Curcumin Reverses 5-Fluorouracil Resistance by Promoting Human Colon Cancer HCT-8/5-FU Cell Apoptosis and Down-regulating Heat Shock Protein 27 and P-Glycoprotein / 中国结合医学杂志

OBJECTIVE@#To investigate the potential mechanisms that curcumin reverses 5-fluorouracil (5-FU) multidrug resistance (MDR).@*METHODS@#Cell growth and the inhibitory rate of curcumin (2-25 μg/mL) and/or 5-FU (0.05-1000 μg/mL) on human colon cancer HCT-8 and HCT-8/5-FU (5-FU-resistant cell line) were determined using cell counting kit-8 (CCK-8) assay. Apoptosis and cell cycle after 5-FU and/or curcumin treatment were detected by flow cytometry (FCM) and transmission electron microscopy (TEM). The expression of the multidrug resistance related factors p-glycoprotein (P-gp) and heat shock protein 27 (HSP-27) genes and proteins were analyzed by reverse transcription polymerase chain reaction (RT-PCR) and Western blotting (WB), respectively.@*RESULTS@#The inhibitory rate of curcumin or 5-FU on HCT-8 and HCT-8/5-FU cells proliferation at exponential phase were in a dosedependent manner, HCT-8 cell line was more sensitive to curcumin or 5-FU when compared the inhibitory rate of HCT-8/5-FU. The 50% inhibitory concentration (IC) of combination 5-FU and curcumin (4.0 μg/mL) in HCT-8/5-FU was calculated as 179.26 μg/mL, with reversal fold of 1.85. Another IC of combination 5-FU and curcumin (5.5 μg/mL) in HCT-8/5-FU was calculated as 89.25 μg/mL, with reversal fold of 3.71. Synergistic effect of 5-FU and curcumin on HCT-8 and HCT-8/5-FU cells were found. The cell cycle analysis performed by FCM showed that HCT-8 and HCT-8/5-FU cells mostly accumulated at G/G phase, which suggested a synergistic effect of curcumin and 5-FU to induce apoptosis. FCM analysis found that the percentage of apoptosis of cells treated with curcumin, 5-FU and their combination were significantly increased compared to the control group (P<0.05), and the percentage of apoptosis of the combination groups were slightly higher than other groups (P<0.05). The mRNA levels of P-gp (0.28±0.02) and HSP-27 (0.28±0.09) in HCT-8/5-FU cells treated with combination drugs were lower than cells treated with 5-FU alone (P-gp, 0.48±0.07, P=0.009; HSP-27, 0.57±0.10, P=0.007). The protein levels of P-gp (0.25±0.06) and HSP-27 (0.09±0.02) in HCT-8/5-FU cells treated with combination drugs were decreased when compared to 5-FU alone (P-gp, 0.46±0.02, P=0.005; HSP-27, 0.43±0.01, P=0.000).@*CONCLUSIONS@#Curcumin can inhibit the proliferation of human colon cancer cells. Curcumin has the ability of reversal effects on the multidrug resistance of human colon cancer cells lines HCT-8/5-FU. Down-regulation of P-gp and HSP-27 may be the mechanism of curcumin reversing the drug resistance of HCT-8/5-FU to 5-FU.

Neuroprotective effects of the effective components group of xiaoshuantongluo against oxygen-glucose deprivation in primary cultured rat cortical neurons / 药学学报

This study is to investigate the effect of the effective components group of Xiaoshuantongluo (XECG) on neuronal injury induced by oxygen-glucose deprivation (OGD) in primary cortical cultures isolated from SD rat cortex at day 3 and the possible mechanism. Cells were divided into control group, OGD model group and XECG group (1, 3 and 10 mg x L(-1)). The cell viability was assessed with MTT assay and the LDH release rate was measured by enzyme label kit. The cell apoptosis was analyzed using Hoechst staining. RT-PCR was applied to detect the mRNA levels of JAK2 and STAT3. Western blotting was used to detect the expressions of Bcl-2, Bax, p-JAK2 and p-STAT3 proteins. Results showed that XECG resulted in an obvious resistance to oxygen-glucose deprivation-induced cell apoptosis and decrement of cell viability, decrease the cell LDH release rate. XECG could adjust the expression of Bcl-2 and Bax proteins and increase Bcl-2/Bax ratio, up-regulate the expression of p-JAK2 and p-STAT3. In conclusion, XECG could protect against the neuronal injury cells exposed to OGD, which may be relevant to the promotion of JAK2/STAT3 signaling pathway, and impact the expression of Bax and Bcl-2.

Protective effect of mailuoning injection on cerebral ischemia/reperfusion injury in rats and its mechanism / 中国中药杂志

<p><b>OBJECTIVE</b>To discuss the protective effect of Mailuoning injection on ischemia/reperfusion (I/R) injury in rats and its mechanism.</p><p><b>METHOD</b>Healthy male adult Sprague-Dawley (SD) rats were randomly divided into the sham operation group, the model group, the edaravone (3 mg x kg(-1)) control group, and Mailuoning high, middle and low-dose groups (4, 2, 1 mL x kg(-1)), with 10 rats in each group, and administered with drugs through tail intravenous injection. The middle cerebral artery occlusion (MCAO) was adopted to establish the rat ischemia/reperfusion model. After the ischemia for 2 h and reperfusion for 24 h, the pathological changes in neurovascular units (NVU) of brain tissues at the ischemia side was observed by HE staining. The expressions of glialfibrillary acidic protein (GFAP) and ionized calcium-binding adaptor molecule 1 (Ibal) were detected by the immunohistochemical method. The expressions of tumor necrosis factor-alpha (TNF-alpha), interleukin 1beta (IL-1beta), vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) were detected by the western blotting technique.</p><p><b>RESULT</b>Mailuoning injection could significantly improve the pathological changes in cortical penumbra brain tissue UVN of (I/R) rats, reduce the number of GFAP and Ibal positive cells, and significantly decrease the expressions of TNF-alpha, IL-1beta, VCAM-1 and ICAM-1 of brain tissues of I/R rats.</p><p><b>CONCLUSION</b>Mailuoning injection shows an obvious protective effect on UVN of I/R rats. Its mechanism may involve the inhibition of the activation of astrocyte and microglia and the secretion and expression of various inflammatory factors.</p>

Hypoglycemic effect and mechanism of raspberry ketone on diabetic model mice / 中国药学杂志

OBJECTIVE: To observe the hypoglycemic effect of raspberry ketone and its mechanism on diabetic model mice induced by alloxan. METHODS: Healthy male KM mice were used to establish diabetic models by injecting alloxan via tail vein, and then randomly divided into model control group, metformin group (90 mg · kg-1), and raspberry ketone low, middle and high (200, 400, 800 mg · kg-1) dose groups. Normal control group was set. All groups had been treated for 20 d. Fasting blood glucose (FBG) was measured on 0, 7 and 14 d. After 20 d, glucose tolerance test was carried out. Fast insulin (FINS) of the mice were measured, and the insulin sensitivity index(ISI) was calculated by determining the contents of FBG and FINS. Superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and malonaldehyde (MDA) in serum were measured. Pathological changes of pancreas and insulin expression were examined. RESULTS: Raspberry ketone could effectively control the increase of fasting plasma glucose (P < 0.05) and reduce the role of the area under the glucose curve. Compared with the model group, the levels of FINS, SOD and GSH-Px activity were significantly improved (P < 0.05), and MDA content was decreased (P < 0.05) in the high dose raspberry ketone group. The pathological symptoms of pancreas were relieved in the high dose group. CONCLUSION: Raspberry ketone can effectively control blood glucose, protect pancreatic islet β cells, and improve insulin secretion in diabetic mice by effectively inhibiting the oxidative stress.

High-throughput screening of human soluble protein tyrosine phosphatase 1B inhibitors / 药学学报

To screen potential human soluble protein tyrosine phosphatase 1B (PTP1B) inhibitors, a high-throughput screening (HTS) model in 384-well microplate with total volume of 50 microL was established. Recombinant PTP1B was cloned and expressed in E. coli. with its specific substrate 4-nitrophenyl phosphate disodium salt hexahydrate (PNPP). The HTS model was based on enzyme reaction rate with enhanced sensitivity and specificity (Z' = 0.78). A total of 24,240 samples were screened, among them 80 samples with inhibition greater than 70% were selected for further rescreening. Finally, six compounds with high inhibitory activity were identified, whose IC50 values were 21.58, 18.39, 15.37, 11.92, 37.27, and 36.61 microg x mL(-1), separately. The results indicated that the method was stable, sensitive, reproducible and also suitable for high-throughput screening.