Levels Of Boric Acid Research Articles

Impact of boric acid exposure at different concentrations on testicular DNA and male rats fertility

The aim of this study was to investigate the consequences of exposure to three levels of boric acid (BA) on male rats reproduction, fertility and progeny outcome, with emphasis on testicular DNA level and quality. Adult male rats (12 weeks old) were treated orally with 125, 250 and 500 mg/kg bwt/d of BA for 60 d. The results indicated that BA administration at 125 mg/kg bwt had no adverse effects on fertility, sperm characteristics or prenatal development of the impregnated females. However, at dose 250 mg, BA treatment significantly increased serum nitric oxide, testosterone, estradiol levels and testicular boron and calcium levels and also significantly reduced serum arginase activity, sperm quality and testicular DNA content with minor DNA fragmentation. The impact of BA exposure at dose 250 mg on male rats fertility was translated into increases in pre-implantation loss with a resulting decrease in the number of live fetuses/litter. In addition to the significant alteration of biochemical measurements, observed at dose 250 mg, administration of BA at 500 mg caused testicular atrophy, severe damage of spermatogenesis, spermiation failure and significant reduction of Mg and Zn testicular levels. None of the male rats, treated with 500 mg/kg bwt, could impregnate untreated females, suggesting the occurrence of definitive loss of fertility. In conclusion, BA impaired fertility, in a dose-dependant manner, by targeting the highly proliferative cells, the germ cells, through decreasing DNA synthetic rate rather than the induction of DNA damage.

Interactive effects of boron and NaCl stress on water and nutrient transport in two broccoli cultivars.

In arid regions, the water from aquifers usually contains high NaCl levels, and alternative water sources, such as desalination plants, produce boron accumulation and have an adverse effect on crops. We studied the water transport and membrane integrity of two broccoli (Brassica oleracea L.) cultivars (Naxos and Viola) in the response to two boric acid levels, (1.8mgL-1 and 4.3mgL-1), alone or in combination with salinity (0 or 80mM), and the involvement of plasma membrane intrinsic protein (PIP) aquaporins in this response. Nutritional status was also evaluated, as it affects the structural and functional integrity of the membranes. Since B is partly responsible for changes in the concentration and metabolism of phenolic compounds in vascular plants, these compounds were determined. In Naxos, the effect of 1.8mgL-1 B concentration on the plasma membrane influenced plant salinity tolerance through the associated changes in the root hydraulic conductivity and the recovery of biomass production with regard to the NaCl treatment. By contrast, in Viola, a different PIP abundance pattern was observed indicating that the threshold B concentration differs between Viola and Naxos, resulting in higher sensitivity. In fact, a decreased transpiration and photosynthetic rate observed in Viola after the addition of 4.3mgL-1 boric acid highlighted the highest sensitivity to boron, although this level had no adverse effect on the plasma membrane. The results suggest that B and NaCl trigger a hydric response involving aquaporins, together with changes in nutrient transport and plasma membrane stability.

Standardization of different media for in vitro pollen germination of almond and evaluation of the germination capacity of stored pollen

Almond is an important nut crop which, mostly for fruit set, needs the pollination of flowers followed by fertilization. Therefore, pollen viability and its germination capability are essential. To optimize the pollen culture medium of almond and standardization of the best medium, the present study was carried out with 48 different culture media containing different compositions, including diverse levels of boric acid (0 and 100 mg/L), calcium nitrate (0, 150 and 300 mg/l), magnesium sulphate (0 and 200 mg/l), potassium nitrate (0 and 100 mg/l), sucrose (10 and 15%) and agar (1%). Following the optimization of the best medium, pollen grains of three almond cultivars were cultured in the same optimized medium and subjected to three temperature treatments (15, 24 and 30°C) in order to determine the best thermal condition for pollen germination. Furthermore, the viability of stored pollens of these almond cultivars, three months after maintenance at 4, -20 and -80°C, was assessed through evaluation of their germination percentage using optimized medium. Maximum pollen germination (99.80%) was recorded in B2K1M2C1S2 medium containing boric acid (100 mg/l), magnesium sulphate (100 mg/l), potassium nitrate (0.0 mg/l), calcium nitrate (0.0 mg/l), sucrose (15%) and agar (1%), while the lowest (30.57%) was found in B1K1M2C3S1 medium containing boric acid (0.0 mg/l), potassium nitrate (0.0 mg/l), magnesium sulphate (100 mg/l), calcium nitrate (150 mg/l), sucrose (10%) and agar (1%). Pollen culture at 15 and 24°C showed better germination percentage than at 30°C. The data recorded for the pollen germination of stored pollens shows that Rabie pollen stored at -80°C has the highest germination rate (90.66%), while Touno pollen stored at 4°C has the lowest germination rate (36.66%). However, the findings of the present study may be of help to fruit breeders and anyone involved in pollen analysis studies. Keywords: In vitro , pollen viability, almond

Boric Acid Toxicity Trials on the Wood Borer <i>Heterobostrychus aequalis</i> Waterhouse (Coleoptera: Bostrychidae)

: Problem statement: The Heterobostrychus aequalis Waterhouse was a serious pest lumber of timber heveawood. The H. aequalis infest and tunnel along the wood grain, depositing eggs, which concomitantly turn into larvae and reduces the wood starch to a soft powder. The objectives of the study were to establish a suitable method for preservative trials on the wood borer and access the toxicity levels of boric acid for controlling the H. aequalis infestation. Approach: The voracious H. aequalis was collected from infested heveawood, mated and cultured on cassava. The adult beetles were exposed to boric acid treated cassava blocks as pilot trials. The boric acid concentration used was 1-5% including a control. Each treatment consists of five replicates. The voracious of H. aequalis generation was cultured for obtaining its freshly new emerged adult by exposing a number of H. aequalis directly from infested heveawood into artificial diet block and cassava. The mortality, weight loss of the test blocks, frass discharge duration and numbers of holes caused by H. aequalis were observed. Results: The results showed that the H. aequalis infested tended to penetrate the film after wrapping the heveawood with a layer of transparent cling film for 24 h experiment. The H. aequalis larvae stock cultured collected from infested heveawood exhibited differences in colour, activeness and aggression among males and females. The suitable test block size used was (2.0×5.0×1.5) cm3. The freshly emerged voracious of H. aequalis adults was more suitable than the larvae for boric acid toxicity trials. The 2% concentration was sufficiently killed the 4% boric acid treated test blocks. There was no hole observed on 5% boric acid treated test block and hence these concentrations were not infested by H. aequalis due to absence of frass in exposed blocks. Conclusion/Recommendations: There are noticeable physical and behavioural differences between voracious of H. aequalis collected from infested heveawood. The freshly emerged of H. aequalis adults were found suitable than the larvae as an indicator for determining the boric acid toxicity trials. The 5% of boric acid concentration was sufficient to control the infection of H. aequalis on heveawood. Further studies focusing on interaction between larvae, adults and population growth of H. aequalis with different hosts need to be carried out towards clarifying the predisposing factors that induce the infestation processes.

A case report of massive acute boric acid poisoning

Boric acid comes as colourless, odourless white powder and, if ingested, has potential fatal effects including metabolic acidosis, acute renal failure and shock. An 82-year-old male was brought to the emergency room 3 h after unintentional ingestion of a large amount of boric acid. Clinical course was monitored by collecting data at admittance, 12 h after admission, every 24 h for 5 days and again 1 week after admission. During the first 132 h, serum and urinary concentrations of boric acid were measured. Serum boric acid levels decreased from 1800 to 530 microg/ml after haemodialysis and from 530 to 30 microg/ml during the forced diuresis period. During dialysis, boric acid clearance averaged 235 ml/min with an extraction ratio of 70%. The overall patient's condition steadily improved over 84 h after admission. In conclusion, early treatment with forced diuresis and haemodialysis may be considered for boric acid poisoning, even if signs of renal dysfunction are not apparent, to prevent severe renal damage and its complications.

Successful Treatment of a Rare Case of Boric Acid Overdose With Hemodialysis

There is little published experience with the extracorporeal treatment of boric acid overdose, although the pharmacokinetic properties of boric acid suggest a potential role for hemodialysis. We report a rare case of potentially toxic boric acid overdose that was treated successfully with hemodialysis. Based on our experience in this patient and a review of previously reported cases, hemodialysis is effective in decreasing serum boric acid levels and should be considered in the treatment of patients with acute boric acid intoxication.

Preliminary report on yield productivity and mineral composition of the fig tree as a function of boron and cattle manure fertilization in Brazil

Introduction . Information correlating leaf nutrient contents to fig tree yield is still rare in Brazil. The objective of our research was to evaluate the effect of fertilization with boron and cattle manure on fig tree productivity and the leaf and fruit nutrient contents, and to estimate the extraction of nutrients by the crop. Materials and methods . The treatments consisted of five boric acid levels [(0, 20, 40, 60 and 100) g per plant] combined with two levels of cattle manure [(0 and 10) kg per plant]. The experimental design was in randomized blocks in a split-plot scheme with four replicates. The cattle manure levels constituted the plots, and the boron levels the subplots. We studied tree productivity, macronutrient and micronutrient leaf and fruit contents, amounts of nutrients extracted per ha and per crop yield, and fig tree leaf and fruit dry matter nutrient contents as a function of sampling dates. Results . Fruit yield productivity, average fruit weight and number of fruits per tree were not affected by B fertilization but they were by cattle manure levels, which increased the fig tree productivity. The macronutrient and micronutrient leaf and fruit contents obtained are discussed in relation to Brazilian results already published. The levels of cattle manure did not significantly affect the amount of nutrients extracted from green fig yield. The Mn, Zn and B leaf contents and the fruit extraction of Mn and B increased linearly with boric acid levels. The fig tree leaf nutrient contents varied with the plant physiological stages during its production cycle. Conclusion . These results should be taken into account for the development of fig tree fertilization programs in Brazil.

Efeito da adubação com boro e esterco bovino sobre a produtividade da figueira e as propriedades químicas do solo

O objetivo deste trabalho foi verificar o efeito da adubação da cultura da figueira com boro e esterco bovino sobre a produtividade de figos verdes e as propriedades químicas do solo. Os tratamentos foram cinco doses de ácido bórico (0, 20, 40, 60 e 100g planta-1) combinadas com dois níveis de adubação de esterco (sem esterco e 10kg de esterco/planta). O delineamento experimental foi o de blocos casualizados em esquema de parcelas subdivididas e quatro repetições. A adubação com ácido bórico não afetou a produtividade de figos, enquanto que o esterco bovino aumentou-a. Os teores de fósforo e potássio no solo aumentaram significativamente e o teor de alumínio diminuiu significativamente em função da adubação com esterco bovino. O teor de B no solo, extraído pelo método da água quente, aumentou linearmente em função das doses de ácido bórico.

Cellular changes in boric acid-treated DU-145 prostate cancer cells

Epidemiological, animal, and cell culture studies have identified boron as a chemopreventative agent in prostate cancer. The present objective was to identify boron-induced changes in the DU-145 human prostate cancer cell line. We show that prolonged exposure to pharmacologically-relevant levels of boric acid, the naturally occurring form of boron circulating in human plasma, induces the following morphological changes in cells: increases in granularity and intracellular vesicle content, enhanced cell spreading and decreased cell volume. Documented increases in β-galactosidase activity suggest that boric acid induces conversion to a senescent-like cellular phenotype. Boric acid also causes a dose-dependent reduction in cyclins A–E, as well as MAPK proteins, suggesting their contribution to proliferative inhibition. Furthermore, treated cells display reduced adhesion, migration and invasion potential, along with F-actin changes indicative of reduced metastatic potential. Finally, the observation of media acidosis in treated cells correlated with an accumulation of lysosome-associated membrane protein type 2 (LAMP-2)-negative acidic compartments. The challenge of future studies will be to identify the underlying mechanism responsible for the observed cellular responses to this natural blood constituent.

Silicic acid: boric acid complexes as wood preservatives

Wood was treated with a low molecular-weight silicic acid: boric acid agent and examined for increased resistance to termites and combustion. Wood treated with silicic acid only exhibited increased termite resistance, but not to the marked extent observed after treatment with a mixture of silicic and boric acids. Increasing the quantity of boric acid also increased the termite mortality rate and shortened the time to death. Oral-toxicity tests using dyed silicic acid: boric acid suggested that the boric acid in the agent acted as a stomach poison. Field tests on stakes over three years showed that even if stakes were placed near the termite exit, those treated with silicic acid and high levels of boric acid had no attack by termites and maintained their original form. Though these specimens were installed in the field during three rainy seasons (about six months in total) in three years, the termite resistance ability of these chemicals was maintained. It became clear that this silicic acid: boric acid agent has a high water resistance ability worthy of application in the outdoors. Combustion tests showed that flame and glowing combustion times were shortened at high levels of boric acid. When a boric acid: methanol solution was added at of rate of not less than 25 ml for 100 g of colloidal silicic acid solution (CSAS), flaming and glowing combustion were not observed. Although the charring length of the wood specimen which was treated with a low molecular weight silicic acid: boric acid agent decreased to 2/3 of that of the control wood, the charring lengths were not influenced by the level of boric acid. However, the volume of smoke decreased relative to the amount of boric acid that had been added.

Development of granular boric acid sugar baits for house flies (Diptera: Muscidae).

Freeze-dried, granular sugar baits containing boric acid as the toxicant were evaluated against house flies, Musca domestica L., in two bioassays with toxicant dose ranges of 3, 5, 7, 8, and 12%, and 3, 5, 9, 17, and 33% boric acid, respectively, calculated and expressed on a dry weight basis. Flies in bioassay 1 were mixed sex and unstarved and flies in bioassay 2 were females only and starved 4 h before testing began. LC50s were 8.97 and 14.33%, and LT50s were 59.75 and 53.34 h in bioassays 1 and 2, respectively. Baits were tested at concentrations as high as 33%, however there was no indication of repellency as seen previously with liquid baits. Reasons for lack of repellency and potential uses for baits are discussed. Development of efficacious granular baits would allow the presentation of higher levels of boric acid in volumes much smaller than required for liquid baits.

Assessing the effects of low boron diets on embryonic and fetal development in rodents using in vitro and in vivo model systems.

To date, boron (B) essentiality has not been conclusively shown in mammals. This article summarizes the results of a series of in vitro and in vivo experiments designed to investigate the role of B in mammalian reproduction. In the first study, rat dams were fed either a low (0.04 microg B/g) or an adequate (2.00 microg B/g) B diet for 6 wk before breeding and through pregnancy; reproductive outcome was monitored on gestation day 20. Although low dietary B significantly lowered maternal blood, liver, and bone B concentrations, it had no marked effects on fetal growth or development. The goal of the second study was to assess the effects of B on the in vitro development of rat postimplantation embryos. Day 10 embryos collected from dams fed either the low or adequate B diets for at least 12 wk were cultured in serum collected from male rats exposed to one of the two dietary B treatments. Dams fed the low B diet had a significantly reduced number of implantation sites compared to dams fed the B-adequate diet. However, embryonic growth in vitro was not affected by B treatment. The aim of study 3 was to define the limits of boric acid (BA) toxicity on mouse preimplantation development in vitro. Two-cell mouse embryos were cultured in media containing graded levels of BA (from 6 to 10,000 microM). Impaired embryonic differentiation and proliferation were observed only when embryos were exposed to high levels of BA (>2000 microM), reflecting a very low level of toxicity of BA on early mouse embryonic development. Study 4 tested the effects of low (0.04 microg B/g) and adequate (2.00 microg B/g) dietary B on the in vitro development of mouse preimplantation embryos. Two-cell embryos obtained from the dams were cultured in vitro for 72 h. Maternal exposure to the low B diet for 10, 12, and 16 wk was associated with a reduction in blastocyst formation, a reduction in blastocyst cell number, and an increased number of degenerates. Collectively, these studies support the concept that B deficiency impairs early embryonic development in rodents.

Effects of boric acid on axial skeletal development in rats.

Prenatal exposure to elevated levels of boric acid (BA) causes reduced incidences of supernumerary ribs and shortening/absence of the 13th rib in multiple laboratory species. To explore this further, Sprague-Dawley rats received 500 mg/kg b.i.d. on gestation days (gd) 5-9, 6-9, 6-10, or on single days between gd 6 and 11 (plug day = gd 0); gd-21 fetuses were stained for skeletal examination. Following multiday exposures, malformations of the axial skeleton involved the head, sternum, ribs, and vertebrae. Shortening/absence of the 13th rib was seen particularly in the gd 5-9 and 6-10 exposure groups. Although most groups exposed on single days were generally unaffected, about 90% of the gd-9 exposed fetuses had only six cervical vertebrae; the deficient region was usually C3-C5. In contrast, gd-10 treatment caused agenesis of a thoracic/lumbar vertebra in over 60% of the fetuses; the deficient region was usually T11. For 13-ribbed fetuses, the length of rib 13 was shortened compared to controls. Postnatal assessment suggested increased mortality for gd-10 exposed pups. Embryos in culture showed reduced development when exposed to BA for 48 h. These findings demonstrate the critical periods for axial development in the rat and provide an experimental model for the study of homeotic shifts.

Repellency of Aqueous Solutions of Boric Acid and Polybor 3 to House Flies (Diptera: Muscidae)

Mixed-sex 3- to 5-d-old adult house flies, Musca domestica (L.), were exposed in nonchoice, choice, and consumption tests to increasing levels of boric acid and polybor formulated in 10% sucrose to test for repellent effects. Results of nonchoice and choice tests suggested repellency to high levels of both borates. Consumption decreased at levels >2.25% boric acid and 3.0% polybor, with approximate intake of 0.102 and 0.161 mg of boron, respectively. Our results indicate that 2.25% boric acid and 3.0% polybor are optimal treatment levels.

Perak, Malaysia, mass poisoning. Tale of the Nine Emperor Gods and rat tail noodles.

In October 1988, a series of food poisoning cases occurred in the State of Perak in Malaysia. Most of the victims were children. Ultimately 13 children between the ages of 2.5 and 11 years died. Epidemiological investigations showed that the probable source of the poison was Loh See Fun, a noodles in the shape of a rat's tail. All the deceased ate the noodles from one supplier. Clinical and pathological findings were similar in each case. Postmortem examination was performed in 11 cases. Toxicological examination on organs in 10 cases showed a high concentration of aflatoxin in tissues of the deceased. High levels of boric acid were excreted from most of the victims. Histological examination of the liver in these cases showed necrotic changes found in aflatoxin poisoning. Combination of the epidemiological, clinical, toxicological, and pathological findings pointed to the fact that there was a common toxin or toxins responsible for the deaths. These were thought to be a combination of boric acid and aflatoxin.

Boric Acid

With the advent of boric acid insecticides, accidental ingestion of the compound can be encountered in animals. Toxic levels of boric acid most commonly cause vomiting, depression, and, occasionally, diarrhea. Boric acid is, however, cytotoxic to all cells. If a sufficiently high level is ingested, seizures, renal tubular nephrosis, and, rarely, hepatotoxicity may be noted. Gastrointestinal evaluation and supportive care are usually of primary therapeutic importance, although in severe cases, exchange transfusion and/or peritoneal dialysis may be required to decrease blood boron concentrations.

In Vitro Germination of Eucalyptus Pollen: Response to Variation in Boric Acid and Sucrose

The effect of boric acid (0-450 ppm) and sucrose (0-40%) on pollen germination and pollen tube growth in Eucalyptus globulus, E. morrisbyi, E. ovata and E. tirnigera was examined in vitro. Over the con- centrations tested, sucrose had by far the largest effect upon both pollen germination and tube lengths. The optimum sucrose concentration for pollen germination (30%) and pollen tube growth (20%) differed markedly with very little (<lo%) germination occurring in the absence of sucrose. The interaction of sucrose and boric acid was significant. However, in general both pollen germination and pollen tube growth were increased by the addition of up to 100 ppm boric acid, but above this level the response plateauxed. The four species differed significantly in their pattern of response to both boric acid and sucrose and the predicted optima derived from analysis of response surfaces differed between species. The predicted sucrose concentration for optimal germination and growth of E. urnigera pollen was consistently less than the other species and in terms of the optimal level of boric acid for pollen tube growth species can be ranked in the order E. globulus > E. ovata > E. morrisbyi = E. urnigera. Pollen germination and tube growth of all four species on a medium comprising 20% sucrose and 200 ppm boric acid would not differ significantly from the observed maximum response of each species and this could suffice as a generalised medium. However, if only percentage germination is to be assessed 30% sucrose would be preferable. It is argued that subtle interspecific differences in optimal in vitro con- ditions for pollen germination and pollen tube growth are likely to reflect differences in pollen physiology which in vivo may have important implications for the success of hybridisation where pollen competition occurs.

Clinical manifestations of toxicity in a series of 784 boric acid ingestions

A retrospective chart review was conducted at two regional poison centers to determine the clinical outcome of boric acid ingestions and to assess the relationship between serum boric acid levels and clinical presentation. A total of 784 cases were studied; all but 2 were acute ingestions. No patients developed severe manifestations of toxicity, and 88.3% were entirely asymptomatic. The most common symptoms were vomiting, abdominal pain, and diarrhea. Lethargy, headache, lightheadedness, and atypical rash were seen less frequently. Boric acid levels were obtained in 51 patients and ranged from 0 to 340 μg/mL. Blood levels were 70 μg/mL or more in 7 patients; 4 remained asymptomatic, whereas the other 3 had nausea or vomiting. Dialysis was performed in 4 of these 7 patients, only 1 of whom had symptoms (vomiting). On the basis of data from 9 patients, the mean half-life of boric acid was determined to be 13.4 hours (range, 4.0 to 27.8). Hemodialysis in 3 patients significantly shortened the half-life compared with pre- and postdialysis half-lives. Our results suggest that acute boric acid ingestions produce minimal or no toxicity and that aggressive treatment is not necessary in most patients.

Combined Boric Acid and Cinchocaine Chloride Poisoning in a 12-month-old Infant: Evaluation of Haemodialysis

A mixture containing 3 g of boric acid and 300 mg of cinchocaine chloride prescribed due to painful dental protrusion was accidentally ingested by a 12-month-old girl. She developed violent vomiting and coughing. Irritability, tremor, seizures and a delirious reaction. She was treated with diazepam, intubated, sedated and ventilated. Her diuresis was stimulated with furosemide and fluid. Within the first 24 h she was treated with haemodialysis twice on femoral catheters. Her renal function was unaffected. In two days she fully recovered. The maximum measured levels of boric acid and cinchocaine chloride approximately 6 h after ingestion were 26 micrograms/ml and 71 ng/ml respectively. The plasma half-life of boric acid was 7.0 h and decreased to 3.6 and 4.4 h during the two haemodialyses. The total body clearance of boric acid increased correspondingly from 21 ml/min to 41 and 34 ml/min. The in vitro clearance of boric acid of the dialyser was later determined to be 18 ml/min. It is concluded that haemodialysis is valuable in the treatment of boric acid intoxication because it increases the elimination of the drug even in patients without any sign of renal toxicity.

Ingestion of boric acid by infants

Boric acid solution was inadvertantly used to dilute concentrated formula and was fed to 24-day-old and 14-month-old siblings. Total amounts ingested were 2.6 g and 1.95 g, respectively. Symptoms of toxicity included irritability, diarrhea, and perineal erythema (in the younger child only). Peak boric acid levels were 147 μg/ml in the 24-day-old and 56 μg/ml in the 14-month-old. Peritoneal dialysis was utilized in the younger child, while the older child required only symptomatic care. Serum boric acid half-lives were approximately ten hours (24-day-old) and eight hours. Neither child developed severe toxicity; both were asymptomatic at one-month follow-up.