Fluoride-treated Group Research Articles

Fluoride Ingestion Induces Formation of Unusual Macromolecular Complexes in Gut Lumen Which Retard Absorption of Essential Minerals and Trace Elements by Chelation.

This study investigates the impact of chronic fluoride exposure on the absorption of essential minerals in the gut and explores the mechanisms underlying mineral deficiencies due to fluoride ingestion. Male Wistar rats were randomly assigned to three groups: group 1 (G-1) served as the control (non-fluoride exposed), while group 2 (G-2) and group 3 (G-3) received human equivalent doses (HED) of fluoride (50 and 100ppm ad libitum, corresponding to 5 and 10ppm in humans, respectively) for 75days. Serum fluoride concentrations were measured, and the levels of essential minerals and trace elements in blood and stool were analyzed using ICP-MS. X-ray diffraction (XRD) analysis was performed on stool samples to identify chemical compounds. The chemical compounds and macromolecular complexes containing fluoride and essential minerals were identified and quantified using Match3 software. Results indicated that the blood concentrations of essential minerals were significantly lower (p ≤ 0.05) in the fluoride-exposed groups compared to the control, while excretion of essential elements in stool was significantly higher (p ≤ 0.05) in the fluoride-administered groups. XRD analysis revealed the formation of unusual macromolecular chemical complexes in the stool of fluoride-treated groups, with the types and concentrations of these compounds increasing with higher fluoride doses. The study concludes that fluoride in the stomach chelates minerals, reducing their absorption, and induces the formation of unusual high molecular weight macromolecular chelation complexes, which alter the chemical species in the gut and further impair the absorption of essential minerals.

Dental Erosion in Competitive Swimmers and Preventive Treatments: An In Vitro Study.

The aim of this in vitro study was to evaluate the effectiveness of highly concentrated fluoride products and remineralizing products (F-APC) in preventing erosive dental lesions in competitive swimming patients. A total of 48 teeth were extracted, preserved in saline solution and divided into three groups. In G1 (control group), each tooth was half-immersed in chlorinated pool water; in G2 (fluoride-treated group), after being totally immersed in chlorinated water, each tooth had half of its surface treated with a highly concentrated fluoride product once a week; in G3 (remineralization product-treated group), each tooth was totally immersed in chlorinated water and half of its surface was treated with a remineralizing product after each immersion. The study was conducted over a 4-week period, immersing the teeth for 4 h per day. In G1, statistically significant differences were observed in submerged versus non-submerged tooth surfaces at week 3 (T3) (p = 0.019) and week 4 (T4) (p = 0.0007), with four and eight surfaces showing erosive tooth wear (ETW), respectively. In G2, a difference was observed between fluoride-treated and non-fluoride-treated surfaces at T4 (p = 0.039), with three surfaces with ETW among the non-treated ones. In G3, the difference was observed between portions treated with F-APC and those not treated at T4 (p = 0.019), with four surfaces with ETW among the untreated ones. Chlorinated pool water is a potential erosive agent for teeth if water pH values reach a critical value. Treating the teeth surface with highly concentrated fluoride products, once a week for 5 min, and F-APC are effective in protecting teeth against tooth erosion.

Effects of water fluoridation on early embryonic development of zebrafish

Fluoride has strong electronegativity and exposes diversely in nature. Water fluoridation is the most pervasive form of occurrence, representing a significant threat to human health. In this study, we investigate the morphometric and physiological alterations triggered by fluoride stimulation during the embryogenesis of zebrafish and reveal its putative effects of stage- and/or dose-dependent. Fluoride exhibits potent biological activity and can be extensively absorbed by the yolk sac, exerting significant effects on the development of multiple organs. This is primarily manifested as restricted nutrient utilization and elevated levels of lipid peroxidation, further leading to the accumulation of superoxide in the yolk sac, liver, and intestines. Moreover, pericardial edema exerts pressure on the brain and eye development, resulting in spinal curvature and reduced body length. Besides, acute fluoride exposure with varying concentrations has led to diverse teratogenic outcomes. A low dose of water fluoridation tends to induce abnormal development of the embryonic yolk sac, while vascular malformation is widely observed in all fluoride-treated groups. The effect of fluoride exposure on blood circulation is universally present, even in zebrafish larvae that do not exhibit obvious deformities. Their swimming behavior is also affected by water fluoridation, resulting in reduced activity and delayed reactions. In conclusion, this study provides valuable insights into the monitoring of environmental quality related to water fluoridation and disease prevention.

Royal jelly protects brain tissue against fluoride-induced damage by activating Bcl-2/NF-κB/caspase-3/caspase-6/Bax and Erk signaling pathways in rats.

This study is aimed at determining whether royal jelly (RJ) which has a powerful antioxidant property prevents fluoride-induced brain tissue damage and exploring whether Bcl-2/NF-κB/ and caspase-3/caspase-6/Bax/Erk pathways play a critical role in the neuroprotective effect of RJ. Wistar albino rats were chosen for the study, and they were randomly distributed into six groups: (i) control; (ii) royal jelly; (iii) fluoride-50; (iv) fluoride-100; (v) fluoride-50 + royal jelly; (vi) fluoride-100 + royal jelly. We established fluoride-induced brain tissue damage with 8-week-old male Wistar albino rats by administration of fluoride exposure (either 50mg/kg or 100mg/kg bw) through drinking water for 8weeks. Then, the study duration is for 56days where the rats were treated with or without RJ (100mg/kg bw) through oral gavage. The effects of RJ on glutathione (GSH), catalaseactivity (CAT), and malondialdehyde (MDA) levels were determined via spectrophotometer. Western blot analysis was performed to investigate the effectsof royal jelly on the protein expression levels of Bax, caspase-3, caspase-6, Bcl-2, NF-κB, COX-2, and Erk. It was also studied the effects of RJ on histopathological alterations in fluoride-induced damage to the rat brain. As a result,the Bcl-2, NF-κB, and COX-2 protein expression levels were increased in the fluoride-treated (50 and 100mg/kg) groups but theywere decreased significantly by RJ treatment in the brain tissue. Additionally, the protein expression of caspase-3, caspase-6, Bax, and Erk were decreased in fluoride-treated groups and theywere significantly increased by RJ treatment compared to theun-treated rats. Our results suggested that RJ prevented fluoride-induced brain tissue damage through anti-antioxidant activities.

Effects of Fluoride on Metabolic enzymes of brain and Gastrocnemius muscle of mice: protective role of selenium and alpha-tocopherol

The present study aimed to investigate the ameliorative effects of Selenium and Alpha-tocopherol on activities of enzymes involved in metabolic functions, energy production and transfer in the brain and gastrocnemius muscle of mice treated with sodium fluoride. Animals were separated into five groups and treated with Selenium (05 µg/kg BW), Alpha-tocopherol (2mg/kg BW) alone, and in combination for 15 days to evaluate their ameliorative effects against fluoride (20mg/kg BW) toxicity. The obtained results showed a statistically significant (p<0.05) decrease in the body weight, organo-somatic index, protein content, ALAT, AAT, CPK, acid phosphatase and alkaline phosphatase enzymes activities in the fluoride-treated group in comparison with control group indicates oxidative stress induced by fluoride. The effect of fluoride on enzymes of muscle was comparatively higher, which suggests the greater accumulation of fluoride in muscle than brain. These changes were reverted moderately in Selenium and alpha-tocopherol alone treated groups, and significantly (p<0.05) in Selenium + alpha-tocopherol treated group suggests the combinatorial effect of Selenium and alpha-tocopherol in the amelioration of fluoride-induced toxicity. In conclusion, the findings all pointed to the fact that Selenium and alpha-tocopherol showed combinatorial effects in the amelioration of oxidative stress induced by fluoride.

Remineralizing efficacy of fluoride in the presence of oral microcosm biofilms

ObjectivesThe oral biofilm structure or composition can affect the penetration of remineralizing agents. Therefore, this study evaluated the remineralizing efficacy of fluoride using a pH-cycling model with oral microcosm biofilms. MethodsArtificial carious lesions were formed in 80 bovine incisors. The pH-cycling conditions with or without oral microcosm biofilms were applied to 40 specimens each. The pH-cycling scheme was repeated for 12 days. Fluorescence loss (ΔF,%) of early carious lesions was measured for all specimens using a quantitative light-induced fluorescence-digital camera, before and after fluoride application. Biofilms on specimens were further analyzed for red fluorescence intensity (red/green ratios) and colony-forming unit counts. The effects of pH-cycling conditions and treatments on changes in ΔF (ΔΔF) and the effects of interactions between factors were analyzed using two-way analysis of variance. ResultsThe fluoride-treated group with oral biofilms had an approximately 0.89-fold lower ΔΔF than the fluoride-treated group without oral biofilms (p < 0.0001). When oral biofilms were absent, the fluoride-treated group showed a 1.31-fold greater ΔΔF compared to that in the distilled water-treated group (p < 0.0001). When oral biofilms were present, the fluoride-treated group showed a 1.14-fold greater ΔΔF compared to that in the distilled water-treated group; however, this difference was not statistically significant. ConclusionsThere was a significant difference in fluoride remineralizing efficacy based on the presence of biofilms on early carious lesions. Therefore, fluoride remineralization assessment in the absence of oral biofilms could lead to an overestimation of efficacy. Clinical SignificanceFluoride application might not have a robust remineralization effect on early carious lesions in the presence of a mature biofilm on the tooth surface.

The therapeutic effects of Prunella vulgaris against fluoride-induced oxidative damage by using the metabolomics method.

Fluoride is considered as one of the most ubiquitous environmental pollutants. Numerous studies have linked reactive oxygen species (ROS)-dependent oxidative damage with fluoride intoxication, which could be prevented by antioxidants. However, the metabolomic changes induced by ROS disruptions in fluoride intoxication are yet unknown. The present study aimed to provide novel mechanistic insights into the fluoride-induced oxidative damage and to investigate the potential protective effects of ethanolic extract of Prunella vulgaris (natural antioxidant, PV) against fluoride-induced oxidative damage. The serum biochemical indicators related to fluoride-induced oxidative damage, such as lipid peroxidation parameter, inflammation and marker enzymes in the liver increased significantly in the fluoride-treated group, while antioxidant enzymes were decreased. However, PV treatment restored the level of these biochemical indicators, indicating satisfactory antioxidant, anti-inflammatory, and hepatoprotective potential of PV. The metabolomics analysis in the serum was performed by liquid chromatography-mass spectroscopy, whereas the fluoride treatment caused severe metabolic disorders in rats, which could be improved by PV. The differential metabolites screened by multivariate analysis after fluoride and PV treatment, were organic acids, fatty acids, and lipids. These differential metabolites represented disorders of glyoxylate and dicarboxylate metabolism and the citrate cycle (TCA) according to metabolic pathway analysis in fluoride treatment rats. Interestingly, the result of metabolic pathway analysis of post-treatment with PV was consistent with that of fluoride treatment, indicating that the energy metabolism plays a major role in the progress of fluoride-induced oxidative damage, as well as the therapeutic effect of PV. These findings provided a theoretical basis for understanding the mechanism underlying metabolic disorders of fluoride toxicity and the effect of PV.

Vitamin C and E Supplementation Can Mitigate NaF Mediated Hematological and Hepatic Disorders in Adult Wistar Rats

The study aimed to investigate the effect of combined vitamin E and C, on hematological and hepatic systems of adult male Wistar rats with fluoride toxicity. Eighteen rats were randomly divided into three groups such as control, treated (given NaF, 20 mg/kg bw/rat/day), and supplemented (NaF and vitamin E-200 mg/kg bw + C- 400 mg/kg bw). Altered hematological parameters like erythrocyte count, leukocyte count and hemoglobin concentration were seen in NaF groups. Estimation of osmotic fragility of erythrocyte showed a marked increase fragile erythrocytes in fluoride-treated groups compared to control and supplemented groups. Total thiol concentration was also decreased due fluoride fluoride-induced oxidative stress and it was protected in supplementary groups. The oxidative imbalance induced by NaF in liver was evaluated by estimating the activity of antioxidant enzyme superoxide dismutase and catalase and with estimation of lipid peroxidation and protein oxidation product malondialdehyde and protein carbonyl. All enzymatic and non-enzymatic markers of oxidative imbalance were significantly altered (increased/decreased) due to fluoride toxicity, which was again observed to be protected in the supplemented group. The histopathological analysis of the liver also proved the mitigatory effect of the combined vitamin E+C on fluorideinduced hepatic insult.

Building an aprismatic enamel-like layer on a demineralized enamel surface by using carboxymethyl chitosan and lysozyme-encapsulated amorphous calcium phosphate nanogels

ObjectivesThe purpose of this study was to prepare carboxymethyl chitosan (CMC) and lysozyme nanogels that could encapsulate amorphous calcium phosphate (ACP) for achieving its controlled delivery, thus forming an aprismatic enamel-like layer on the demineralized enamel surface. MethodsCMC/LYZ-ACP nanogels were developed, and the controlled delivery of ACP from the nanogels was induced by the presence of NaCl. The nanogel morphologies at various NaCl concentrations was measured by transmission electron microscopy (TEM). The particle sizes and zeta potentials (ζ-potential) of the samples were determined using a combined dynamic light scattering/particle electrophoresis instrument. Comparing the remineralization effect of the CMC/LYZ-ACP nanogels on the demineralized enamel surface with that of a fluoride treatment, the remineralization effect was examined by nanoindentation tests, X-ray diffraction (XRD), confocal laser scanning microscopy (CLSM), and scanning electron microscopy (SEM). ResultsCMC/LYZ-ACP nanogels were negatively charged spherical structures with a particle size of approximately 300 nm. At high concentrations of NaCl (0.15 M), ACP was dissociated from the disassembled nanogels and transformed into hydroxyapatite (HAP). Groups treated with the CMC/LYZ-ACP nanogels showed the regeneration of an aprismatic enamel-like layer on an acid-etched enamel surface, which provided increased mechanical properties (P < 0.05) and a high impermeability (P < 0.01) compared to those of the fluoride-treated group. ConclusionsThis research provides a new idea for the stable and controllable delivery of ACP from CMC/LYZ-ACP nanogels, which can form an aprismatic enamel-like layer in situ on the surface of demineralized enamel. In regard to further clinical development, this material and method may be promising for treating early enamel caries.

Influence of a novel pH-cycling model using dental microcosm biofilm on the remineralizing efficacy of fluoride in early carious lesions.

To evaluate the remineralizing efficacy of fluoride in early carious lesions using a novel microbial pH-cycling model that combines the chemical pH-cycling model with dental microcosm biofilms. Artificial carious lesions were formed in 48 bovine incisors. The chemical and microbial pH-cycling models were applied to 24 specimens, respectively; the latter was applied after formation of dental microcosm biofilms for 6days, based on the human saliva inoculation. The pH-cycling schedule was repeated for 12days. All specimens were evaluated for fluorescence loss (ΔF) using quantitative light-induced fluorescence-digital before and after the pH-cycling. Specimen biofilms were further analyzed for red/green values (R/G ratios) and colony-forming units (CFUs). One-way analysis of variance and Tukey's post hoc analysis were used to analyze change in fluorescence loss (ΔΔF) according to the pH-cycling model and treatment. When the chemical pH-cycling and microbial pH-cycling models were used, ΔΔF was 1.36 (p = 0.008) and 1.17 (p > 0.05) times higher, respectively, in the fluoride-treated group than that in the distilled water-treated group. In the microbial pH-cycling model, R/G ratios and CFU counts of biofilms were not significantly different between treatments (p > 0.05). No significant difference was observed in the remineralizing efficacy of fluoride according to the presence of dental biofilms covering early carious lesions. The remineralizing efficacy of fluoride could be overestimated in the absence of dental biofilms. Therefore, for accurate evaluation of the clinical value of remineralizing agents, dental biofilms should be included in in vitro tests.

Apoptotic and Degenerative Changes in the Enteric Nervous System Following Exposure to Fluoride During Pre- and Post-natal Periods.

Children born in fluorosis endemic areas usually suffer from gastrointestinal complications and are unable to attain normal growth as per their age group. The enteric nervous system (ENS) controls gut movement and functions. It is highly vulnerable to any ingested toxins. Based on observations, it was hypothesized that fluoride exposure during pregnancy and lactation might induce ENS developmental defects. The aim of this study is to investigate the effects of fluoride exposure during pregnancy and lactation on ENS of the first-generation rat pups. After confirmation of pregnancy, female rats were divided into 3 groups and kept on normal water (group 1), 50 ppm of fluoride (group 2), and 100 ppm of fluoride (group 3). The fluoride exposure started at the start of pregnancy and continued until lactation. On the 21st post-natal day, the pups were euthanized and the gut tissue and blood were harvested and subjected to fluoride measurement, oxidative stress estimation, histopathological and ultrastructural analysis, TUNEL, and immunofluorescence. The quantitative expressional analysis of embryonic lethal abnormal vision-like 4 (ELAVL4) (a pan-neuronal marker) and glial fibrillary acidic protein (GFAP) (a glial cell marker) genes was performed by RT-qPCR. An increase in oxidative stress, subcellular and cellular injuries, and apoptosis in enteric neuronal, glial, and epithelial cells was observed in the distal colon of the first-generation pups. Ganglionic degeneration, reduced expression of HuC/D and GFAP, altered colon muscle layer thickness, and tissue edema were observed in the fluoride-treated groups compared with the control. Fluoride exposure during prenatal and lactation period leads to subcellular and cellular injuries due to increased oxidative stress and apoptosis in the ENS. The reduction in the number of neurons and glia due to increased apoptosis may cause alterations in ENS development.

Excess dietary fluoride affects laying performance, egg quality, tissue retention, serum biochemical indices, and reproductive hormones of laying hens

The present study aimed to evaluate the effects of excess dietary fluoride (F) on laying performance, egg quality, tissue retention, serum biochemical indices, and serum reproductive hormones of laying hens. A total of 384 Hy-Line Gray hens, 37 wk old, were treated with sodium fluoride added to a corn-soybean meal basal diet at 0, 400, 800, and 1200 mg fluorine/kg feed. The results showed that dietary F levels at 800 and 1200 mg/kg markedly decreased ADFI, laying rate, average egg weight, and increased feed conversion ratio (FCR) (P < 0.05). Dietary F levels at 800 and 1200 mg/kg dramatically decreased the egg quality of albumen height, yolk color, eggshell strength, and eggshell thickness, and on the 49th D, 400 mg/kg F group significantly decreased the eggshell strength, compared to those of control group. Fluoride residues in tissues of hens were increased significantly with the increase of dietary F supplemental levels (P < 0.05). Fluoride concentrations were generally high in feces, eggshell, tibia, kidney, and ovary, and the highest in feces, following with eggshell and tibia, lower in kidney and ovary, and the lowest in serum. Serum uric acid levels and alanine aminotransferase activity increased significantly (P < 0.05), and glucose, triglycerides, and phosphorus decreased significantly (P < 0.05) in response to dietary F concentration, compared to those of the control group, respectively. Dietary F supplementation at 1200 mg/kg significantly decreased (P < 0.05) the estrogen concentrations in serum, compared to those of the control group. Concentrations of progesterone in the fluoride-treated groups were significantly (P < 0.05) decreased relative to those of the control group. In conclusion, these results indicated that the excessive ingestion of F has had a detrimental effect on egg laying rate and quality of eggs by damaging the function of the liver, kidney, and ovary of laying hens.

Fluoride regulates the expression of extracellular matrix HSPG and related signaling pathways FGFR3 and Ihh/PTHrP feedback loop during endochondral ossification

Skeletal fluorosis causes growth plate impairment and growth retardation during bone development. Longitudinal bone development is accomplished by endochondral ossification in growth plate. However, the mechanism of fluoride impairs growth plate is unclear. To explore the effect of fluoride on various glycosaminoglycans (GAGs) and related signaling pathways in growth plate during endochondral ossification, SD rats and ATDC5 cells were treated with fluoride and carried out a series of experiments. We found that the expression of heparan sulfate (HS), a kind of GAGs in extracellular matrix, was significantly increased in the growth plate of fluoride-treated rats compared with control rats. Furthermore, the expression of HS synthetic enzyme exostosin 1 (EXT1) and glypican 6 (GPC6), a core protein of HS proteoglycan (HSPG), were significantly increased in fluoride-treated ATDC5 cells compared with control cells (P < 0.05). The expression of related molecules including fibroblast growth factor receptor-3 (FGFR3), signal transducer and activator of transcription 1 (STAT1) and parathyroid hormone-related protein (PTHrP) were significantly increased in the fluoride-treated groups compared with control groups (P < 0.05), and there was significantly decreased in the expression of Indian hedgehog (Ihh) in fluoride-treated groups compared with control groups (P < 0.05). Our data suggested that fluoride increased the content of HSPG in extracellular matrix by promoting the expression of EXT1 and GPC6. Fluoride also activated FGFR3 signaling pathway, inhibited Ihh/PTHrP feedback loop and inhibited endochondral ossification. Nevertheless, the regulation of fluoride on HSPG and related pathways FGFR3 and Ihh/PTHrP feedback loop during endochondral ossification needs to be further studied.

Changes of DNA repair gene methylation in blood of chronic fluorosis patients and rats

To investigate the relationship between DNA repair gene methylation and chronic coal-burning fluorosis. The methylation rates of O6-methylguanine-DNA- methyltransferase gene MGMT, a DNA repair gene and mismatch repair gene MutL homolog 1 (MLH1) were analysed by methylation of specific PCR (MSP), and the levels of mRNA in the blood of the chronic fluorosis rats and the patients in the region of endemic coal-burning fluorosis were determined by real-time PCR. The levels of mRNA and protein of MGMT and MLH1 in the liver tissue of the chronic fluorosis rats were determined by real-time PCR and Western blot respectively. The results showed an increased methylation of the MGMT and MLH1 genes in the blood of the patients in the fluorosis region that correlated positively with the severity of fluorosis. The mRNA levels of MGMT and MLH1 genes from the patients in fluorosis region were lower than those of a control group, and also showed a positive correlation with the severity of fluorosis. Both the protein and mRNA levels of MGMT and MLH1 genes from the blood of rats and liver tissue in a fluoride-treated group were lower than those of a control non-fluoride treated group. These results indicate that the degree of methylation of MGMT and MLH1 genes is altered in fluorosis disease, the resulting changed expression of these repair genes may play a role in the liver damage caused by fluoride.

Effect of fluoride on major organs with the different time of exposure in rats

BackgroundHigh fluoride levels in drinking water in relation to the prevalence of chronic kidney disease of unknown etiology (CKDu) in Sri Lanka were investigated using rats as an experimental model.MethodThe effects of fluoride after oral administration of Sodium fluoride (NaF) at levels of 0, 0.5, 5 and 20 ppm F− were evaluated in adult male Wistar rats. Thirty-six rats were randomly divided into 4 groups (n = 9), namely, control, test I, II, and III. Control group was given daily 1 ml/rat of distilled water and test groups I, II, and III were treated 1 ml/rat of NaF doses of 0.5, 5, and 20 ppm, respectively, by using a stomach tube. Three rats from the control group and each experimental group were sacrificed after 15, 30, and 60 days following treatment. Serological and histopathological investigations were carried out using blood, kidney, and liver.ResultsNo significant differences were observed in body weight gain and relative organ weights of the liver and kidney in fluoride-treated groups compared to control group. After 60 days of fluoride administration, group I showed a mild portal inflammation with lytic necrosis while multiple areas of focal necrosis and various degrees of portal inflammation were observed in groups II and III. This was further confirmed by increased serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) activities. As compared with control and other treated groups, group III showed a significantly higher serum AST activity (p < 0.05) and ALT activity (p < 0.05) after 60 days and ALP activity with a significant difference (p < 0.05) after 15, 30, and 60 days. The renal histological analysis showed normal histological features in all groups with the elevated serum creatinine levels in group III compared to those in the groups I and II (p < 0.05) after 60 days. Significantly elevated serum fluoride levels were observed in group II of 30 and 60 days and group III after 15, 30, and 60 days with respective to control groups (p < 0.05).ConclusionTaken together, these findings indicate that there can be some alterations in liver enzyme activities at early stages of fluoride intoxication followed by renal damage.

Fluoride-induced alterations of synapse-related proteins in the cerebral cortex of ICR offspring mouse brain

Fluoride (F) exposure causes cognitive dysfunction in humans and animals. However, the precise molecular mechanisms by which fluoride exerts its neurotoxic effects are poorly understood. In this study, an animal model of fluoride exposure was created by providing ICR mice were treated with vehicle F at a dose of 0 (control group), 50 (low-fluoride group) or 100 mg/L (high-fluoride group) in water for one month. After the mice mated, parents and offspring were treated and maintained under these conditions. The cognitive abilities of the mice were examined using a Morris water maze test. Results indicated that fluoride exposure significantly prolonged the escape latency period and decreased the number of crossings in a particular zone. Histopathologic analysis revealed the shrinkage and fragmentation of glial cells in the fluoride-treated groups. Pyramidal cells in the cerebral cortices of fluoride-treated groups were fewer than those of the control group. The expression of microtubule-associated protein 2 (MAP2) and synaptic proteins of the cerebral cortex in mouse offspring was assayed using RT-PCR and Western blot. Fluoride exposure possibly induced a significantly decreased expression of MAP2, synaptophysin (SYP) and developmentally regulated brain protein (Dbn) at protein and mRNA levels. Glutamate receptor (N-methyl-d-aspartate receptor, NMDAR) was also expressed, and this finding was consistent with the reduced MAP2, SYP and Dbn expression. Therefore, fluoride-mediated reduction in cognitive dysfunction is likely caused by the disruption of the expression of these synapse-associated proteins, resulting in attenuated neuronal functioning.

Ameliorating Role of Lycopene, Tomato Puree, and Spirulina + Tomato Puree on the Hematology of Fluoride-Exposed Swiss Albino Mice

ABSTRACTPlant species rich in antioxidants (vitamins, flavonoids, lignans, and carotenoids) have been explored for complementary therapy of chronic diseases (cancers, coronary heart disease) and mitigation of pollutant toxicity. This article investigates their ameliorative role on selective hematological and serum biochemical parameters in fluoride-exposed (190 mg/kg body weight) Swiss albino mice pretreated with the antioxidant-rich diet supplements tomato puree (with and without peels), spirulina (cyanobacteria), and lycopene (present in tomato) for 45 days prior to entry into experimental protocol. Compared with standard feed control, diet-modulated controls had more hairy and lustrous white fur, hemodilution, increase in platelet counts (2- to 5-fold), red blood cell (RBC) size (11%–14%), mean corpuscular hemoglobin (Hb) concentration (MCHC; 5%–14%), and serum albumin (23%–27%). Fluoride-exposed mice reared on standard feed had less hairy, pale white, lusterless fur and black nails, reduction in RBC and white blood cell (WBC) counts and Hb content, and morphological abnormalities in RBCs (poikilocytosis). By contrast, fur quality of fluoride-treated diet-modulated groups was similar to standard feed control; counts and morphology of their RBCs and Hb content similar to the respective controls, and increase in WBC counts greater than controls. In comparison to the fluoride-treated standard feed group, platelet counts were higher in the treated mice of the diet-modulated groups. This study thus revealed the hemoprotective role of diet supplements in fluoride-treated mice. Considering the prevalence of fluoride-induced chronic toxicity in developing countries, our findings have relevance in minimizing hematological disorders among people residing in the fluoride-affected areas, because indigenously cultivated low-price tomato fruits are easily available for consumption.

Effects of fluoride on morphology, growth, development, and thyroid hormone of Chinese toad (Bufo gargarizans) embryos.

Excessive fluoride in natural water ecosystem has the potential to detrimentally affect amphibians, but little is known of such effects or underlying mechanisms in Bufo gargarizans embryos. In the present study, the effects of fluoride exposure on B. gargarizans embryos were investigated. First, fluoride teratogenic experiment showed that the 9 days EC50 of fluoride on B. gargarizans embryos was 177.62mg/L. Then, we studied the sublethal effects of fluoride on B. gargarizans embryos at control, 0.7, 4.1, 19.6, 41.9, and 62.7mg/L fluoride concentration. Malformation, growth, and development of embryos were monitored, and type 2 and 3 iodothyronine deiodinase (Dio2 and Dio3), thyroid hormone receptors (TRα and TRβ) mRNA levels were measured. Our results showed the morphological malformations, such as tail curvature (lordosis), edema, cuticularized ciliated cells, and hyperplasia were occurred during fluoride exposure. Growth and development were all inhibited at 19.5, 41.9, and 62.7mg/L fluoride-treated groups after 9days' exposure. According to real-time PCR results, exposure to fluoride upregulated Dio3 and TRβ mRNA expression and downregulated Dio2 and TRα mRNA level. All above indicated that excessive fluoride could induce morphology malformations, inhibit embryonic growth and development, and disrupt the normal function of maternal thyroid hormone in B. gargarizans embryos. Environ. Mol. Mutagen. 59:123-133, 2018. © 2017 Wiley Periodicals, Inc.

SEED EXTRACT OF ABELMOSCHUS MOSCHATUS MEDIK REVERSES NAF-INDUCED BEHAVIORAL CHANGES THROUGH NEURODEGENERATION AND OXIDATIVE STRESS IN BRAIN OF RAT

Objective: This study reports protective effect of Abelmoschus moschatus seed extract against sodium fluoride-induced neurodegeneration through oxidative stress, neurohistological, and behavioral observations in Wistar rats.Methods: A total of 20 Wistar rats (around 250 g) were randomly classified into four groups, namely, control, fluoride (NaF), fluoride + A. moschatus seed aqueous extract (AMAE), and fluoride + A. moschatus seed ethanol extract (AMEE). The control group animals received normal tap water, fluoride group received fluoridated water at the rate of 40 mg/kg b. wt., 3rd group rats treated with fluoride (40 mg/kg b. wt.) + AMAE (300 mg/kg b. wt.), and 4th group rats treated with fluoride (40 mg/kg b. wt.) + AMEE (300 mg/kg b. wt.). Neurobehavioral responses of rotarod, hot plate, and maze learning tests and oxidantive stress markers including lipid peroxidation (LPO), GSH levels, superoxide dismutase, CAT, and GSH peroxidase (GPx) activities, and also histology with H and E as well as congo red staining were studied in control, fluoride, and A. moschatus seed extract treated against fluoride groups.Results: Decreased neurobehavioral responses with rotarod, hot plate, and maze and enhanced LPO (p&lt;0.05) levels were found in fluoride received animals. Whereas, the superoxide dismutase (SOD), CAT, GSH, and GPx were decreased (p&lt;0.05) in NaF treatment. The rats received seed extract along with NaF showed significant reversal of behavioral and oxidative stress markers and the effect of ethanol extract was more pronounced than aqueous extract. The fluoride-treated group showed disturbed cell structure and reduced number of cells in H and E as well as congo red staining which was reversed in cell morphology and restored cell number in seed extract against NaF-treated group. As a result of increased LPO, decreased antioxidant system, and decreased number of cells, neurodegeneration was observed resulting in the disturbance in functions associated with reported behavior.Conclusion: Okra with high antioxidants activity, seed extract showed reversal of LPO levels and antioxidant status in the brain tissue. And also plant extract administered rats displayed normal cell structure and number of cells than only fluoride received group. Therefore, the aqueous and ethanolic extract of A. moschatus plant seeds has neuroprotective effects against fluoride-induced motor, nociceptive, learning behavior, and on histological structure of brain through antioxidant mechanism. The ethanol extract has shown more efficacy than aqueous extract.

Developmental fluoride exposure influenced rat's splenic development and cell cycle via disruption of the ERK signal pathway

Excessive fluoride exposure has been reported to cause damage to spleen. Neonatal period is characterized by rapid proliferation and differentiation of lymphocyte in the spleen. Children may be more sensitive to the toxicity of fluoride compared to the adults. The aim of this study was to investigate the effects of postnatal exposure (from neonatal period to early adulthood) to fluoride on the development of spleen on a regular basis and the underlying signal pathway. Results showed a marked decrease in spleen weight index and altered morphology in the spleen of fluoride-treated group on PND-84, which reflected fluoride inhibition of the development of spleen. Fluoride exposure induced cell cycle arrest of splenocytes and decreased the mRNA expression of IL-2, which indicated compromised baseline lymphocyte proliferation in the spleen. Time course research from 3-wk-of-age until 12-wk-of-age showed an adverse and cumulative impact of fluoride on the development of spleen. In view of the key role of MAPK/ERK pathway in lymphocyte development, Raf-1/MEK-1/ERK-2/c-fos mRNA expression and ERK/p-ERK protein expression were detected. Results showed despite a transitory increase in mRNA expression from PND-42 to PND-63 in fluoride-treated group, the expression of these genes on PND-84 decreased significantly compared with PND-42 or PND-63. NaF significantly inhibited the phosphorylation of ERK protein on PND-84. Taken together, these results emphasized the vital role of ERK pathway in the interfered development of spleen induced by a high dose of fluoride exposure in rats.