Acute and subchronic dermal toxicity of Vitex negundo essential oil

Vitex negundo is a common herb in different herbal formulation. The potential acute and sub-chronic dermal toxicities were evaluated as per OECD (Organization for Economic Cooperation and Development) guidelines 402 and 411, respectively. Both sexes of Wistar rats were exposed to Vitex negundo oil of 2000?mg/kg body weight for acute dermal toxicity, whereas in the dermal sub-chronic toxicity study, rats were exposed to Vitex negundo oil 250, 500 and 1000?mg/kg body weight, respectively, for five times a week for 90?d. In acute and sub-chronic toxicity studies, all animals were normal without any behavioral, serum biochemistry, hematology, necroscopical and histopathological changes. The no observed effect level (NOEL) and no observed adverse effect level (NOAEL) of Vitex negundo oil were 250 and 1000?mg/kg/day, respectively. Vitex negundo oil is under the category 5 (Unclassified) according to the Globally Harmonized System, with an LD₅₀ value of over 2000?mg/kg.     

Effects of rosiglitazone added to submaximal doses of metformin compared with dose escalation of metformin in type 2 diabetes: the EMPIRE Study

ABSTRACT

Objective: This study was designed to compare the efficacy, safety and tolerability of rosiglitazone (RSG) added to submaximal doses of metformin (MET) with dose escalation to the maximal effective dose of MET monotherapy in type 2 diabetes mellitus.

Research design and methods: In this multi-center, double-blind, randomized, parallel-group study, 766 subjects with a baseline MET dose of 1000?mg/day were randomized to receive either RSG 4?mg/day (4?mg/1000?mg) or MET 500?mg/day (1500?mg/day total dose) for 8 weeks. Only the RSG dose was increased in the combination group – to 8?mg/day (8?mg/1000?mg) – and only the MET dose was increased in the MET monotherapy group – to 2000?mg/day for the remaining 16 weeks.

Results: After 24 weeks, RSG added to MET (8?mg/1000?mg/day) was at least as effective as 2000?mg/day of MET in improving HbA_1c’, with mean reductions of –0.93% (95% CI: –1.06%, –0.80%) and –0.71% (95% CI: –0.83%, –0.60%), respectively, from baseline in subjects that completed the study according to the investigator (mean treatment effect/difference of –0.20% [95% CI: –0.36%,–0.04%]). In addition, a higher percentage of subjects in the RSG + MET group achieved American Diabetes Association target levels of HbA_1c < 7% (58.1% versus 48.4%) and American Association of Clinical Endocrinologists target levels of HbA_1c ≤ 6.5% (40.9% versus 28.2%). This combination provided significantly greater reductions from baseline in fasting plasma glucose (FPG; –2.29?mmol/L [± 2.37?mmol/L] and –1.12?mmol/L [± 2.41?mmol/L], respectively), with a treatment difference of –0.85?mmol/L (95% Cl: –1.23?mmol/L, –0.47?mmol/L). For the intent-to-treat (ITT) population, the percentage of subjects experiencing a gastrointestinal side-effect was 27.9% and 38.7% for the RSG + MET and MET groups, respectively (OR = 1.63, 95% CI: 1.19, 2.24). Mean body weight (± SD) increased in all randomized subjects treated with the combination therapy (+ 1.79 ± 4.15?kg) compared with a mean weight loss in the up-titrated MET group (–1.78 ± 3.50?kg).

Conclusions: This study suggests that addition of RSG to submaximal doses of MET may be a suitable alternative to the maximal effective dose of MET monotherapy.     

Comparative ecotoxicity of single and binary mixtures exposures of nickel and zinc on growth and biomarkers of Lemna gibba

The aim of this study was to compare the ecotoxicity of nickel (Ni) and zinc (Zn) assayed as single and as binary mixture. In addition, how were affected the population growth rates and oxidative stress biomarkers, comparing single to binary exposures. The toxicity tests were performed on Lemna gibba using a 7-day test. All calculations were made using measured total dissolved metal concentrations. IC50-7d, based on growth rate calculated on frond number and fresh weight, were 2.47/3.89 mg/L, and 76.73/76.93 mg/L, for Ni and Zn, respectively. Single metals affected plant growth following a non-linear concentration–response relationship. LOEC values for each metal were obtained at 0.92 and 20.1 mg/L for Ni and Zn, respectively. Biomarkers of the antioxidant response like Catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APOX; EC 1.11.1.11) and guaiacol peroxidase (GPOX; EC 1.11.1.7) activities in single metals assays were higher than controls, but when similar concentrations were added as mixtures, that increase was reduced and inhibition with respect to the control was observed for GPOX. APOX showed the highest activity. The concentration addition (CA) approach was evaluated and resulted in a correct predictor of Ni-Zn mixture toxicity on Lemna gibba. This was made comparing the EC50 and LOEC, measured taking the growth rate as endpoint, with those expected values according to the CA model. However, the measured biomarkers indicating a positive response to free radicals did not fit to concentration addition model when assayed in the binary mixture. Also, the main activity response of these was observed within a range of concentrations below the LOEC values for the mixture.

     

Essential oil from fruit of Xylopia langsdorffiana: antitumour activity and toxicity

Context: The genus Xylopia L. (Annonaceae) includes aromatic plants that have both nutritional and medicinal uses. Essential oils of Xylopia species have antitumour effects. However, the efficacy of the essential oil from the fruit of Xylopia langsdorffiana St. Hil & Tul. (EOX) has not been examined.

Objective: EOX was evaluated to determine its chemical composition, antitumour activity and toxicity.

Materials and methods: EOX was obtained from fresh fruits of X. langsdorffiana subjected to hydrodistillation, and gas chromatography-mass spectrometry was used to characterize the chemical composition of EOX. The toxicity of EOX was evaluated using haemolysis, acute toxicity and micronucleus assays. The in vitro antitumour activity of EOX was investigated using the sulforhodamine B assay. The sarcoma 180 murine tumour model was used to evaluate the in vivo antitumour activity and toxicity of EOX (50 and 100?mg/kg) after 7 d of treatment.

Results: The major components of EOX were α-pinene (34.57%) and limonene (31.75%). The HC₅₀ (concentration producing 50% haemolysis) was 293.6?μg/ml. EOX showed greater selectivity for the leukaemia cell line K562, with total growth inhibition (TGI) (concentration producing TGI) of 1.8?μg/ml, and for multidrug-resistant ovarian tumour cell line NCI/ADR-RES (TGI of 45.4?μg/ml). The LD₅₀ was approximately 351.09?mg/kg. At doses of 50 and 100?mg/kg, EOX inhibited the in vivo growth of sarcoma 180 by 38.67 and 54.32%, respectively. EOX displayed minor hepatic alterations characteristic of acute hepatitis and induced no genotoxicity.

Conclusion: EOX showed in vitro and in vivo antitumour activity and low toxicity, which warrants further pharmacological studies.     

Subchronic toxicity of Citrus aurantium L. (Rutaceae) extract and p-synephrine in mice

Extracts of Citrus aurantium L. (Rutaceae) unripe fruits have gained popularity for the treatment of obesity. Due to the wide use of C. aurantium/p-synephrine-containing products, this research was undertaken to evaluate its subchronic toxicity in mice and their actions in oxidative stress biomarkers. Groups of 9–10 mice received for 28 consecutive days a commercial C. aurantium dried extract (containing 7.5% p-synephrine) 400, 2000 or 4000 mg/kg and p-synephrine 30 or 300 mg/kg by oral gavage. There was a reduction in body weight gain of animals treated with both doses of p-synephrine. Organs relative weight, biochemical and hematological parameters were not altered in all treated mice. There was an increase in reduced glutathione (GSH) concentration in groups treated with C. aurantium 4000 mg/kg and p-synephrine 30 and 300 mg/kg. In glutathione peroxidase (GPx), there were an inhibition of the activity in C. aurantium 400 and 2000 mg/kg and p-synephrine 30 and 300 mg/kg treated animals, respectively, and was no alteration in malondialdehyde (MDA) levels. Thus, the results indicate a low subchronic toxicity of the tested materials in mice and a possible alteration in the oxidative metabolism. However, further tests are required to better elucidate the effects of these compounds in the antioxidant system.     

Comparative ecotoxicity of single and binary mixtures exposures of cadmium and zinc on growth and biomarkers of Lemna gibba

In the present study, single and mixture effects of cadmium (Cd) and zinc (Zn) on Lemna gibba were analyzed and compared using growth parameters, based on frond number and fresh weight, and biochemical parameters, such as pigment, protein content and activity of antioxidant enzymes. Plants were exposed for 7 days to these metals in nutrient solution. Single and mixture exposures affected plant growth and the biomarkers of the antioxidant response. Considering the growth parameters, Cd was found to be much more toxic than Zn. IC50-7d, based on growth rate calculated on frond number, were 17.8 and 76.73 mg/L, and on fresh weight were 1.08 and 76.93 mg/L, for Cd and Zn respectively. For Cd, LOEC values were obtained at 2.06 and 1.03 mg/L, for frond number and fresh weight respectively; while for Zn, at 20.1 and 74.6 mg/L. A high toxicity effect, considering the same response variables, was observed in plants exposed to the mixtures. Three fixed ratios, based on toxic units (TU) were assayed, ratio 1: 2/3 Cd−1/3 Zn, ratio 2: 1/2 Cd−1/2 Zn and ratio 3: 1/3 Cd−2/3 Zn. Ratio 3 (where Zn was added in higher proportion) was the less toxic. All concentrations of Ratio 1 and 2 significantly inhibited plant growth, showing a 100% inhibition of growth rate at the highest concentrations when based on frond number. Catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APOX; EC 1.11.1.11) and guaiacol peroxidase (GPOX; EC 1.11.1.7) activities in single metals assays were higher than controls. In mixture tests, the activity of APOX and GPOX was significantly stimulated in plants exposed to all evaluated combinations, while CAT was mainly stimulated in Ratio 3. It was observed that the activity of the enzymes was increased in the mixtures compared with similar concentrations evaluated individually. APOX activity was observed to fit the CA model and following a concentration-response pattern. The response of this antioxidant enzyme could serve as a sensitive stressor biomarker for Cd–Zn interactions. Frond number in Cd–Zn mixtures was not well predicted from dissolved metal concentration in solution using concentration addition (CA) as reference model, as results showed that toxicity was more than additive, with an average of ΣTU = 0.75. This synergistic effect was observed up to 50 mg Zn/L in the mixture, but when it was present in higher concentrations a less than additive effect was observed, indicating a protective effect of Zn. A synergistic and dose-ratio deviations from CA model were also observed.     

Safety and toxicological evaluation of a synthetic vitamin K2, menaquinone-7

Menaquinone-7 (MK-7) is part of a family of vitamin K that are essential co-factors for the enzyme γ-glutamyl carboxylase, which is involved in the activation of γ-carboxy glutamate (Gla) proteins in the body. Gla proteins are important for normal blood coagulation and normality of bones and arteries. The objective of this study was to examine the potential toxicity of synthetic MK-7 in BomTac:NMRI mice and in Sprague-Dawley rats. In an acute oral toxicity test, mice were administered a single oral dose of 2000?mg/kg body weight (limit dose) and no toxicity was observed during the 14-day observation period. In the subchronic oral toxicity test in rats, animals were administered MK-7 for 90 days by gavage at the following doses: 0 (vehicle control, corn oil), 2.5, 5, and 10?mg/kg body weight/day. All generated data, including clinical observations, ophthalmology, clinical pathology, gross necropsy, and histopathology, revealed no compound-related toxicity in rats. Any statistically significant findings in clinical pathology parameters and/or organ weights noted were considered to be within normal biological variability. Therefore, under the conditions of this experiment, the median lethal dose (LD₅₀) of MK-7 after a single oral administration in mice was determined to be greater than the limit dose level of 2000?mg/kg body weight. The no observed adverse effect level (NOAEL) of MK-7, when administered orally to rats for 90 days, was considered to be equal to 10?mg/kg body weight/day, the highest dose tested, based on lack of toxicity during the 90-day study period.     

Effect of Spirulina platensis ingestion on the abnormal biochemical and oxidative stress parameters in the pancreas and liver of alloxan-induced diabetic rats

Context: Previous studies have shown that Spirulina platensis Gomont (Phormidiaceae) (SP) extract has beneficial effects on many disease conditions. The putative protective effects of SP were investigated in diabetic rats.

Objective: The current study investigates the antioxidant effects of SP in diabetic Wistar rats.

Materials and methods: Alloxan monohydrate (150?mg/kg body weight) was intraperitoneally administrated to induce diabetes. An aqueous suspension of SP powder in distillate water (10% w/v) was administrated orally by gavage (1?mL/day) for 50?days. Histopathological, biochemical and antioxidant analyses were performed. Glycemia, liver function and HOMA-IR were assessed using Spinreact and ELISA kits.

Results: SP exhibited high-antioxidant activity. The IC₅₀ values of the SP aqueous extract were 70.40 and 45.69?mg/L compared to those of the standard antioxidant BHT, which were 27.97 and 19.77?mg/L, for the DPPH and ABTS tests, respectively. The diabetic animals showed a significant increase in glycaemia (from 4.05 to 4.28?g/L) and thiobarbituric acid reactive substances (50.17?mmol/g protein) levels. Treatment with SP significantly reduced glycaemia by 79% and liver function markers [glutamate pyruvate transaminase (GPT), glutamate oxaloacetate transaminase (GOT) and alkaline phosphatase (Alk-p)]) by 25, 36 and 20%, respectively, compared to that of the controls. There was a significant increase in superoxide dismutase (48%), total antioxidant status (43%), glutathione peroxidase (37%) and glutathione reductase (16%) in the diabetic rats treated with SP.

Discussion and conclusion: These results showed that SP has high antioxidant activity, free radical scavenging, antihyperglycemic and hepatoprotective effects in diabetes.     

Mutagenicity and preclinical safety assessment of the aqueous extract of Clinacanthus nutans leaves

Context: Clinacanthus nutans (CN) is used traditionally for treating various illnesses. Robust safety data to support its use is lacking. Objective: To evaluate the adverse effects of aqueous extract of CN leaves (AECNL). Materials and methods: The oral toxicity of the AECNL was tested following Organisation for Economic Co-operation and Development (OECD) guidelines. Mutagenicity (Ames test) of AECNL was evaluated using TA98 and TA100 Salmonella typhimurium strains. Results: No mortality or morbidity was found in the animals upon single and repeated dose administration. However, significant body weight loss was observed at 2000?mg/kg during sub-chronic (90 d) exposure. In addition, increased eosinophil at 500?mg/kg and decreased serum alkaline phosphatase levels at 2000?mg/kg were observed in male rats. Variations in glucose and lipid profiles in treated groups were also observed compared to control. Ames test revealed no evidence of mutagenic or carcinogenic effects at 500?μg/well of AECNL. Conclusion: The median lethal dose (LD₅₀) of the AECNL is >5000?mg/kg and the no-observed-adverse-effect level is identified to be greater than 2000?mg/kg/day in 90-d study.     

Retrieve of residual waste of carbon dots derived from straw mushroom as a hydrochar for the removal of organic dyes from aqueous solutions

The residual waste during the separation of carbon dots (C-dots) solution derived from natural resources was usually discarded without further use. In this study, the simultaneous production of C-dots and hydrochar (HC) from straw mushroom through hydrothermal carbonization treatment was carried out to increase the utilities of sustainable resources. The obtained C-dots exhibited good physicochemical and optical properties. The residual waste was retrieved as the HC for the removal of organic dyes. The HC had the BET surface of 11.68 m²/g with an average pore size and pore volume of 15.42 nm and 0.045 m³/g, respectively. The HC showed excellent removal efficiencies for crystal violet (CV) and methylene blue (MB) from aqueous solutions of more than 90%. Under Langmuir's isotherm, the maximum adsorption capacity (q_max) of the HC was 1.88 mg/g and 3.11 mg/g for MB and CV, respectively. The adsorption capacities at time (q_t) of MB and CV were in the range of 1.85–1.94 mg/g and 2.46–2.65 mg/g, respectively. The equilibrium stage happened above 30 min with a mixing time of 2 min. The HC could completely adsorb 2.5 × 10¹⁶ molecules of 25 μM MB and 3.0 × 10¹⁶ molecules of 50 μM CV. The original colors of MB and CV were almost completely removed after introducing the HC to the dye solutions, which demonstrates the possibility of overcoming the environmental pollution problems by sustainably residual waste materials.     

Surveillance of tigecycline activity tested against clinical isolates from a global (North America,Europe, Latin America and Asia-Pacific) collection (2016)

Tigecycline and comparators were tested by the reference broth microdilution method against 33 348 non-duplicate bacterial isolates collected prospectively in 2016 from medical centres in the Asia-Pacific (3443 isolates), Europe (13 530 isolates), Latin America (3327 isolates) and the USA (13 048 isolates). Among 7098 Staphylococcus aureus isolates tested, >99.9% were inhibited by ≤0.5?mg/L tigecycline (MIC_50/90, 0.06/0.12?mg/L), including >99.9% of methicillin-resistant S. aureus and 100.0% of methicillin-susceptible S. aureus. Tigecycline was slightly more active against Enterococcus faecium (MIC_50/90, 0.03/0.06?mg/L) compared with Enterococcus faecalis (MIC_50/90, 0.06/0.12?mg/L) and its activity was not adversely affected by vancomycin resistance when tested against these organisms. Tigecycline potency was comparable for Streptococcus pneumoniae (MIC_50/90, 0.03/0.06?mg/L), viridans group streptococci (MIC_50/90, 0.03/0.06?mg/L) and β-haemolytic streptococci (MIC_50/90, 0.06/0.06?mg/L) regardless of species and penicillin susceptibility. Tigecycline was active against Enterobacteriaceae (MIC_50/90, 0.25/1?mg/L; 97.8% inhibited at ≤2?mg/L) but was slightly less active against Enterobacteriaceae isolates expressing resistant phenotypes: carbapenem-resistant Enterobacteriaceae (MIC_50/90, 0.5/2?mg/L; 98.0% susceptible); multidrug-resistant (MIC_50/90, 0.5/2?mg/L; 93.1% susceptible); and extensively drug-resistant (MIC_50/90, 0.5/4?mg/L; 87.8% susceptible). Tigecycline inhibited 74.4% of 888 Acinetobacter baumannii isolates at ≤2?mg/L (MIC_50/90, 2/4?mg/L) and demonstrated good in vitro activity against Stenotrophomonas maltophilia (MIC_50/90, 1/2?mg/L; 90.6% inhibited at ≤2?mg/L) Tigecycline was active against Haemophilus influenzae (MIC_50/90, 0.12/0.25?mg/L) regardless of β-lactamase status. Tigecycline represents an important treatment option for resistant Gram-negative and Gram-positive bacterial infections.     

Genotoxicity and antioxidant enzyme activity induced by hexavalent chromium in Cyprinus carpio after in vivo exposure

Abstract

Fish, being an important native of the aquatic ecosystem, are exposed to multipollution states and are therefore considered as model organisms for ecotoxicological studies of aquatic pollutants, including metal toxicity. We investigated oxidative stress (OS) in liver, kidney and gill tissues through antioxidant enzyme activities and genotoxicity induced in whole blood and gill tissues through comet assay and micronucleus (MN) test in Cyprinus carpio after 96-hour in vivo static exposure to potassium dichromate at three sublethal (SL) test concentrations, including SL-I [93.95?mg/L, i.e. one quarter of half-maximal lethal concentration (LC₅₀)], SL-II (187.9?mg/L, i.e. one half of LC₅₀), and SL-III (281.85?mg/L, i.e. three quarters of LC₅₀), along with a control. The 96-hour LC₅₀ value for potassium dichromate was estimated to be 375.8?mg/L in a static system in the test species. Tissues samples were collected at 24, 48, 72 and 96 hours postexposure. Results indicated that the exposed fish experienced OS as characterized by significant (p?<?0.05) variation in antioxidant enzyme activities, as compared to the control. Activities of superoxide dismutase and glutathione peroxidase increased, whereas activity of catalase decreased with the progression of the experiment. The mean percent DNA damage in comet tail and MN induction in gills and whole blood showed a concentration-dependent increase up to 96-hour exposure. The findings of this study would be helpful in organ-specific risk assessment of Cr(VI)-induced OS and genotoxicity in fishes.     

Pharmacological evaluation of the anxiolytic-like effects of Lippia graveolens and bioactive compounds

Context: Lippia species (Verbenaceae) are widely used in Latin America and Africa as folk medicine for their tranquilizing properties.

Objective: To evaluate the anxiolytic-like effects and safety of Lippia graveolens Kunth. by exploring its aqueous and organic leaf extracts and identifying the responsible chemical constituents.

Material and methods: Aqueous and organic extracts (hexane, ethyl acetate and methanol) were pharmacologically evaluated at several doses. Chemical constituents were identified using MS, NMR and GC-MS analysis. The isolated compounds (3?mg/kg, i.p.), extracts (1, 3, 10 and 30?mg/kg, i.p.), and the reference drug diazepam (0.1?mg/kg, i.p.) were assessed in CD-1 mice using experimental behavioural models: open-field, cylinder, hole-board, plus-maze and sodium pentobarbital-induced hypnosis, as well as their acute toxicity (LD₅₀).

Results: After administration of the extracts and bioactive compounds, a significant anxiolytic-like response from 1?mg/kg, i.p. was observed, resembling the effect of diazepam. Major presence of thymol (33.40%) was observed in the hexane extract; whereas for the first time in this species a p-cymene?+?thymol mixture (9.78%), naringenin (0.18%) and cirsimaritin (1.16%) were obtained as bioactive constituents of the ethyl acetate crude extract. Acute toxicity was calculated to be LD₅₀ =?1000?mg/kg for the crude hexane extract, lower in comparison to the other extracts analyzed (LD₅₀ >?2000?mg/kg).

Discussion and conclusion: Our results suggest that L. graveolens exerts anxiolytic-like activity involving many kinds of constituents, mainly of the terpenoid and flavonoid nature. These results reinforce the potential use of this species in the therapy of anxiety.     

Effects of 3-Nitro-1,2,4-triazol-5-one on Survival,Growth and Metamorphosis in the Northern Leopard Frog, <Emphasis Type="Italic">Lithobates pipiens</Emphasis>

New explosive formulations are being developed to be less sensitive to impact and inadvertent explosion, increasing safety for the warfighter. Since testing and training make environmental releases imminent, the toxicity of 3-nitro-1,2,4-triazol-5-one (NTO), a component of Insensitive Munitions eXplosive (IMX) formulations, was assessed in a one-generation study to the northern leopard frog (Lithobates (?=?Rana) pipiens). Because NTO in water creates acidic conditions, acute studies were conducted with non-pH-adjusted NTO, while a long-term (70-d) study was conducted with neutralized NTO. In the acute study, 48-h and 7-d LC₅₀s were ~250?mg NTO/L. In the long-term study, tadpoles were dead by day 2 in 11,350?mg/L NTO, and by day 63 in 8382?mg/L. The 70-d LC₅₀ was 3670?mg (neutralized) NTO/L. The number of organisms reaching complete metamorphosis was reduced by NTO; the lowest IC₂₅ was 1999 mg NTO/L for the Number Completing Metamorphosis. The NOECs for Time to Front Limb Eruption or Time to Metamorphosis were the same at 1346?mg/L. Histopathology did not significantly distinguish between NTO-exposed and unexposed animals, although possible effects on the density of spermatogonia in NTO-exposed males was suggested. The test data indicate that acute toxicity to ambient NTO can be attributed primarily to its acidic nature; relatively low chronic toxicity of neutralized NTO is due to delays in metamorphosis. The consequence from this latter observation may be ecologically significant as delays of even a few days could increase mortality through predation and/or loss of the aquatic medium in temporary water bodies.     

Origin of the different phytotoxicity and biotransformation of cerium and lanthanum oxide nanoparticles in cucumber

Abstract

To investigate how the physicochemical properties of nanoparticles (NPs) affect their biological and toxicological effects, we evaluated the phytotoxicity of CeO₂ and La₂O₃ NPs to cucumber (Cucumis sativus) plants and tried to clarify the relation between physicochemical properties of NPs and their behaviors. CeO₂ NPs had no phytotoxicity to cucumber at all tested concentrations, while La₂O₃ NPs showed significant inhibition on root elongation (?≥?2?mg/L), shoot elongation (at 2000?mg/L), root biomass (?≥?2?mg/L), and shoot biomass (?≥?20?mg/L), as well as induced more reactive oxygen species and cell death in roots (2000?mg/L). The different distribution and speciation of Ce and La in plants were determined by synchrotron-based micro X-ray fluorescence microscopy and X-ray absorption spectroscopy. In the aerial parts, all of La was combined with phosphate or carboxylic group, while a fraction of Ce was changed to Ce(III)–carboxyl complexes, implying that La₂O₃ acted as its ionic form, while CeO₂ displayed the behavior of particles or particle–ion mixtures. The higher dissolution of La₂O₃ than CeO₂ NPs might be the reason for their significant difference in phytotoxicity and transporting behaviors in cucumbers. To our knowledge, this is the first detailed study of the relation between the level of dissolution of NPs and their behaviors in plant systems.     

Production of eurycomanone from cell suspension culture of Eurycoma longifolia

Context: Eurycomanone is found in the Eurycoma longifolia Jack (Simaroubaceae) tree, exhibits significant antimalarial activity, improves spermatogenesis, suppresses expression of lung cancer cell tumour markers and regulates signalling pathways involved in proliferation, cell death and inflammation.

Objectives: Establishment of cell suspension culture of E. longifolia to determine the eurycomanone accumulation during cultures.

Materials and methods: Callus of E. longifolia was cultured in MS medium supplemented with 0.8% agar, 30/L sucrose, 1.25?mg/L NAA and 1?mg/L KIN for biomass production. Cell suspension culture was established by transferring friable calli to the same medium without agar. Eurycomanone content during cell culture was determined by HPLC with a C18 column, flow rate of 0.8?mL/min, run time of 17.5?min, detector wavelength of 254?nm. The stationary phase was silica gel and the mobile phase was acetonitric:H₂O. Roots of 5 year-old trees were used as the control.

Results: The cells from 3?g of inoculum increased in biomass with a maximum value of 16?g fresh weight (0.7?g dry weight) at 14th day of culture. The cell growth then decreased from day 14 to day 20. Eurycomanone was produced during culture from the beginning to 20th day, its highest content (1.7?mg/g dry weight) also obtained at 14th day (the control is 2.1?mg/g dry weight).

Discussion and conclusions: Cell suspension culture of E. longifolia is a suitable procedure to produce eurycomanone. The yield of eurycomanone biosynthesis in 14 days-old cells are relatively high, approximately 0.8 times the control.     

GHS additivity formula: A true replacement method for acute systemic toxicity testing of agrochemical formulations

Acute systemic (oral, dermal, inhalation) toxicity testing of agrochemical formulations (end-use products) is mainly needed for Classification and Labelling (C&L) and definition of personal protection equipment (PPE). A retrospective analysis of 225 formulations with available in vivo data showed that: A) LD₅₀/LC₅₀ values were above limit doses in <20.2% via oral route but only in <1% and <2.4% of cases via dermal and inhalation route, respectively; B) for each formulation the acute oral toxicity is always equal or greater than the Acute Toxicity Estimate (ATE) via the other two routes; C) the GHS (Global Harmonised System) computational method based on ATE, currently of limited acceptance, has very high accuracy and specificity for prediction of agrochemical mixture toxicity according to the internationally established classification thresholds.By integrating this evidence, an exposure- and data-based waiving strategy is proposed to determine classification and adequate PPE and to ensure only triggered animal testing is used. Safety characterisation above 2000 mg/kg body weight or 1.0 mg/L air should not be recommended, based on the agrochemical exposure scenarios. The global implementation of these tools would allow a remarkable reduction (up to 95%) in in vivo testing, often inducing lethality and/or severe toxicity, for agrochemical formulations.     

Toxicity of CeO2 nanoparticles on a freshwater experimental trophic chain: A study in environmentally relevant conditions through the use of mesocosms

The toxicity of CeO₂ NPs on an experimental freshwater ecosystem was studied in mesocosm, with a focus being placed on the higher trophic level, i.e. the carnivorous amphibian species Pleurodeles waltl. The system comprised species at three trophic levels: (i) bacteria, fungi and diatoms, (ii) Chironomus riparius larvae as primary consumers and (iii) Pleurodeles larvae as secondary consumers. NP contamination consisted of repeated additions of CeO₂ NPs over 4 weeks, to obtain a final concentration of 1?mg/L. NPs were found to settle and accumulate in the sediment. No effects were observed on litter decomposition or associated fungal biomass. Changes in bacterial communities were observed from the third week of NP contamination. Morphological changes in CeO₂ NPs were observed at the end of the experiment. No toxicity was recorded in chironomids, despite substantial NP accumulation (265.8?±?14.1?mg Ce/kg). Mortality (35.3?±?6.8%) and a mean Ce concentration of 13.5?±?3.9?mg/kg were reported for Pleurodeles. Parallel experiments were performed on Pleurodeles to determine toxicity pathways: no toxicity was observed by direct or dietary exposures, although Ce concentrations almost reached 100?mg/kg. In view of these results, various toxicity mechanisms are proposed and discussed. The toxicity observed on Pleurodeles in mesocosm may be indirect, due to microorganism’s interaction with CeO₂ NPs, or NP dissolution could have occurred in mesocosm due to the structural complexity of the biological environment, resulting in toxicity to Pleurodeles. This study strongly supports the importance of ecotoxicological assessment of NPs under environmentally relevant conditions, using complex biological systems.     

Population pharmacokinetics of arginine glutamate in healthy Chinese volunteers

1.?The present study developed population pharmacokinetic models of arginine and glutamate in healthy Chinese volunteers. Two nonlinear mixed-effect models were developed using NONMEM® software (ICON Development Solutions, Ellicott City, MD) to describe the pharmacokinetic properties and to assess the relevant parameters as well as the inter-individual variability. The potential covariates were screened using stepwise approach and the stability and predictive capability of the models were performed using bootstrap and visual predictive check.

2.?The concentration time curves of arginine and glutamate were best described by a first-order elimination two-compartment model and a nonlinear elimination one-compartment model, respectively. The final parameter estimation of arginine for CL was 44.1?L/h. Q, V₁ and V₂ were 23?L/h, 20.3?L and 46?L, respectively. The final parameter estimation of glutamate for V_max and K_m were 18.8?mg/h and 77.2?mg/L, respectively. V for low dose and high dose was 23.1?L and 36.3?L, respectively.

3.?For arginine, weight was significant covariate on the apparent distribution volume of peripheral compartment. The gain in weight remarkably increases V_2. For glutamate, dose as a significant covariate on the apparent distribution volume was included, subjects received high dose (20?g) have remarkably higher V compared to subjects received low dose (10?g).