Influence of in vitro Methods, Receptor Fluids on Percutaneous Absorption and Validation of a Novel in vitro Method

In vitro experiment using excised skin has been valuable for studying the mechanism of percutaneous absorption. Based on previously established static diffusion cell system in this laboratory, a novel model-peifused glass diffusion cell system is desboed. The results of initial comporative study on percutaneous absorption between glass perfused diffusion cell and static diffusion cell, ih vitro and in vivo permeation as well as factors affecting permeation with seven radiolabelled chemicals are presented. The results demonstrate that the peifused diffusion cell system, which used a perfusion nuid betow the suiface of skin to take up the materials which penetrated the skin, is more similar to physiologic condition,convenient and automatic than that of the static cell. It well predicts the in vivo percutaneous absorption if appropriate areptor fluid is chosen. The results also show that the selection of receptor fluid is critical for in vitro permeation of chemicals with different soubility

Application of in Vitro Alternative Tests Based on AOP in Skin Sensitization Evaluation of Cosmetics

To evaluate and discuss two novels in vitro alternative tests which based on the 2nd and 4th event of the AOP in skin sensitization and their application in skin sensitization evaluation of cosmetics in vitro.The DSens(DSens method)and Jurkat(TCPA method)were used as the test models and 9 of reference chemicals and 12 kinds of cosmetic products were used to confirm and assess the application capability in skin sensitization.The results showed that the DSens method was more sensitive to the reference chemicals compare to the TCPA method.All the results of cosmetic products showed a high consistency between these two assays and h-CLAT or in vivo assay.As the new screening method for skin sensitization evaluation of cosmetics,the in vitro alternative tests based on AOP have certain effectiveness.The reasonable combination strategy can bring a bright future for the development and application of animal alternative test in China.

Evaluation of the Toxicity of Stone Hair Dye ＆ Paraphenylenediamine by MTT Bioassays in Vitro

Para-phenylenediamine （PPD）, tile main toxic ingredients of hair dyes, have been used by millions of consumers to improve their appearance. Stone Hair Dye （SHD） mainly contain PPD. SHD and PPD were evaluated by 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyltetrazdium bromide or MTT assay, which measures mitochondria metabolism in the entire cell culture and provides information about the percentage of cell survival. Utilizing the MTT assay, the cytotoxicity of SHD and PPD was determining on SH Sy5y culture from nervous system of rat. The short term exposure SH Sy5y culture were incubated with various aqueous solutions of different concentrations of SHD and PPD, and the LC50 of SHD and para-phenylenediamine was found to be 9.15 and 12.4 mg/ml. With increasing the concentration, cytotoxicity effect increase in PPD and SHD. There is a significant differences （P〈0.01） of cytotoxicity among concentrations used. It concluded that in vitro assay could give important information of the mechanism of toxicity at low dosages.

Overload type and optimization of meadow carrying capacity in Maqin County in the Three-River Source Region,China

Alpine meadows,comprising the main ecosystem of the Three-River Source Region,play an important role in the economic development of western pastoral areas.To determine whether the grazing level was too intense or the nutrient-carrying capacity of the meadows was overloaded,and to offer solutions in Maqin County,Qinghai Province,China,the meadows carrying capacity was determined by combining grass-yield and nutrients data for different seasons across different meadows.The results showed that the levels of crude protein(CP),ether extract(EE),ash,soluble sugars(SS),gas production,and energy value of forage in the summer–autumn grazing meadows were higher than those of the winter–spring meadows.Neutral detergent fiber(NDF)and acid detergent fiber(ADF)of forage in the summer–autumn grazing meadows were lower than those of the winter–spring meadows.We found that no pastures were overloaded with metabolizable energy(ME)for the whole year but digestible crude protein(DCP)was overloaded in winter–spring.And there were differences in the amount carrying capacity(forage yield)of seasonal grazing meadows for the different herds,the overload types were annual overloading(herd A),overloaded in summer–autumn(herd B),overloaded in winter–spring(herd C),and not overloaded(herd D).Compared with the previous grazing mode,theoretical carrying capacity,DCP carrying capacity,and ME carrying capacity of herd A increased by 20,19,and 27 sheep units,respectively,after optimization;herd B:36,31,and 45 sheep units,respectively;herd C:28,23,and 44 sheep units,respectively;and herd D:43,40,and 61 sheep units,respectively.In the Three-River Source Region and similar alpine pastoral areas,the grassland-livestock structure should be optimized to improve grassland vegetation status and increase the theoretical carrying capacity.

Protein and energy concentrations of meat meal and meat and bone meal fed to pigs based on in vitro assays

The objective of this study was to develop equations for estimating ileal digestible crude protein(CP)and metabolizable energy(ME)contents of meat meal(MM)and meat and bone meal(MBM)as feed in-gredients for pigs based on in vitro assays.Test ingredients were 4 sources of MM and 3 sources of MBM.Ash and CP contents of the ingredients ranged from 3.8%to 33.1%and 46.8%to 82.9%(as-is basis),respectively.In vitro ileal disappearance(IVID)of CP was determined and ileal digestible CP content was calculated by multiplying CP content by IVID of CP.In vitro total tract disappearance(IVTTD)of dry matter(DM)was determined and ME was calculated using gross energy,CP contents,and IVTTD of DM.The IVID of CP and IVTTD of DM ranged from 77.2%to 88.7%and from 82.7%to 92.4%,respectively.Calculated ileal digestible CP and ME contents ranged from 37.8%to 73.5%DM and 2,405 to 3,905 kcal/kg DM,respectively.Ash contents were negatively correlated(P<0.001)with CP(r=-0.99),in vitro ileal digestible CP(r=-0.97),gross energy(r-1.00),in vitro digestible energy(r=-0.97),and adjusted ME(r=-0.97).The most fitting equations for ileal digestible CP and adjusted ME were:ileal digestible CP(%DM)=11.91-0.90×Ash(%DM)+0.74×IVID of CP(%)(R2=0.99)and adjusted ME(kcal/kg DM)=130.85-50.90×ash(%DM)+47.06×IVTTD of DM(%)(R2=0.99).To validate the accuracy of the prediction equations for ME,mean bias and linear bias were determined using a regression analysis.Calculated ME values of MM and MBM were in a good agreement with data obtained from animal ex-periments based on a statistically insignificant bias in the models.In conclusion,ME concentrations of MM and MBM as swine feed ingredients can be calculated using ash concentration and in vitro disap-pearance of dry matter.

Review of the Studies on the Anti-Tumoral Effect of <i>Prunella vulgaris</i>

Prunella vulgaris (PV) is a herb which grows widely around the world. It is used in traditional medicine in different continents worldwide. This article reviewed the research studies in the last three decades about the use of this herb in the treatment of cancer. Specifically, this study concentrates on the scientific in-vitro methods used, as the in-vitro methods were the most preferred methods used in the past. Cell viability/apoptosis, migration, anti-oxidative activities, and the underlying molecular mechanisms were the features which most of the research focused. The aim of this article was to summarize on what molecular mechanisms, which these previous research found responsible for the anti-tumoral effect of PV. The assays to investigate the aforementioned items were organized and displayed, including the proteomic methods which study the underlying molecular mechanisms. By categorizing and organizing these methods, the directions and emphases taken by the research efforts were revealed.