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

Multifaceted physiological and therapeutical impact of curcumin on hormone-related endocrine dysfunctions: A comprehensive review

Over the past five decades, Curcumin (Cur), derived from turmeric (Curcuma longa), has gained considerable attention for its potential therapeutic applications. Synthesizing insights from clinical trials conducted over the last 25 years, this review delves into diseases where Cur has demonstrated promise, offering a nuanced understanding of its pharmacokinetics, safety, and effectiveness. Focusing on specific examples, the impact of Cur on various human diseases is explored. Endocrine glands and associated signaling pathways are highlighted, elucidating how Cur influences cellular signaling. The article underscores molecular mechanisms such as hormone level alteration, receptor interaction, cytokine and adipokine expression inhibition, antioxidant enzyme activity, and modulation of transcription factors. Cur showcases diverse protective mechanisms against inflammation and oxidative damage by suppressing antiapoptotic genes and impeding tumor promotion. This comprehensive overview emphasizes the potential of Cur as a natural agent for countering aging and degenerative diseases, calling for further dedicated research in this realm.

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.

Zeta potential of Z-DNA: A new signature to study B-Z transition in linear and branched DNA

Zeta potential is commonly referred as surface charge density and is a key factor in modulating the structural and functional properties of nucleic acids. Although the negative charge density of B-DNA is well understood, there is no prior description of the zeta potential measurement of Z-DNA. In this study, for the first time we discover the zeta potential difference between B-DNA and lanthanum chloride-induced Z-DNA. A series of linear repeat i.e. (CG)n and (GC)n DNA as well as branched DNA (bDNA) structures was used for the B-to-Z DNA transition. Herein, the positive zeta potential of Z-DNA has been demonstrated as a powerful tool to discriminate between B-form and Z-form of DNA. The generality of the approach has been validated both in linear and bDNA nanostructures. Thus, we suggest zeta potential can be used as an ideal signature for the left-handed Z-DNA.

The effects of pioglitazone and rosiglitazone on liver function in hypothyroid rats

OBJECTIVES

This study aimed to investigate the antioxidant effect of rosiglitazone (ROG) and pioglitazone (POG) on oxidative damage and dysfunction of hepatic tissue in hypothyroid rats.

METHODS

The male rats were classified into six groups: (1) Control; (2) Hypothyroid, (3) Hypothyroid-POG 10, (4) Hypothyroid-POG 20, (5) Hypothyroid-ROG 2, and (6) Hypothyroid-ROG 4. To induction hypothyroidism in rats, propylthiouracil (PTU) (0.05 %w/v) was added to drinking water. In groups 2-6, besides PTU, the rats were also intraperitoneal administrated with 10 or 20 mg/kg POG or 2 or 4 mg/kg ROG for six weeks. Finally, after deep anesthesia, the blood was collected to measure the serum biochemical markers and hepatic tissue was separated for biochemical oxidative stress markers.

RESULTS

Administration of PTU significantly reduced serum thyroxin concentration, total thiol levels, activity of superoxide dismutase (SOD) and catalase (CAT) enzymes, and increased serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (Alk-P) and malondialdehyde (MDA) in the liver. Additionally, our results showed that prescription of POG or ROG for six weeks to hypothyroid rats resulted in an improvement in liver dysfunction (decrease in serum levels of AST, ALT, and ALK-P) through reducing oxidative damage in hepatic tissue (increase in CAT, SOD, or total thiols and decrease in MDA levels).

CONCLUSIONS

The findings of the present study presented that the IP administration of POG and ROG for six weeks improves liver dysfunction induced by hypothyroidism in juvenile rats by reducing oxidative damage.

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.

Nano-selenium relieved hepatic and renal oxidative damage in hypothyroid rats

Hypothyroidism can induce oxidative stress. Nano-selenium (Nano Sel) has antioxidant effects. The current research explored Nano Sel effects on hepatic and renal oxidative damage induced by hypothyroidism in rats. Animals were grouped into (1) Control; (2) Propylthiouracil (PTU) group which received water mixed with 0.05% of PTU; (3) PTU-Nano Sel 50; (4) PTU-Nano Sel 100; and (5) PTU-Nano Sel 150. Besides PTU, the PTU-Nano Sel groups were treated with 50, 100, or 150 μg/kg of Nano Sel intraperitoneally. Treatments were done for 6 weeks. The serum level of T4, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), albumin, total protein, creatinine, and blood urea nitrogen (BUN) was evaluated. Malondialdehyde (MDA) and total thiol concentration and the activity of catalase (CAT) and superoxide dismutase (SOD) in hepatic and renal tissues also were checked. Hypothyroidism induced by PTU significantly increased AST, ALT, ALP, creatinine, BUN, and MDA concentration and noticeably reduced albumin, total protein, total thiol level, and SOD and CAT activity. Administration of Nano Sel ameliorated the adverse effects of hypothyroidism on liver and kidney function. Nano Sel applied protective effects against hepatic and renal damage resulting from hypothyroidism via ameliorating the oxidative stress status. More cellular and molecular experiments need to be done to understand the exact mechanisms.

Phytochemical profiling of polyphenols and thyroid stimulatory activity of Ficus religiosa leaf extract in 6-propyl-thiouracil-induced hypothyroid rats

ETHNOPHARMACOLOGICAL RELEVANCE

The plant, Ficus religiosa (L.) from the family Moraceae, has been extensively used in Ayurveda and Unani. Traditionally this plant is known for the treatment of constipation, liver diseases and neurological disorders that are related to hypothyroidism.

AIM OF THE STUDY

This study was primarily designed to evaluate the effect of Ficus religiosa leaf (FL) extract in ameliorating hypothyroidism in rats and to identify the major bioactive compounds in the test extract that might be responsible for the thyroid-altering activity. In addition, the probable mechanism underlying the thyroid regulation of the main FL constituents were analyzed by molecular docking.

MATERIALS AND METHODS

Adult female Wistar rats were used. LC-ESI-MS/MS was performed to identify the compounds present in the extract. HPLC analysis of FL extract was also performed. A pilot study was made using 3 doses of FL extract. Out of 50, 100, and 200 mg/kg, 100 mg/kg appeared to be the most effective one as it could increase thyroid hormones and decreased TSH levels. In the final experiment, propyl-thiouracil (PTU)-induced hypothyroid rats were orally treated with FL extract (100 mg/kg) or L-thyroxine (100 μg/kg, i.p.) daily for 28 consecutive days. On 29th day, all rats were sacrificed and the serum levels of triiodothyronine (T₃), thyroxine (T₄), thyrotropin (TSH), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and hepatic 5' deiodinase-1(5'D1) were estimated by ELISA. Liver marker enzymes (alanine aminotransferase, ALT and aspartate aminotransferase, AST); total cholesterol (TC) and triglycerides (TG); hepatic lipid peroxidation (LPO) and the activities of antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione (GSH) content were estimated in liver tissues.

RESULTS

LC-MS-MS analyses of the leaf extract identified 11 compounds including the three major compounds, betulinic acid (BA), chlorogenic acid (CGA), and quinic acid (QA). While the PTU treatment decreased the levels of thyroid hormones and 5'D1 activity, it increased the TSH, ALT, AST, TNF-α, IL-6, TC, and TG levels. Furthermore, hepatic LPO significantly increased with a decrease in reduced GSH, SOD, CAT, and GPx. However, FL treatment in PTU-induced animals nearly reversed these adverse effects and improved liver function by decreasing ALT, AST, hepatic LPO and increasing the levels of antioxidants. FL not only improved the liver histology, but also suppressed the inflammatory cytokines, TNF-α and IL-6 in PTU-induced animals. A molecular docking study towards the understanding of the thyroid stimulatory mechanism of action revealed that BA, CGA, and QA might have augmented thyroid hormones by interacting with the thyroid hormone receptor (TRβ1) and TSH receptor (TSHR).

CONCLUSION

For the first time, we report the pro-thyroidal potential of Ficus religiosa leaf extract. We postulate that its main bioactive compounds, BA, CGA, and QA involved in this action may serve as novel thyroid agonists in ameliorating hypothyroidism.

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.

Cellular and molecular mechanisms of curcumin on thyroid gland disorders

There is growing literature on the positive therapeutic potentials of curcumin. Curcumin or diferuloylmethane is a polyphenol obtained from the plant Curcuma longa. Curcumin has been used widely in Ayurvedic and Chinese medicine for various conditions. The role of curcumin on thyroid glands has been shown by its effects on various biological pathways, including anti-inflammatory, antioxidant, anti-proliferative, apoptosis, angiogenesis, cell cycle and metastasis. We reviewed the recent literature on curcumin applications for thyroid dysfunction, including hyperthyroidism and hypothyroidism, and discussed the molecular mechanisms of these effects. This review aims to summarize the wealth of research related to the thyroid gland therapeutic effect of curcumin.

Plant constituents and thyroid: A revision of the main phytochemicals that interfere with thyroid function

In the past few decades, there has been a lot of interest in plant constituents for their antioxidant, anti-inflammatory, anti-microbial and anti-proliferative properties. However, concerns have been raised on their potential toxic effects particularly when consumed at high dose. The anti-thyroid effects of some plant constituents have been known for some time. Indeed, epidemiological observations have shown the causal association between staple food based on brassicaceae or soybeans and the development of goiter and/or hypothyroidism. Herein, we review the main plant constituents that interfere with normal thyroid function such as cyanogenic glucosides, polyphenols, phenolic acids, and alkaloids. In detail, we summarize the in vitro and in vivo studies present in the literature, focusing on the compounds that are more abundant in foods or that are available as dietary supplements. We highlight the mechanism of action of these compounds on thyroid cells by giving a particular emphasis to the experimental studies that can be significant for human health. Furthermore, we reveal that the anti-thyroid effects of these plant constituents are clinically evident only when they are consumed in very large amounts or when their ingestion is associated with other conditions that impair thyroid function.

Experimental and clinical reports on anti-inflammatory, antioxidant, and immunomodulatory effects of Curcuma longa and curcumin, an updated and comprehensive review

Curcuma longa (C. longa) or turmeric is a plant with a long history of use in traditional medicine, especially for treating inflammatory conditions C. longa and its main constituent, curcumin (CUR), showed various pharmacological effects such as antioxidant and anti-microbial properties. The updated knowledge of anti-inflammatory, antioxidant, and immunomodulatory effects of C. longa and CUR is provided in this review article. Pharmacological effects of C. longa, and CUR, including anti-inflammatory, antioxidant, and immunomodulatory properties, were searched using various databases and appropriate keywords until September 2020. Various studies showed anti-inflammatory effects of C. longa and CUR, including decreased white blood cell, neutrophil, and eosinophil numbers, and its protective effects on serum levels of inflammatory mediators such as phospholipase A2 and total protein in different inflammatory disorders. The antioxidant effects of C. longa and CUR were also reported in several studies. The plant extracts and CUR decreased malondialdehyde and nitric oxide levels but increased thiol, superoxide dismutase, and catalase levels in oxidative stress conditions. Treatment with C. longa and CUR also improved immunoglobulin E (Ig)E, pro-inflammatory cytokine interleukin 4 (IL)-4, transforming growth factor-beta, IL-17, interferon-gamma levels, and type 1/type 2 helper cells (Th1)/(Th2) ratio in conditions with disturbance in the immune system. Therefore C. longa and CUR showed anti-inflammatory, antioxidant, and immunomodulatory effects, indicating a potential therapeutic effect of the plant and its constituent, CUR, for treating of inflammatory, oxidative, and immune dysregulation disorders.

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.

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.

Curcumin Mitigates AFB1-Induced Hepatic Toxicity by Triggering Cattle Antioxidant and Anti-inflammatory Pathways: A Whole Transcriptomic In Vitro Study

Aflatoxin B1 (AFB1) toxicity in livestock and human beings is a major economic and health concern. Natural polyphenolic substances with antioxidant properties have proven to be effective in ameliorating AFB1-induced toxicity. Here we assessed the potential anti-AFB1 activity of curcumin (pure curcumin, C, and curcumin from Curcuma longa, CL) in a bovine fetal hepatocyte-derived cell line (BFH12). First, we measured viability of cells exposed to AFB1 in presence or absence of curcumin treatment. Then, we explored all the transcriptional changes occurring in AFB1-exposed cells cotreated with curcumin. Results demonstrated that curcumin is effective in reducing AFB1-induced toxicity, decreasing cells mortality by approximately 30%. C and CL induced similar transcriptional changes in BFH12 exposed to AFB1, yet C treatment resulted in a larger number of significant genes compared to CL. The mitigating effects of curcuminoids towards AFB1 toxicity were mainly related to molecular pathways associated with antioxidant and anti-inflammatory response, cancer, and drug metabolism. Investigating mRNA changes induced by curcumin in cattle BFH12 cells exposed to AFB1 will help us to better characterize possible tools to reduce its consequences in this susceptible and economically important food-producing species.

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.

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.

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.

Vitamin E improved redox homeostasis in heart and aorta of hypothyroid rats

OBJECTIVES

The objective of this study was to evaluate the effect of vitamin E on the oxidative stress parameters and antioxidant defense enzymes in the heart and aorta of 6-n-propylthiouracil (PTU)-induced hypothyroid rats.

METHODS

The animals were divided into 4 experimental groups: Group 1 (Euthyroid) received tap water, Group 2 (Hypothyroid) received 0.05 % of PTU in dissolved in their drinking water, Group 3 (PTU+Vit E) hypothyroid rats treated with vitamin E, and Group 4 (Euthyroid+Vit E). Vitamin E was injected daily (20 mg/kg) to groups 3 and 4 via daily gavage for 6 weeks. Malondialdehyde (MDA) levels, total thiol levels, and the activities of Cu, Zn-superoxide dismutase (SOD) and catalase (CAT) were evaluated in the aortic and cardiac tissues.

RESULTS

A significant decrease of thyroxine (T4) serum levels confirmed hypothyroidism in rats, which received PTU. The MDA level increased and total thiol level decreased in the hypothyroid group compared to control group (p<0.001). Th e activities of SOD and CAT significantly decreased in the hypothyroid rats in comparison to the control. Vitamin E treatment resulted in increased levels of total thiol, SOD, and CAT within aortic and cardiac tissues and decreased levels of MDA in comparison with the hypothyroid group (p<0.01-p<0.001).

CONCLUSIONS

PTU-induced hypothyroidism resulted in oxidative stress. Chronic administration of vitamin E to hypothyroid rats decreased the oxidative stress markers in the aortic and cardiac tissues.

Combination curcumin and vitamin E treatment attenuates diet-induced steatosis in Hfe-/- mice

AIM

To investigate the synergistic hepato-protective properties of curcumin and vitamin E in an Hfe^-/- high calorie diet model of steatohepatitis.

METHODS

Hfe^-/- C57BL/6J mice were fed either a high calorie diet or a high calorie diet with 1 mg/g curcumin; 1.5 mg/g vitamin E; or combination of 1 mg/g curcumin + 1.5 mg/g vitamin E for 20 wk. Serum and liver tissue were collected at the completion of the experiment. Liver histology was graded by a pathologist for steatosis, inflammation and fibrosis. RNA and protein was extracted from liver tissue to examine gene and protein expression associated with fatty acid oxidation, mitochondrial biogenesis and oxidative stress pathways.

RESULTS

Hfe^-/- mice fed the high calorie diet developed steatohepatitis and pericentral fibrosis. Combination treatment with curcumin and vitamin E resulted in a greater reduction of percent steatosis than either vitamin E or curcumin therapy alone. Serum alanine aminotransferase and non-alcoholic fatty liver disease (NAFLD) activity score were decreased following combination therapy with curcumin and vitamin E compared with high calorie diet alone. No changes were observed in inflammatory or fibrosis markers following treatment. Epididymal fat pad weights were significantly reduced following combination therapy, however total body weight and liver weight were unchanged. Combination therapy increased the mRNA expression of AdipoR2, Ppar-α, Cpt1a, Nrf-1 and Tfb2m suggesting enhanced fatty acid oxidation and mitochondrial biogenesis. In addition, combination treatment resulted in increased catalase activity in Hfe^-/- mice.

CONCLUSION

Combination curcumin and vitamin E treatment decreases liver injury in this steatohepatitis model, indicating that combination therapy may be of value in NAFLD.

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.

Histidine Prevents Cu-Induced Oxidative Stress and the Associated Decreases in mRNA from Encoding Tight Junction Proteins in the Intestine of Grass Carp (Ctenopharyngodon idella)

Copper (Cu) is a common heavy metal pollutant in aquatic environments that originates from natural as well as anthropogenic sources. The present study investigated whether Cu causes oxidative damage and induces changes in the expression of genes that encode tight junction (TJ) proteins, cytokines and antioxidant-related genes in the intestine of the grass carp (Ctenopharyngodon idella). We demonstrated that Cu decreases the survival rate of fish and increases oxidative damage as measured by increases in malondialdehyde and protein carbonyl contents. Cu exposure significantly decreased the expression of genes that encode the tight junction proteins, namely, claudin (CLDN)-c, -3 and -15 as well as occludin and zonula occludens-1, in the intestine of fish. In addition, Cu exposure increases the mRNA levels of the pro-inflammatory cytokines, specifically, IL-8, TNF-α and its related signalling factor (nuclear factor kappa B, NF-κB), which was partly correlated to the decreased mRNA levels of NF-κB inhibitor protein (IκB). These changes were associated with Cu-induced oxidative stress detected by corresponding decreases in glutathione (GSH) content, as well as decreases in the copper, zinc-superoxide dismutase (SOD1) and glutathione peroxidase (GPx) activities and mRNA levels, which were associated with the down-regulated antioxidant signalling factor NF-E2-related factor-2 (Nrf2) mRNA levels, and the Kelch-like-ECH-associated protein1 (Keap1) mRNA levels in the intestine of fish. Histidine supplementation in diets (3.7 up to 12.2 g/kg) blocked Cu-induced changes. These results indicated that Cu-induced decreases in intestinal TJ proteins and cytokine mRNA levels might be partially mediated by oxidative stress and are prevented by histidine supplementation in fish diet.

Lanthanum induced B-to-Z transition in self-assembled Y-shaped branched DNA structure

Controlled conversion of right-handed B-DNA to left-handed Z-DNA is one of the greatest conformational transitions in biology. Recently, the B-Z transition has been explored from nanotechnological points of view and used as the driving machinery of many nanomechanical devices. Using a combination of CD spectroscopy, fluorescence spectroscopy, and PAGE, we demonstrate that low concentration of lanthanum chloride can mediate B-to-Z transition in self-assembled Y-shaped branched DNA (bDNA) structure. The transition is sensitive to the sequence and structure of the bDNA. Thermal melting and competitive dye binding experiments suggest that La³⁺ ions are loaded to the major and minor grooves of DNA and stabilize the Z-conformation. Our studies also show that EDTA and EtBr play an active role in reversing the transition from Z-to-B DNA.

Mitochondria: a new therapeutic target in chronic kidney disease

Cellular metabolic changes during chronic kidney disease (CKD) may induce higher production of oxygen radicals that play a significant role in the progression of renal damage and in the onset of important comorbidities. This condition seems to be in part related to dysfunctional mitochondria that cause an increased electron "leakage" from the respiratory chain during oxidative phosphorylation with a consequent generation of reactive oxygen species (ROS). ROS are highly active molecules that may oxidize proteins, lipids and nucleic acids with a consequent damage of cells and tissues. To mitigate this mitochondria-related functional impairment, a variety of agents (including endogenous and food derived antioxidants, natural plants extracts, mitochondria-targeted molecules) combined with conventional therapies could be employed. However, although the anti-oxidant properties of these substances are well known, their use in clinical practice has been only partially investigated. Additionally, for their correct utilization is extremely important to understand their effects, to identify the correct target of intervention and to minimize adverse effects. Therefore, in this manuscript, we reviewed the characteristics of the available mitochondria-targeted anti-oxidant compounds that could be employed routinely in our nephrology, internal medicine and renal transplant centers. Nevertheless, large clinical trials are needed to provide more definitive information about their use and to assess their overall efficacy or toxicity.

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.

The ameliorating effects of vitamin E on hepatic antioxidant system and xenobiotic-metabolizing enzymes in fenvalerate-exposed iodine-deficient rats

This study investigated the effects of vitamin E (VE) on hepatic antioxidant system and drug-metabolizing enzymes in fenvalerate (FEN)-exposed iodine-deficient (ID) Wistar rats. ID was produced by perchlorate containing drinking water. VE was introduced by a loading dose of 100 mg/kg/d, i.g. for the first three days in the last week of feeding period; then with a single maintenance dose of 40 mg/kg on the 4th day. During last week, FEN groups (F) received 100 mg/kg/d, i.p. FEN. VE alone did not significantly affect thyroid hormones and antioxidant parameters; however, significantly increased total cytochrome P450 (38%) and cytochrome b5 levels (36%). In all ID groups, plasma thyroid-stimulating hormone (TSH) levels increased markedly, but remained at control level in vitamin E plus FEN receiving iodine-deficient group (IDVF) group. Glutathione peroxidase activity showed marked increases in F (19%) and FEN-exposed iodine-deficient group (IDF, 48%) groups. FEN treatment significantly increased total cytochrome P450 (28%) and thiobarbituric acid reactive substance levels (36%), as well as 7-ethoxyresorufin O-deethylase (120%), 7-penthoxyresorufin O-deethylase (139%) and glutathione S-transferase (15%) activities and decreased total glutathione concentrations (28%) versus control. Overall results suggest that vitamin E has ameliorating effects on the measured parameters in ID and/or FEN exposure.

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.

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.