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Nookabkaew S.,Chulabhorn Research Institute | Rangkadilok N.,Chulabhorn Research Institute | Rangkadilok N.,Chulabhorn Graduate Institute CGI | Mahidol C.,Chulabhorn Research Institute | And 3 more authors.
Journal of Agricultural and Food Chemistry | Year: 2013

Human exposure to arsenic (As) via rice consumption is of increasing concern. In the present study, the extraction and HPLC-ICP-MS analysis for As speciation in rice were investigated. A simple extraction with water and digestion with α-amylase followed by the analysis using ion-paring mode HPLC separation was developed. The method showed good extraction efficiencies (generally >80%) and column efficiencies (>90%) for rice samples. The optimization of mobile phase showed well separated peaks of As species. The limits of quantification (LOQ) of AsIII, AsV, MMA, and DMA that were calculated based on sample mass were 1.6, 2.0, 2.0, and 1.6 μg kg-1, respectively. A total of 185 rice samples (various types of rice) collected from different four regions in Thailand and some other Asian countries were analyzed. The total As and inorganic As in rice samples were in the ranges of 22.51-375.39 and 13.89-232.62 μg kg-1, respectively. The estimated weekly intake of inorganic As from rice by Thai people accounted for 13.91-29.22% of the provisional tolerable weekly intake (PTWI). © 2013 American Chemical Society.

Pholphana N.,Chulabhorn Research Institute | Rangkadilok N.,Chulabhorn Research Institute | Rangkadilok N.,Chulabhorn Graduate Institute CGI | Saehun J.,Chulabhorn Research Institute | And 3 more authors.
Chinese Medicine (United Kingdom) | Year: 2013

Background: The therapeutic activities of Andrographis paniculata are attributed to four major active diterpenoids: andrographolide (AP1), 14-deoxy-11,12-didehydroandrographolide (AP3), neoandrographolide (AP4), and 14-deoxyandrographolide (AP6). This study aims to quantify the four active diterpenoids in various plant organs of A. paniculata at different growth stages in greenhouse and field experiments, with a developed HPLC-diode array detector (HPLC-DAD) method for simultaneous determination of these diterpenoids.Methods: Plants were grown in greenhouse and in field conditions, harvested at different growth stages, and separated into different organs for determination of the four active diterpenoids by an HPLC-DAD method.Results: The most abundant diterpenoid was AP6 between seedling and vegetative stages in the greenhouse experiment (13.38 to 23.71 mg/g in 2006 and 10.67 to 24.54 mg/g in 2007). High levels of AP6 were also detected in leaves at the transfer stage in the greenhouse experiment (36.05 ± 0.69 mg/g) and field experiment (30.59 ± 1.39 mg/g). The levels of AP6 then decreased as plants matured. The highest content of AP4 was in cotyledons (16.65 ± 4.48 mg/g) at the transfer stage. The highest contents of AP1 were detected in leaves at seed-forming stage in greenhouse experiment (24.72 ± 1.89 mg/g) and vegetative stage in field experiment (43.16 ± 0.92 mg/g). Flowers of A. paniculata contained high levels of AP1 (21.42 ± 3.74 mg/g). AP3 and AP4 were at low levels in leaves at all growth stages.Conclusion: In A. paniculata, AP6 was at the highest level in leaves at transfer stage in both greenhouse and field experiments. AP1 was at the highest level in leaves at vegetative stage and seed-forming stage in field and greenhouse experiments, respectively. The contents of AP3 and AP4 in leaves were low at all growth stages. © 2013 Pholphana et al.; licensee BioMed Central Ltd.

Rangkadilok N.,Chulabhorn Research Institute | Rangkadilok N.,Chulabhorn Graduate Institute CGI | Siripriwon P.,Chulabhorn Graduate Institute CGI | Nookabkaew S.,Chulabhorn Research Institute | And 3 more authors.
Archives of Environmental Contamination and Toxicology | Year: 2015

Map Ta Phut Industrial Estate is a major industrial area in Thailand for both petrochemical and heavy industries. The release of hazardous wastes and other pollutants from these industries increases the potential for contamination in foods in the surrounding area, especially farmed shellfish. This study determined the arsenic (As), cadmium (Cd), and manganese (Mn) concentrations in the edible flesh of farmed shellfish, including Perna viridis, Meretrix meretrix, and Scapharca inaequivalvis, around the Map Ta Phut area using inductively coupled plasma mass spectrometry. The results showed that shellfish samples contained high levels of total As [1.84-6.42mgkg-1 wet weight (ww)]. High Mn concentrations were found in P. viridis and M. meretrix, whereas S. inaequivalis contained the highest Cd. Arsenobetaine (AsB) was found to be the major As species in shellfish (>45% of total As). The in vitro cytotoxicity of these elements was evaluated using human cancer cells (T47D, A549, and Jurkat cells). An observed decrease in cell viability in T47D and Jurkat cells was mainly caused by exposure to inorganic As (iAs) or Mn but not to AsB or Cd. The combined elements (AsB+Mn+Cd) at concentrations predicted to result from the estimated daily intake of shellfish flesh by the local people showed significant cytotoxicity in T47D and Jurkat cells. © 2014 Springer Science+Business Media New York.

Nookabkaew S.,Chulabhorn Research Institute | Rangkadilok N.,Chulabhorn Research Institute | Rangkadilok N.,Chulabhorn Graduate Institute CGI | Prachoom N.,Chulabhorn Research Institute | And 2 more authors.
Journal of Agricultural and Food Chemistry | Year: 2016

Thailand is predominantly an agriculture-based country. Organic farming is enlisted as an important national agenda to promote food safety and international export. The present study aimed to determine the concentrations of trace elements in commercial organic fertilizers (fermented and nonfermented) composed of pig and cattle manures available in Thailand. Pig and cattle manures as well as animal feeds were also collected from either animal farms or markets. The results were compared to the literature data from other countries. Fermented fertilizer composed of pig manure contained higher concentrations of nitrogen (N) and phosphorus (P) than fertilizer composed of cattle manure. High concentrations of copper (Cu) and zinc (Zn) were also found in fertilizers and manures. Some organic fertilizers had high concentrations of arsenic (As), cadmium (Cd), and lead (Pb). The range of As concentration in these fertilizers was 0.50-24.4 mg/kg, whereas the ranges of Cd and Pb were 0.10-11.4 and 1.13-126 mg/kg, respectively. Moreover, pig manure contained As and Cd (15.7 and 4.59 mg/kg, respectively), higher than their levels in cattle manure (1.95 and 0.16 mg/kg, respectively). The use of pig manure as soil supplement also resulted in high Cd contamination in herbal tea (Gynostemma pentaphyllum Makino; GP). The Cd concentration in GP plants positively correlated with the Cd concentration in the soil. Therefore, the application of some organic fertilizers or animal manures to agricultural soil could increase some potentially toxic elements in soil, which may be absorbed by plants and, thus, increase the risk of contamination in agricultural products. © 2016 American Chemical Society.

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