Using Nassarius stolatus as a potential heavy metal biomonitor

Nassarius stolatus was evaluated as the potential heavy metal (Cd, Fe, Mn, Ni and Pb) accumulator in Don Hoi Lot sandbar, Samut Songkhram province, Thailand. This selected species belongs to the Gastropoda, which is widely distributed in the coastal areas from the upper Gulf through the southern part of Thailand. From our findings, the heavy metal accumulations in N. stolatus tissues were Fe ＞ Pb ＞ Mn ＞ Ni ＞ Cd. The retrieved bioaccumulation factor (BAF) indicated that N. Stolatus has high potential to be a biomonitor for the contaminations of Fe and Mn in water and Cd, Ni and Pb in sediment

Fate and tissue depletion of nivalenol in ducks

Nivalenol (NIV), a mycotoxin belonging to the trichothecenes type B group, has recently been identified as causing one of the more potent toxicities among mycotoxins of this group. The purpose of this study was to clarify the toxicokinetics, and residues of NIV in ducks. Then, NIV was administered intravenously (iv) or orally (po) to ducks at a dosage of 0.8 mg/kg body weight. The concentrations of NIV in plasma and various tissues were quantified using liquid chromatography tandem-mass spectrometry. The plasma concentrations of NIV were measurable up to 12 h after iv and po administrations, respectively. A non-compartmental model was used to describe the toxicokinetics of NIV in ducks. The values of elimination half-life and volume of distribution were 2.24 ± 0.34 h and 1081.87 ± 306.56 ml/kg, respectively, after iv administration. The absolute oral bioavailability was 8.91 ± 1.69%. NIV was measurable in the vital organs after po administration. These results suggest that NIV is not favorably absorbed from the gastrointestinal tract, but it has the ability to penetrate into the various tissues of ducks

A New Benzaldehyde Derivative Exhibits Antiaflatoxigenic Activity against <i>Aspergillus flavus</i>

Aflatoxin B1 (AFB1) is the most potent naturally occurring carcinogen for humans and animals produced by the common fungus Aspergillus flavus (A. flavus). Aflatoxin (AF) contamination in commodities is a global concern related to the safety of food and feed, and it also impacts the agricultural economy. In this study, we investigated the AFB1-inhibiting activity of a new benzaldehyde derivative, 2-[(2-methylpyridin-3-yl)oxy]benzaldehyde (MPOBA), on A. flavus. It was found that MPOBA inhibited the production of AFB1 by A. flavus, with an IC50 value of 0.55 mM. Moreover, the inhibition of conidiation was also observed at the same concentration. The addition of MPOBA resulted in decreased transcript levels of the aflR gene, which encodes a key regulatory protein for the biosynthesis of AF, and also decreased transcript levels of the global regulator genes veA and laeA. These results suggested that MPOBA has an effect on the regulatory mechanism of the development and differentiation of conidia, leading to the inhibition of AFB1 production. In addition, the cytotoxicity study showed that MPOBA had a very low cytotoxic effect on the Madin-Darby canine kidney (MDCK) cell line. Therefore, MPOBA may be a potential compound for developing practically effective agents to control AF contamination

Correlation of ATP Citrate Lyase and Acetyl CoA Levels with Trichothecene Production in Fusarium graminearum

The correlation of ATP citrate lyase (ACL) and acetyl CoA levels with trichothecene production in Fusarium graminearum was investigated using an inhibitor (precocene II) and an enhancer (cobalt chloride) of trichothecene production by changing carbon sources in liquid medium. When precocene II (30 µM) was added to inhibit trichothecene production in a trichothecene high-production medium containing sucrose, ACL expression was reduced and ACL mRNA level as well as acetyl CoA amount in the fungal cells were reduced to the levels observed in a trichothecene trace-production medium containing glucose or fructose. The ACL mRNA level was greatly increased by addition of cobalt chloride in the trichothecene high-production medium, but not in the trichothecene trace-production medium. Levels were reduced to those level in the trichothecene trace-production medium by addition of precocene II (300 µM) together with cobalt chloride. These results suggest that ACL expression is activated in the presence of sucrose and that acetyl CoA produced by the increased ALC level may be used for trichothecene production in the fungus. These findings also suggest that sucrose is important for the action of cobalt chloride in activating trichothecene production and that precocene II may affect a step down-stream of the target of cobalt chloride

Pharmacokinetics of ceftriaxone in Green sea turtles (Chelonia mydas) following intravenous and intramuscular administration at two dosages

Green sea turtles are widely distributed in tropical and subtropical waters. Adult green sea turtles face many threats, primarily from humans, including injuries from boat propellers, being caught in fishing nets, pollution, poaching, and infectious diseases. To the best of our knowledge, limited pharmacokinetic information to establish suitable therapeutic plans is available for green sea turtles. Therefore, the present study aimed to describe the pharmacokinetic characteristics of ceftriaxone (CEF) in green sea turtles, Chelonia mydas, following single intravenous and intramuscular administrations at two dosages of 10 and 25&nbsp;mg/kg body weight (b.w.). Blood samples were collected at assigned times up to 96&nbsp;hr. The plasma concentrations of CEF were measured by liquid chromatography tandem mass spectrometry. The concentrations of CEF in the plasma were quantified up to 24 and 48&nbsp;hr after i.v. and i.m. administrations at dosages of 10 and 25&nbsp;mg/kg b.w., respectively. The Cmax values of CEF were 15.43&nbsp;±&nbsp;3.71&nbsp;μg/ml and 43.48&nbsp;±&nbsp;4.29&nbsp;μg/ml at dosages of 10 and 25&nbsp;mg/kg, respectively. The AUClast values increased in a dose-dependent fashion. The half-life values were 2.89&nbsp;±&nbsp;0.41&nbsp;hr and 5.96&nbsp;±&nbsp;0.26&nbsp;hr at dosages of 10 and 25&nbsp;mg/kg b.w, respectively. The absolute i.m. bioavailability was 67% and 108%, and the binding percentage of CEF to plasma protein was ranged from 20% to 29% with an average of 24.6%. Based on the pharmacokinetic data, susceptibility break-point and PK-PD index (T&nbsp;&gt;&nbsp;MIC, 0.2&nbsp;μg/ml), i.m. administration of CEF at a dosage of 10&nbsp;mg/kg b.w. might be appropriate for initiating treatment of susceptible bacterial infections in green sea turtles

Fate and tissue depletion of nivalenol in ducks

Nivalenol (NIV), a mycotoxin belonging to the trichothecenes type B group, has recently been identified as causing one of the more potent toxicities among mycotoxins of this group. The purpose of this study was to clarify the toxicokinetics, and residues of NIV in ducks. Then, NIV was administered intravenously (iv) or orally (po) to ducks at a dosage of 0.8 mg/kg body weight. The concentrations of NIV in plasma and various tissues were quantified using liquid chromatography tandem-mass spectrometry. The plasma concentrations of NIV were measurable up to 12 h after iv and po administrations, respectively. A non-compartmental model was used to describe the toxicokinetics of NIV in ducks. The values of elimination half-life and volume of distribution were 2.24 ± 0.34 h and 1081.87 ± 306.56 ml/kg, respectively, after iv administration. The absolute oral bioavailability was 8.91 ± 1.69%. NIV was measurable in the vital organs after po administration. These results suggest that NIV is not favorably absorbed from the gastrointestinal tract, but it has the ability to penetrate into the various tissues of ducks