Arsenic Accumulation and Biotransformation Affected by Nutrients (N and P) in Common Blooming-Forming Microcystis wesenbergii (Komárek) Komárek ex Komárek (Cyanobacteria)

Arsenic accumulation and biotransformation in algae was mostly carried out in a medium that contained far higher nutrient concentrations than that in natural freshwaters. The obtained results might have limited environmental validity and result in a failure to describe authentic arsenic biogeochemical cycles in natural freshwater systems. To validate the assumption, arsenic accumulation, and biotransformation in common bloom forming Microcystis wesenbergii was performed under a high nutrient concentration in BG11 medium (N = 250 mg/L, P = 7.13 mg/L), and adjusted low nutrients that mimicked values in natural freshwaters (N = 1.5 mg/L, P = 0.3 mg/L). The growth rate and maximum M. wesenbergii cell density were much lower in the high nutrient set, but more inhibition was shown with increasing ambient iAs(V) concentrations both in the high and low nutrient sets. The proportion of intracellular contents in total arsenicals decreased with increasing iAs(V) concentrations in both high and low nutrient sets but increased with incubation time. Intracellular iAs(III) was not found in the high nutrient set, while it formed high concentrations that could be comparable to that of an extracellular level in the low nutrient set. M. wesenbergii could methylate arsenic, and a higher proportion of organoarsenicals was formed in the low nutrient set. Lower intracellular MMA(V) and DMA(V) concentrations were found in the high nutrient set; contrarily, they presented a higher concentration that could be comparable to the extracellular ones in the low nutrient set. The results demonstrated that different nutrient regimes could affect arsenic accumulation and biotransformation in M. wesenbergii, and low nutrient concentrations could inhibit the excretion of iAs(III), MMA(V) and DMA(V) out of cells. Further investigations should be based on natural freshwater systems to obtain an authentic arsenic accumulation and biotransformation in cyanobacteria.

The influences of lime and irrigation water on arsenic accumulation of rice, maize and mungbean in the nethouse condition

This research found the great hold of liming, soils and irrigation water on the arsenic (As) accumulation of rice, maize and mung bean in the nethouse research. Two greenhouse experiments had various plant types of rice, maize and mung bean with two soils inside and outside the dyke, two irrigated waters of 0.0 and 200 ?g As/L and three different lime ratios (0, 7.0 and 9.0 tons CaO/ha). The whole treatments were twenty one (12 treatments of experiment 1 and 9 of experiment 2) with 4 repetitions. The results of this study showed that the lime application raised both soil pH and crop yield. The arsenic (As) absorption of plant bodies in stems and seeds inside the dyke increased from 67.8 to 68.3% higher than those outside the dyke, respectively. The arsenic contents of stems and seeds with the treatments of 200 ?g As/L irrigation water were higher from 81.5 to 89.4% than that of non As irrigation water, respectively. The lime supplementation of 7.0 and 9.0 tons CaO per ha reduced the As accumulation of stems and seeds of rice, maize and mung bean was lower than the one without lime supplement from 38.6 (stems) and 54.5 (seeds). Mung bean absorbed the highest As, followed by rice and maize with the lowest As value. However, the lime supplementation of 9.0 tons CaO/ha had so high soil pH of soil that restricted the growth and yield of crops. More different lime concentrations need to search for more new details and new discovery of positive effects of this research.

Summary of four scientific studies on Arsenicum album high dilution effect against Arsenic intoxication in mice

Background: Groundwater arsenic affects millions of people in about 20 countries. In West Bengal (India) and Bangladesh alone over 100 million people are exposed. The arsenic concentration in contaminated groundwater in Bangladesh was above the maximum permissible level of 0.05 mg/l as recommended by WHO for developing countries [1]. Drinking water is not the only source of poisoning. In arsenic contaminated areas, crops, vegetables, cereals, poultry, cattle, etc, also contain traces of arsenic. Chronic arsenic intoxication has been associated with several diseases such as melanosis, leuco-melanosis, hyperkeratosis, oedema, skin cancer… Cazin et al [2], have demonstrated the effect of high dilutions of arsenic compounds. They noted increased arsenic elimination from blood through urine and faeces in intoxicated rats. According to these research, the aim of Khuda Buksh studies [3-4-5] was to investigate whether high dilution Arsenicum album have any effect on arsenic accumulation in different tissues and to understand also how this high dilution could produce a protective effect on all the different organs. Methodology: Firstly, the effect of Arsenicum album 30 cH on the amount of arsenic accumulation was determined by spectrophotometric analysis in four tissues namely liver, kidney and testis in mice intoxicated by arsenic. The protective effect in chronic and acute arsenic intoxicated mice of Arsenicum Album 6cH, 30cH and 200cH has been evaluated using not only the activities of enzymatic and biomarker toxicity (aspartate amino transferase (AST), alanine amino transferase (ALT), acid phosphatase (AcP), alkaline phosphatase (AlkP), lipid peroxidation (LPO) and reduced glutathione (GSH)) but also the cytogenetical parameters (chromosome aberrations (CA), mitotic index (MI), sperm head anomaly (SHA) etc., ). Because, it is well demonstrated that these enzymes biomarkers reflect the degree of hepatotoxicity and oxidative stress caused by arsenic intoxication. Results: Compared to controls, Arsenicum album 30cH induced a significant decrease in accumulation of arsenic in 4 tissues namely liver, spleen, kidney and testis in intoxicated mice. In addition, both Arsenicum album 6cH, 30cH and 200cH reduced chromosome aberrations, sperm head abnormality frequencies and activities of acid and alkaline phosphatases, aspartate and alanine aminotransferases and lipid peroxidation, while mitotic index and activities of glutathione, catalase and succinate dehydrogenase were increased compared to controls. Conclusion: Altogether, theses results provide evidence of protective potentials of the Arsenicum album dilution against acute and chronic arsenic intoxication in mice. They also offer a new hypothesis that the mechanism of the homeopathic dilution could act through regulation of expression of certain genes. This explanation seems to be plausible because all biomarker tests are regulated by specific genetic regulatory mechanisms [6]. keywords: Arsenicum album, arsenic intoxication, enzymatic and biomarker toxicity. References: [1] WHO. WHO Guidelines for Drinking Water Quality, Vol. 2, 2nd edition. Geneva: WHO, 1996, 940–9. [2] Cazin JC, Cazin M, Gaborit JL, Chaoui A, Boiron J, Belon P, et al. A study of the effect of decimal and centesimal dilutions of arsenic on the retention and mobilization of arsenic in the rat. Hum Toxicol 1987;6:315–20. [3] Mitra K, Kundu SN, Khuda-Bukhsh AR. Efficacy of a potentized homoeopathic drug (Arsenicum Album-30) in reducing toxic effects produced by of arsenic trioxide in mice. I. On rate accumulation of arsenic in certain vital organs. Comp Ther Med 1998;6:178–84. [4] Pathikrit Banerjee. Evidences of Protective Potentials of Microdoses of Ultra-high Diluted Arsenic Trioxide in Mice Receiving Repeated Injections of Arsenic Trioxide. eCAM 2009; 1-10. [5] Pathikrit Banerjee, Comparative Efficacy of Two Microdoses of a Potentized Homeopathic Drug, Arsenicum Album, to Ameliorate Toxicity Induced by Repeated Sublethal Injections of Arsenic Trioxide in Mice. Pathobiology 2008;75:156–170. [6]/ Khuda-Bukhsh AR. Potentized homeopathic drugs act through regulation of gene expression: a hypothesis to explain their mechanism and pathways of action in vivo. Comp Ther Med 1997;5:43–6

Effect of Soil Water Contents on Arsenic Accumulation in Phytoliths of Pteris Multifida and Phragmites Australis

Purpose: The encapsulation of toxic metal(loid)s in phytoliths represents a new area of research. The accumulation of metal(loid)s in phytoliths can alter the fate and toxicity of soil metal(loid). Pteris multifida is a well-known As hyperaccumulator which also harbors phytoliths. However, As accumulation in phytoliths has not yet been studied. Soil water content is considered the main factor influencing phytolith accumulation and also remains unexplored with respect to As accumulation in phytoliths. In this study, As concentration in the phytoliths of P. multifida was compared with that in Phragmites australis phytoliths as a function of the soil water content. Methods: P. multifida and P. australis were grown under different soil water contents. The As concentration in phytoliths, roots, and shoots of plants was then determined.Results: The range of As concentration in the phytoliths of P. multifida was 414.70 - 1610.74 mg kg-1, and that for P. australis phytoliths was 41.67 - 126.54 mg kg-1. In P. multifida, higher soil water content increased As accumulation in phytoliths but did not affect phytolith content in the plant. In P. australis, the higher soil water content increased phytolith content in the plant but decreased As concentration in phytoliths. Conclusion: This study suggests that P. multifida has higher As content in phytoliths than P. australis, and this accumulation can be affected by soil water content. The current findings provide insight into the accumulation of As in phytoliths and provide a theoretical basis for our understanding on the fate of As in the environment.

Interferences of Inorganic Arsenic (III & V) on Growth and Development of Rice (Oryza sativa L.) With Special Emphasis on Root and Coleoptile Growth

A short-term phytotoxicity experiment was conducted on four varieties of rice (Oryza sativa L.) under the influence of arsenic (III & V) to evaluate the impact on root and coleoptiles growth. Four varieties (GB-1, IET-4786, IET-4094, and MTU-1010) of rice were undertaken for this study with different concentrations (0, 5, 10, 25 and 50 mg/L) of arsenic (III & V). Germination along with mean daily germination (MDG), length of root and coleoptile, water holding capacity of root and coleoptiles, fresh and dry weight, arsenic accumulation, MDA and root ion leakage were evaluated. Results highlighted that the percent germination of IET-4094 and MTU-1010 varieties of rice seed over control decreased significantly (p < 0.05) with increasing concentration of both arsenite and arsenate. However, the percent germination of GB-I and IET-4786 dose not affected on the different concentration of both arsenate and arsenite. The root and coleoptile length of all the four varieties showed remarkable decreasing trend over control with increasing concentration of both arsenite and arsenate. However, more pronounced effects were observed for arsenite than arsenate. Similarly, biomass of shoot is less affected than root under different concentration of arsenite and arsenate. The variety IET-4786 and MTU-1010, accumulated lower level of arsenic and variety GB-1 accumulate higher level of MDA level in root under both arsenite and arsenate treatments. Therefore, it can be concluded that the variety IET-4786 and MTU-1010 are the suitable varieties towards phytoremediation of both arsenite and arsenate. Moreover, farmers of arsenic contaminated area are recommended to cultivate IET-4786 and MTU-1010 varieties.