Germination and morphological responses of Triticum aestivum L. to different concentrations of fluoride

A laboratory experiment was conducted on germination papers to study the effect of fluoride (F) at 0 (T1), 50 (T2), 100 (T3), 200 (T4), 250 (T5) and 300 (T6) ppm on germination and morphological parameters in wheat (Triticum aestivum L.) variety, HUW-234 at 2, 4 and 6 days after initiation of germination process. Fluoride toxicity caused reduction in germination per cent, germination index, coefficient of velocity of germination and germination energy (%) while mean germination time increased with fluoride concentration. Root and shoot lengths and dry matters decreased with increased concentrations of fluoride. Ratio of root: shoot weight increased with increased concentration of fluoride. Elongation of seminal roots was adversely affected by increased fluoride level. Increased fluoride level in the germination medium decreased RGR of seedlings progressively. Present study revealed that enhanced fluoride concentration in germination medium caused reduction in germination and germination related parameters.

Molecular Mechanism of Changes in Gene Expression of Cytosolic Cu/Zn SOD, Lipid Peroxidation and Hepatic Function Impairments during Experimental Fluorosis

Background: Long term intake of high amount of fluoride leads to fluorosis causing metabolic, functional and structural damages affecting many tissues and organs including dental and skeletal manifestations. The liver is the most susceptible organ to fluoride toxicity because of its active and major role in digestion and detoxification. Aim: The present study aims to elucidate the effects of sodium fluoride on hepatic function biomarkers, lipid peroxidation and gene expression of Cu/Zn SOD in albino rats. Materials and Methods: Wistar albino rats were randomly assigned to three groups. The control rats were given 1 ml deionized water orally for 40 days. Groups II and III were administered 300 and 600 mg NaF/kg b.w. /day for the same period. Animals were sacrificed under anaesthesia, liver tissue was excised and used for biochemical and molecular analysis. The level of fluoride and lipid peroxidation (MDA) as well as reduced glutathione (GSH) content was determined. The activities of cytosolic copper/zinc superoxide dismutase (Cu/Zn SOD), aminotransferases (ALT and AST), lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) in the hepatic tissue were determined. The analysis of gene expression of Cu/Zn SOD in the liver was determined using Real-time PCR. Results: The results revealed significantly (P<0.0001) higher concentration of fluoride and MDA in the liver of rats exposed to fluoride when compared to control. The GSH content reduced significantly (P<0.0001) in fluorotic rats. The activities of hepatic function biomarkers viz; ALT, AST, LDH and ALP elevated significantly (P<0.0001) compared to the control. An elevation of 108.60% (ALP), 121.45% (AST), 33.77% (LDH) and least 24.40% (ALT) was found in rats treated with 300 mg/L fluoride and maximum elevation of 226.20% (ALP), 211.52% (AST), 57.75% (LDH) and least 56.79% (ALT) was registered in rats exposed to 600 mg/L fluoride in drinking water. The activity of cytosolic Cu/Zn SOD decreased significantly (P<0.0001) in fluorotic rats. Pearson’s bivariate correlation and simple linear regression analysis exhibited strong positive correlation between level of hepatic tissue fluoride and activities of ALT (Pearson r= 0.85), AST (Pearson r= 0.94), LDH (Pearson r= 0.89), ALP (Pearson r= 0.86) and in MDA (Pearson r=0.984) while negative correlations existed between levels of fluoride and GSH (Pearson r=-0.93) as well as activity of Cu/Zn SOD (Pearson r= -0.99). The gene expression of cytosolic Cu/Zn SOD was significantly (P<0.0001) reduced in fluorotic rats. Conclusion: The present study revealed that fluoride declined the antioxidant activity of hepatic Cu/Zn SOD at biochemical as well as molecular level which leads to oxidative stress and tissue damage. This further affirms by increased activities of hepatic function biomarkers in correlation with high fluoride level during experimental fluorosis.

Prophylaxis of caries with fluoride for children under five years

We looked at existing recommendations and supporting evidence on the effectiveness and potential harms of the different fluoride interventions in preventing dental caries in children under 5 years of age.We conducted a literature search up to the 12th of September 2019 by using key terms and manual search in selected sources. We summarized the recommendations and the strength of the recommendation when and as reported by the authors. We summarized the main findings of systematic reviews with the certainty of the evidence as reported.Water fluoridation has been widely implemented worldwide for several decades and evidence shows it reduces the prevalence of dental caries. Salt or milk fluoridation are other collective fluoride interventions that are also effective to prevent dental caries in children. The evidence of effects of oral fluoride supplements for caries prevention is limited and inconsistent. The use of fluoride toothpastes has consistently been proven to be effective in the prevention of dental caries. The evidence for the effects of the different levels of fluoride concentration in toothpastes is more limited. Topical fluorides (gels and varnishes) are effective in preventing dental caries and are mainly recommended to children with high risk of dental caries. Early childhood intake of fluoride supplements and fluoride level of 0.7 ppm (ppm) in drinking water are associated with the risk of dental fluorosis, ranging from minor forms to severe forms that are of aesthetic concerns.

The Efficiency of Natural Adsorbents to Remove Fluoride from Drinking Water: A Review

Widespread existence of fluoride above the desirable limit in ground water, reported that 17 states of India are facing endemic fluorosis problem. Excess amount of fluoride is being emitted due to increase in human activities. Businesses release effluents exceptionally stacked with fluoride. The over abundance of fluoride is destructive from numerous points of view this there is a need to cut down the fluoride level to the safe limits. For this reason the treatment of water is done using number of techniques like coagulation and flocculation, ion-exchange, electrochemical methods, nano filtration, adsorption etc. Adsorption is a significant process in which the fluoride is adsorbed on to a membrane or fixed bed. Activated carbon is a commonly used adsorbent for water and waste water treatment, but the main disadvantage of the activated carbon is the cost and rejuvenation difficulty. Many attempts are done to defluoride water from high concentration to permissible level, still the studies are going on to implement a user friendly defluoridation methods using low cost, sufficiently available and highly effective adsorbent.

Fluorine load in children

Aim. To study the association between the prevalence of caries and the fluorine load in children according to fluoride in the urine.Materials and methods. Fluoride level examination was conducted among 45 patients aged 3,6,12,15 years old. The assessment of the intensity of dental caries was carried out according to the KPU / kp index as recommended by WHO (1997). Dental examination in children was carried out in the Scientific Clinical Institute of Dentistry and Maxillofacial Surgery of the Ministry of Health and SZN of the Republic of Tajikistan, Dushanbe.Results and discussion. The fluorine status of breastfed children corresponded to a low level of fluoruria. In children aged 4-6 years fluorine load corresponded to a low level in 15.7% of the children, the optimal level was noted in 61.6% of the children, and a high level of the trace element over 2.5 mg/day was found in 22.7% of the children. High KPU index (3.1 and 5.7, respectively), determined in those cases where there was a low level of access to fluoride.Conclusion. In infants, the level of urinary fluoride excretion depends on the feeding pattern. The level of fluoruria in (60.0%) children aged 12 years and (66.6%) 15 years old was below the standard indicators. The intensity of caries in 15-year-old children was higher than in 12-year-old children.

Dental caries and its association with increasing water fluoride concentration in district Rudraprayag, Uttarakhand

Background: Evidence from scientific literature confirms both beneficial and detrimental effects of fluoride on human health with only a narrow range between intakes associated with these effects. The limits of this range have been controversial among researchers since the 1930s. Considering this, the World Health Organization (WHO) permissible limit of fluoride in India has been reduced from 1.5 to 1.0 mg/l in 1998. This study aimed to evaluate the association between increasing water fluoride levels and dental caries prevention on permanent teeth.Methods: This cross-sectional study involved 1400 children (aged 6–19 years). Caries experience and dental fluorosis were recorded using DMFT/deft and Dean's index respectively. Also, fluoride concentration in drinking water was analyzed. Around 14.4% of children had dental caries with maximum frequency among 9-10 years of age. A significant negative correlation between caries experience and water fluoride level was found (p<0.05), with the lowest DMFT scores at the fluoride level of 0.61–2 mg/l and the highest at 0.0–0.3 mg/l. Whereas, high prevalence of dental fluorosis was observed above 0.7 mg/l.Results: The study revealed that the presence of 0.3-0.7 mg/l fluoride in drinking water reduces dental caries, without an objectionable rise in dental fluorosis.Conclusions: It can be suggested that fluoride has anticaries property but due to a ‘narrow therapeutic window’ of 0.3-0.7 mg/l, in a country like India where endemic fluorosis is prevalent, its topical application should be encouraged which is almost equally effective with less systemic adverse effects.

Urinary Fluoride Levels among Canadians with and without Community Water Fluoridation

Drinking water is a major source of dietary fluoride intake in communities with water fluoridation. We examined the association between urinary fluoride adjusted for specific gravity (UFSG) and tap water fluoride levels, by age and sex, among individuals living in Canada. Participants included 1629 individuals aged 3 to 79 years from Cycle 3 (2012–2013) of the Canadian Health Measures Survey. We used multiple linear regression to estimate unique associations of tap water fluoride levels, age, sex, ethnicity, body mass index (BMI), use of fluoride-containing dental products, smoking in the home, and tea consumption with UFSG. UFSG concentration was significantly higher among participants who received fluoridated drinking water (mean = 1.06 mg/L, standard deviation = 0.83) than among those who did not (M = 0.58 mg/L, SD = 0.47), p < 0.01. UFSG increased over adulthood (ages 19 to 79). Higher UFSG concentration was associated with being female, tea drinking, and smoking in the home. In conclusion, community water fluoridation is a major source of contemporary fluoride exposure for Canadians. Lifestyle factors including tea consumption, as well as demographic variables such as age and sex, also predict urinary fluoride level, and are therefore important factors when interpreting population-based fluoride biomonitoring data.

Processing Mixed Mesopelagic Biomass from the North-East Atlantic into Aquafeed Resources; Implication for Food Safety

Aquaculture produces most of the world’s seafood and is a valuable food source for an increasing global population. Low trophic mesopelagic biomasses have the potential to sustainably supplement aquafeed demands for increased seafood production. The present study is a theoretical whole-chain feed and food safety assessment on ingredients from mesopelagic biomass and the resulting farmed fish fed these ingredients, based on analysis of processed mesopelagic biomass. Earlier theoretical estimations have indicated that several undesirable compounds (e.g., dioxins and metals and fluoride) would exceed the legal maximum levels for feed and food safety. Our measurements on processed mesopelagic biomasses show that only fluoride exceeds legal feed safety limits. Due to high levels of fluoride in crustaceans, their catch proportion will dictate the fluoride level in the whole biomass and can be highly variable. Processing factors are established that can be used to estimate the levels of undesirables in mesopelagic aquafeed ingredients from highly variable species biomass catches. Levels of most the studied undesirables (dioxins, PCBs, organochlorine pesticides, brominated flame retardant, metals, metalloids) were generally low compared to aquafeed ingredients based on pelagic fish. Using a feed-to-fillet aquaculture transfer model, the use of mesopelagic processed aquafeed ingredients was estimated to reduce the level of dioxins and PCBs by ~30% in farmed seafood such as Atlantic salmon.

JNK Signaling Pathway Mediates Fluoride-Induced Upregulation of CK1α during Enamel Formation

Fluorosis is a defect in the enamel mineral content caused by excessive fluoride intake during amelogenesis; the interaction of various factors in the development and progression of fluorosis has not been defined. Casein kinase 1α (CK1α) is constitutively active in cells and is involved in diverse cellular processes; however, its expression in fluorosis has not been measured. This study aimed to investigate the effects of fluoride on CK1α expression and to assess the regulation of molecular signaling involving fluoride and CK1α during enamel development. Kunming mice were randomly divided into the control and F groups with induced clinical features of fluorosis. The F group mice, including mothers and newborns, were treated with 50 ppm fluoridated water. Immunohistochemical staining of the sections of the embryonic mandible regions was performed at the bell stage. Protein expression and signaling pathways in a mouse-derived ameloblast-like cell line (LS8) exposed to fluoride or a Jun N-terminal kinase (JNK) inhibitor were compared to those in control cells without exposure. CK1α and proteins of the JNK signaling pathways were assayed by quantitative real-time PCR and Western blotting. Mice of the F group developed dental fluorosis. Scanning electron microscopy showed a significant reduction in the degree of mineralization in the F group mice, which manifested as thin, loosely arranged, and disorganized enamel rods. Additional analysis revealed that the expression of CK1α in the F group was significantly elevated compared with that in the control group; LS8 cells responded to fluoride by upregulation of CK1α expression through the JNK pathway. Our findings identified the potential effects of CK1α on fluorosis using a mouse model and revealed that a high fluoride level increases the expression of CK1α and that JNK can be a key regulatory factor in CK1α expression.