Effects of fluoride on insulin signaling and bone metabolism in ovariectomized rats

Fluoride-Induced Alterations in the Pancreas of Mammals: A Meta-analysis

This review explores the diverse effects of fluoride on pancreatic function, encompassing both in vitro and in vivo studies. Fluoride exposure induces notable alterations at the cellular and molecular levels, affecting pancreatic morphology, histology, and enzymatic activity. In vitro studies demonstrate significant inhibition of pancreatic α-amylase activity and apoptosis in pancreatic beta cells. In vivo investigations reveal structural abnormalities in pancreatic cells, including mitochondrial damage, vacuolation, and nuclear damage. Moreover, fluoride exposure disrupts antioxidant enzyme activity, exacerbating oxidative stress and lipid peroxidation. Changes in digestive enzyme activity, such as the inhibition of pancreatic lipase and α-amylase, further contribute to pancreatic dysfunction. Additionally, alterations in hormone secretion, notably insulin levels and disturbed glucose homeostasis, highlight the complex effects of fluoride on the pancreatic endocrine system. These findings underscore fluoride-induced pancreatic toxicity and highlight the need for a comprehensive understanding and mitigation strategies to safeguard pancreatic health.

Impact of fluorosis on molecular predictors in pathogenesis of type 2 diabetes associated microvascular complications

AIM

This review presents specific insights on the molecular underpinnings of the connection between fluorosis, type 2 diabetes, and microvascular complications, along with the novel biomarkers that are available for early detection.

SUMMARY

Fluoride is an essential trace element for the mineralization of teeth and bones in humans. Exposure to higher concentrations of fluoride has harmful effects that significantly outweigh its advantageous ones. Dental fluorosis and skeletal fluorosis are the common side effects of exposure to fluoride, which affect millions of individuals globally. Alongside, it also causes non-skeletal fluorosis, which affects the population suffering from non-communicable diseases like diabetes by impacting the soft tissues and causing diabetic microvascular complications. Previous studies reported the prevalence range of these diabetic complications of neuropathy (3-65 %), nephropathy (1-63 %), and retinopathy (2-33 %). Fluoride contributes to the development of these complications by causing oxidative stress, cellular damage, degrading the functioning capability of mitochondria, and thickening the retinal vein basement.

CONCLUSION

Early diagnosis is a prompt way of prevention, and for that, biomarkers have emerged as an innovative and useful technique. This allows healthcare practitioners and policymakers in endemic areas to comprehend the molecular complexities involved in the advancement of diabetic microvascular problems in the context of high fluoride exposure.

Correlations between bone metabolism biomarkers and fluoride exposure in adults and children

Increased exposure to fluoride, which notably affects bone metabolism, is a global concern. However, the correlations and sensitivity of bone metabolism to fluoride remain controversial. In this cross-sectional study, 549 children (aged 7-12 years) and 504 adults (≥ 18 years old) were recruited in the high-fluoride areas of the Henan Province. Urinary fluoride (UF) level was determined using a fluoride electrode. Fasting venous blood serum was collected to measure bone metabolism biomarkers. The selected bone metabolism biomarkers for children included bone alkaline phosphatase (BALP), serum alkaline phosphatase (ALP), osteocalcin (OCN), calcitonin (CT), parathyroid hormone (PTH), phosphorus (P5+), and calcium (Ca2+). For adults, the biomarkers included ALP, CT, PTH, β-CrossLaps (β-CTX), P5+, and Ca2+. The correlations between UF and bone metabolism biomarkers were analyzed using binary logistic regression, a trend test, a generalized additive model, and threshold effect analysis. Regression analysis indicated a significant correlation between serum OCN, PTH, and UF levels in children aged 7-9 years. Serum OCN, PTH, and BALP contents were significantly correlated with UF in boys (P < 0.05). Furthermore, the interaction between age and UF affected serum P5+ and PTH (P < 0.05). The generalized additive model revealed nonlinear dose-response relationships between P5+, BALP, and UF contents in children (P < 0.05). Serum OCN level was linearly correlated with the UF concentration (P < 0.05). Similarly, a significant correlation was observed between β-CTX and UF levels in adults. In addition, significant correlations were observed between UF-age and serum Ca2+, β-CTX, and PTH contents. There was a non-linear correlation between serum Ca2+, P5+, and β- CTX and UF levels (P < 0.05). Overall, serum OCN, BALP, and P5+ levels can serve as sensitive bone metabolism biomarkers in children, while β-CTX, P5+, and Ca2+ can be considered fluoride-sensitive bone metabolism biomarkers in adults.

Construction of microgravity biological knowledge graph and its applications in anti-osteoporosis drug prediction

Microgravity in the space environment can potentially have various negative effects on the human body, one of which is bone loss. Given the increasing frequency of human space activities, there is an urgent need to identify effective anti-osteoporosis drugs for the microgravity environment. Traditional microgravity experiments conducted in space suffer from limitations such as time-consuming procedures, high costs, and small sample sizes. In recent years, the in-silico drug discovery method has emerged as a promising strategy due to the advancements in bioinformatics and computer technology. In this study, we first collected a total of 184,915 literature articles related to microgravity and bone loss. We employed a combination of dependency path extraction and clustering techniques to extract data from the text. Afterwards, we conducted data cleaning and standardization to integrate data from several sources, including The Global Network of Biomedical Relationships (GNBR), Curated Drug-Drug Interactions Database (DDInter), Search Tool for Interacting Chemicals (STITCH), DrugBank, and Traditional Chinese Medicines Integrated Database (TCMID). Through this integration process, we constructed the Microgravity Biology Knowledge Graph (MBKG) consisting of 134,796 biological entities and 3,395,273 triplets. Subsequently, the TransE model was utilized to perform knowledge graph embedding. By calculating the distances between entities in the model space, the model successfully predicted potential drugs for treating osteoporosis and microgravity-induced bone loss. The results indicate that out of the top 10 ranked western medicines, 7 have been approved for the treatment of osteoporosis. Additionally, among the top 10 ranked traditional Chinese medicines, 5 have scientific literature supporting their effectiveness in treating bone loss. Among the top 20 predicted medicines for microgravity-induced bone loss, 15 have been studied in microgravity or simulated microgravity environments, while the remaining 5 are also applicable for treating osteoporosis. This research highlights the potential application of MBKG in the field of space drug discovery.

Unraveling gene expression and genetic instability in dental fluorosis: Investigating the impact of chronic fluoride exposure

Chronic fluoride exposure, even in small quantities, when continuously ingested by the human population, can lead to a significant public health concern known as fluorosis. Our understanding of the effects of fluoride on human health, as well as its potential to impact DNA, is limited. The present study aimed to assess genetic instability in 20 individuals diagnosed with dental fluorosis and 20 individuals without the condition from the state of Rio Grande do Sul, Brazil. The participants' dental fluorosis was evaluated using the Thylstrup-Fejerskov index (TF). To further evaluate genetic instability, several assays were conducted, including the alkaline and modified (+FPG) comet assay (using a visual score, VS), the buccal micronucleus (MN) cytome (BMCyt) assay, the cytokinesis-block MN (CBMN-Cyt) assay, and the measurement of telomere length (TL). In addition, the study utilized tools from Systems Biology to gain insights into the effects of fluoride exposure on humans, which aided in the selection and evaluation of mRNA expression levels of specific genes, namely PPA1 (inorganic pyrophosphatase 1), AQP5 (Aquaporin 5), and MT-ATP6 (Mitochondrially Encoded Adenosine Triphosphate Synthase Membrane Subunit 6). Furthermore, fluoride levels in the blood and urine were assessed using an ion-selective electrode, along with the evaluation of the inflammatory response in serum. The group with dental fluorosis exhibited 2.18 times higher MN frequencies specifically when assessed using the CBMN-Cyt assay, in comparison with individuals without fluorosis. Findings from the enzyme-modified comet assay indicated oxidative damage to purines in DNA. Furthermore, a decrease in TL was observed, along with elevated expression patterns of the PPA1 and AQP5 genes, and significant alterations in cytokine release. Significant correlations were identified between the TF and age, as well as the levels of necrotic cells. Additionally, noteworthy correlations were established between fluoride levels and the levels of MN, VS, and MT-ATP6. Although dental fluorosis results from fluoride exposure, our research highlights the potential influence of this condition on genomic instability and gene expression. Consequently, our findings stress the importance of continuously monitoring populations with a high incidence of dental fluorosis to enhance our comprehension of how genomic instability might correlate with the origins and consequences of health problems in these individuals.

Melatonin alleviated fluoride-induced impairment of spermatogenesis and sperm maturation process via Interleukin-17A

Fluoride-induced male reproductive failure is a major environmental and human health concern, but interventions are still lacking. Melatonin (MLT) has potential functions in regulating testicular damage and interleukin-17 (IL-17) production. This study aims to explore whether MLT can mitigate fluoride-induced male reproductive toxicity through IL-17A, and screen the potential targets. So the wild type and IL-17A knockout mice were employed and treated with sodium fluoride (100 mg/L) by drinking water and MLT (10 mg/kg.BW, intraperitoneal injection per two days starting from week 16) for 18 weeks. Bone F- concentrations, grade of dental damage, sperm quality, spermatogenic cells counts, histological morphology of testis and epididymis, and the mRNA expression of spermatogenesis and maturation, classical pyroptosis related and immune factor genes were detected respectively. The results revealed that MLT supplementations alleviated fluoride-induced impairment of spermatogenesis and maturation process, protecting the morphology of testis and epididymis through IL-17A pathway, and Tesk1 and Pten were identified as candidate targets from 29 regulation genes. Taken together, this study demonstrated a new physiological role for MLT in the protection against fluoride-induced reproductive injury and possible regulation mechanisms, which providing a useful therapeutic strategy for male reproductive function failure caused by fluoride or other environmental pollutants.

Necessity to Pay Attention to the Effects of Low Fluoride on Human Health: an Overview of Skeletal and Non-skeletal Damages in Epidemiologic Investigations and Laboratory Studies

Due to the implementation of water improvement and fluoride reduction plans supported by central and local governments in recent years, areas with high fluoride exposure are being gradually decreased. Therefore, it is of practical importance to study the effect of low fluoride on human health. Epidemiologic investigations and in vivo and in vitro studies based on low fluoride have also confirmed that fluoride not only causes skeletal damage, such as dental fluorosis, but also causes non-skeletal damage involving the cardiovascular system, nervous system, hepatic and renal function, reproductive system, thyroid function, blood glucose homeostasis, and the immune system. This article summarizes the effects of low fluoride on human and animal skeletal and non-skeletal systems. A preliminary exploration of corresponding mechanisms that will help to fully understand the harm of low fluoride on human health was undertaken to provide the basis for establishing new water fluoride standards and help to implement individual guidance.

Challenges of fluoride pollution in environment: Mechanisms and pathological significance of toxicity - A review

Fluoride is an important trace element in the living body. A suitable amount of fluoride has a beneficial effect on the body, but disproportionate fluoride entering the body will affect various organs and systems, especially the liver, kidneys, nervous system, endocrine system, reproductive system, bone, and intestinal system. In recent years, with the rapid development of agriculture and industry, fluoride pollution has become one of the important factors of environmental pollution, and fluoride pollution in any form is becoming a serious problem. Although countries around the world have made great breakthroughs in controlling fluoride pollution, however fluorosis still exists. A large amount of fluoride accumulated in animals will not only produce the toxic effects, but it also causes cell damage and affect the normal physiological activities of the body. There is no systematic description of the damage mechanism of fluoride. Therefore, the study on the toxicity mechanism of fluoride is still in progress. This review summarizes the existing information of several molecular mechanisms of the fluoride toxicity comprehensively, aiming to clarify the toxic mechanism of fluoride on various body systems. We have also summerized the pathological changes of those organ systems after fluoride poisoning in order to provide some ideas and solutions to the reader for the prevention and control of modern fluoride pollution.

Advances in Our Understanding of the Mechanism of Action of Drugs (including Traditional Chinese Medicines) for the Intervention and Treatment of Osteoporosis

Osteoporosis (OP) is known as a silent disease in which the loss of bone mass and bone density does not cause obvious symptoms, resulting in insufficient treatment and preventive measures. The losses of bone mass and bone density become more severe over time and an only small percentage of patients are diagnosed when OP-related fractures occur. The high disability and mortality rates of OP-related fractures cause great psychological and physical damage and impose a heavy economic burden on individuals and society. Therefore, early intervention and treatment must be emphasized to achieve the overall goal of reducing the fracture risk. Anti-OP drugs are currently divided into three classes: antiresorptive agents, anabolic agents, and drugs with other mechanisms. In this review, research progress related to common anti-OP drugs in these three classes as well as targeted therapies is summarized to help researchers and clinicians understand their mechanisms of action and to promote pharmacological research and novel drug development.

Association between low-to-moderate fluoride exposure and bone mineral density in Chinese adults: Non-negligible role of RUNX2 promoter methylation

Bone mineral density (BMD) changes were reported to be associated with excessive fluoride exposure and abnormal expression of RUNX2. However, whether the alteration of methylation status, a most commonly used marker for the alteration of gene expression in epidemiological investigation, of RUNX2 is associated with low-to-moderate fluoride exposure and BMD changes has not been reported. Our study aims to explore the role of RUNX2 promoter methylation in BMD changes induced by low-to-moderate fluoride exposure. A total of 1124 adults (413 men and 711 women) were recruited from Kaifeng City in 2017. We measured BMD using ultrasound bone densitometer. Concentrations of urinary fluoride (UF) were measured using ion-selective electrode, and the participants were grouped into control group (CG) and excessive fluoride group (EFG) according to the concentration of UF. We extracted DNA from fasting peripheral blood samples and then detected the promoter methylation levels of RUNX2 using quantitative methylation-specific PCR. Relationships between UF concentration, RUNX2 promoter methylation and BMD changes were analyzed using generalized linear model and logistic regression. Results showed in EFG (UF concentration > 1.6 mg/L), BMD was negatively correlated with UF concentration (β: -0.14; 95%CI: -0.26, -0.01) and RUNX2 promoter methylation (β: -0.13; 95%CI: -0.22, -0.03) in women. The methylation rate of RUNX2 promoter increased by 2.16% for each 1 mg/L increment in UF concentration of women in EFG (95%CI: 0.37, 3.96). No any significant associations between UF concentration, RUNX2 promoter methylation, and BMD were observed in the individuals in CG. Mediation analysis showed that RUNX2 promoter methylation mediated 18.2% (95% CI: 4.2%, 53.2%) of the association between UF concentration and BMD of women in EFG. In conclusion, excessive fluoride exposure (>1.6 mg/L) is associated with changes of BMD in women, and this association is mediated by RUNX2 promoter methylation.

Fluoride exposure and CALCA methylation is associated with the bone mineral density of Chinese women

Excessive exposure to fluoride has been reported to affect bone mineral density (BMD). CALCA expression plays a critical part in bone formation. However, the role of CALCA in the association between fluoride and BMD is not known. We conducted a cross-sectional study and recruited 722 women in rural areas of Henan Province, China, to assess the relationship between fluoride exposure, CALCA methylation, and BMD. Urinary levels of fluoride, CALCA methylation, and BMD were measured by a fluoride ion-selective electrode, standalone ultrasound bone densitometer, and quantitative methylation-specific polymerases chain reaction, respectively. The association among fluoride exposure, CALCA methylation, and BMD was age-specific. Specifically, BMD was negatively correlated with methylation (β: -0.008; 95% CI: -0.016, 0.000) and fluoride exposure (β: -0.063; 95% CI: -0.129, -0.002) in women over 45 years and 50-54 years of age, respectively, whereas methylation was positively correlated with fluoride exposure (β: 4.953; 95% CI: 1.162, 8.743) in women aged 40-44 years. Besides, increased BMD in women aged 45-49 years induced by the interactive effect of the highest methylation of CALCA exon 1 (tertile 3) and fluoride exposure was observed (P for interaction < 0.05). Our findings suggest an age-specific association between exposure to excessive fluoride, CALCA methylation, and BMD in a rural population of women in China. Notably, the susceptibility of BMD to fluoride exposure may be modified by CALCA methylation.

Diet-derived nutrient patterns and components of metabolic syndrome: a cross-sectional community- based study

BACKGROUND

Metabolic syndrome (MetS) is one of the main public health problems worldwide. Although some relations between dietary intakes and MetS have been found, few studies have focused on association between dietary nutrients interactions and the risk of the MetS and its components. The aim of the present study was to examine the association between nutrient patterns and MetS and its components among Iranian adult population.

METHODS

A total of 588 subjects (aged 18-64 years, 271 males and 317 females) enrolled in the cross sectional study. Dietary consumption was evaluated using an 80-item food frequency questionnaire (FFQ). Biochemical assessments including fasting blood sugar (FBS), aspartate aminotransferase (AST), alanine amino transferase (ALT) and serum lipids were performed by enzymatic methods. Nutrient patterns were obtained by factor analysis procedure using principal component method. Multinational logistic regression analysis was used to evaluate the association between nutrient patterns and MetS and its components.

RESULTS

Three nutrient patterns explaining 53.66% of the variance in dietary nutrients intake, were recognized in the current study. Animal-sourced nutrient pattern was significantly associated with the higher odds of MetS and high triglyceride (TG) levels. Plant-sourced nutrient pattern (high intake of fiber, carbohydrate, vitamins B₆, B₃, C, B₁, E, D, magnesium, potassium, and linoleic acid) was significantly associated with lower risk of MetS and lower blood pressure (p < 0.05). Third nutrient pattern (mixed-source) was significantly related to higher risk of MetS, high waist circumference (WC) and high systolic blood pressure (SBP).

CONCLUSION

This present study confirms the important effect of nutrients and their patterns on MetS risk. Our results suggest that adherence to the nutrient pattern rich in fiber, carbohydrate, vitamins D, B₆, B₃, C, B₁, E, magnesium, potassium, linoleic acid, and docosahexaenoic acid (DHA) is associated with a lower risk of MetS, while animal- and mixed-sourced nutrient patterns are positively associated with greater odds of MetS; However, further longitudinal and interventional studies are required to make a clear conclusion.

Cell Growth Stimulation, Cell Cycle Alternation, and Anti-Apoptosis Effects of Bovine Bone Collagen Hydrolysates Derived Peptides on MC3T3-E1 Cells Ex Vivo

Bovine bone collagen hydrolysates promote bone formation through regulating bone growth. However, the peptide sequences within these isolates have not been characterized. In this study, twenty-nine peptides from bovine bone collagen hydrolysates were purified and identified using nano-HPLC-MS-MS and Peak Studio analysis. HHGDQGAPGAVGPAGPRGPAGPSGPAGKDGR (Deamidation) and GPAGANGDRGEAGPAGPAGPAGPR (Deamidation) enhanced cell viability, inhibited apoptosis, and significantly altered the cell cycle of MC3T3-E1 osteoblast cells. These peptides were selected to perform molecular docking analysis to examine the mechanism underlying these bioactivities. Molecular docking analysis showed that these two peptides formed hydrophobic interactions and hydrogen bonds with epidermal growth factor receptor (EGFR) to activate the EGFR-signaling pathway, which may explain their bioactivity. These findings indicate that these and other similar peptides might be candidates for the treatment of osteoporosis.

Association between fluoride exposure and cardiometabolic risk in peripubertal Mexican children

BACKGROUND

Several animal studies have suggested that fluoride exposure may increase the levels of cardiometabolic risk factors, but little is known about whether fluoride exposure is associated with such risk in humans.

OBJECTIVES

We examined the cross-sectional association between peripubertal exposure to fluoride and markers of cardiometabolic risk in 280 girls and 256 boys at age 10-18 years living in Mexico City.

METHODS

We measured plasma fluoride concentration using a microdiffusion method. We collected data on anthropometry including BMI, waist circumference (WC) and trunk fat percentage. We measured serum markers of cardiometabolic risk, including fasting glucose, insulin and lipids. All the indicators of outcome were converted to age- and sex-specific z-scores. We also calculated a summary cardiometabolic risk score for each participant. Multivariable linear regression models were used to examine these associations.

RESULTS

The geometric mean (95% confidence interval (CI)) of plasma fluoride was 0.21 μmol/L (0.20, 0.23 μmol/L) in the total sample. In girls, plasma fluoride concentrations were associated with higher z-scores for all the individual markers (except for lipids) and for the combined cardiometabolic risk score (risk score: β = 1.28, 95% CI: 0.57-2.00, p-sex interaction = 0.02)), adjusting for covariates. No associations were found in boys.

CONCLUSIONS

We found that higher peripubertal fluoride exposure at the levels observed in this study population was significantly associated with increased levels of cardiometabolic risk factors in Mexican girls but not boys. Future studies with a longitudinal design are needed to confirm our findings and further elucidate the role of fluoride in cardiometabolic risk.

Metabolic Syndrome Features: Is There a Modulation Role by Mineral Water Consumption? A Review

Metabolic syndrome (MetSyn) promotes, among others, the development of atherosclerotic cardiovascular disease and diabetes. Its prevalence increases with age, highlighting the relevance of promoting precocious MetSyn primary prevention and treatment with easy-to-implement lifestyle interventions. MetSyn features modulation through mineral water consumption was reviewed on Pubmed, Scopus and Google Scholar databases, using the following keywords: metabolic syndrome, hypertension, blood pressure (BP), cholesterol, triglycerides, apolipoprotein, chylomicron, very low-density lipoprotein, low-density lipoprotein, high-density lipoprotein (HDL), glucose, insulin, body weight, body mass index, waist circumference (WC), obesity and mineral(-rich) water. Twenty studies were selected: 12 evaluated BP, 13 assessed total-triglycerides and/or HDL-cholesterol, 10 analysed glucose and/or 3 measured WC. Mineral waters were tested in diverse protocols regarding type and composition of water, amount consumed, diet and type and duration of the study. Human and animal studies were performed in populations with different sizes and characteristics. Distinct sets of five studies showed beneficial effects upon BP, total-triglycerides, HDL-cholesterol and glucose. WC modulation was not reported. Minerals/elements and active ions/molecules present in mineral waters (and their pH) are crucial to counterbalance their inadequate intake and body status as well as metabolic dysfunction and increased diet-induced acid-load observed in MetSyn. Study characteristics and molecular/physiologic mechanisms that could explain the different effects observed are discussed. Further studies are warranted for determining the mechanisms involved in the putative protective action of mineral water consumption against MetSyn features.

Fluoride Exposure Induces Inhibition of Sodium/Iodide Symporter (NIS) Contributing to Impaired Iodine Absorption and Iodine Deficiency: Molecular Mechanisms of Inhibition and Implications for Public Health

The sodium iodide symporter (NIS) is the plasma membrane glycoprotein that mediates active iodide transport in the thyroid and other tissues, such as the salivary, gastric mucosa, rectal mucosa, bronchial mucosa, placenta and mammary glands. In the thyroid, NIS mediates the uptake and accumulation of iodine and its activity is crucial for the development of the central nervous system and disease prevention. Since the discovery of NIS in 1996, research has further shown that NIS functionality and iodine transport is dependent on the activity of the sodium potassium activated adenosine 5'-triphosphatase pump (Na+, K+-ATPase). In this article, I review the molecular mechanisms by which F inhibits NIS expression and functionality which in turn contributes to impaired iodide absorption, diminished iodide-concentrating ability and iodine deficiency disorders. I discuss how NIS expression and activity is inhibited by thyroglobulin (Tg), tumour necrosis factor alpha (TNF-α), transforming growth factor beta 1 (TGF-β1), interleukin 6 (IL-6) and Interleukin 1 beta (IL-1β), interferon-γ (IFN-γ), insulin like growth factor 1 (IGF-1) and phosphoinositide 3-kinase (PI3K) and how fluoride upregulates expression and activity of these biomarkers. I further describe the crucial role of prolactin and megalin in regulation of NIS expression and iodine homeostasis and the effect of fluoride in down regulating prolactin and megalin expression. Among many other issues, I discuss the potential conflict between public health policies such as water fluoridation and its contribution to iodine deficiency, neurodevelopmental and pathological disorders. Further studies are warranted to examine these associations.

Sodium fluoride induced skeletal muscle changes: Degradation of proteins and signaling mechanism

Fluoride is a well-known compound for its usefulness in healing dental caries. Similarly, fluoride is also known for its toxicity to various tissues in animals and humans. It causes skeletal fluorosis leading to osteoporosis of the bones. We hypothesized that when bones are affected by fluoride, the skeletal muscles are also likely to be affected by underlying molecular events involving myogenic differentiation. Murine myoblasts C2C12 were cultured in differentiation media with or without NaF (1 ppm-5 ppm) for four days. The effects of NaF on myoblasts and myotubes when exposed to low (1.5 ppm) and high concentration (5 ppm) were assessed based on the proliferation, alteration in gene expression, ROS production, and production of inflammatory cytokines. Changes based on morphology, multinucleated myotube formation, expression of MyHC1 and signaling pathways were also investigated. Concentrations of NaF tested had no effects on cell viability. NaF at low concentration (1.5 ppm) caused myoblast proliferation and when subjected to myogenic differentiation it induced hypertrophy of the myotubes by activating the IGF-1/AKT pathway. NaF at higher concentration (5 ppm), significantly inhibited myotube formation, increased skeletal muscle catabolism, generated reactive oxygen species (ROS) and inflammatory cytokines (TNF-α and IL-6) in C2C12 cells. NaF also enhanced the production of muscle atrophy-related genes, myostatin, and atrogin-1. The data suggest that NaF at low concentration can be used as muscle enhancing factor (hypertrophy), and at higher concentration, it accelerates skeletal muscle atrophy by activating the ubiquitin-proteosome pathway.

Amelioration of the Protein Expression of Cox2, NFB, and STAT-3 by Some Antioxidants in the Liver of Sodium Fluoride-Intoxicated Rats

The present study aimed to explore the efficiency of N-acetyl cysteine (NACC) or thymoquinone (TMQ) alone or in combination in the downregulation of inflammatory molecule expression and decreasing hepatic injury in response to sodium fluoride (SF). Sodium fluoride upregulated serum alanine and aspartate transferases activities, tumor necrosis factor α and hepatic malondialdehyde and nitric oxide levels, and the expression of cyclooxygenase 2, nuclear factor κB cell, and signal transducer and activator of transcription 3. In contrast, hepatic glutathione level, superoxide dismutase activity, and nuclear factor erythroid 2-related factor 2 expression were decreased. However, the concurrent treatment with antioxidants, alone or in combination, modulated the levels of these parameters. Histopathological examination revealed that SF treatment resulted in focal areas of massive hepatic degeneration and many degenerated hepatocytes, whereas the treatment with TMQ or NACC exhibited moderate improvement in cellular degeneration of the liver with many abnormal cells. Rats receiving a combination of TMQ and NACC showed marked improvement in cellular degeneration of liver with apparently normal hepatic architecture with very few degenerated hepatocytes. The results also revealed that the combination of TMQ and NACC is the most effective regimen in ameliorating SF toxicity, suggesting their efficacy against the toxicity of fluoride compounds. Their activities might be mediated via multiple molecular pathways.

The morphological changes and molecular biomarker responses in the liver of fluoride-exposed Bufo gargarizans larvae

The goal of the current study was to evaluate the negative influences of fluoride on liver of Bufo gargarizans larvae. B. gargarizans larvae were treated with 42.4mgF^-/L for 0, 24, 48 and 72h at Gosner stage 37. The morphological changes and responses of molecular biomarkers involved in lipid metabolism, oxidative stress and apoptosis were examined in liver. Disappearance of cell boundaries, degeneration of hepatic parenchyma cells and significant increase in the number of melanomacrophage centres and the quantity of lipid droplets were found in the liver treated with 42.4mgF^-/L for 72h. In addition, in the relative expression of acetyl CoA carboxylase 1 (ACC-1), fatty acid elongase 1 (FAE-1), sterol carrier protein 2 (SCP-2), and carnitine palmitoyltransferase-1 (CPT-1), decrease was observed after 24, 48 and 72h of 42.4mgF^-/L exposure. Furthermore, the transcript levels of superoxide dismutase (SOD) and glutathione peroxidase (GPx) were downregulated in tadpoles exposed for 24, 48 and 72h to 42.4mgF^-/L, while the transcript level of heat shock protein 90 (HSP90) was upregulated at 42.4mgF^-/L for 72h. Also, mRNA expression of Bcl-2-associated transcription factor 1(BCLAF1) and thyroid hormone receptors (TRα and TRβ) was significantly upregulated in tadpoles treated with 42.4mgF^-/L for 72h. Therefore, our results suggested that the liver injury induced by fluoride might result from disruption of lipid metabolism, oxidative damage and apoptosis.

Haematological evaluation of sodium fluoride toxicity in oryctolagus cunniculus

Blood is promptly affected by environmental pollutants and toxicants that can cause many metabolic disorders. The high level of fluoride acts as a potential pollutant, insecticide and rodenticide with very high toxicity, associated with the hematological damage. This study aimed to determine the toxicity of Sodium Fluoride on hematological parameters in Oryctolagus cunniculus. Twenty rabbits were acclimatized and divided in to control group and three experimental groups.Experimental group-I, II and III were treated with 10, 30 and 50 mg/kg body weight doses of Sodium Fluoride orally. Various blood parameters such as TEC, Hb, HCT, MCV, MCH, MCHC, TLC and PLT count were investigated. Result findings showed that values of blood indices in experimental groups were significantly lower than the control group. Oneway ANOVA was applied for statistical analysis. The outcomes of the current studies indicated the reduction in RBC counts (anemia), leukocyte count (leukocytopenia), monocytosis, eosinopenia, neutrophilia and thrombocytosis on fluoride intoxication. Hematological disruptions like microcytic hypochromic anemia and decreased leukocyte count may be linked to the inflammatory effects of Sodium Fluoride on lymphatic organs.