• Toxicological Research
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• 제29권4호
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• pp.285-292
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• 2013

Ginseng is a well-known traditional medicine used in Asian countries for several thousand years, and it is currently applied to medicine, cosmetics, and nutritional supplements due to its many healing and energygiving properties. It is well demonstrated that ginsenosides, the main ingredient of ginseng, produce a variety of pharmacological and therapeutic effects on central nerve system (CNS) disorders, cardiovascular disease, endocrine secretions, aging, and immune function. Korean red ginseng extract is a dietary supplement containing ginsenoside Rb1 and ginsenoside Rg1 extracted from Panax ginseng. While the pharmacokinetics and bioavailability of the extract have been well established, its toxicological properties remain obscure. Thus, four-week oral toxicity studies in rats were conducted to investigate whether Korean red ginseng extract could have a potential toxicity to humans. The test article was administered once daily by oral gavage to four groups of male and female Sprague-Dawley (SD) rats at dose levels of 0, 500, 1,000, and 2,000 mg/kg/day for four weeks. Neither deaths nor clinical symptoms were observed in any group during the experiment. Furthermore, no abnormalities in body weight, food consumption, ophthalmology, urinalysis, hematology, serum biochemistry, gross findings, organ weights, or histopathology were revealed related to the administration of the test article in either sex of any dosed group. Therefore, a target organ was not determined in this study, and the no observed adverse effect level (NOAEL) of Korean red ginseng extract was established to be 2,000 mg/kg/day.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권3호
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• pp.15-24
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• 2014

Soil pollution has been recognized as a serious problem because it causes groundwater pollution through medium contacts. Although concentration of individual chemical could be more easily measured by physico-chemical analysis, it is not easy to consider the bioavailability of edaphic receptors living in soil or groundwater. To measure the toxicity of soil, the soil extracts (soil elutriates or soil suspensions in the other words) are often used due to the difficulties of extracting soil pore water. In this study, we reviewed 15 toxicity test methods found in literature to analyze the detail of each extraction method and to recommend the most frequently used extraction methods. The identified most commonly used extraction methods are as following: The 1 : 4 soil:water ratio, 24 hours shaking time, room temperature, dark, and separation of supernatant using a $0.45{\mu}m$ pore size filter.

• 한국토양비료학회지
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• 제49권6호
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• pp.644-650
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• 2016

In soil-to-plant transfer of heavy metals, the amount absorbed and accumulated varies depending on the environment conditions. The absorption rate of cadmium (Cd) in plants differs considerably depending on the bioavailability of Cd in the soil, while usage by various organic matters is also reported to affect absorption patterns. Therefore, this study aimed to identify the difference in the transfer of essential metal ions and Cd to various plant parts when rice straw compost was used to cultivate soybean (Glycine max L. cv. Daepung). In the two-leaf stage of soybean cultivated in a greenhouse, Cd was mixed in the soil, after which the Cd and essential metal ions contents, and physiological changes of soybean seedlings were studied on the 15th and 25th day. The Cd toxicity in the plant was reduced with the use of rice straw compost. Further, the Cd content varied with the plant part, and was higher in young leaves (3rd and 4th leaf) than in the stem. When analyzed by leaf age, the Cd transfer was highest in young leaves (3rd and 4th leaf), followed by mature leaves (1st and 2nd leaf). While there was no significant difference between plant tissues in the absorption rate of copper (Cu) and zinc (Zn) when rice straw compost was used against Cd toxicity, the absorption rate of manganese (Mn) and iron (Fe) showed a significant decline in both the control and rice straw compost treatment conditions, as well as a significant difference between leaf ages. Therefore, these results confirm that the use of rice straw compost against Cd toxicity is effective, and implies that the rate of Cd transfer in the soybean plant varies significantly with leaf age.

• Journal of Dairy Science and Biotechnology
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• 제36권4호
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• pp.187-195
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• 2018

Nano-delivery systems, such as nanoparticles, nanoemulsions, and nanoliposomes, are carriers that have been used to enhance the chemical as well as physical stability and bioavailability of bioactive compound. Food-grade nano-delivery system can be produced with edible biopolymers including proteins and carbohydrates. In addition to the low-toxicity, biocompatibility, and biodegradability of these biopolymers, their functional characteristics, such as their ability to bind hydrophobic bioactive compounds and form a gel, make them potential and ideal candidates for the fortification of bioactive compounds in functional dairy foods. This review focuses on different types of nano-delivery systems and edible biopolymers as delivery materials. In addition, the applications of food-grade nano-delivery systems to dairy foods are also described.

• Journal of Pharmaceutical Investigation
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• 제40권spc호
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• pp.45-61
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• 2010

Polymeric based nanomedicines have been developed for diagnosing, treating, and preventing diseases in human body. The nanosized drug delivery systems having various structures such as micelles, nanogels, drug-conjugates, and polyplex were investigated for a great goal in pharmaceutics: increasing therapeutic efficacy for diseases and decreasing drug toxicity for normal tissues. The functional polymers used for constituting these drug delivery systems should have several favorable properties such as stimuli-responsibility and biodegrdability for controlled drug release, and solublization capacity for programmed drug encapsulation. This review discusses recent developments and trends of functional polymers (e.g., pH-sensitive polymers, biodegradable polymers, and cationic polymers) used for nanosized drug carriers.

• 한국잡초학회지
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• 제17권1호
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• pp.73-79
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• 1997

Governments and industry have a growing interest in the harmonization of environmental test methods and risk assessment procedures. OECD are currently producing a set of harmonised test guidelines for studying the environmental fate and ecological effects of pesticides. FAO has published an environmental risk assessment procedure. This procedure, which is similar to those used in US and Europe, is based on calculating the ratio of the toxicity of a pesticide to indicator organisms to their level of exposure to the pesticide. The exposure depends on both the concentration of the pesticide and its bioavailability. Ratios which indicate a pesticide will not produce a harmful effect have been established using ecological field studies. Examples are presented for assessing the risk to aquatic ecosystems, earthworms and honeybees. Long-term field studies(up to 20 years) have also shown that pesticides can be used indefinitely without harming soil fertility. Herbicides can be used to avoid the ecologically damaging effects of using soil cultivations excessively for weed control.

• Journal of Preventive Medicine and Public Health
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• 제45권6호
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• pp.344-352
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• 2012

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.

• Mass Spectrometry Letters
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• 제12권4호
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• pp.200-205
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• 2021

Polynemoraline C, a pyridocoumarin alkaloid, exhibits anticholinergic, anti-inflammatory, antitumor, and antimicrobial activities. A sensitive analytical method of polynemoraline C in mouse plasma was developed and validated using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Polynemoraline C and ¹³C-caffeine (internal standard) in mouse plasma were extracted using a liquid-liquid extraction method coupled with ethyl acetate. This extraction method resulted in high and reproducible extraction recovery in the range of 73.49%-77.31% with no interfering peaks around the peak retention time of polynemoraline C and ¹³C-caffeine. The standard calibration curves for polynemoraline C were linear over the range of 0.5-200 ng/mL with r² > 0.985. The accuracy, precision, and the stability of the data were within acceptable limits on the FDA guideline. After intravenous and oral administration of polynemoraline C at doses of 5 and 30 mg/kg, respectively, the present method was successfully applied to the pharmacokinetic study of polynemoraline C. Polynemoraline C in mouse plasma showed a multi-exponential elimination pattern with a high volume of distribution values. This compound's absolute oral bioavailability was found to be 17.0%. Polynemoraline C's newly developed LC-MS/MS method can be used for further studies on the efficacy, toxicity, and biopharmaceutics of polynemoraline C, as well as its pharmacokinetic studies.

• 한국환경농학회지
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• 제33권1호
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• pp.1-8
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• 2014

BACKGROUND: Recent studies using many amendments for heavy metal stabilization in soil were conducted in order to find out new materials. But, the studies accounting for the use of appropriate amendments considering soil pH remain incomplete. The aim of this study was to investigate the effects of initial soil pH on the efficiency of various amendments. METHODS AND RESULTS: Acid soil and alkali soil contaminated with heavy metals were collected from the agricultural soils affected by the abandoned mine sites nearby. Three different types of amendments were selected with hypothesis being different in stabilization mechanisms; organic matter, lime stone and iron, and added with different combination. For determining the changes in the extractable heavy metals, water soluble, Mehlich-3, Toxicity Characteristic Leaching Procedure, Simple Bioavailability Extraction Test method were applied as chemical assessments for metal stabilization. For biological assessments, soil respiration and root elongation of bok choy (Brassica campestris ssp. Chinensis Jusl.) were determined. CONCLUSION: It was revealed that lime stone reduced heavy metal mobility in acid soil by increasing soil pH and iron was good at stabilizing heavy metals by supplying adsorption sites in alkali soil. Organic matter was a good source in terms of supplying nutrients, but it was concerning when accounting for increasing metal availability.

• 한국물환경학회지
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• 제24권5호
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• pp.603-610
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• 2008

A mathematical model was developed to understand how the presence of plants affects vertical profiles of electron acceptors, their reduced species, and trace metals in the wetland sediments. The model accounted for biodegradation of organic matter utilizing sequential electron acceptors and subsequent chemical reactions using stoichiometric relationship. These biogeochemical reactions were affected by the combined effects of oxygen release and evapotranspiration driven by wetland plants. The measured data showed that $SO_4{^{2-}}$ concentrations increased at the beginning of the growing season and then gradually decreased. Based on the measured data, it was hypothesized that the limitation of the solid phase sulfide in direct contact with the roots may result in the gradual decrease of $SO_4{^{2-}}$ concentrations. With the dynamic formulation for the limitation of the solid phase sulfide, model simulated time variable sulfate profiles using published model parameters. Oxygen release from roots produced divalent metal species (i.e. $Cd^{2+}$) as well as oxidized sulfur species (i.e. $SO_4{^{2-}}$) in the sediment pore water. Evapotranspiration-induced advection increased flux of divalent metal species from the overlying water column into the rhizosphere. The increased divalent metal species were converted to the metal sulfide with sufficient FeS around the rhizosphere, which contributed to the decrease of bioavailability and toxicity of divalent metal activity in the pore water. Since the divalent metal activity is a good predictor of the metal bioavailability, this model with a proper simulation of solid phase sulfide plays an essential role to predict the dynamics of trace metals in the wetland sediments.