Alleviation of enhanced oxidative stress and oxygen consumption of L-thyroxine induced hyperthyroid rat liver mitochondria by vitamin E and curcumin

Association between oxidative balance score and thyroid function and all-cause mortality in euthyroid adults

Abnormal fluctuations in thyroid function within the reference range were strongly associated with increased all-cause mortality. This study aimed to analyze the association between oxidative balance score (OBS) and free thyroxine (FT4) and thyrotropin (TSH) in euthyroid adults, as well as their interrelationships with mortality. 5727 euthyroid adults were selected from the National Health and Nutrition Examination Survey (NHANES). Weighted linear regression investigated the potential association of OBS with FT4 and TSH. In addition, COX proportional hazard models and restricted cubic spline (RCS) were used to investigate the association between OBS, FT4, TSH, and all-cause mortality. The results showed that OBS was negatively associated with serum FT4 concentrations in euthyroid adults (- 2.95%, 95% CI - 5.16%, - 0.92%). Additionally, the all-cause mortality rate was significantly higher in the fourth quartile (Q4) of FT4 compared to the first quartile (Q1) (HR 1.40, 95% CI 1.07-1.85). In the fourth quartile of OBS, the all-cause mortality rate was 31% lower than in Q1 (HR 0.69, 95% CI 0.52-0.92). Mediation analyses indicated that FT4 partially mediated the relationship between OBS and all-cause mortality. These results suggest a significant negative association between OBS and serum FT4, while both OBS and FT4 are strongly associated with mortality. However, the effect of OBS on serum FT4 is relatively limited, and therefore its clinical significance needs to be interpreted objectively.

Protective Effects of Atractylodis Rhizoma Extracts on Lung Injury Induced by Particulate Matter 2.5 in Mice

This study investigated the lung-protective effects of Atractylodis Rhizoma extracts (the root of Atractylodes japonica Koidz. ex Kitam), known as AJ extracts, in mitigating subacute pulmonary injuries caused by particulate matter 2.5 (PM2.5) exposure in Balb/c mice. AJ was given orally at concentrations of 400, 200, and 100 mg/kg, demonstrating a promising impact by mitigating oxidative stress and inflammation associated with phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) and p38 mitogen-activated protein kinase α (p38 MAPKα) pathways and reducing mucus overproduction. These protective effects were achieved through the downregulation of p38 MAPKα and PI3K/Akt mRNA expressions, enhanced anti-inflammatory and antioxidant activities, and increased mucolytic expectorant effects arbitrated by elevated lung acetylcholine (ACh) and substance P levels, along with decreased mRNA expressions of MUC5AC and MUC5B. Importantly, these outcomes occurred without significant hepatotoxicity. While all AJ dosages provided dose-dependent pulmonary protection, their effects were less pronounced than those of dexamethasone (DEXA) at 0.75 mg/kg. However, AJ uniquely exhibited mucolytic expectorant activities absent in DEXA-treated mice. The results indicate that A. japonica may serve as a potential candidate for creating alternative treatments for respiratory conditions or as an ingredient in functional foods.

Catalase-associated immune responses in plant-microbe interactions: A review

Catalase, an enzyme central to maintaining redox balance and combating oxidative stress in plants, has emerged as a key player in plant defense mechanisms and interactions with microbes. This review article provides a comprehensive analysis of catalase-associated immune responses in plant-microbe interactions. It underscores the importance of catalase in plant defense mechanisms, highlights its influence on plant susceptibility to pathogens, and discusses its implications for understanding plant immunity and host-microbe dynamics. This review contributes to the growing body of knowledge on catalase-mediated immune responses and offers insights that can aid in the development of strategies for improved plant health and disease resistance.

Medium-Chain Chlorinated Paraffins Trigger Thyroid Hormone Synthesis and Interfere with Mitochondrial Function in the Thyroid Gland

Medium-chain chlorinated paraffins (MCCPs, C14-C17) are frequently detected in diverse environmental media. It has been proposed to be listed in Annex A of the Convention on Persistent Organic Pollutants in 2023. Although MCCPs are a crucial health concern, their toxicity remains unclear. This study investigated the toxic effects of MCCPs (0.1-50 mg/kg body weight/day) on the thyroid gland of female Sprague-Dawley rats and characterized the potential toxic pathways via transcriptomics and metabolomics approaches. MCCPs exposure caused histopathological changes to the endoplasmic reticula and mitochondria in thyroid follicular cells at a dose of 50 mg/kg bw/d and increased serum thyrotropin-releasing hormone, thyroid-stimulating hormones, and thyroxine when exposed to a higher dose of MCCPs. Transcriptomic analysis indicated the excessive expression of key genes related to thyroid hormone synthesis induced by MCCPs. Integrating the dual-omics analysis revealed mitochondrial dysfunction of the thyroid by mediating fatty acid oxidation, Kreb's cycle, and oxidative phosphorylation. Significant metabolic toxicity on the thyroid might be linked to the characteristics of the chlorine content of MCCPs. This study revealed the toxicity of MCCPs to the thyroid gland via triggering thyroid hormone synthesis and interfering with mitochondrial function, which can provide new insights into the modes of action and mechanism-based risk assessment of MCCPs.

Protective effect of Korean red ginseng water extract on levothyroxine-induced hyperthyroidism and propylthiouracil-induced hypothyroidism in rats

Background

Korean red ginseng extract (KRGE) (Family: Araliaceae) is one of the most widely used traditional herbs in Asia. Multiple studies have shown that KRGE has anti-inflammation, anti-fatigue, anti-obesity, anti-oxidant, and anti-cancer effects.

Methods

Sprague-Dawley rats were divided into five groups for PTU-induced hypothyroidism and six groups for LT4-induced hyperthyroidism. At the experiment's conclusion, rats were sacrificed, and blood, thyroid gland, and liver samples were collected. Body weight was recorded weekly, and serum hormone levels were assessed using enzyme-linked immunoassay. Thyroid gland and liver tissues were stained with hematoxylin and eosin. KRGE was prepared in 0.5% CMC and stored at 4 °C before administration.

Results

In the LT4-induced hyperthyroidism model, KRGE prevented decreases in body weight, thyroid gland weight, liver weight, serum glucose, and thyroid hormone levels compared to the PTU group. It also reduced increases in T3, T4, and serum aspartate aminotransferase levels after LT4 treatment. Additionally, KRGE improved thyroid gland and liver histopathology, effects not observed in the PTU-induced hypothyroidism model.

Conclusion

All things considered, our research points to KRGE's potential protective role in rat hyperthyroidism caused by LT4 by lowering thyroid hormone production.

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.

Nrf2-Mediated Antioxidant Defense and Thyroid Hormone Signaling: A Focus on Cardioprotective Effects

Thyroid hormones (TH) perform a plethora of actions in numerous tissues and induce an overall increase in metabolism, with an augmentation in energy demand and oxygen expenditure. Oxidants are required for normal thyroid-cell proliferation, as well as for the synthesis of the main hormones secreted by the thyroid gland, triiodothyronine (T3) and thyroxine (T4). However, an uncontrolled excess of oxidants can cause oxidative stress, a major trigger in the pathogenesis of a broad spectrum of diseases, including inflammation and cancer. In particular, oxidative stress is implicated in both hypo- and hyper-thyroid diseases. Furthermore, it is important for the TH system to rely on efficient antioxidant defense, to maintain balance, despite sustained tissue exposure to oxidants. One of the main endogenous antioxidant responses is the pathway centered on the nuclear factor erythroid 2-related factor (Nrf2). The aim of the present review is to explore the multiple links between Nrf2-related pathways and various TH-associated conditions. The main aspect of TH signaling is described and the role of Nrf2 in oxidant-antioxidant homeostasis in the TH system is evaluated. Next, the antioxidant function of Nrf2 associated with oxidative stress induced by TH pathological excess is discussed and, subsequently, particular attention is given to the cardioprotective role of TH, which also acts through the mediation of Nrf2. In conclusion, the interaction between Nrf2 and most common natural antioxidant agents in altered states of TH is briefly evaluated.

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.

Promoter sequence interaction and structure based multi-targeted (redox regulatory genes) molecular docking analysis of vitamin E and curcumin in T4 induced oxidative stress model using H9C2 cardiac cell line

A positive association between oxidative stress and hyper-thyroid conditions is well established. Vitamin E (VIT-E) and curcumin (CRM) are considered as potent antioxidant small molecules. Nuclear factor erythroid 2-related factor 2(NRF-2) is known to bind with antioxidant response element and subsequently activate expression of antioxidant enzymes. However, the activation of NRF-2 depends on removal of its regulator Kelch-like ECH-associated protein 1(NRF-2). In the current study, an attempt is made to demonstrate whether effects of VIT-E and CRM are due to direct interaction with the target proteins (i.e. NRF-2, NRF-2, SOD, catalase and LDH) or by possible interaction with the flanking region of their promoters by in silico analysis. Further, these results were corroborated by pretreatment of H9C2 cells (1 x 10⁶ cells per mL of media) with VIT-E (50 μM) and/or CRM (20 μM) for 24 h followed by induction of oxidative stress via T4 (100 nm) administration and assaying the active oxygen metabolism. Discriminant function analyses (DFA) indicated that T4 has a definite role in increasing oxidative stress as evidenced by induction of ROS generation, increase in mitochondrial membrane potential and elevated lipid peroxidation (LPx). Pretreatment with the two antioxidants have ameliorative effects more so when given in combination. The decline in biological activities of the principal antioxidant enzymes SOD and CAT with respect to T4 treatment and its restoration in antioxidant pretreated group further validated our in silico data. Communicated by Ramaswamy H. Sarma.

Deneysel hipertiroidide fiziksel ve vital bulguların ve karnozinin etkisinin değerlendirilmesi

Purpose: This study aims to investigate the effects of experimental hyperthyroidism and carnosine which is known to have antioxidant properties on physical and vital findings in rats, and to determine the relationship between these parameters and free T3 (FT3) levels. Materials and Methods: Rats were analyzed in 7 groups (each containing 12 animals); control (CONT), hyperthyroidism-1 (T:10-day L-thyroxine (L-T4) administration), hyperthyroidism-2 (T-T: 20-day L-T4 administration), Carnosine (10 day carnosine administration), Hyperthyroidism-1 + Carnosine (T-C), Hyperthyroidism-2 + Carnosine (T-TC), and Carnosine + Hyperthyroidism-1 (C-T). In order to create a hyperthyroidism model, L-thyroxine (L-T4) doses of 300 µg/kg rat weight/day and carnosine doses of 300 µg/kg rat weight/ day were intraperitoneally (ip) administered to the rats. Results: After 10 and 20 days of thyroxine administration, FT3 levels (T:3.640.51pg/mL, T-T: 4.060.91pg/mL) and body temperature (T:37.10.3oC, T-T: 37.60.3oC), significantly increased while body weight decreased (T:240.722.0g, T-T:263.028.7g). Carnosine administration only prevented the increase of FT3 levels, but had no effect on other parameters. Conclusion: The increased FT3 levels observed with L-T4 administration were consistent with the physical and vital findings, but carnosine administration did not reflect the expected effects on the physical findings observed in the hyperthyroid condition.

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.

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.

Chronic chlorpyrifos exposure induces oxidative stress, apoptosis and immune dysfunction in largemouth bass (Micropterus salmoides)

This study was undertaken to (a) evaluate the destructive effects of chronic exposure to low-dose of chlorpyrifos (CPF) on antioxidant system and immune function in largemouth bass (Micropterus salmoides), and (b) to examine whether dietary supplementation of curcumin can mitigate the adverse effects induced by CPF contamination. The experiment consisted of three groups (with three replicates, 30 fish per replicate) which lasted for 60 days: A control group (without CPF exposure or CU application), CP group (exposed to 0.004 mg/L of CPF), and CU group (exposed to 0.004 mg/L of CPF and fed a diet containing 100 mg curcumin per kg feed). The results showed that CPF contamination leads to reduced weight gain, severe histopathological lesions, decreased activity of antioxidant enzymes and down-regulated expression of antioxidant-related genes. Moreover, CPF upregulated the expression of pro-inflammatory genes such as TNF-α, IL-8, IL-15, downregulated anti-inflammatory genes TGF-β1, IL-10, and promoted apoptosis through overexpression of Caspase-3, Caspase-8, caspase-9 and Bax. In addition, curcumin supplementation showed significant improvement in oxidative stress, apoptosis and immune dysfunction, but the improved effect gradually weakened during the exposure last. Gas chromatography-mass spectrometry (GC-MS) analysis for accumulation of CPF in muscle supported the changes of general physiological structure, excessive apoptotic responses, abnormal antioxidant and immune system functions and posed potential human health risks to children based on target hazard quotient. These results suggested that chronic exposure to CPF can cause oxidative stress, apoptosis and immune dysfunction, and that curcumin have the potential to reduce pesticides residues in fish. This also highlights the importance of monitoring pesticides residues in aquatic products and aquaculture aquatic environments.

The positive effect of black seed (Nigella sativa L.) essential oil on thyroid hormones in rats with hypothyroidism and hyperthyroidism

In our study, the effect of essential oil obtained from Nigella sativa L. (NSE) on thyroid hormones and antioxidant balance in hypothyroidism (HT) and hyperthyroidism (HP) models induced by propylthiouracil(PTU) and L-thyroxine(LT₄ ), respectively, in rats were investigated for 4 weeks. NSE was administered by gastric gavage at a dose of 200 mg/kg body weight. In this study, 48 male Wistar albino rats with an average weight of 180-290 g and age 5-6 months were divided into eight groups, as follows: groups with HT, (1) control, (2) HT, (3) NSE, and (4) HT + NSE; groups with HP, (1) control, (2) HP, (3), and NSE (4) HP + NSE. As a result, we found that NSE administration increased total triiodothyronine (TT₃ ) and decreased nitric oxide in HT + NSE. Besides, it decreased TT₃ in HP + NSE and increased total antioxidant capacity. Our findings suggest that NSE may have beneficial effects on thyroid gland abnormalities owing to its antioxidant properties. PRACTICAL APPLICATIONS: Essential oils derived from Nigella sativa L. seed contain many bioactive substances such as thymoquinone and cymene. This paper emphasizes the effect of NSE on thyroid hormone abnormalities and negative oxidative state that occurs in HT and HP models. The present study provides evidence of a positive effect of NSE particularly on TT₃ levels in the HT and HP models. It can therefore be assumed that NSE could be used as a supportive natural alternative source to improve thyroid hormone levels and relieve increased oxidative stress.

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.

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 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.

Nutraceuticals in Thyroidology: A Review of in Vitro, and in Vivo Animal Studies

Nutraceuticals are defined as a food, or parts of a food, that provide medical or health benefits, including the prevention of different pathological conditions, and thyroid diseases, or the treatment of them. Nutraceuticals have a place in complementary medicines, being positioned in an area among food, food supplements, and pharmaceuticals. The market of certain nutraceuticals such as thyroid supplements has been growing in the last years. In addition, iodine is a fundamental micronutrient for thyroid function, but also other dietary components can have a key role in clinical thyroidology. Here, we have summarized the in vitro, and in vivo animal studies present in literature, focusing on the commonest nutraceuticals generally encountered in the clinical practice (such as carnitine, flavonoids, melatonin, omega-3, resveratrol, selenium, vitamins, zinc, and inositol), highlighting conflicting results. These experimental studies are expected to improve clinicians’ knowledge about the main supplements being used, in order to clarify the potential risks or side effects and support patients in their use.

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.

The effect of eplerenone on the renin-angiotensin-aldosterone system of rats with thyroid dysfunction

OBJECTIVES

This study was conducted to evaluate the effect of eplerenone on the RAAS and kidney function in rats with thyroid hormone disorders.

METHODS

This study involved 30 male Wistar albino rats, divided into three groups. The first group (N = 6) served as a control. The second group involved 12 rats with experimentally induced hypothyroidism through receiving propylthiouracil (0.05% w/v) in drinking water for one month, which was divided into two subgroups of six rats each. The first subgroup served as a positive hypothyroid control, and the second subgroup received oral daily dose of eplerenone (100 mg/kg) for 14 days. The third group included 12 rats with induced hyperthyroidism with L-thyroxin (0.0012% w/v) in drinking water, and rats in this group were also divided into two subgroups. The first subgroup served as a positive hyperthyroid control, and the second subgroup received oral eplerenone 100 mg/kg.

RESULTS

Eplerenone indicated a significant increase in renin and angiotensin I from 184.09 pg/ml and 178.66 pg/ml to 603.31 pg/ml and 250.88 pg/ml, respectively, meanwhile, aldosterone indicated no significant changes after inducing hypothyroidism and eplerenone administration. The induction of hyperthyroidism led to a significant increase in angiotensin I from 248.84 pg/ml to 292.22 pg/ml. Oral administration of eplerenone for 14 days caused a significant increase aldosterone from 364.23 pg/ml to 497.02 pg/ml.

CONCLUSION

Eplerenone significantly increased the serum renin and angiotensin I in hypothyroid and aldosterone and angiotensin I in hyperthyroid rats. Aldosterone in hypothyroid rats was not changed by eplerenone.

Allylpyrocatechol, isolated from betel leaf ameliorates thyrotoxicosis in rats by altering thyroid peroxidase and thyrotropin receptors

Allylpyrocatechol (APC) was isolated from betel leaf and its possible role in L-thyroxin (L-T4)-induced thyrotoxic rats was evaluated. The disease condition, thyrotoxicosis was confirmed by higher levels of thyroid hormones and low thyrotropin (TSH) in serum. Increased hepatic activities of 5'-mono-deiodinase(5'D1), glucose-6-phospatase (G-6-Pase); serum concentrations of alanine transaminase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase(LDH) and tumour necrosis factor-alpha(TNF-α) were observed in thyrotoxic rats. Hepatic lipid peroxidation(LPO) was also increased and the endogenous antioxidants were depleted in these rats. In western blot analysis thyroid peroxidase expression was found to be reduced, whereas thyrotropin receptor(TSHR) expression was enhanced in thyroid gland of these animals. On the other hand, APC treatment in thyrotoxic rats decreased the levels of serum thyroid hormones, ALT, AST, TNF-α and LDH, as well as hepatic 5' D1 and G-6-Pase activities. However, it increased the serum TSH levels. APC also reduced the hepatic LPO and increased the cellular antioxidants in thyrotoxic rats. However, expression of TSHR was inhibited and TPO was increased by APC. The test compound also improved histological features in both liver and thyroid. Present report appears to be the first one that indicates the positive role of APC in ameliorating T4-induced thyrotoxicosis.

Protective effects of a mixed plant extracts derived from Astragalus membranaceus and Laminaria japonica on PTU-induced hypothyroidism and liver damages

Protective effects of a mixed hot water extracts of Astragalus membranaceus (AWE) and Laminaria japonica (LWE), AWE: LWE 85:15 (g/g; AL mix), were investigated against propylthiouracil (PTU)-induced hypothyroidism in rats. Rats were challenged with PTU, resulting in, increased thyroid gland weight, decreased liver weight and antioxidant activities, reduced serum tri-iodothyronine and thyroxine levels with increased thyroid stimulating hormone levels, and elevated serum aspartate aminotransferase level. However, orally administered AL mix with 100, 200, and 400 mg kg-1  day-1 , significantly inhibited such abnormalities, dose-dependently. Moreover, PTU-induced abnormal histological architecture of the rat thyroid gland and liver were also significantly ameliorated by an AL mix. The results suggested that, therapeutic use of AL mix for treating hypothyroidism can be characterized by its diversified active ingredients particularly iodine and ferulic acid as confirmed by phytochemical analyses. PRACTICAL APPLICATIONS: The AL mix has synergistic effects in modulating thyroid hormone synthesis and preventing liver damages in PTU-induced hypothyroid rats. These effects of AL mix are mainly related to its richness specifically in iodine and ferulic acid. The growing interests of iodine and ferulic acid in AL mix are principally due to their beneficial effects in releasing sufficient thyroid hormones in hypothyroid conditions and promoting liver-protective functions through its antioxidant and anti-inflammatory potentials, respectively. Moreover, the results of AL mix are well-matched with the effects of standard drug levothyroxine in the present study. Therefore, appropriate dosage of AL mix will be promising as new medicinal food for preventing thyroid dysfunctions and its related liver damages.

Curcumin-loaded PLA-PEG copolymer nanoparticles for treatment of liver inflammation in streptozotocin-induced diabetic rats

This report focused on loading curcumin (CUR) drug into biodegradable Polylactide-poly(ethylene glycol) (PLA-PEG) copolymer nanoparticles as an effective anti-inflammatory agent in vivo to overcome the limitations resulted from the free CUR. By a simple nano-emulsification technique, hydrophobic CUR was loaded into hydrophobic polymer's segments and stabilized by cationic surfactant. They were then characterized by DLS, TEM, and SEM techniques providing monodispersed and spherical nanoparticles with an average diameter of 117 nm and high surface charge of +35 mV. Thereafter, they were orally administrated into five groups of rats, typically, control (healthy rats), streptozotocin (STZ)-induced diabetic rats, diabetics treated with free CUR, diabetics treated with PLA-PEG NPs, and diabetics treated with CUR-encapsulated PLA-PEG NPs. Next, complete blood analyses were assessed including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and nuclear factor kappa B (NF-ҡB), reduced glutathione (GSH), malondialdehyde (MDA), nitric oxide (NO), cyclooxygenase (COX-2), Peroxisome proliferator-activated receptors (PPAR-γ) and transforming growth factor-β1 (TGF-β1). The obtained results demonstrated that diabetes initially produced liver inflammation in rats manifested by leveraging the mean levels of serum AST, ALT inducing oxidative stress resulting in a clear increase in the levels of hepatic MDA and NO concomitant with a remarkable decrease in GSH. Moreover, diabetes significantly increased serum NF-ҡB, hepatic COX-2 and TGF-β1, while highly reduced hepatic PPAR-γ. In contrast, both CUR free and CUR-encapsulated NPs ameliorated the negative changes in diabetes but CUR-encapsulated NPs showed more pronounced treated effect than free CUR. In addition, histopathological investigations were performed on the liver tissues of all groups, showing a mitigation in inflammation while treating with CUR-NPs.

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.

Hepatoprotective effects of blue honeysuckle on CCl4-induced acute liver damaged mice

The objective of this study was to evaluate the hepatoprotective effects of blue honeysuckle (BH) on carbon tetrachloride (CCl4)-induced acute hepatic damage in mice. The experiment used a total of 60 ICR mice, which were divided into six groups. Except for the intact control groups, all groups received a single intraperitoneal injection of CCl4 after a 7 day pre-treatment period with distilled water, BH extracts, or silymarin. Twenty-four hours after the CCl4 injection, the following observations, representative of classical oxidative stress-mediated centrolobular necrotic acute liver injuries, were observed: decreased body weight; small nodule formation and enlargement on the gross inspections with related liver weight increase; elevation of serum AST and ALT, increases in hepatic lipid peroxidation and related depletion of endogenous antioxidants and antioxidative enzymes; centrolobular necrosis; increases in apoptotic markers, lipid peroxidation markers, and oxidative stress markers. However, liver damage was significantly inhibited by the pre-treatment with BH extracts. The present study demonstrated that oral administration of BH extracts prior to exposure to CCl4 conferred favorable hepatoprotective effects. These results demonstrated that BHe possessed suitable properties for use as a potent hepatoprotective medicinal food.

Therapeutic effects of acupuncture with MOK, a polyherbal medicine, on PTU-induced hypothyroidism in rats

Acupuncture with MOK, a polyherbal medicine (MOK pharmacopuncture), has been used for the treatment of thyroid syndromes including hypothyroidism and hyperthyroidism in traditional Korean medicine. The present study investigated the effect of MOK pharmacopuncture on hypothyroidism and the mechanism underlying its antioxidation and immune regulation effects. Hypothyroidism was induced in Sprague-Dawley rats by subcutaneous injection of Propylthiouracil (PTU; 10 mg/kg) once daily for 4 weeks. MOK was administered by acupuncture on the acupoints around the thyroid gland of PTU-induced hypothyroidism rats once daily for 2 weeks following hypothyroidism induction. Administration of MOK pharmacopuncture significantly increased the PTU-induced decrease in body temperature of hypothyroidism rats. The weights of the spleen were also significantly decreased in hyperthyroidism rats following MOK pharmacopuncture. MOK pharmacopuncture significantly decreased the thyroid stimulating hormone level and increased the T3 and T4 levels in hypothyroidism rats. Administration of MOK pharmacopuncture significantly increased the glucose levels and decreased the levels of triglycerides, total cholesterol, low-density lipoprotein-cholesterol, and alanine transaminase in the sera of hypothyroidism rats. The expression of transient receptor potential cation channel subfamily V member 1 was increased in dorsal root ganglion and brain tissues by administration of MOK pharmacopuncture, and glutathione levels and the expression of superoxide dismutase 1 and catalase were increased in the liver and brain tissues. Administration of MOK pharmacopuncture significantly inhibited interferon-γ expression and increased the expression of interleukin (IL)-4, IL-10, and Forkhead Box P3 in the spleen tissues of hypothyroidism rats. In histological analysis, the administration of MOK pharmacopuncture improved the pathological features in the thyroid glands of hypothyroidism rats. The results suggested that the administration of pharmacopuncture may ameliorate the pathological progression of hypothyroidism by multiple actions, including normalization of the hypothyroidism-induced thyroid hormone imbalance, stimulation of the antioxidant defense system, and regulation of the T helper (Th)1/Th2 imbalance. Therefore, MOK extract may be used for the treatment of hypothyroidism in Korean clinics as a useful pharmacopuncture medicine.

Hypothyroidism and hyperthyroidism change ectoenzyme activity in rat platelets

The purinergic system has an important role in the regulation of vascular functions. The interference of thyroid hormones in this system and in cardiovascular events has been studied in recent years. However, the mechanisms involved in vascular, purinergic, and oxidative changes in thyroid disorders are not completely understood. Therefore, the present study aimed to assess purinergic enzyme activity in platelets from rats with hypothyroidism and hyperthyroidism induced, respectively, by continuous exposure to methimazole (MMI) at 20 mg/100 mL or L-thyroxine at 1.2 mg/100 mL in drinking water for 1 month. Results showed that rats exposed to L-thyroxine had a significant decrease in NTPDase activity, wherein ATP hydrolysis was 53% lower and ADP hydrolysis was 40% lower. Moreover, ecto-5'-nucleotidase activity was decreased in both groups, by 39% in the hypothyroidism group and by 52% in the hyperthyroidism group. On the other hand, adenosine deaminase (ADA) activity was increased in hyperthyroidism (75%), and nucleotide pyrophosphatase/phosphodiesterase (NPP) activity was increased in animals with hypothyroidism (127%) and those with hyperthyroidism (128%). Our findings suggest that changes in purinergic enzyme and purine levels could contribute to the undesirable effects of thyroid disturbances. Moreover, oxidative stress and, in particular, a high level of ROS production, showed a causal relation with changes in ectonucleotidase activity and nucleotide and nucleoside levels.

Supplementation with turmeric residue increased survival of the Chinese soft-shelled turtle (Pelodiscus sinensis) under high ambient temperatures

Turmeric residue (TR), containing residual levels of curcumin, is a solid by-product waste generated after the extraction and separation of curcumin from turmeric root. A feeding trial was conducted to evaluate the effects of TR on the survival of Chinese soft-shelled turtles (SSTs), Pelodiscus sinensis, under a high ambient temperature. A total of 320 female SSTs were assigned randomly to two diets: basal diet (the control group, n=160) and an interventional diet supplemented with 10% TR (the TR group, n=160). Our results demonstrated that supplementation of TR increased the SST survival rate by 135.5%, and superoxide dismutase (SOD) activity of SST liver by 112.8%, and decreased the malondialdehyde (MDA) content of SST liver by 36.4%, compared to the control group. The skin of the SST fed TR showed a golden color. High-performance liquid chromatography (HPLC) analysis indicated that the concentrations of curcumin in TR and the skin of the SST fed TR were (1.69±0.30) and (0.14±0.03) μg/g, respectively. Our observation suggests that supplementation of TR increased the survival rate of SST under high ambient temperatures. We speculated that the increased survival rate and tolerance at the high ambient temperature were associated with the anti-oxidation activity of curcumin from TR. Moreover, curcumin in TR could be deposited in SST skin, which made it more favored in the market of China. Our findings provide new knowledge and evidence to effectively reuse TR as a feed additive in animal and aquatic farming.

MOK, a pharmacopuncture medicine, regulates thyroid dysfunction in L-thyroxin-induced hyperthyroidism in rats through the regulation of oxidation and the TRPV1 ion channel

Background

In this study, we evaluated the therapeutic effect of MOK, a pharmacopuncture medicine, on thyroid dysfunction in L-thyroxin (LT4)-induced hyperthyroidism rats.

Methods

The experimental hyperthyroidism model was prepared by the intraperitoneal injection of LT4 (0.5 mg/kg) once daily for 2 weeks in SD rats. MOK extract was injected at doses of 0.3 or 3 mg/kg on acupuncture points in the thyroid glands of LT4-induced hypothyroidism rats once a day for 2 weeks. The body temperature, body weight, and food/water intake were measured once a week for 2 weeks. The levels of thyroid hormones, total cholesterol, LDL-cholesterol, GOT, and GPT were measured in the sera of rats using ELISA and an automatic blood analyzer. The histological changes of thyroid tissues were observed by H&E staining. The expression of thermo-regulating protein, TRPV1 was determined by western blot in dorsal root ganglion (DRG) and brain tissues. We also measured the contents of GSH in the liver and antioxidant enzymes, SOD, and catalase in the liver, heart, and brain tissues by enzyme-based assay and Western blot, respectively.

Results

The acupuncture of MOK extract on the thyroid gland of LT4-induced hyperthyroidism rats significantly decreased the body temperature, and did not change body weight and food and water intakes. MOK acupuncture significantly increased the level of TSH, and decreased the levels of T3 and T4 in hyperthyroidism rats. The expression of TRPV1 was inhibited in both DRG and brain tissues after MOK acupuncture, and the levels of GOT, GPT, total cholesterol, and LDL-cholesterol were also decreased. MOK acupuncture also inhibited the pathological feature with follicular lining epithelial thicknesses and increased follicular colloid depositions in the thyroid glands of hypothyroidism. MOK acupuncture significantly increased hepatic GSH levels and decreased the expression of SOD and catalase in the liver, heart, and brain tissues of hyperthyroidism rats.

Conclusions

These results suggest that the pharmacopuncture with MOK extract in hyperthyroidism can improve the pathophysiological changes through regulating the body temperature, thyroid hormones imbalance, lipid accumulation, and oxidation. This anti-hyperthyroidism effect of MOK pharmacopuncture is thought to be related to the control of thermo-regulating protein TRPV1 in DRG and brain.

Cadmium-induced toxicity is rescued by curcumin: A review

Cadmium (Cd) is one of the most common environmental and occupational heavy metals with extended distribution. Exposure to Cd may be associated with several deleterious consequences on the liver, bones, kidneys, lungs, testes, brain, immunological, and cardiovascular systems. Overproduction of reactive oxygen species (ROS) as the main mechanism behind its toxicity causes oxidative stress and subsequent damages to lipids, proteins, and DNA. Therefore, antioxidants along with chelating agents have shown promising outcomes against Cd-induced toxicity. Curcumin with various beneficial effects and medical efficacy has been evaluated for its inhibitory activities against biological impairments caused by Cd. Thus, this article is intended to address the effectiveness of curcumin against toxicity following Cd entry. Curcumin can afford to attenuate lipid peroxidation, glutathione depletion, alterations in antioxidant enzyme, and so forth through scavenging and chelating activities or Nrf2/Keap1/ARE pathway induction. © 2017 BioFactors, 43(5):645-661, 2017.

Therapeutic Effects of Blue Honeysuckle on Lesions of Hyperthyroidism in Rats

Hyperthyroidism is a hypermetabolic syndrome characterized by an overproduction of thyroid hormones, which enhances the hormone-induced oxidative stress responsible for some complications in the liver, heart and muscle. Blue honeysuckle (BH) is an edible berry, rich in polyphenols, especially flavonoids or anthocyanins, known as strong antioxidants. The chemo-protective activities of the berry have been connected to the improvement of symptoms in cancer, diabetes mellitus, tumor or cardiovascular diseases. Therefore, the therapeutic effects of BH were examined in hyperthyroidism rat model. The hyperthyroidism was induced by injection with levothyroxine (LT4), and the model was treated with distilled water (LT4 control), propylthiouracil (PTU) or BH at 3 dosages of 500, 250 and 125[Formula: see text]mg/kg. The treatment was performed once a day for 15 days. Compared to LT4 control, the oral administration of BH dose-dependently ameliorated the hyperthyroidism, reducing thyroid hormones and increasing thyroid stimulating hormones. These effects were accompanied by improvement of body weight loss and atrophy in the thyroid gland, liver and epididymal fat pads. BH treatments also reduced the levels of hepatic enzymes (AST and ALT), which suggests BH exerts protective effects on hepatocytes. BH might also be involved in the augmentation of the anti-oxidant activities, supported by increased endogenous antioxidant (glutathione). In addition, the histopathological analyses revealed the beneficial effects of BH on the atrophic changes and cellular injuries in the thyroid gland, liver and epididymal fat pads. The therapeutic potentials of BH were either similar or more effective than PTU. These results provide valuable information that will guide more detailed studies to use the BH as a complementary and alternative medicine.

Hepatoprotective effects of hoveniae semen cum fructus extracts in ethanol intoxicated mice

[Purpose]

The objective of this study was to evaluate the hepatoprotective effects of Hoveniae Semen Cum Fructus extract in ethanol induced hepatic damages.

[Methods]

Hepatic damages were induced by oral administration of ethanol and then Hoveniae Semen Cum Fructus extract was administered.

[Results]

Following Hoveniae Semen Cum Fructus extract administration, body and liver weights were increased, while aspartate aminotransferase, alanine aminotransferase, albumin, γ-glutamyl transferase, and triglyceride levels in the serum, triglyceride contents, tumor necrosis factor -α level, cytochrome (CY) P450 2E1 activity in the liver and mRNA expression of hepatic lipogenic genes, and Nitrotyrosine and 4-HNE-immunolabelled hepatocytes were decreased. However, mRNA expression of genes involved in fatty acid oxidation was increased. Also, as a protective mechanism for hepatic antioxidant defense systems, decreased liver MDA contents, increased glutathione contents, increased dismutase and catalase activities were observed when compared to the ethanol control.

[Conclusion]

Hoveniae Semen Cum Fructus extract favorably protected against liver damages, mediated by its potent anti-inflammatory and anti-steatosis properties through the augmentation of the hepatic antioxidant defense system by NF-E2-related factor-2 activation, and down-regulation of the mRNA expression of hepatic lipogenic genes or up-regulation of the mRNA expression of genes involved in fatty acid oxidation.

Dextran based nanosized carrier for the controlled and targeted delivery of curcumin to liver cancer cells

Curcumin (Cur), a poly phenolic yellow colored compound present in Indian spice turmeric, has a wide variety of biological properties. Bioavailability of Cur is limited by its low water solubility, rapid metabolism and low stability. In the present study, we mainly focus on synthesis and characterization of dextran based nano-sized drug carrier (GHDx) for the delivery of Cur. A liver targeting moiety is incorporated in GHDx so as to improve the therapeutic efficiency and decrease adverse effects of conventional cancer therapy. The effect of different parameters on grafting variables was studied. GHDx was characterised by FTIR, (1)H NMR XRD, TG/DTG, TEM, SEM, AFM, DLS and zeta potential analyses. Adsorption experiments were carried out for drug loading. Swelling of GHDx was studied as a function of pH and temperature. Three step release of Cur from GHDx was confirmed by analyzing in vitro release data in simulated intracellular pH using different kinetic models. In vitro cytotoxicity analysis on L929 and Hep G2 cells shows that GHDx is safe carrier while Cur loaded GHDx exhibits high toxicity with slow drug release towards hepatic cells. The results show that the GHDx can be customized as a stimuli sensitive potential carrier for the delivery of drugs.

Curcumin prevents paracetamol-induced liver mitochondrial alterations

OBJECTIVE

In the present study was evaluated if curcumin is able to attenuate paracetamol (PCM)-induced mitochondrial alterations in liver of mice.

METHODS

Mice (n = 5-6/group) received curcumin (35, 50 or 100 mg/kg bw) 90 min before PCM injection (350 mg/kg bw). Plasma activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) was measured; histological analyses were done; and measurement of mitochondrial oxygen consumption, mitochondrial membrane potential, ATP synthesis, aconitase activity and activity of respiratory complexes was carried out.

KEY FINDINGS

Curcumin prevented in a dose-dependent manner PCM-induced liver damage. Curcumin (100 mg/kg) attenuated PCM-induced liver histological damage (damaged hepatocytes from 28.3 ± 7.7 to 8.3 ± 0.7%) and increment in plasma ALT (from 2300 ± 150 to 690 ± 28 U/l) and AST (from 1603 ± 43 to 379 ± 22 U/l) activity. Moreover, curcumin attenuated the decrease in oxygen consumption using either succinate or malate/glutamate as substrates (evaluated by state 3, respiratory control ratio, uncoupled respiration and adenosine diphosphate/oxygen ratio), in membrane potential, in ATP synthesis, in aconitase activity and in the activity of respiratory complexes I, III and IV.

CONCLUSIONS

These results indicate that the protective effect of curcumin in PCM-induced hepatotoxicity is associated with attenuation of mitochondrial dysfunction.

Effects of 3,5-Diiodotyrosine and Potassium Iodide on Thyroid Function and Oxidative Stress in Iodine-Excess Wistar Rats

The objective of this study was to investigate the effects of organic iodine (3,5-diiodotyrosine, DIT) and inorganic iodine (potassium iodine, KI) on thyroid function and oxidative stress in iodine-excess Wistar rats. Seventy-two Wistar rats were randomly divided into eight groups: normal control (NC), thyroid tablet-induced hyperthyroidism model (HM), low DIT (L-DIT), medium DIT (M-DIT), high DIT (H-DIT), low KI (L-KI), medium KI (M-KI), and high KI (H-KI). All rats were fed ad libitum for 30 days. Morphological changes in the thyroid, absolute and relative weights of the thyroid, thyroid function markers free triiodothyronine (FT3) and free thyroxine (FT4), urinary iodine level, and oxidative stress indicators were measured. Compared to the HM groups, the FT3 and FT4 levels decreased in the L-DIT groups; the thyroid weight and thyroid weight/body weight values decreased markedly in the L-DIT and M-DIT groups; serum superoxide dismutase/malondialdehyde increased markedly; glutathione peroxidase activity increased markedly in the L-DIT groups; and malondialdehyde levels decreased significantly in the M-DIT groups. However, the FT3 and FT4 levels decreased and glutathione peroxidase levels increased significantly in the DIT groups compared to their corresponding KI groups. Additionally, urinary iodine levels increased significantly in both DIT and KI groups, while the highest urinary iodine excretion was showed in the DIT groups among groups. When the addition of iodine with the same doses in iodine-excess rats, although neither DIT nor KI normalized iodine levels in the iodine-excess rats, the DIT did less damage than did KI to thyroid follicular cells. Therefore, DIT rather than KI had a protective effect by balancing the antioxidant system when exposed to supraphysiological iodine. These suggest that DIT may be used as a new alternative iodized salt in the universal salt iodization to avoid the potential damage of surplus KI.

Recent developments in curcumin and curcumin based polymeric materials for biomedical applications: A review

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, anticoagulant and anti-infective effects. This review summarizes and discusses recently published papers on the key biomedical applications of curcumin based materials. The highlighted studies in the review provide evidence of the ability of curcumin to show the significant vitro antioxidant, diabetic complication, antimicrobial, neuroprotective, anti-cancer activities and detection of hypochlorous acid, wound healing, treatment of major depression, healing of paracentesis, and treatment of carcinoma and optical detection of pyrrole properties. Hydrophobic nature of this polyphenolic compound along with its rapid metabolism, physicochemical and biological instability contribute to its poor bioavailability. To redress these problems several approaches have been proposed like encapsulation of curcumin in liposomes and polymeric micelles, inclusion complex formation with cyclodextrin, formation of polymer-curcumin conjugates, etc.

Pyrroloquinoline quinone (PQQ) has potential to ameliorate streptozotocin-induced diabetes mellitus and oxidative stress in mice: A histopathological and biochemical study

Enhanced oxidative stress and hyperglycemia are associated with diabetes mellitus (DM). As pyrroloquinoline quinone (PQQ) is known to protect cells from oxidative stress, the present study was undertaken to reveal the hitherto unknown effects of PQQ in DM and associated problems in different tissues. Forty two mice were randomly divided into six groups. Group I receiving only citrate buffer served as the normal control, while group II animals were injected with citrate buffer and PQQ at 20 mg/kg for 15 days and served as test drug control. Animals of groups III-VI were rendered diabetic by single dose of streptozotocin (STZ, 150 mg/kg body weight), following which PQQ at a dose of 5, 10 and 20 mg/kg, was injected to the animals of group IV, V and VI respectively for 15 days. At the end, alterations in serum indices such as glucose, different lipids, insulin, amylase, urea, uric acid, serum glutamate pyruvate transaminase and serum glutamate oxaloacetate transaminase; tissue antioxidants and histopathological alterations in liver, kidney and pancreas were evaluated. STZ-treated animals developed oxidative stress as indicated by a significant increase in tissue lipid peroxidation (LPO) and lipid hydroperoxide, serum glucose, total cholesterol, triglyceride and urea, with a parallel decrease in the levels of serum insulin and tissue antioxidants. When diabetic animals received different doses of PQQ, these adverse effects were ameliorated. However, 20 mg/kg of PQQ appeared to be most effective. Findings revealed for the first time that PQQ has the potential to mitigate STZ-induced DM and oxidative damage in different organs of mice, suggesting that it may ameliorate diabetes mellitus and associated problems.

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.

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.

Effects of temperature on complexes I and II mediated respiration, ROS generation and oxidative stress status in isolated gill mitochondria of the mud crab Scylla serrata

Effects of fluctuations in habitat temperature (18-30°) on mitochondrial respiratory behavior and oxidative metabolic responses in the euryhaline ectotherm Scylla serrata are not fully understood. In the present study, effects of different temperatures ranging from 12 to 40°C on glutamate and succinate mediated mitochondrial respiration, respiratory control ratio (RCR), ATP generation rate, ratio for the utilization of phosphate molecules per atomic oxygen consumption (P/O), levels of lipid peroxidation and H2O2 in isolated gill mitochondria of S. serrata are reported. The pattern of variation in the studied parameters was similar for the two substrates at different temperatures. The values recorded for RCR (≥3) and P/O ratio (1.4-2.7) at the temperature range of 15-25°C were within the normal range reported for other animals (3-10 for RCR and 1.5-3 for P/O). Values for P/O ratio, ATP generation rate and RCR were highest at 18°C when compared to the other assay temperatures. However, at low and high extreme temperatures, i.e. at 12 and 40°C, states III and IV respiration rates were not clearly distinguishable from each other indicating that mitochondria were completely uncoupled. Positive correlations were noticed between temperature and the levels of both lipid peroxidation and H2O2. It is inferred that fluctuations on either side of ambient habitat temperature may adversely influence mitochondrial respiration and oxidative metabolism in S. serrata. The results provide baseline data to understand the impacts of acute changes in temperature on ectotherms inhabiting estuarine or marine environments.

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.

The role of thyroid hormones as inductors of oxidative stress and neurodegeneration

Reactive oxygen species (ROS) are oxidizing agents amply implicated in tissue damage. ROS production is inevitably linked to ATP synthesis in most cells, and the rate of production is related to the rate of cell respiration. Multiple antioxidant mechanisms limit ROS dispersion and interaction with cell components, but, when the balance between ROS production and scavenging is lost, oxidative damage develops. Many traits of aging are related to oxidative damage by ROS, including neurodegenerative diseases. Thyroid hormones (THs) are a major factor controlling metabolic and respiratory rates in virtually all cell types in mammals. The general metabolic effect of THs is a relative acceleration of the basal metabolism that includes an increase of the rate of both catabolic and anabolic reactions. THs are related to oxidative stress not only by their stimulation of metabolism but also by their effects on antioxidant mechanisms. Thyroid dysfunction increases with age, so changes in THs levels in the elderly could be a factor affecting the development of neurodegenerative diseases. However, the relationship is not always clear. In this review, we analyze the participation of thyroid hormones on ROS production and oxidative stress, and the way the changes in thyroid status in aging are involved in neurodegenerative diseases.

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.

Curcumin pretreatment prevents potassium dichromate-induced hepatotoxicity, oxidative stress, decreased respiratory complex I activity, and membrane permeability transition pore opening

Curcumin is a polyphenol derived from turmeric with recognized antioxidant properties. Hexavalent chromium is an environmental toxic and carcinogen compound that induces oxidative stress. The objective of this study was to evaluate the potential protective effect of curcumin on the hepatic damage generated by potassium dichromate (K₂Cr₂O₇) in rats. Animals were pretreated daily by 9-10 days with curcumin (400 mg/kg b.w.) before the injection of a single intraperitoneal of K₂Cr₂O₇ (15 mg/kg b.w.). Groups of animals were sacrificed 24 and 48 h later. K₂Cr₂O₇-induced damage to the liver was evident by histological alterations and increase in the liver weight and in the activity of alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and alkaline phosphatase in plasma. In addition, K₂Cr₂O₇ induced oxidative damage in liver and isolated mitochondria, which was evident by the increase in the content of malondialdehyde and protein carbonyl and decrease in the glutathione content and in the activity of several antioxidant enzymes. Moreover, K₂Cr₂O₇ induced decrease in mitochondrial oxygen consumption, in the activity of respiratory complex I, and permeability transition pore opening. All the above-mentioned alterations were prevented by curcumin pretreatment. The beneficial effects of curcumin against K₂Cr₂O₇-induced liver oxidative damage were associated with prevention of mitochondrial dysfunction.

A comparative study of hepatic mitochondrial oxygen consumption in four vertebrates by using Clark-type electrode

The present study was undertaken to establish a comparative account on hepatic mitochondrial oxygen consumption of Clarias gariepinus (fish), Bufo melanostictus (amphibian), Gallus gallus (bird) and Rattus norvegicus (mammal) and to correlate it with their specific metabolic rate (SMR). Mitochondrial oxygen consumption was measured with a Clarke-type electrode with succinate and pyruvate/malate as substrates. ADP was used to start state-III respiration. The results show that rats and chickens have higher oxygen consumption rate than that of fish and toads. Similarly, a species and substrate specific difference was also noticed in P/O (phosphate utilized per oxygen atom) ratio and respiratory control index. In case of rat, a significant negative correlation was noticed between P/O ratio and SMR with succinate as substrate. It is surmised that the observed difference in the mitochondrial respiration and P/O ratio in the above vertebrates is due to the difference in their metabolic activities.