Sodium fluoride-induced hypoproteinemia and hypoglycemia in parental and F(1)-generation rats and amelioration by vitamins

Fluoride in the Central Nervous System and Its Potential Influence on the Development and Invasiveness of Brain Tumours-A Research Hypothesis

The purpose of this review is to attempt to outline the potential role of fluoride in the pathogenesis of brain tumours, including glioblastoma (GBM). In this paper, we show for the first time that fluoride can potentially affect the generally accepted signalling pathways implicated in the formation and clinical course of GBM. Fluorine compounds easily cross the blood-brain barrier. Enhanced oxidative stress, disruption of multiple cellular pathways, and microglial activation are just a few examples of recent reports on the role of fluoride in the central nervous system (CNS). We sought to present the key mechanisms underlying the development and invasiveness of GBM, as well as evidence on the current state of knowledge about the pleiotropic, direct, or indirect involvement of fluoride in the regulation of these mechanisms in various tissues, including neural and tumour tissue. The effects of fluoride on the human body are still a matter of controversy. However, given the growing incidence of brain tumours, especially in children, and numerous reports on the effects of fluoride on the CNS, it is worth taking a closer look at these mechanisms in the context of brain tumours, including gliomas.

Time-dependent effect of ground water fluoride on motility, abnormality and antioxidant status of spermatozoa: An in vitro study

The present study was undertaken to investigate the toxic effect of ground water fluoride (F) on motility, abnormality, and antioxidant status of spermatozoa. Treatment of ground water F with epididymal sperm suspension caused complete loss of sperm motility and decrease in the activities of superoxide dismutase (SOD) and catalase (CAT) and increase in the concentration of malondialdehyde (MDA) and abnormality of spermatozoa at 15 and 30 min time intervals. Further, incubation of spermatozoa with ground water F for 5, 10, and 15 min time intervals significantly reduced the sperm motility and activities of SOD and CAT and increased the concentration of MDA and abnormality of spermatozoa. The study revealed that F-induced effect on sperm motility and antioxidant status is time dependent. Increase in oxidative stress and concomitant decrease in motility of spermatozoa in ground water F clearly indicates that F-induced oxidative stress affected the sperm motility. The present study for the first time demonstrated the toxic effect of ground water F on spermatozoa at shorter duration of exposure, which affects the capability of spermatozoa in fertilization.

Impact of Prenatal and Postnatal Treatment of Sodium Fluoride and Aluminum Chloride on Some Hormonal and Sensorimotor Aspects in Rats

In most communities, there is a constant exposure to environmental pollutants with probable negative impact on the development of the nervous system. Among these pollutants are the sodium fluoride (NaF) and aluminum chloride (AlCl₃) which may represent a real threat to the proper functioning of the brain. This study comprises two fundamentally different strategies; in the first one, pregnant rats were administered a daily dose of NaF (0.15 g /L) or AlCl₃ (500 mg/L) in the drinking water either separately or in combination with each other from day 6 of gestation until just after weaning. In the second approach, the male rats born to mothers exposed to the pollutants were divided into two groups. In the first, rats were continued to be treated with the same pollutants administered to them in the drinking water at the same dose level until the age of 70 days. The rats of the second group were supplied with drinking water without either one of the pollutants for a similar period of time. The rats exposed to NaF separately or in combination with AlCl₃ during the prenatal life and subsequently through the postnatal stages exhibited disturbance in the locomotor activities. This was concomitant with alterations in plasma, PTH, ACTH, and estradiol levels. Additionally, the serum levels of LH and testosterone were altered in the two groups treated with sodium fluoride during the prenatal and up to the weaning periods or in the group which continued to have the NaF until day 70 after birth.

Fluoride Alteration of [3H]Glucose Uptake in Wistar Rat Brain and Peripheral Tissues

The present study was designed to investigate the role of postnatal fluoride intake on [3H]glucose uptake and transport in rat brain and peripheral tissues. Sodium fluoride (NaF) in a concentration of 10 or 50 ppm was added to the drinking water of adult Wistar rats. The control group received distilled water. After 4 weeks, respective plasma fluoride levels were 0.0541 ± 0.0135 μg/ml (control), 0.0596 ± 0.0202 μg/ml (10 ppm), and 0.0823 ± 0.0199 μg/ml (50 ppm). Although plasma glucose levels were not altered in any group, the plasma insulin level in the fluoride (50 ppm) group was elevated (0.72 ± 0.13 μg/ml) versus the control group (0.48 ± 0.24 μg/ml) and fluoride (10 ppm) group. In rats receiving fluoride for 4 weeks at 10 ppm in drinking water, [3H]glucose uptake was unaltered in all tested parts of the brain. However, in rats receiving fluoride at 50 ppm, [3H]glucose uptake in cerebral cortex, hippocampus, and thalamus with hypothalamus was elevated, versus the saline group. Fluoride intake had a negligible effect on [3H]glucose uptake by peripheral tissues (liver, pancreas, stomach, small intestine, atrium, aorta, kidney, visceral tissue, lung, skin, oral mucosa, tongue, salivary gland, incisor, molars, and jawbone). In neither fluoride group was glucose transporter proteins 1 (GLUT 1) or 3 (GLUT 3) altered in frontal cortex and striatum versus control. On the assumption that increased glucose uptake (by neural tissue) reasonably reflects neuronal activity, it appears that fluoride damage to the brain results in a compensatory increase in glucose uptake and utilization without changes in GLUT 1 and GLUT 3 expression.

Fluoride impairs oocyte maturation and subsequent embryonic development in mice

The damage caused by fluorosis is permanent, and has been recognized as a public health problem in a number of regions of the world. Although multiple studies provided evidence that sodium fluoride (NaF) elicits adverse effects on reproductive function, the effect of fluoride on female germ cell development is not well understood. Therefore, the present study aimed at evaluating the effect of fluoride treatments on in vivo maturation and developmental potential of mouse oocytes, in which female ICR mice were treated with a range of doses (0, 30, 60, and 150 mg/L) of NaF. After treatment, mice were superovulated to collect ovulated oocytes. The effects of NaF on oocyte quality, fertilization potential and early embryonic development were evaluated, as well as the underlying mechanisms were primarily investigated. The findings of this study showed that NaF treatment resulted in abnormal spindle configuration, actin cap formation, and cortical granule-free domain formation. Additionally, overexposure of mice to NaF notably reduced ATP production and mitochondrial membrane potential, further influencing in vitro fertilization and subsequent embryonic development. These results indicated that NaF treatment impairs the subsequent embryonic developmental potential of the oocytes. In conclusion, overexposure to fluoride in vivo was associated with a significant disruption of cytoskeletal dynamics and decreased oocyte quality, affecting the oocyte's subsequent fertilization and embryonic development. Results of this study provide a rationale for treating reproductive diseases such as infertility or miscarriage caused by environmental contaminants. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1486-1495, 2016.

Neurobehavioural effects of exposure to fluoride in the earliest stages of rat development

It is known that exposure to high concentrations of Fluoride (F) produces deleterious health effects in human population. However, in the last years it has been concluded that low concentrations of F may have adverse health effects as well. Transplacental passage of F and its incorporation into foetal tissues has been demonstrated. Therefore, the purpose of the present work was to study the effects of the exposure to low levels of F during pregnancy and lactation on the central nervous system functionality. Wistar rats were exposed to low F concentrations (5 and 10 mg/l) during pregnancy and lactation. Sensorimotor reflexes in the each pup were analysed and the postnatal day on which both eyes and auditory canals were opened was recorded. Locomotor activity and anxiety were subsequently analysed in 45- and 90-day-old offspring by an open field test and plus maze test, respectively. A significant delay in the development of eye opening was observed in all offspring whose mothers had been exposed to the two F concentrations tested. Exposure to 5 and 10 mg/l F was also found to significantly decrease locomotor activity only in 90-day-old male and female offspring. A low index of anxiety in the young females and in all adult offspring exposed to the two F concentrations tested was also detected. Taken together, findings from the present study show that exposure to low F concentrations during pregnancy and lactation produces dysfunction in the central nervous system mechanisms which regulate motor and sensitive development, locomotor activity and anxiety

Ameliorative effect of resveratrol against fluoride-induced alteration of thyroid function in male wistar rats

Resveratrol (3,4,5-trihydroxystilbene), a polyphenol and well-known natural antioxidant has been evaluated for its protective effect against fluoride-induced metabolic dysfunctions in rat thyroid gland. Fluoride, the most abundant anions present in groundwater throughout the world, creates a major problem in safe drinking water and causes metabolic, structural, and functional injuries in different organ systems. Sub-acute exposure to sodium fluoride at a dose of 20 mg/kg b.w./day orally to rat for 30 days induces thyroidal dysfunction including suppressed synthetic machinery of the thyroid gland to produce nucleic acids and thyroid hormones, mainly T3 and T4. Other functional changes are alteration of certain metabolic enzyme activities like Na(+)-K(+)-ATPase, thyroid peroxidase, and 5,5'-deiodinase. Structural abnormality of thyroid follicles by fluoride intoxication clearly indicates its thyrotoxic manifestation. Resveratrol supplementation in fluoride-exposed animals appreciably prevented metabolic toxicity caused by fluoride and restored both functional status and ultra-structural organization of the thyroid gland towards normalcy. This study first establishes the therapeutic efficacy of resveratrol as a natural antioxidant in thyroprotection against toxic insult caused by fluoride.

Physiologic and Metabolic Benefits of Formulated Diets and Mangifera indica in Fluoride Toxicity

Fluorosis is a major health problem affecting normal physiological and metabolic functions in people living in endemic fluoride areas. The present work was aimed at investigating the role of basal, high carbohydrate low protein (HCLP) and high protein low carbohydrate (HPLC) diets and Mangifera indica fruit powder as a food supplement in fluoride-induced metabolic toxicity. Exposure to fluoride resulted in elevation of plasma glucose levels, ACP, ALP, SGPT, SGOT, and hepatic G-6-Pase activities, plasma and hepatic lipid profiles with decreased plasma protein, HDL-C, hepatic glycogen content and hexokinase activity in basal, HCLP and HPLC diet fed albino rats. However among the three diets tested, HPLC diet was found to be relatively, a better metabolic regulator. All the three formulated diets (basal, HCLP and HPLC) supplemented with mango fruit powder (5 and 10 g), decreased plasma glucose content, ACP, ALP, SGPT, SGOT and hepatic G-6-Pase activities and plasma as well as hepatic lipid profiles. These diets also elevated the hepatic glycogen content and hexokinase activities. These effects however, were prominent with the HPLC diet supplemented with mango fruit powder and, among the two doses of mango fruit powder, the higher dose (10 g) yielded more promising results. It is surmised that the micronutrients and phytochemicals present in the diets and the mango fruit could be responsible for attenuation of fluoride-induced metabolic toxicity.

Study on changes of clinical indicators and key proteins from fluoride exposure

Few studies have evaluated the biomarker changes of fluoride exposure. In order to explore early and sensitive indicators, animal experiment was designed. Ninety-six healthy SD rats (48 males and 48 females) weighing approximately 60 g were randomly divided into six groups of 16 animals each by gender average. Control animals were supplied with distilled water only as group 1. Exposure groups' animals were treated with 2, 4, 8, 16, and 32 mg NaF/kg bw, respectively, as groups 2, 3, 4, 5, and 6. Our study found that contents of white blood cell (WBC), lymphocyte percentage (LYMPH%), lymphocyte (LYM), mean platelet volume (MPV), and platelet distribution width (PDW) increased significantly in high-fluoride-exposure groups (p < 0.05), which revealed that immune system may be interfered by high fluoride. Meanwhile, levels of alanine aminotransaminase (ALT), aspartate aminotransaminase (AST), and ALT/AST in groups 5 and 6 decreased significantly compared to those in control group (p < 0.05), as well as the concentration of uric acid (UA) in groups 3, 4, 5, and 6 exhibited the same trends (p < 0.05). On the contrary, the level of blood B2 microglobulin (BB2MG) increased significantly (p < 0.05) in groups 4, 5, and 6. Changes of ALT, AST, UA, and BB2MG suggested the functions of the liver and kidney be altered by fluoride exposure. At the same time, the ATF4 content decreased gradually with the increase of fluoride concentration; furthermore, a highly significant (r = -0.586, p < 0.01) negative relationship between ATF4 content and fluoride exposure level was found. Results meant that clinical indicators cannot act as indicators of high fluoride exposure, and it also suggested that protein ATF4 might be the early and sensitive indicator in epidemiologic study of high fluoride exposure.

Ameliorative effects of oleanolic acid on fluoride induced metabolic and oxidative dysfunctions in rat brain: Experimental and biochemical studies

Beneficial effects of oleanolic acid on fluoride-induced oxidative stress and certain metabolic dysfunctions were studied in four regions of rat brain. Male Wistar rats were treated with sodium fluoride at a dose of 20 mg/kg b.w./day (orally) for 30 days. Results indicate marked reduction in acidic, basic and neutral protein contents due to fluoride toxicity in cerebrum, cerebellum, pons and medulla. DNA, RNA contents significantly decreased in those regions after fluoride exposure. Activities of proteolytic enzymes (such as cathepsin, trypsin and pronase) were inhibited by fluoride, whereas transaminase enzyme (GOT and GPT) activities increased significantly in brain tissue. Fluoride appreciably elevated brain malondialdehyde level, free amino acid nitrogen, NO content and free OH radical generation. Additionally, fluoride perturbed GSH content and markedly reduced SOD, GPx, GR and CAT activities in brain tissues. Oral supplementation of oleanolic acid (a plant triterpenoid), at a dose of 5mg/kgb.w./day for last 14 days of fluoride treatment appreciably ameliorated fluoride-induced alteration of brain metabolic functions. Appreciable counteractive effects of oleanolic acid against fluoride-induced changes in protein and nucleic acid contents, proteolytic enzyme activities and other oxidative stress parameters indicate that oleanolic acid has potential antioxidative effects against fluoride-induced oxidative brain damage.

N. A multigrain protein enriched diet mitigates fluoride toxicity

Fluorosis is a major health problem in many parts of the world. The present work focuses on investigating the utility of nutrient and antioxidant rich grains- ragi, jowar, bajra, maize in formulation of basal, high carbohydrate low protein and low carbohydrate high protein diets in mitigating fluoride toxicity. Exposure to fluoride through drinking water not only significantly increased plasma glucose and lipid profiles, but also elevated both hepatic and renal lipid peroxidation, hepatic lipid profiles and G-6-Pase activity with a reduction in plasma HDL-C, hepatic glycogen content, hexokinase activity and antioxidant status. Even though basal and high carbohydrate diets did not significantly alter plasma glucose, lipid profiles in fluoride administered animals, protein enriched multigrain diet significantly decreased plasma glucose and lipid levels. However, the multigrain basal and high carbohydrate diets influenced the hepatic glycogen, lipid profiles, hexokinase and G-6-Pase activities, hepatic and renal lipid peroxidation and antioxidant status though not as significantly as that of multigrain diet enriched with protein. Thus the results of the present study indicate that both a multigrain diet rich in nutrients and antioxidants, and fortified with protein is useful in mitigating the fluoride toxicity.

Chronic fluoride toxicity and myocardial damage: antioxidant offered protection in second generation rats

This experiment was designed to investigate the extent of peroxidative changes and histological alterations in the myocardium of rats exposed to high fluoride for two generations, in addition to ameliorative role of selenium and vitamin E on the above indices. Adult albino Wistar rats were given fluoride through drinking water (200 ppm F) and maintained subsequently for two generations, while they were exposed to fluoride throughout the experiment. Fluoride treatment significantly increased the lipid peroxidation and decreased the activity of antioxidant enzymes, viz., catalase, superoxide dismutase, and glutathione level in auricle and ventricle regions of the heart. Decreased feed and water consumption, organ somatic index and marginal drop in body growth rate were observed. Decreased antioxidant enzymes and increased malondialdehyde levels might be related to oxidative damage that occurs variably in the myocardium of rats. Biochemical changes were supported by the histological observations, which also revealed that chronic exposure to fluoride causes damage to the myocardium. Results of this study can be taken as an index of cardio-toxicity in rats exposed to water fluoridation. Further, oral supplementation of selenium and vitamin E not only inhibited oxidative stress but also enhanced the activities of antioxidant enzymes. Administration of antioxidants during fluoride exposure significantly overcame cardiac fluoride toxicity and therefore may be a therapeutic strategy for fluorotic victims.

Changes of learning and memory ability and brain nicotinic receptors of rat offspring with coal burning fluorosis

The purpose of the investigation is to reveal the mechanism of the decreased ability of learning and memory induced by coal burning fluorosis. Ten offspring SD rats aged 30days, who were born from the mothers with chronic coal burning fluorosis, and ten offspring with same age from the normal mothers as controls were selected. Spatial learning and memory of the rats were evaluated by Morris Water Maze test. Cholinesterase activity was detected by photometric method. The expressions of nicotinic acetylcholine receptors (nAChRs) at protein and mRNA levels were detected by Western blotting and Real-time PCR, respectively. The results showed that in the rat offspring exposed to higher fluoride as compared to controls, the learning and memory ability declined; the cholinesterase activities in the brains were inhibited; the protein levels of alpha3, alpha4 and alpha7 nAChR subunits were decreased which showed certain significant correlations with the declined learning and memory ability; and the mRNA levels of alpha3 and alpha4 nAChRs were decreased, whereas the alpha7 mRNA increased. The data indicated that coal burning fluorosis can induce the decreased ability of learning and memory of rat offspring, in which the mechanism might be connected to the changed nAChRs and cholinesterase.

Effect of fluoride exposure on serum glycoprotein pattern and sialic acid level in rabbits

This study describes the effects of fluoride exposure on the protein profile, glycoprotein pattern, and total sialic acid concentration of serum in rabbits. For this aim; 20 healthy New Zealand rabbits were used. The rabbits were divided into two equal groups each with ten animals according to their weighing: control group and experimental group. The rabbits in control group were given drinking tap water containing 0.29 mg/l sodium fluoride and experimental group received the same tap water to which was added 40 mg/l sodium fluoride for 70 days. Blood samples were taken from each rabbit on day 70. Serum fluoride concentrations were measured by a fluoride-specific ion electrode in serum. The fluoride levels in the serum were found as 18.4 (+/-1.58) microg/L in control and 301.3 (+/-52.18) microg/L in fluoride exposed rabbits. The sialic acid levels were found as 69.2 (+/-0.32) mg/dL in control and 43.4 (+/-0.13) mg/dL in fluoride exposed group. The electrophoretic patterns of serum proteins, glycoproteins, and total sialic acid concentration were determined. Fifteen different protein fractions with molecular weights ranging from 22 to 249 kDa were displayed in the serum protein electrophoretic gel of both groups. The raw concentrations of the protein fractions decreased in fluoride exposed rabbits as compared with the control rabbits. The serum glycoprotein pattern revealed seven major protein bands from 47 to 167 kDa in experimental and control groups. The slight decrease of raw concentration of the protein bands in glycoprotein pattern of serum was observed in fluoride toxication comparing to control. The results suggest that serum TSA determination and serum protein electrophoresis can be used to evaluate prognosis of fluoride exposure as a supplementary laboratory test in combination with clinical and other laboratory findings of fluorosis.

Effects of sodium fluoride exposure on some biochemical parameters in mice: evaluation of the ameliorative effect of royal jelly applications on these parameters

Forty eight male Balb/c mice, each weighing 30-35 g, were used in the present study. The animals were divided into four equal groups. The first group served as the control group, and the second group was administered royal jelly at a dose of 50 mg/kg bw by gavage for a period of 7 days. The third group received 200 ppm fluoride, as sodium fluoride, for a period of 7 days, in drinking water. Lastly, the fourth group was given 200 ppm fluoride in drinking water, in association with royal jelly at a dose of 50 mg/kg bw by gavage, for a period of 7 days. At the end of the seventh day, blood samples were collected from all groups into heparinised and dry tubes, and liver samples were taken concurrently. Erythrocyte and liver tissue malondialdehyde (MDA) levels and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities were evaluated in the blood and tissue samples obtained. Furthermore, serum cholesterol, triglyceride, glucose, total protein and albumin levels, and aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alcaline phosphatase (ALP) activities were evaluated. In conclusion, fluoride was determined to cause adverse effects in mice, and the administration of royal jelly to these animals alleviated the adverse effects of fluoride.