Subacute toxicity and chemical analysis of Tibetan medicine Oxytropis falcata / 中国中药杂志

Four different extracts of Oxytropis falcata, including the aerial aqueous extract, and the underground aqueous extract, the aerial lipophilic extract, and the underground lipophilic extract were prepared and then administrated orally to mice at the maximum dose (50 g x kg(-1) x d(-1) calculated by raw material) for fifteen days respectively. Compared with the control group, which was administrated of 1.0% tween-80, the treatment groups did not show significant differences in appearance and behavior. However, the organcoefficient, blood biochemical indicator and pathological section results showed that the lipophilic extracts of the aerial and underground parts of O. flacata showed mild injury to the liver of mice, while the aerial and underground aqueous extracts and the underground lipophilic extract showed mild toxicity to the kidney of male mice. Chemical analysis showed that the lipophilic extracts of the aerial and underground parts, especially aerial lipophilic extract, consisted of large amount of flavonoid aglycones with little amount of polysaccharides and proteins, while the aqueous extracts contained much polysaccharides and proteins with almost no flavonoid aglycones detected.

Interaction of microRNA-338 and its potential targeting protein eiF4E3 / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To analyze the interaction between the microRNA-338 and its targeting proteins during the cerebral ischemia and reperfusion injury.</p><p><b>METHODS</b>TargetScan was used to predict the targets of microRNA-338. The potential targeting proteins were then selected according to their secondary structures using RNA structure 4.6 software and their involvement in cerebral ischemia and reperfusion injury was studied. Dual-luciferase reporter assay was used to testify whether microRNA-338 can recognize the 3'UTR of target protein. Western blot was applied to analyze the expression of eiF4E3 in both experimental group and control group.</p><p><b>RESULT</b>EiF4E3 was the most likely potential targeting protein of microRNA-338. The secondary structure of local region of eiF4E3 recognizing microRNA-338 was conservative. The ratio of firefly to renilla luciferase activity in the experimental group was much higher than that of control group. However, there was no significant difference in the expression of eiF4E3 between these two groups.</p><p><b>CONCLUSION</b>MicroRNA-338 can recognize the 3'UTR of eiF4E3 while it has no significant effect on the expression of eiF4E3. The post-target-recognizing regulation for miRNA do exist and this mechanism is possibly related to the tertiary structure of target mRNA.</p>

Study of Low Dose Irradiation Enhancing the Effect of Chemotherapeutic Agents against Leukemia and Its Mechanism / 中国实验血液学杂志

For effectively enhancing the anti-leukemia effect of chemotherapeutic agents, and meanwhile decreasing the side effect of these agents, the study has been made to explore the synergistic effect of low dose irradiation (LDI) combined with Ara-C on murine leukemia and its mechanism. Firstly, an optimal scheme of low dose total body irradiation combined with Ara-C was established in L615 leukemia (T lymphocytic leukemia) mouse model. The machanism of the enhancing effect was explored by patho-morphological observation, examination of residual leukemia cells, the expression of GM-CSF on the surface of marrow stromal cells and in the bone marrow cultural supernatants. The results showed that the optimal scheme was 300 cGy irradiation at 4 days after inoculation of leukemic cells followed by Ara-C 30 mg/kg x 3 days in an interval of 1, 2 or 3 days after irradiation. The mean survival time of the L615 leukemia mice in LDI + Ara-C combined treatment groups was longer than that of control groups. The percentage of long-term survival mice (> 30 days) was the highest (58% - 72%), too. 17% of the mice were be cured. The numbers of blood leukocytes and marrow nucleated cells were transiently decreased in combined treatment group, and then recovered rapidly. Slight myelosuppression and marrow sinus dilation and congestion were seen after 300 cGy irradiation. The expression of GM-CSF either on the stromal cells or in marrow cultural supernatant after irradiation increased strikingly (P < 0.05). Therefore, LDI combined with Ara-C possesses synergistic effect. The mechanism is possibly related to three facts: LDI could increase the permeability of bone marrow sinus; LDI could promote marrow stromal cells to produce some cytokines (such as GM-CSF, etc.) which drive leukemia cells into cell cycle to make the cells more sensitive to chemotherapeutic agents; and LDI could augment Ara-C-induced cytotoxicity through the mechanism of apoptosis.