Oral absorption of asiatic acid nanoparticles modified with PEG / 中国中药杂志

A solvent diffusion method was used to prepare pegylated asiatic acid (AA) loaded nanostructured lipid carriers (p-AA-NLC), and the ligated intestinal circulation model was established to observe the absorption and distribution in small intestine. The concentration of AA in bile after oral administration of p-AA-NLC was detected by HPLC in healthy SD rats to indirectly evaluate the oral absorption promoting effect of PEG-modified namoparticles. The results showed that the penetration of p-AA-NLC was enhanced significantly and the transport capacity was increased greatly in small intestinal after PEG modification. As compared with the normal nanoparticles (AA-NLC), the Cmax of the drug excretion was increased by 76%, the time to reach the peak (tmax ) was decreased and the elimination half-life t1/2 was doubled in the rats after oral administration of p-AA-NLC, and the AUC0→t was 1.5 times of the AA-NLC group, indicating that the oral bioavailability of AA-NLC was significantly improved by hydrophilic modification of PEG.

Response surface method for optimization of asiatic acid nanoparticles modified with PEG and its enhancing effects on intestinal absorption / 中国中药杂志

A solvent diffusion method was used to prepare pegylated asiatic acid (AA) loaded nanostructured lipid carriers (p-AA-NLC). Then central composite design-response surface method was used to obtain optimum condition for preparation technology of p-AA-NLC, where PEG/lipid ratio was 8.0% and AA/lipid ratio was 22.0%. Under the optimum condition, the system had particle size of (111.2±2.9) nm, Zeta potential of (-37.1±0.9) mV, drug loading of (15.4±0.2)% and entrapment efficiency greater than 90%. The deviations between observed values and predicated values were all below 5%, indicating that the established model had a good predictability. Meanwhile, a low-speed single pass perfusion model of rat in situ was set up to estimate the absorption kinetics of p-AA-NLC in small intestine, where the effective permeability (Peff), absorption rate constant (Ka) and other parameters were used to evaluate the drug absorption. It turned out that Peff and Ka in p-AA-NLC group were significantly higher than those in unmodified group (P<0.05), indicating that asiatic acid loaded nanostructured lipid carriers (AA-NLC) could enhance the effects on intestinal absorption after being modified with hydrophilic PEG.

Effect of suyu capsule on behavior and injury of hippocampal neurons in depression model mice / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effect of Suyu capsule on behavior, injury of hippocampal neurons and Ca2+ ion in hippocampal synaptic in the depression model mice.</p><p><b>METHOD</b>Sixty male Kunming mice were randomly divided into 5 groups, the control group, the model group and three Suyu capsule groups (the doses were 22.8, 11.4, 5.7 g x kg(-1) respectively). The model was established by separation and chronic unpredictable mild stimulation. The increased weight and crossing score, rearing score were measured by open-field and sweet water consumption of mice. Cone cell and configuration of neuron in CA1, CA3 region of hippocampus were observed by Nissl. The concentration of hippocampal synaptic Ca2+ ion was detected by fluorimetry.</p><p><b>RESULT</b>Comparing with the mice of control, the increased weight was slowered ( P < 0.01), the scores of rearing and crossing were decreased (P < 0.01), sweet water consumption were decreased too (P < 0.01), numbers of cone cell in CA3 region of hippocampus were decreased obviously (P < 0.01), and Ca2+ ion in hippocampal synaptic was increased obviously. Comparing with the mice of model, Suyu capsule (22.8 g kg(-1)) could increase the increased weight on the 14th and 21 st day obviously (P < 0.05); Suyu capsule (22.8 g x kg(-1)) could increase the scores of crossing obviously (P < 0.05), Suyu capsule (22.8, 11.4 g x kg(-1)) could increase the scores of rearing obviously (P < 0.01, P < 0.05); Suyu capsule (22.8, 11.4, 5.8 g x kg(-1)) could increase sweet water consumption obviously (P < 0.01, P < 0.05, P < 0.05; Suyu capsule (22.8, 11.4, 5.8 g x kg(-1)) could increase numbers of cone cell in CA3 region of hippocampus obviously (P < 0.01, P < 0.05, P < 0.05); Suyu capsule (22.8, 11.4, 5.8 g x kg(-1)) decreased Ca2+ ion in hippocampal synaptic with dose-effect relationship (P < 0.01, P < 0.01, P < 0.05).</p><p><b>CONCLUSION</b>Suyu capsule can improve all the symptoms of the depression model mice and protect injury of hippocampal neurons in the depression model mice. The possible mechanism of action is to restrict Ca2+ ion overfreight.</p>

An improved imaging analysis for quantitative measurement of brain slice volume / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To improve computer-assisted imaging analysis for quantitatively measuring brain slice volume of rats and mice in comparison with conventional measuring methods,and to evaluate its usefulness in assessment of focal cerebral ischemia.</p><p><b>METHODS</b>The accurate volumes of rat and mouse brain slices were measured by weight and special gravity measuring. The areas of brain slices were measured by imaging analysis, then the slice volumes of right and left hemispheres were calculated by multiplying the adjusted thickness of the slices. In addition, the brain slice volumes of right and left hemispheres from focal cerebral ischemic mice were compared to assess ischemic injury using the imaging analysis.</p><p><b>RESULT</b>Area measurement by computer-assisted imaging analysis was linear with different accurate areas (r=1.000). Slice volumes measured by imaging analysis correlated well with the accurate volumes measured by special gravity method, r=0.809 (n=45, P<0.001) in rats, and r=0.844 (n=74, P<0.001) in mice. The brain volumes in ischemic hemispheres were larger than in non-ischemic hemispheres in ischemic mice.</p><p><b>CONCLUSION</b>Computer-assisted imaging analysis can measure the brain slice volumes accurately and compare right and left hemisphere volumes quantitatively.</p>