Protective effect and mechanism of baicalein on hypoxia-induced cortical neuron injury in rats / 中国药房

OBJECTIVE To explore the protective effect and possible mechanism of baicalein on hypoxia-induced cortical neuron injury in rats. METHODS The cortical neurons of rats （RN-C cells） were studied and cultured under hypoxic conditions （5%CO2， 94% N2， 1%O2） for 24 hours； the effects of different concentrations of baicalein （0.01， 0.1， 1， 10， 100 μmol/L） on the survival rate of hypoxic RN-C cells were investigated； the effects of baicalein （0.1 μmol/L） on the activities of lactate dehydrogenase （LDH） and superoxide dismutase （SOD）， the content of malondialdehyde （MDA）， migration rate， apoptotic rate， cell cycle and the expressions of cleaved caspase-3， B-cell lymphoma-2 （Bcl-2） and Bcl-2 X protein （Bax） were all detected. RESULTS Compared with control group， the survival rate of cells in the hypoxia group was significantly reduced （P＜0.01）； 0.01， 0.1 and 1 μmol/L baicalein could reverse survival rate of hypoxia-induced cortical neurons （P＜0.05 or P＜0.01）. Scratch experiments showed that baicalein significantly increased the migration rate of hypoxic RN-C cells （P＜0.01）. Compared with control group， the activity of LDH in the supernatant and the content of MDA in the cells， apoptotic rate and the proportion of cells in G1 phase， were significantly increased in the hypoxia group， while SOD activity and the proportion of cells in G2+S phase was decreased significantly （P＜0.01）. The protein expressions of cleaved caspase-3 were increased significantly， while the ratio of Bcl-2/Bax in cells was significantly reduced （P＜0.05 or P＜0.01）. Compared with hypoxia group， the above indexes were all reversed significantly in baicalein group （P＜0.01）. CONCLUSIONS Baicalein can promote the proliferation and migration of cortical neurons， improve hypoxia-induced cell apoptosis and cell cycle distribution， decrease the activity of LDH in supernatant and the level of cellular lipid peroxidation， and improve antioxidant levels. Its mechanism may be related to regulating the caspase- 3/Bax/Bcl-2 pathway.

Research progress on the preparation and application of flavonoid nanocrystals / 浙江大学学报·医学版

Flavonoids have been reported to possess significant pharmacological activities,such as antioxidant, anti-inflammatory and anticancer effects. However, the low solubility and low bioavailability limits their clinical application. Nanocrystal technology can solve the delivery problems of flavonoids by reducing particle size, increasing the solubility of insoluble drugs and improving their bioavailability. This article summaries nanosuspension preparation methods and the stabilizers for flavonoid nanocrystals, and reviews the drug delivery routes including oral, Injection and transdermal of flavonoid nanocrystals, to provide information for further research on nanocrystal delivery system of flavonoids.

Protective effects of active compounds from on heart and brain of mice at simulated high altitude / 浙江大学学报·医学版

To investigate the active compounds from on the heart and brain of mice at simulated high altitude.Fifty healthy male adult BALB/c mice were randomly divided into normal control group, hypoxic model group, acetazolamide group, petroleum ether extract of (PESI) group and octacosan group with 10 mice in each group. Acetazolamide group, PESI group and octacosan group were treated with acetazolamide PESI (200 mg/kg) or octacosan by single tail vein injection, respectively. Except normal control group, the mice were exposed to a simulated high altitude of for in an animal decompression chamber. After the mice were sacrificed by cervical dislocation, the heart and brain were histologically observed by HE staining; superoxide dismutase (SOD) activity, total anti-oxidant capacity (T-AOC) and the content of malondialdehyde (MDA) in plasma, heart and brain tissues were detected by WST-1 method, ABTS method and TBA method, respectively; lactic acid and lactate dehydrogenase (LDH) activity in plasma, heart and brain tissues were detected by colorimetric method and microwell plate method, respectively; ATP content and ATPase activity in heart and brain tissues were detected by colorimetric method. PESI and octacosane significantly attenuated the pathological damages of heart and brain tissue at simulated high altitude; increased SOD activity, T-AOC and LDH activity, and decreased the contents of MDA and lactic acid in plasma, heart and brain tissues; increased the content of ATP in heart and brain tissues; increased the activities of Na-K ATPase, Mg ATPase, Ca ATPase and Ca-Mg ATPase in myocardial tissue; and increased the activities of Mg ATPase, Ca-Mg ATPase in brain tissue. PESI and octacosan exert anti-hypoxic activity by improving the antioxidant capacity, reducing the free radical levels, promoting the anaerobic fermentation, and alleviating the energy deficiency and metabolic disorders caused by hypoxia in mice.