Evaluation of the toxicity of clozapine on the freshwater diatom Navicula sp. using the FTIR spectroscopy.

Clozapine is an often prescribed neuroactive pharmaceutical and frequently detected in the aquatic environments. However, its toxicity on low trophic level species (i.e., diatoms) and associated mechanisms are seldom reported. In this study, the toxicity of clozapine on a widely distributed freshwater diatom Navicula sp. was evaluated using the FTIR spectroscopy along with biochemical analyses. The diatoms were exposed to various concentrations of clozapine (0, 0.01, 0.05, 0.10, 0.50, 1.00, 2.00, 5.00 mg/L) for 96 h. The results revealed that clozapine reached up to 392.8 µg/g in the cell wall and 550.4 µg/g within the cells at 5.00 mg/L, suggesting that clozapine could be adsorbed extracellularly and accumulated intracellularly in diatoms. In addition, hormetic effects were displayed on the growth and photosynthetic pigments (chlorophyll a and carotenoid) of Navicula sp., with a promotive effect at concentrations less than 1.00 mg/L while an inhibited effect at concentrations over 2 mg/L. Clozapine induced oxidative stress in Navicula sp., accompanied by decreased levels of total antioxidant capacity (T-AOC) (>0.05 mg/L), in which, the activity of superoxide dismutase (SOD) (at 5.00 mg/L) was increased whereas the activity of catalase (CAT) (>0.05 mg/L) was decreased. Furthermore, FTIR spectroscopic analysis showed that exposure to clozapine resulted in accumulation of lipid peroxidation products, increased sparse ß-sheet structures, and altered DNA structures in Navicula sp. This study can facilitate the ecological risk assessment of clozapine in the aquatic ecosystems.

Integrated physiological, biochemical, and transcriptomic analysis of thallium toxicity in zebrafish (Danio rerio) larvae.

Although several studies have evaluated the effects of Thallium (Tl) in adult species of fish, the developmental toxicity of Tl has not been previously explored. In this study, zebrafish embryos (<4 h post fertilization (hpf)) were exposed to Tl at concentrations from 0.8 to 400 µg L-1 for 7 d. The results showed that the decreased hatching rate and increased malformation rate were observed in the larvae. The swimming velocity of larvae from 200 and 400 µg L-1 treatments was respectively reduced by ~26 % and 15 %. Histopathological analysis of liver indicated the number of cells of karyolysis (143 % and 202 %) and pyknosis (170 % and 131 %) were respectively increased in 200 and 400 µg L-1 Tl treatments. Meanwhile, the Tl body burden and metallothionein (MT) levels in the larvae were increased with elevated Tl concentrations. The level of malondialdehyde (MDA) was increased by ~20 to 51 % in all Tl treatments and total antioxidant capacity (TAC) was decreased by ~12 % at 200 µg L-1. The activities of Na+/K+-ATPase and protease were inhibited in 200 and 400 µg L-1 Tl treatments. Moreover, the transcripts of genes (Nrf2, HO-1, TNF-α, IL-1ß, IL-8, IL-10, TGF) were significantly altered. In addition, a total of 930 differentially expressed genes (DEGs) and 1549 DEGs were found in the 200 and 400 µg L-1 treatments with 458 overlapped DEGs by transcriptomic analysis. The protein digestion and absorption, ECM-receptor interaction, and complement and coagulation cascades pathways were shown to be the most significantly enriched pathways. This study helps better understand the molecular mechanisms of Tl toxicity in fish.

Altered life history traits and transcripts of molting- and reproduction-related genes by cadmium in Daphnia magna.

Cadmium (Cd) is a non-essential element and can be toxic to aquatic organisms at low concentrations. Despite its well-known toxicity to Daphnia magna, the effects of Cd on physiological parameters (heart rate and thoracic limb activity) and molting- and reproduction-related genes are relatively understudied. In this study, D. magna were exposed to 0 (control), 25, 50 and 75 µg L-1 of Cd for 7 d and 21 d to determine the toxicity of Cd. The results showed that the Cd body burden in D. magna was significantly increased with elevated Cd concentrations, up to 13.4 µg Cd/g dry weight (dw) after exposure to 75 µg L-1 for 21 d. After 21 d of exposure, the body length and body weight of D. magna were significantly decreased in all Cd treatments compared to the control. The heart rate and thoracic limb activity were reduced by 4.3-11.7 and 5.0-10.3%, respectively. The levels of malondialdehyde (MDA) were increased by ~24-37% and the activity of catalase (CAT) was inhibited by ~50% compared to the control. The reproductive parameters (i.e., size of the first brood, the total number of offspring per female and the number of offspring per brood) were remarkably reduced, causing adverse effects on the population dynamics. In addition, the transcripts of genes (cyp314, cyp18a1, ecra, usp, hr3, cut, cht and cht3) related to the molting of D. magna were altered, whereas the transcripts of genes (vtg1, vtg2 and vmo1) related to reproduction were down-regulated. This study helps better understand the effects of Cd at different biological levels.

Dietary Seleno-l-Methionine Causes Alterations in Neurotransmitters, Ultrastructure of the Brain, and Behaviors in Zebrafish (Danio rerio).

Elevated concentrations of dietary selenium (Se) cause abnormalities and extirpation of fish inhabiting in Se-contaminated environments. However, its effect on fish behavior and the underlying mechanisms remain largely unknown. In this study, two-month-old zebrafish (Danio rerio) was fed seleno-l-methionine (Se-Met) at environmentally relevant concentrations (i.e., control (2.61), low (5.43), medium (12.16), and high (34.61) µg Se/g dry weight (dw), respectively, corresponding to the C, L, M, and H treatments) for 60 days. Targeted metabolomics, histopathological, and targeted transcriptional endpoints were compared to behavioral metrics to evaluate the effects of dietary exposure to Se-Met . The results showed that the levels of total Se and malondialdehyde in fish brains were increased in a dose-dependent pattern. Meanwhile, mitochondrial damages and decreased activities of the mitochondria respiratory chain complexes were observed in the neurons at the M and H treatments. In addition, dietary Se-Met affected neurotransmitters, metabolites, and transcripts of the genes associated with the dopamine, serotonin, gamma-aminobutyric acid, acetylcholine, and histamine signaling pathways in zebrafish brains at the H treatments. The total swimming distance and duration in the Novel Arm were lowered in fish from the H treatment. This study has demonstrated that dietary Se-Met affects the ultrastructure of the zebrafish brain, neurotransmitters, and associated fish behaviors and may help enhance adverse outcome pathways for neurotransmitter-behavior key events in zebrafish.

[Comparative study on main economic characters of different populations of Pinellia ternata in China].

OBJECTIVE: To analyze the content of guanosine, total alkaloid and individual yield of Pinellia ternata from different populations in China and evaluate its quality. METHOD: Reversed-phase high-performance liquid chromatography (HPLC) was used to determine the content of guanosine. The content of alkaloid was determined by ultra violet spectrophometry. The results were analyzed by SPSS software. RESULT: The contents of guanosine and total alkaloid in P. ternata were 0.0136% -0.0264% and 0.0155% -0.0652% respectively. Individual yield was 0.5536-2.9740 g. All of the populations could be classified into 3 types through hierarchical cluster analysis. CONCLUSION: There exist significant differences in the content of guanosine, total content of alkaloid and individual yield of P. ternata from different populations. It is suggested that breeding and selection for type II of P. ternata should be strengthened.

[Preliminary study on the characteristics of Bupleurum chinense in nutrition uptake].

It was studied that the characteristics of Bupleurum chinense DC. in nutrition uptake based on potted and field experiment to provide a properly fertilizer application measure. The result showed that the absorption amounts of N, P and K were in the order of K > N > P under field condition. For one-year-old B. chinesnse DC., the average N, P2O5 and K2O absorption per 100 kg dry matter of root were 11.77 kg, 2.43 kg, 14.07 kg respectively; for two-year-old, the average N, P2O5 and K2O absorption amount per 100 kg dry matter of root were 12.11 kg, 2.74 kg, 18.39 kg respectively. The total absorption amount of N, P2O5 and K2O were lower in the first year, while the percentage of content was higher, that was to say, the demand for N, P and K was urgent in the first year. The accumulation peak of N, P2O5 and K2O occurred regreening to later elongation stage in the second year. The ratio of N, P and K were differential in different growth stages.

[Preliminary study on N, P, K fertilizer to control of root rot of Bupleurum chinense].

The application of N and K fertillizer could improve the sensibility of Bupleurvum chinense DC. to Root Rot, while large application of P fertilizer could decrase the sensibility. The fertilizer measure which could obtain highest yield but could not increase its disease resistense. To protect Bupleurum chinense against root rot, more phosphorous fertilizer, certain nitrogen and potassium ferilizer should be applied in early elongation stage in the second growing year.

[The growth of Salvia miltiorrhiza seedling and root system following transplantation].

OBJECTIVE: To study the relationship between plant growth and accumulation of active ingredients in Salvia miltiorrhiza. METHOD: Transplants of S. miltiorrhiza were sampled at 20 day intervals. At each stage, the growth of seedling and root system was recorded and the contents of tanshinone II (A) and salvia acid were measured. RESULT AND CONCLUSION: This study showed that the rapid growth stage of the root system lags behind that of the seedling system, but the growing period of root system lasts longer. The quantitative change of roots reveals a double "S" curve; two rapid growth stages emerge during 30 - 70 days and 140 - 200 days after the seedlings were transplanted. The content of salvia acid reaches the highest level during 140 - 180 days, whereas the content of tanshinone peaks during 100 - 120 days.

[Study on the characteristic of assimilating nitrogenous phosphorous fertilizer and the accumulation disciplinarian of total tanshinons of Salvia miltiorrhiza].

OBJECTIVE: To confirm the amount of fertilizer and the ration of fertilizer. METHOD: Through the experiment of planting Salvia miltiorrhiza in pot and in field were carried out. RESULT: When N:P = 1:1, The production was 1.8 times more than the contrast group in plotting experiment, and in field the production of the highest fertilizer plot were 2.5 times more than the contrast and the higher and high fertilizer plot is 2.25 and 1.2 times respective were than those in the contrast group. CONCLUSION: The proper ration of nitrogenous fertilizer and phosphorous fertilizer is 1:1. Nitrogen shows negative effects to the accumulation of tanshinon IIA, the more the nitrogen ous fertilizer, The less the content of tanshinon IIA. In contrast, phosphor ous fertilizer shows good effects on the accumulation of tanshinon IIA. Phosphorous fertilizer could alleviate the decline of the content of tanshinon IIA by using nitrogenous fertilizer. The accumulation peak of the tanshinon IIA emerge in the period of 150 d.

[Study on configuration fabric and germinative conditions of Salvia miltiorrhizy seeds].

OBJECTIVE: To provide theoretic warrant and technical reference for Salvia miltiorrhizr standardization planting, by carrying out various systemic studies such as observation of seeds configuration fabric, idiosyncrasy of water absorption and groping germinating conditions. METHOD: In the study of configuration fabric, seeds were observed and taken photos by scanning electronic microscope, and heft method was used for measuring changes of water absorption velocity and dehydration velocity. Seeds germination conditions were probed into under the national test regulations for crop seeds and related prescription from international standards. RESULT: (1) There was a layer of slime about 10-20 microm thickness covering epicarp of Danshen seeds. The slime formed as diamond meshwork (reseau) and the weight of it was 8%-10% of total seeds weight. (2) The speed of water absorption of seeds was extremely rapid. The weight of seeds could increase above 10 times as original while the dehydration velocity was quite low. (3) The optimal temperature for the seeds germination is around 25 degrees C, and the germination rate of the new seeds gained yearly was above 75%, but the rate would decrease sharply as years went by. It was also found that the seeds germination power and exponent of vigor were quite high under the temperature transformation between 23 degrees C, 28 degrees C. Such treatments as pre-cool, PEG treatment and infusing with GA3 could increase the rate of seeds germination capacity obviously.