than in controls. The expression of p53 and PCNA in PTU-treated rats was significantly higher and lower, respectively, than that in control rats.

CONCLUSION

The results suggest that neonatal exposure of male rats to PTU resulted in alteration in the expression of proteins that are associated with DNA methylation and genome stabilization in adult rat liver.

Surface-assisted DNA self-assembly: An enzyme-free strategy towards formation of branched DNA lattice

DNA based self-assembled nanostructures and DNA origami has proven useful for organizing nanomaterials with firm precision. However, for advanced applications like nanoelectronics and photonics, large-scale organization of self-assembled branched DNA (bDNA) into periodic lattices is desired. In this communication for the first time we report a facile method of self-assembly of Y-shaped bDNA nanostructures on the cationic surface of Aluminum (Al) foil to prepare periodic two dimensional (2D) bDNA lattice. Particularly those Y-shaped bDNA structures having smaller overhangs and unable to self-assemble in solution, they are easily assembled on the surface of Al foil in the absence of ligase. Field emission scanning electron microscopy (FESEM) analysis shows homogenous distribution of two-dimensional bDNA lattices across the Al foil. When the assembled bDNA structures were recovered from the Al foil and electrophoresed in nPAGE only higher order polymeric bDNA structures were observed without a trace of monomeric structures which confirms the stability and high yield of the bDNA lattices. Therefore, this enzyme-free economic and efficient strategy for developing bDNA lattices can be utilized in assembling various nanomaterials for functional molecular components towards development of DNA based self-assembled nanodevices.

Omega-3 fatty acids decreases oxidative stress, tumor necrosis factor-alpha, and interleukin-1 beta in hyperthyroidism-induced hepatic dysfunction rat model

Hyperthyroidism is associated with abnormalities of the liver. Omega-3 polyunsaturated fatty acids, especially their long-chain forms: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have beneficial health effects. The objectives of the present study were to assess hyperthyroidism-induced hepatic dysfunction in adult male rats and to evaluate the ameliorative effects of omega-3 on hyperthyroidism-induced hepatic dysfunction and the underlying mechanisms. Twenty four adult male rats were randomly divided into three equal groups; control group which received water for 6 weeks, hyperthyroid group which received L-thyroxine orally for 6 weeks and hyperthyroid omega-3 treated group which received L-thyroxine for 2 weeks and then co-treated with L-thyroxine and omega-3 oral compound containing 18% of EPA and 12% of DHA for 4 weeks. Hyperthyroid omega-3 treated group showed significantly increased final body weight and body weight gain, decreased liver weight to body weight ratio, decreased serum triiodo-l-thyronine level, increased serum thyroid stimulating hormone level, decreased serum levels of alanine transaminase, aspartate transaminase and tumor necrosis factor-alpha, increased hepatic levels of total antioxidant capacity and decreased hepatic levels of total peroxide and interleukin-1 beta when compared with the hyperthyroid group. Furthermore, histopathological studies revealed also marked improvement. We concluded that omega-3 had encouraging therapeutic effects against hyperthyroidism-induced hepatic dysfunction attributable to more than one mechanism: antioxidant, anti-inflammatory and anti-fibrotic effects.

Neonatal Persistent Exposure to 6-Propyl-2-thiouracil, a Thyroid-Disrupting Chemical, Differentially Modulates Expression of Hepatic Catalase and C/EBP-β in Adult Rats

Persistent exposure of rats to 6-propyl-2-thiouracil (PTU) from birth resulted in decreases in plasma thyroid hormone (TH) levels and hepatic expression of catalase and CCAAT enhancer binding protein β (C/EBP-β). Catalase promoter region (-185 to +52) that contains binding sites for C/EBP-β showed an augmentation in the methylation level along with a change in methylation pattern of CpG islands in response to PTU treatment. PTU withdrawal on 30 days of birth restored TH levels and C/EBP-β to control rats in adulthood. Although catalase expression was restored to some extent in adult rats in response to PTU withdrawal, a permanent change in its promoter CpG methylation pattern was recorded. The results suggest that downregulation of adult hepatic catalase gene in response to persistent neonatal PTU exposure may not solely be attributed to thyroid-disrupting properties of PTU. It is possible that besides thyroid-disrupting behavior, PTU may impair expression of hepatic catalase by altering methylation pattern of its promoter.

Protective effects of curcumin and vitamin E against chlorpyrifos-induced lung oxidative damage

There are increasing concerns regarding the toxic effects of chlorpyrifos (CPF) on human health. Curcumin (CUR) is a yellow pigment isolated from turmeric ground rhizome of Curcuma longa Linn., which has been identified as an antioxidant agent. This study was designed to examine the protective effect of CUR and vitamin E (Vit E) on CPF-induced lung toxicity. Rats were divided into seven groups: control, CPF (13.5 mg/kg, orally), CPF + CUR (100 and 300 mg/kg, respectively, orally), CPF + α-tocopherol (Vit E, 150 mg/kg, intraperitoneally), CPF and CUR (100 and 300 mg/kg, respectively) in combination with α-tocopherol. The regimens were administered once daily for 28 days. At the end of the treatment period, lungs were collected for evaluation of oxidative factors and histopathological parameters. CUR and Vit E led to a decrease in lipid peroxidation in the lungs of the CPF-injected animals (48% and 51%, respectively). Glutathione peroxidase inhibited by CPF (91.9 nmol/min/mg protein) was induced again by CUR and Vit E (167.1 and 171.8 nmol/min/mg protein). CUR and Vit E caused a significant induction of superoxide dismutase (103.4 U/mg protein). Catalase activity almost returned to normalcy in CPF-intoxicated rats subjected to CUR + Vit E treatment ( p < 0.001). Lung sections from CPF-treated rats displayed histopathological damages, while coadministration of CUR and Vit E resulted in apparently normal morphology with a significant decrease in injuries ( p < 0.05). Our findings revealed that coadministration of Vit E and CUR to CPF-treated animals prevents the oxidative damages in the lung tissues.

Curcumin as a wound healing agent

Turmeric (Curcuma longa) is a popular Indian spice that has been used for centuries in herbal medicines for the treatment of a variety of ailments such as rheumatism, diabetic ulcers, anorexia, cough and sinusitis. Curcumin (diferuloylmethane) is the main curcuminoid present in turmeric and responsible for its yellow color. Curcumin has been shown to possess significant anti-inflammatory, anti-oxidant, anti-carcinogenic, anti-mutagenic, anti-coagulant and anti-infective effects. Curcumin has also been shown to have significant wound healing properties. It acts on various stages of the natural wound healing process to hasten healing. This review summarizes and discusses recently published papers on the effects of curcumin on skin wound healing. The highlighted studies in the review provide evidence of the ability of curcumin to reduce the body's natural response to cutaneous wounds such as inflammation and oxidation. The recent literature on the wound healing properties of curcumin also provides evidence for its ability to enhance granulation tissue formation, collagen deposition, tissue remodeling and wound contraction. It has become evident that optimizing the topical application of curcumin through altering its formulation is essential to ensure the maximum therapeutical effects of curcumin on skin wounds.

Protective effect of curcumin against heavy metals-induced liver damage

Occupational or environmental exposures to heavy metals produce several adverse health effects. The common mechanism determining their toxicity and carcinogenicity is the generation of oxidative stress that leads to hepatic damage. In addition, oxidative stress induced by metal exposure leads to the activation of the nuclear factor (erythroid-derived 2)-like 2/Kelch-like ECH-associated protein 1/antioxidant response elements (Nrf2/Keap1/ARE) pathway. Since antioxidant and chelating agents are generally used for the treatment of heavy metals poisoning, this review is focused on the protective role of curcumin against liver injury induced by heavy metals. Curcumin has shown, in clinical and preclinical studies, numerous biological activities including therapeutic efficacy against various human diseases and anti-hepatotoxic effects against environmental or occupational toxins. Curcumin reduces the hepatotoxicity induced by arsenic, cadmium, chromium, copper, lead and mercury, prevents histological injury, lipid peroxidation and glutathione (GSH) depletion, maintains the liver antioxidant enzyme status and protects against mitochondrial dysfunction. The preventive effect of curcumin on the noxious effects induced by heavy metals has been attributed to its scavenging and chelating properties, and/or to the ability to induce the Nrf2/Keap1/ARE pathway. However, additional research is needed in order to propose curcumin as a potential protective agent against liver damage induced by heavy metals.

Hepatoprotective effect of curcumin and alpha-tocopherol against cisplatin-induced oxidative stress

Background

cis-Diammineplatinum (II) dichloride (cisplatin) is the important anti-cancer agent useful in treatment of various cancers. Unfortunately, it can produce unwanted side effects in various tissues, including the liver. The present study investigated the possible protective role of curcumin and α-tocopherol against oxidative stress-induced hepatotoxicity in rats upon cisplatin treatment.

Methods

Male Wistar rats were divided into five groups (n = 5). Saline and Cis groups, rats were intraperitoneal (i.p.) injected with normal saline and cisplatin [20 mg/kg body weight (b.w.)], respectively. Cis + α-tocopherol group, Cis + Cur group and Cis + α-tocopherol + Cur group, rats were pre-treated with a single dose of α-tocopherol (250 mg/kg b.w.), curcumin (200 mg/kg b.w.) and combined α-tocopherol with curcumin, respectively, for 24 h prior the administration of cisplatin. After 72 h of first injection, specimens were collected. Liver enzyme, lipid peroxidation biomarker, liver histopathology and gene expression of liver nicotinamide adenine dinucleotide phosphate (NADPH) oxidase were investigated.

Results

Cisplatin revealed a significant increase of hepatic malondialdehyde (MDA) levels and a significant reduction of hepatic superoxide dismutase (SOD) and catalase activities compared to the saline group. It elicited a marked increase of the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels and demonstrated the liver pathologies including liver congestion, disorganization of hepatic cords and ground glass appearance of hepatocytes. It also demonstrated a significant increase of NADPH oxidase gene expression compared to saline group. Pre-treatment with combined curcumin and α-tocopherol improved the liver enzymes, lipid peroxidation biomarker, liver histopathology and gene expression of liver NADPH oxidase in cisplatin-treated rats.

Conclusions

The findings indicate that pre-treatment with combined curcumin and α-tocopherol can protect cisplatin-induced hepatotoxicity including the biochemical, histological and molecular aspects. The down-regulations of NADPH oxidase gene expression may be involved in abrogating oxidative stress via reduction of reactive oxygen species (ROS) production.

Diphenyl diselenide modulates gene expression of antioxidant enzymes in the cerebral cortex, hippocampus and striatum of female hypothyroid rats

INTRODUCTION

Cellular antioxidant signaling can be altered either by thyroid disturbances or by selenium status.

AIMS

To investigate whether or not dietary diphenyl diselenide can modify the expression of genes of antioxidant enzymes and endpoint markers of oxidative stress under hypothyroid conditions.

METHODS

Female rats were rendered hypothyroid by continuous exposure to methimazole (MTZ; 20 mg/100 ml in the drinking water) for 3 months. Concomitantly, MTZ-treated rats were either fed or not with a diet containing diphenyl diselenide (5 ppm). mRNA levels of antioxidant enzymes and antioxidant/oxidant status were determined in the cerebral cortex, hippocampus and striatum.

RESULTS

Hypothyroidism caused a marked upregulation in mRNA expression of catalase, superoxide dismutase (SOD-1, SOD-3), glutathione peroxidase (GPx-1, GPx-4) and thioredoxin reductase (TrxR-1) in brain structures. SOD-2 was increased in the cortex and striatum, while TrxR-2 increased in the cerebral cortex. The increase in mRNA expression of antioxidant enzymes was positively correlated with the Nrf-2 transcription in the cortex and hippocampus. Hypothyroidism caused oxidative stress, namely an increase in lipid peroxidation and reactive oxygen species levels in the hippocampus and striatum, and a decrease in nonprotein thiols in the cerebral cortex. Diphenyl diselenide was effective in reducing brain oxidative stress and normalizing most of the changes observed in gene expression of antioxidant enzymes.

CONCLUSION

The present work corroborates and extends that hypothyroidism disrupts antioxidant enzyme gene expression and causes oxidative stress in the brain. Furthermore, diphenyl diselenide may be considered a promising molecule to counteract these effects in a hypothyroidism state.

Vitamin E management of oxidative damage-linked dysfunctions of hyperthyroid tissues

INTRODUCTION

Thyroid hormones affect growth, development, and metabolism of vertebrates, and are considered the major regulators of their homeostasis. On the other hand, elevated circulating levels of thyroid hormones are associated with modifications in the whole organism (weight loss and increased metabolism and temperature) and in several body regions. Indeed, tachycardia, atrial arrhythmias, heart failure, muscle weakness and wasting, bone mass loss, and hepatobiliary complications are commonly found in hyperthyroid animals and humans.

RESULTS

Most thyroid hormone actions result from influences on transcription of T3-responsive genes, which are mediated through nuclear receptors. However, there is significant evidence that tissue oxidative stress underlies some dysfunctions produced by hyperthyroidism.

DISCUSSION

During the last decades, increasing interest has been turned to the use of antioxidants as therapeutic agents in various diseases and pathophysiological disorders believed to be mediated by oxidative stress. In particular, because elevated circulating levels of thyroid hormones are associated with tissue oxidative injury, more attention has been paid to explore the application of antioxidants as therapeutic agents in thyroid related disorders.

CONCLUSIONS

At present, vitamin E is among the most commonly consumed dietary supplements due to the belief that it, as an antioxidant, may attenuate morbidity and mortality. This is due to the results of numerous scientific studies, which demonstrate that vitamin E has a primary function to destroy peroxyl radicals, thus protecting polyunsaturated fatty acids biological membranes from oxidative damage. However, results are also available indicating that protective vitamin E effects against oxidative damage can be obtained even through different mechanisms.

Molecular mechanisms of hypolipidemic effects of curcumin

Recent evidence suggests potential benefits from phytochemicals and micronutrients in reducing the elevated oxidative and lipid-mediated stress associated with inflammation, obesity, and atherosclerosis. These compounds may either directly scavenge reactive oxygen or nitrogen species or they may modulate the activity of signal transduction enzymes leading to changes in the expression of antioxidant genes. Alternatively, they may reduce plasma lipid levels by modulating lipid metabolic genes in tissues and thus reduce indirectly lipid-mediated oxidative and endoplasmic reticulum stress through their hypolipidemic effect. Here we review the proposed molecular mechanisms by which curcumin, a polyphenol present in the rhizomes of turmeric (Curcuma longa) spice, influences oxidative and lipid-mediated stress in the vascular system. At the molecular level, mounting experimental evidence suggests that curcumin may act chemically as scavenger of free radicals and/or influences signal transduction (e.g., Akt, AMPK) and modulates the activity of specific transcription factors (e.g., FOXO1/3a, NRF2, SREBP1/2, CREB, CREBH, PPARγ, and LXRα) that regulate the expression of genes involved in free radicals scavenging (e.g., catalase, MnSOD, and heme oxygenase-1) and lipid homeostasis (e.g., aP2/FABP4, CD36, HMG-CoA reductase, and carnitine palmitoyltransferase-I (CPT-1)). At the cellular level, curcumin may induce a mild oxidative and lipid-metabolic stress leading to an adaptive cellular stress response by hormetic stimulation of these cellular antioxidant defense systems and lipid metabolic enzymes. The resulting lower oxidative and lipid-mediated stress may not only explain the beneficial effects of curcumin on inflammation, cardiovascular, and neurodegenerative disease, but may also contribute to the increase in maximum life-span observed in animal models.

α-Tocopherol prevents lymphoma by improving antioxidant defence system of mice

Increased level of ROS causes oxidative stress and leads to various pathological conditions including cancer. Therefore antioxidants should contribute to cancer prevention by improving antioxidant defense system and thereby protecting the cell from oxidative damage. In the present study we have validated the hypothesis by evaluating the antioxidant action of α-tocopherol. The effect of α-tocopherol is analyzed on oxidative stress as well as its regulation on antioxidant defense system. Oxidative stress is measured in terms of reduced glutathione and protein carbonylation. To evaluate the role of α-tocopherol on antioxidant defense system, the activities and expressions of antioxidant enzymes like glutathione peroxidase, catalase and superoxide dismutase are analyzed by activity gel assay and by RT-PCR respectively. These enzyme activities and/or expressions are found to be improved by α-tocopherol in lymphoma bearing mice which brings down the oxidative stress as reflected by increased level of reduced glutathione as well as decreased protein carbonylation. The effect of α-tocopherol is further analyzed on general characteristics of lymphoma growth like body weight, longevity, accumulation of ascites fluid, angiogenesis in peritoneum, morphology of liver and abundance of lymphocytes. The antioxidant α-tocopherol is found to check lymphoma growth. The results suggest that α-tocopherol contributes to lymphoma prevention by improving antioxidant defence system of mice.

Sustained wound healing activity of curcumin loaded oleic acid based polymeric bandage in a rat model

Wound healing is an intricate multistage process that includes inflammation, cell proliferation, matrix deposition and remodeling phases. It is often associated with oxidative stress and consequent prolonged inflammation, resulting in impaired wound healing. Curcumin has been reported to improve wound healing in different animal models. In order to increase the efficacy of curcumin in the healing arena a curcumin loaded oleic acid based polymeric (COP) bandage was formulated. The in vivo wound healing potency was compared with void bandage and control (cotton gauze treatment) in a rat model. Biochemical parameters and histological analysis revealed increased wound reduction and enhanced cell proliferation in COP bandage treated groups due to its efficient free radical scavenging properties. Comparative acceleration in wound healing was due to early implementation of fibroblasts and its differentiation (increased level of α-smooth muscle actin). Western blotting and semiquantitative PCR analysis clearly indicate that COP bandage can efficiently quench free radicals leading to reduced antioxidative enzyme activity. Further evidence at mRNA and protein level indicates that our system is potent enough to reduce the inflammatory response mediated by the NFκB pathway during wound healing. With this background, we anticipate that such a versatile approach may seed new arena for topical wound healing in the near future.

Curcumin and vitamin E modulate hepatic antioxidant gene expression in PTU-induced hypothyroid rats

In the present study, regulatory role of vitamin E and curcumin on antioxidant gene (AOG) expression in hypothyroid rat liver is reported. Adult male rats were rendered hypothyroid by administration of 0.05 % 6-propyl-thiouracil in their drinking water, while vitamin E (200 mg/kg body weight) and curcumin (30 mg/kg body weight) were supplemented orally for 30 days. Expression of antioxidant genes (Cu/Zn-superoxide dismutase; SOD1, Mn superoxide dismutase; SOD2, catalase; CAT, glutathione peroxidase; GPx1 and glutathione reductase; GR) was evaluated using RT-PCR and Western blot analyses. The activities of antioxidant enzymes were measured in mitochondrial fraction (MF) and post-mitochondrial fraction (PMF) of rat liver. In addition measurement of glutathione redox status was also carried out in both the fractions. The enhanced transcripts of CAT, GPx1 and GR in hypothyroid rat liver were alleviated by administration of vitamin E and curcumin. Elevated levels of translated product of all AOGs in hypothyroid group were remained unchanged after antioxidant administration. However, enhanced SOD1, GPx1 and decreased GR activities in PMF were normalized by vitamin E and curcumin. Similarly the increased SOD2, GPx1 and decreased CAT activities in MF were also normalized by vitamin E and curcumin supplementation. Administration of vitamin E and curcumin enhanced mitochondrial GSH level; whereas the enhanced GSH level in PMF of hypothyroid rats was alleviated by vitamin E. Thus it can be concluded that besides the antioxidant role of vitamin E and curcumin, they also regulate hepatic antioxidant gene expression in hypothyroid rats.