α-HgS is the main component of traditional Chinese medicine cinnabar, while β-HgS is the main component of Tibetan medicine Zuotai. However, there was no comparative study on the dissolution and absorption in gastrointestinal tract and bioaccumulation in organs of mercury in Cinnabar, Zuotai, α-HgS and β-HgS. In this study, the dissolution process of the four compounds in the human gastrointestinal tract was simulated to determine the mercury dissolutions and compare the mercury dissolution of different medicines and the dissolution-promoting capacity of different solutions. To explore the absorption and bioaccumulation of cinnabar and Zuotai in organisms, mice were orally administered with clinical equivalent doses cinnabar and Zuotai. Meanwhile, a group of mice was given α-HgS and β-HgS with the equivalent mercury with cinnabar, while another group was given β-HgS and HgCl2 with the equivalent mercury with Zuotai. The mercury absorption and bioaccumulation capacities of different medicines in mice and their mercury bioaccumulation in different tissues and organs were compared. The experimental results showed a high mercury dissolutions of Zuotai in artificial gastrointestinal fluid, which was followed by β-HgS, cinnabar and α-HgS. As for the mercury absorption and bioaccumulation in mice, HgCl2 was the highest, β-HgS was the next, and a-HgS was slightly higher than cinnabar. The organs with the mercury bioaccumulation from high to low were kidney, liver and brain. This study is close to clinical practices and can provide reference for the clinical safe medication as well as a study model for the safety evaluation on heavy metal-containing medicines by observing the mercury dissolution, absorption, distribution and accumulation of mercury-containing medicines cinnabar and zuotai.
Animals ; Brain ; metabolism ; Drugs, Chinese Herbal ; chemistry ; pharmacokinetics ; Gastrointestinal Tract ; metabolism ; Kidney ; metabolism ; Liver ; metabolism ; Male ; Mercury ; chemistry ; pharmacokinetics ; Mercury Compounds ; chemistry ; pharmacokinetics ; Mice ; Solubility

Mercury is a toxic and non-essential metal in the human body. Mercury is ubiquitously distributed in the environment, present in natural products, and exists extensively in items encountered in daily life. There are three forms of mercury, i.e., elemental (or metallic) mercury, inorganic mercury compounds, and organic mercury compounds. This review examines the toxicity of elemental mercury and inorganic mercury compounds. Inorganic mercury compounds are water soluble with a bioavailability of 7% to 15% after ingestion; they are also irritants and cause gastrointestinal symptoms. Upon entering the body, inorganic mercury compounds are accumulated mainly in the kidneys and produce kidney damage. In contrast, human exposure to elemental mercury is mainly by inhalation, followed by rapid absorption and distribution in all major organs. Elemental mercury from ingestion is poorly absorbed with a bioavailability of less than 0.01%. The primary target organs of elemental mercury are the brain and kidney. Elemental mercury is lipid soluble and can cross the blood-brain barrier, while inorganic mercury compounds are not lipid soluble, rendering them unable to cross the blood-brain barrier. Elemental mercury may also enter the brain from the nasal cavity through the olfactory pathway. The blood mercury is a useful biomarker after short-term and high-level exposure, whereas the urine mercury is the ideal biomarker for long-term exposure to both elemental and inorganic mercury, and also as a good indicator of body burden. This review discusses the common sources of mercury exposure, skin lightening products containing mercury and mercury release from dental amalgam filling, two issues that happen in daily life, bear significant public health importance, and yet undergo extensive debate on their safety.
Biological Availability ; Biological Markers/blood/urine ; Blood-Brain Barrier/metabolism ; Body Burden ; Dental Amalgam/chemistry/metabolism ; *Environmental Exposure ; Humans ; Mercury/chemistry/*metabolism ; Mercury Compounds/chemistry/*metabolism ; Skin Lightening Preparations/chemistry/metabolism

Mercury is a global pollutant. Children are vulnerable to environmental toxicants. Seafood consumption is a major source of methylmercury exposure. In order to ascertain children's mercury exposure levels and study their relationship with seafood consumption, we conducted a cross-sectional study among preschool children in Shanghai. According to our data, the geometric mean of the mercury levels in children's hair was 191.9 (95% CI: 181.8, 202.4) μg/kg. These results indicate that high income may be a predictor of elevated mercury levels in children's hair. Intake of marine fish, especially tuna and pomfret, was documented in our study and found to increase the risk of high mercury levels. Frequency of fish consumption was positively related with hair mercury levels. Our study is the first to provide baseline data for hair mercury concentration among preschool children in Shanghai.
Child, Preschool ; China ; Food Contamination ; Hair ; chemistry ; Humans ; Mercury ; chemistry ; metabolism ; Seafood ; analysis ; Socioeconomic Factors ; Water Pollutants, Chemical ; chemistry

Mercury is emitted to the atmosphere from various natural and anthropogenic sources, and degrades with difficulty in the environment. Mercury exists as various species, mainly elemental (Hg0) and divalent (Hg2+) mercury depending on its oxidation states in air and water. Mercury emitted to the atmosphere can be deposited into aqueous environments by wet and dry depositions, and some can be re-emitted into the atmosphere. The deposited mercury species, mainly Hg2+, can react with various organic compounds in water and sediment by biotic reactions mediated by sulfur-reducing bacteria, and abiotic reactions mediated by sunlight photolysis, resulting in conversion into organic mercury such as methylmercury (MeHg). MeHg can be bioaccumulated through the food web in the ecosystem, finally exposing humans who consume fish. For a better understanding of how humans are exposed to mercury in the environment, this review paper summarizes the mechanisms of emission, fate and transport, speciation chemistry, bioaccumulation, levels of contamination in environmental media, and finally exposure assessment of humans.
Air Pollutants/chemistry/metabolism ; *Environmental Exposure ; Environmental Remediation ; Food Chain ; Humans ; Mercury/chemistry/*metabolism ; Methylmercury Compounds/chemistry/metabolism ; Photolysis ; Sulfur-Reducing Bacteria/metabolism ; Water Pollutants, Chemical/metabolism

Mercury-containing preparations are widely used in surgery department of traditional Chinese medicine and have made remarkable achievements. But they are toxic to human kidney, nerve, immune, etc. Smilacis Glabrae Rhizoma is sweet, tasteless and neutral in nature and able to enter liver and stomach channels and detoxify mercury poisoning. This article summarizes the mercury poisoning and the detoxification effect of Smilacis Glabrae Rhizoma in ancient records, pharmaceutical studies and clinical application, in order to provide ideas and methods for the safe use of mercury-containing preparations in surgery department of traditional Chinese medicine.
Drugs, Chinese Herbal ; therapeutic use ; Humans ; Inactivation, Metabolic ; Liliaceae ; chemistry ; Liver ; drug effects ; metabolism ; Medicine, Chinese Traditional ; Mercury Compounds ; adverse effects ; pharmacokinetics ; therapeutic use ; Mercury Poisoning ; prevention & control ; Plants, Medicinal ; chemistry ; Rhizome ; chemistry ; Stomach ; drug effects ; metabolism

OBJECTIVETo study comparatively the characteristics of absorption and distribution of mercury and arsenic from realgar and cinnabar of Angong Niuhuang Pill in normal rats and the rats with cerebral ischemia after oral administration.

METHODThe blood samples and homogenates of liver, kidney and brain were prepared at various intervals after the animals were treated with Angong Niuhuang pill ig. The levels of total mercury and total arsenic in the blood and the organ homogenates were measured with Microwava Accelerated Reaction System and AAs, respectively.

RESULTThe blood concentrations of mercury and arseic reached the highest point in normal rats at one hour following single oral dosing of Angong Niuhuang pill. In normal rats, the mercury distribution was characterized by its higher level in blood and kidneys than in other organs, while a higher distribution of arsenic was found in blood than in organs. No difference in the distribution of mercury or arsenic was found between normal rats and rats with cerebral ischemia after the treatment with the pill.

CONCLUSIONThe highest level of mercury or arsenic in blood occurs at one hour after oral administration of the pill in normal rats. There is a higher distribution of mercury in blood and kidneys, while a higher distribution of the arsenic only in blood. There is no significant difference in the distribution of mercury or arsenic between the normal rats and the ischemic rats.

Animals ; Arsenic ; blood ; metabolism ; Arsenicals ; pharmacokinetics ; Brain Ischemia ; metabolism ; Drug Combinations ; Drugs, Chinese Herbal ; isolation & purification ; pharmacokinetics ; Male ; Materia Medica ; isolation & purification ; pharmacokinetics ; Mercury ; blood ; metabolism ; Mercury Compounds ; pharmacokinetics ; Plants, Medicinal ; chemistry ; Rats ; Sulfides ; pharmacokinetics ; Tissue Distribution

beta-mannanase (EC 3.2.1.78) from Bacillus subtilis SA-22 was purified successively by ammonium sulfate precipitation, hydroxyapatite chromatography, Sephadex G-75 gel filtration and DEAE-52 anion-exchange chromatography. Through these steps, the enzyme was concentrated 30.75-fold with a recovery rate of 23.43%, with a specific activity of 34780.56 u/mg. Molecular weight of the enzyme was determined to be 38 kD by SDS-PAGE and 34 kD by gel filtration. The results revealed that the optimal pH value for the enzyme was 6.5 and the optimal temperature was 70 degrees C. The enzyme is stable between pH 5 to 10. The enzyme remained most of its activity after a treatment of 4 h at 50 degrees C, but lost 25% of activity at 60 degrees C for 4 h, lost 50% of activity at 70 degrees C for 3 h. The enzyme activity was strongly inhibited by Hg2+. The Michaelis constants (Km) were measured as 11.30 mg/mL for locust bean gum and 4.76 mg/mL for konjac powder, while Vmax for these two polysaccharides were 188.68 (micromol x mL(-1) x min(-1)) and 114.94 (micromol x mL(-1) x min(-1)), respectively.
Bacillus subtilis ; enzymology ; Chromatography, Gel ; Chromatography, Ion Exchange ; Electrophoresis, Polyacrylamide Gel ; Enzyme Activation ; drug effects ; Hydrogen-Ion Concentration ; Kinetics ; Mannosidases ; chemistry ; isolation & purification ; metabolism ; Mercury ; pharmacology

The environmental pollution by heavy metals such as mercury, cadmium and lead has become a worldwide public health hazard. To rapidly and inexpensively monitor environmental heavy metals is a prerequisite for minimizing human and animal exposure. The development of immunoassays to detect mercury ion residues has been a promising trend with the advantage of rapid and cheap operation. We reported the isolation and characterization of mercury-specific monoclonal antibodies. Because Hg2+ ions are too small to elicit an immune response, the metal was coupled to protein carrier (keyhole limpet, KLH) using a chelator (diethylenetriamine pentaacetic acid, DTPA). After the synthesis of antigen and characterization, monoclonal antibodies against mercury ions were generated by immunizing BALB/c mice with mercury conjugated antigen (Hg-DTPA-KLH). The stable hybridoma cell lines were produced by fusion of murine splenocytes and SP2/0 myeloma cells. The hybridoma cells were subcloned by the limiting dilution and screened by ELISA, two hybridoma cell lines producing stably specific monoclonal antibodies (MAbs) against mercury ions were obtained, named H2H5 and H1H8. The ascites fluid was produced in BABL/c mice by intraperitoneal injection of 1 x 10(7) H2H5 and H1H8 cells, respectively. The titers of ascites were all above 1:51 200. The isotyping of secrete antibodies from two hybridoma cell lines was IgG1, kappa type. These data laid a potency of establishing immunoassays methods of determining Hg2+ ion residues and had the realistic significance for improving the efficiency and quality of risk assessment.
Animals ; Antibodies, Monoclonal ; biosynthesis ; immunology ; Chelating Agents ; chemistry ; Environmental Pollutants ; analysis ; immunology ; Female ; Hybridomas ; metabolism ; Immunoassay ; methods ; Mercury ; analysis ; immunology ; Mice ; Mice, Inbred BALB C

OBJECTIVEBloom's syndrome is an autosomal recessive disorder characterized by genomic instability and a predisposition to many cancers. Mutations of the BLM gene (encoding a BLM helicase) may form a structure of the etiology of this disease. As a global pollutant, mercury poses a major threat to human health. The current study was conducted to elucidate the effects of Hg(2+) on the structure and activity of BLM642-1290 recombinant helicase, and to further explore the molecular mechanisms of mercury toxicity to the DNA helicase.

METHODSThe effects of Hg(2+) on biological activity and structure of BLM642-1290 recombinant helicase were determined by fluorescence polarized, ultraviolet spectroscopic, and free-phosphorus assay technologies, respectively.

RESULTSThe helicase activity, the DNA-binding activity, and the ATPase activity of BLM642-1290 recombinant helicase were inhibited by Hg(2+) treatment. The LMCT (ligand-to-metal charge transition) peaks of the helicase were enhanced with the increase of the Hg(2+) level. The LMCT peaks of the same concentration of helicase gradually increased over time.

CONCLUSIONThe biological activity of BLM642-1290 recombinant helicase is inhibited by Hg(2+) treatment. The conformation of the helicase is significantly altered by Hg(2+). There exist two binding sites between Hg(2+) and the helicase, which are located in the amino acid residues 1063-1066 and 940-944 of the helicase, respectively.

Adenosine Triphosphatases ; metabolism ; Base Sequence ; DNA Primers ; Fluorescence Polarization ; Humans ; Mercury ; toxicity ; Protein Conformation ; RecQ Helicases ; chemistry ; drug effects ; metabolism ; Recombinant Proteins ; chemistry ; drug effects ; metabolism ; Spectrophotometry, Ultraviolet ; Structure-Activity Relationship

Methylmercury is a hazardous substance that is of interest with regard to environmental health, as inorganic mercury circulating in the general environment is dissolved into freshwater and seawater, condensed through the food chain, ingested by humans, and consequently affects human health. Recently, there has been much interest and discussion regarding the toxicity of methylmercury, the correlation with fish and shellfish intake, and methods of long-term management of the human health effects of methylmercury. What effects chronic exposure to a low concentration of methylmercury has on human health remains controversial. Although the possibility of methylmercury poisoning the heart and blood vessel system, the reproductive system, and the immune system is continuously raised and discussed, and the carcinogenicity of methylmercury is also under discussion, a clear conclusion regarding the human health effects according to exposure level has not yet been drawn. The Joint FAO/WHO Expert Committee on Food Additives proposed to prepare additional fish and shellfish intake recommendations for consumers based on the quantified evaluation of the hazardousness of methylmercury contained in fish and shellfish, methylmercury management in the Korea has not yet caught up with this international trend. Currently, the methylmercury exposure level of Koreans is known to be very high. The starting point of methylmercury exposure management is inorganic mercury in the general environment, but food intake through methylation is the main exposure source. Along with efforts to reduce mercury in the general environment, food intake management should be undertaken to reduce the human exposure to methylmercury in Korea.
Animals ; *Environmental Exposure ; Fishes/metabolism ; Food Chain ; Humans ; Mercury Poisoning, Nervous System/etiology ; Methylmercury Compounds/chemistry/*metabolism/toxicity ; Neurons/drug effects ; Oxidative Stress/drug effects ; Public Health ; Reproduction/drug effects ; Thymocytes/cytology/drug effects