Investigation of Skin Irritation of Essential Oils from Interior-warming Medicines / 中国实验方剂学杂志

Objective:To investigate the skin irritation of essential oils(EOs) extracted from interior-warming medicines. Method:Three EOs from interior-warming medicines(Cinnamomi Cortex, Caryophylli Flos and Alpiniae Officinarum Rhizoma) were selected as research objects.The in vitro skin cytotoxicity and in vivo skin irritation of these EOs were determined and compared.Moreover, the skin irritation was also predicted by the novel skin test panels. Result:Toxicity of these three EOs to human skin fibroblasts(HSF) was significantly different, half-inhibitory concentration(IC50) values of EOs from Cinnamomi Cortex, Alpiniae Officinarum Rhizoma and Caryophylli Flos were (11.16±0.28), (53.33±1.71), (226.70±17.61) mg·L-1, respectively.However, in vivo skin irritation evaluation showed that the local toxicity of these three EOs was in the order of EO of Cinnamomi Cortex > EO of Caryophylli Flos > EO of Alpiniae Officinarum Rhizoma. The evaluation results of skin test panels for these three EOs were in accordance with the results of in vivo skin irritation evaluation. Conclusion:Toxicity of these three EOs against skin cells in vitro is inconsistent with their in vivo skin irritation. Skin test panels are expected to be able to accurately predict in vivo skin irritation of EOs instead of cytotoxicity evaluation.

[Selection and kinetic mechanism of psychrotrophs in low temperature wastewater treatment].

A study was carried out taking low temperature domestic wastewater as target in laboratory, the composition of bacteria in activated sludge was analyzed and the degradation kinetics of organics was investigated. Six preponderant psychrotrophs were selected out, belonging to Zoogloea, Aeromonas, Flavobacterium, Micrococcus, Bacillus and Pseudomonaus, respectively. Results show that TTC-dehydrogenase activity of the psychrotroph is 25.44 mg/(L x h) which is 20.5 times more than that of ordinary activated sludge at 4 degrees C. The efficiency of COD biodegradation by psychrotrophs at low and normal temperature is 80.9% and 73.4%, respectively. Mesophilic bacteria almost lost their activity at low temperature. Kinetic analysis shows that biodegradation of organics by psychrotrophs at low and mesothermal temperature as well as mesophilic bacteria at mesothermal temperature are in accordance with the model of first-order reaction. Psychrotrophs, which assure the removal efficiency of organic pollutants at low and normal temperature, could keep the uniform reaction velocity as the mesophilic bacteria and also adapt wide ecological amplitude of temperature. Efficient psychrotrophs were immobilized on soft polyurethane foams which acted as carriers in the experiment at 4 degrees C, as a result of that, the removal efficiency of COD was increased about 18% higher than that of mobilized ones at low temperature, the biodegradation kinetics of COD by immobilized psychrotrophs also followed the first-order reaction model. With glucose in water as the source of nutriment, the reaction velocity of immobilized bacteria is 2.35 times higher than that of the mobilized ones. By the immobilized psychrotrophs biodegradation of varied nutriment, the effluent could achieve the first-degree B of pollutants discharge standard for municipal wastewater treatment plant.

Gridded inventories of historical usage for selected organochlorine pesticides in Heilongjiang River Basin, China.

The use of technical HCH (1, 2, 3, 4, 5, 6-hexachlorocyclohexane), DDT (dichlorodiphenyltrichloroethane) and lindane in Heilongjiang River Basin (HRB) of China was studied. Between 1952 and 1984 the total usage in the HRB was 108900 t for technical HCH, and 4900 t for DDT, respectively, and the use of DDT due to dicofol application in the HRB was 220 t from 1984 to 2003. The usage of lindane in HRB was 109 t from 1991 to 2000. The results show that the highest technical HCH use (41800 t) in HRB was on maize, accounting for 38.3% of the total usage on all crops, followed by the use on wheat (28000 t, 25.7%) and on soybean (26600 t, 24.4%). The highest DDT use (2300 t) was on soybean, accounting for 46.8% of the total usage on all crops, followed by the use on maize (1500 t, 31.3%) and on sorghum (600 t, 13.2%). The major use of lindane was mainly on wheat. Gridded usage inventories of these three OCPs (organochlorine pesticides), in HRB with a 1/6 degrees latitude by 1/4 degrees longitude resolution have been created by using different gridded cropland as surrogates. Some soil samples have also been collected in HRB. Data of usage and soil concentrations of sigma HCH in HRB match quite well to those in Shanghai region, and much higher soil concentration of sigma DDT in Shanghai region could be due to much heavier dicofol use in this region.

Isolation and characterization of deodorizing bacteria for organic sulfide malodor.

Strain JII screened out from different odor origins can efficiently degrade methyl mercaptan and ethanethiol whereas has no ability to remove dimethyl sulfide. The results indicated that the strain JII breaks only the C-SH bond. The optimum temperature and pH of JII are 20-30 degrees C and 6.0-8.3 respectively. A systematic identification method-16S rDNA gene sequence comparison, for deodorizing bacteria was carried out. The 16S rDNA gene sequence analysis of strain JII showed the highest level of 97% homology to Rape rhizosphere.