Comparative study of brine shrimp bioassay-based toxic activities of three harmful microalgal species that frequently blooming in aquaculture ponds

Typical harmful micro-algal species constantly occurred in high density in marine aquaculture ponds in Xiangshan and Sanmen Bay, Zhejiang Province. Fates of the microalgal cells influenced by activity of the cultured animals largely determined the ef fects of the harmful microalgae. However, it is difficult to detect the in situ process. In this paper, toxic activities of three harmful microalga, namely P rymnesium parvum, Pleurochrysis elongata, Karlodinium veneficum, which were isolated from the local ponds, were comparatively studied based on brine shrimp toxic bioassays. Diff erent lethal activities of live cells, cell debris, cellular extracts, and cell free mediums prepared by different process were analyzed. The results showed that,(1) all of the three microalgal species had density and time dependent lethal ef fects on A rtermia nauplii, while P. parvum was the most toxic one and had acute lethal eff ects in 5 h. No such acute lethal eff ects were observed in P. elongata or K. veneficum;(2) live cells, cell debris and cellular extracts of P. parvum had the same lethal pattern. Prymnesins, toxin from P. parvum, is probably not exotoxic active; For P. elongata, toxic activity mainly came from live cells and cell debris; For K. veneficum, toxic activity was relatively lower compared with the other two species. However, Karlotoxin, toxin from K. veneficum, is exotoxic active. Physical disturbance triggered K. veneficum cells actively releasing toxins, which made it an active predator.

Toxicity Effects of 1,4-Dinitrobenzene on Oryzias Latipes

Dinitrobenzene(1,4-DNB) is one of the preferential toxicants stipulated by OECD and EPA of USA. With Oryzias latipes, which were chosen as the acceptors according to the international standard, the acute, subacute and accumulative toxicity experiments were conducted. The threshold mass concentration of O.latipes was 1.360 mg/L. The subacute experiment showed that O.latipes were hardly affected when the mass concentration of 1,4-DNB was 0.0292 mg/L, but were significantly affected when the mass concentration of 1,4-DNB was 0.0420, 0.0608 or 0.0875 mg/L in contrast to the control sample(P<0.05). The accumulative rate(K) was 1.21. This shows that there are significant accumulative actions of 1,4-DNB in fish. When the mass concentration of 1,4-DNB is in the range of 0.032_0.320 mg/L, the higher the 1,4-DNB concentration, the more strongly the Na +/K +-ATPase is inhibited. The calculated IC_ 50 values in gill, kidney and liver of O. latipes are 0.128, 0.132 and 0.428 mg/L, respectively.

Effect of Removing Toxic Substances Combined with Activating Blood Circulation on Stabilizing the Atherosclerotic Plaque and Unstable Angina

The therapeutic effects of activating blood circulation to remove stasis of Chinese medicine （CM） in the prevention and treatment of atherosclerotic diseases such as coronary artery disease and angina are generally acknowledged. In recent years, to further improve the therapeutic effects of those Chinese herbs on such diseases, we have carried out a series of studies of CM medications with the function of clearing heat and removing toxic substances combined with activating blood circulation to remove stasis.

Metabolism of Chinese Materia Medica in Gut Microbiota and Its Biological Effects

The drug metabolism in gut microbiota draws increasing attentions. After interacting with the gut bacteria, the biological effects of drugs might be altered, leading to toxicity or detoxification, production of potential bioactivities, regulating intestinal absorption, etc. In this review, we will focus on the metabolism of Chinese materia medica（CMM） in mammal gut microbiota and its biological effects to learn the interaction between gut bacteria and drugs through oral route in CMM.

Integration of Chemical Methods and Biomarkers for Assessment of Chlorimuron-Ethyl Bioavailability in Soil

Bioavailability is a critical factor for assessing the environmental risk of organic pollutants in soil. In this study, extractions with 3 different solvents, including 2 aqueous solutions, calcium chloride(CaCl_2) and a phosphate buffer solution(PBS), and a mixture of aqueous solution and organic solvent, a PBS-methanol(8:2,volume/volume) mixture(PBS-M), were performed to assess the bioavailability of chlorimuron-ethyl in soil in comparison to a battery of toxicity tests in wheat seedlings. The results indicated that the peroxidase(POD) activity in wheat leaves after 7 d of exposure was one of the sensitive biomarkers of chlorimuron-ethyl in soil.The extractability of chlorimuron-ethyl by all the 3 solvents decreased with exposure time, and the rate of decrease of the PBS-M extraction between 1 and 7 d of exposure was substantially higher than those of the aqueous solution extractions. Chlorimuron-ethyl gradually changed from a water-soluble form into a soil organic matter(SOM)-bound form in the soil. The PBS extraction correlated best with the POD activity in the leaves after 7 d of exposure.

Synthesis,characterization and antibacterial screening of some novel 1,2,4-triazine derivatives

A new series of 1, 2, 4-triazine derivatives possessing indole nucleus were synthesized with an aim to explore their effect on in vitro growth of microorganisms causing microbial infection. In vitro antimicrobial activity was performed against S. aureus, S. epidermidis, P. mirabilis and E. coli using disk diffusion method. The MIC was detected using the double dilution method. The results were compared by calculating percent inhibition area/mg of the compounds with the standard drug ＂Ciprofloxacin＂.Selected compounds were evaluated for toxic effects using human hepatocellular carcinoma（HepG2） cell line by MTT-assay. Results revealed that some compounds of the series were found to exhibit better activity with less toxicity than Ciprofloxacin