Chemosensitizing effect and mechanism of imperatorin on the anti-tumor activity of doxorubicin in tumor cells and transplantation tumor model

Multidrug resistance of tumors has been a severe obstacle to the success of cancer chemotherapy. The study wants to investigate the reversal effects of imperatorin (IMP) on doxorubicin (DOX) resistance in K562/DOX leukemia cells, A2780/Taxol cells and in NOD/SCID mice, to explore the possible molecular mechanisms. K562/ DOX and A2780/Taxol cells were treated with various concentrations of DOX and Taol with or without different concentrations of IMP, respectively. K562/DOX xenograft model was used to assess anti-tumor effect of IMP combined with DOX. MTT assay, Rhodamine 123 efflux assay, RT-PCR, and Western blot analysis were determined in vivo and in vitro. Results showed that IMP significantly enhanced the cytotoxicity of DOX and Taxol toward corresponding resistance cells. In vivo results illustrated both the tumor volume and tumor weight were significantly decreased after 2-week treatment with IMP combined with DOX compared to the DOX alone group. Western blotting and RT-PCR analyses indicated that IMP downregulated the expression of P-gp in K562/DOX xenograft tumors in NOD/SCID mice. We also evaluated glycolysis and glutamine metabolism in K562/DOX cells by measuring glucose consumption and lactate production. The results revealed that IMP could significantly reduce the glucose consumption and lactate production of K562/DOX cells. Furthermore, IMP could also remarkably repress the glutamine consumption, α-KG and ATP production of K562/DOX cells. Thus, IMP may sensitize K562/DOX cells to DOX and enhance the antitumor effect of DOX in K562/DOX xenograft tumors in NOD/SCID mice. IMP may be an adjuvant therapy to mitigate the multidrug resistance in leukemia chemotherapy.

Research Progress in Treatment of Chemical Liver Injury with Chinese Medicine Based on Metabolomics / 中国实验方剂学杂志

Liver， as a critical organ of metabolism and detoxification， can be damaged by viral infection， drug abuse， and heavy drinking. Liver diseases pose a serious threat to people's health and life in China.At present， drug therapy has been primarily adopted clinically in the treatment of the liver injury.In-depth investigation of the mechanism of liver-protective drugs is of great significance to the prevention and treatment of clinical liver diseases.In recent years， with the development of the medical industry in China， an increasing number of studies have focused on the treatment of liver injury with Chinese medicine.Compared with western medicine， Chinese medicine is advantageous in few side effects and overall regulation， which plays a pivotal role in liver protection.However， its underlying mechanism in liver protection still needs to be further studied due to its complex compositions and diverse targets.Metabolomics， a new approach to studying the metabolic pathway of biological systems， provides integral and systematic views in the investigation of liver protection with Chinese medicine. By virtue of metabolomics， the mechanism of Chinese medicine in multi-target and multi-pathway liver protection can be analyzed comprehensively， and the corresponding biomarkers can also be screened out. The authors analyzed the studies of the treatment of chemical liver injury models induced by carbon tetrachloride （CCl4）， dimethylnitrosamine （DMN）， α-naphthyl isothiocyanate （ANIT）， and alcohol by Chinese medicinal compounds， single herbal medicines， and monomers of Chinese medicine based on metabolomics， and summarized the biomarkers and related metabolic pathways of Chinese medicine in the intervention of each type of liver injury， aiming at providing a reference for the further research and clinical application in the treatment of different types of liver injuries by Chinese medicine.

Dampness-Heat Accelerates DMBA-Induced Mammary Tumors in Rats / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate the impact of dampness-heat (DH) on the development of mammary tumors in 7,12-dimethylbenz(a)anthracene (DMBA)-induced rats.</p><p><b>METHODS</b>Forty rats were randomly divided into 3 groups in a randomized block design, including the control group (n=13), DMBA group (n=14), and DMBA plus DH group (n=13). Rats in the DMBA group and DMBA plus DH group were intragastrically administrated with DMBA (100 mg/kg) for twice, once per week, while rats in the control group were treated with equivalent volumes of sesame oil. After DMBA administration, rats in the DMBA plus DH group were exposed to a simulated climate chamber with ambient temperature (33.0±0.5°C) and humidity (90%±5%) for 8 weeks, 8 h per day. The body weight, time of tumor formation, and number of tumors were measured weekly to calculate tumor incidence, average latency period, average number of tumors, and average tumor weight. At the end of the experiment, the levels of matrix metalloproteinase 9 (MMP-9) and tissue inhibitor of metalloproteinases 1 (TIMP-1) in serum, and the contents of tumor necrosis factor-α (TNF-α) and interleukin (IL)-1β in serum and tumor tissue were measured, respectively. Some tumor tissues were processed for hematoxylin-eosin staining to determine the histopathological changes.</p><p><b>RESULTS</b>Compared with DMBA, DMBA plus DH significantly increased the average number of tumors, average tumor weight, levels of serum MMP-9, TIMP-1, TNF-α and IL-1β, and contents of tumor tissue TNF-α and IL-1β (P<0.05 or P<0.01).</p><p><b>CONCLUSION</b>DH could accelerate the development of mammary tumors through increasing the expressions of MMP-9, TIMP-1, TNF-α and IL-1β in DMBA-induced rats.</p>

Intervention effect of quercetin on inflammatory secretion of cardiac fibroblasts / 中国中药杂志

To establish neonatal rat cardiac fibroblast inflammatory secretion model by using LPS 100 microg x L(-1) combined with ATP 5 mmol x L(-1), in order to study the inhibitory effect of quercetin on the secretion of inflammatory factors TNF-alpha, IL-1beta and IL-6 of cardiac fibroblasts, further investigate the effect of quercetin on the protein expression of p-NF-kappaB p65 (S276) and p-Akt (S473) by western blot, and discuss the inhibitory effect of quercetin on the inflammatory secretion of cardiac fibroblasts. According to the findings, quercetin with the concentrations between 51.74 micromol x L(-1) and 827.81 micromol x L(-1) had no significant effect on the activity of cardiac fibroblasts. Quercetin with the concentrations of 82.78, 41.39, 20.70 micromol x L(-1) could notably inhibit the increase of TNF-alpha and IL-1beta induced by LPS 100 microg x L(-1) for 3 h and then ATP 5 mmol x L(-1) for 36 h (P < 0.01 or P < 0.05). Quercetin with the concentrations of 82.78, 41.39 micromol x L(-1) could notably inhibit the increase of IL-6 induced LPS 100 microg x L(-1) for 3 h and then ATP 5 mmol x L(-1) for 36 h (P < 0.05), without any notable effect of quercetin with the concentration of 20.70 micromol x L(-1). Quercetin with the concentrations of 82.78, 41.39, 20. 70 micromol x L(-1) could notably inhibit the NF-kappaB p65 (S276) activation induced by LPS 100 microg x L(-1) for 3 h and then ATP 5 mmol x L(-1) for 15 min, with the most significant effect in 20.70 micromol x L(-1). Quercetin with the concentrations of 82.78, 41.39, 20.70 micromol x L(-1) could notably inhibit the increase of p-Akt(473) expression induced by LPS 100 microg x L(-1) for 3 h and then ATP 5 mmol x L(-1) for 240 min (P < 0.05). Therefore, this study believes that quercetin could attenuate the secretion of inflammatory factors TNF-alpha, IL-1beta and IL-6 of cardiac fibroblasts by inhibiting the activation of NF-kappaB p65 (S276) and Akt (473).

Protective effect of succinic acid on primary cardiomyocyte hypoxia/reoxygenation injury / 中国中药杂志

To establish cardiomyocyte hypoxia/reoxygenation injury model by culturing primary cardiomyocytes from suckling SD rats, in order to study the effect of succinic acid on LDH leakage rate cardiomyocyte ischemia/reperfusion injury. Furthermore, flow cytometry and western blot were conducted to detect the effect of succinic acid on cardiomyocyte apoptosis, cleaved caspase-3 and p-Akt, and discuss the protective effect of succinic acid on primary cardiomyocyte hypoxia/reoxygenation injury of primary cardiomyocytes from neonatal SD rats. According to the findings of the study, succinic acid at the concentrations ranging between 31.25 mg x L(-1) and 500 mg x L(-1) had no significant effect on primary cardiomyocyte activity, and succinic acid at the concentrations of 400, 200, 100, 50 mg x L(-1) could notably reduce cardiomyocyte ischemia/reperfusion LDH leakage rate (P < 0.01 or P < 0.05, respectively). Succinic acid at the concentrations of 400 mg x L(-1) and 200 mg x L(-1) could significantly reduce the percentage of cardiomyocyte apoptosis (P < 0.05), and inhibit the protein expression of cleaved caspase-3 caused by cardiomyocyte ischemia/reperfusion (P < 0.05). Succinic acid at the concentration of 400 mg x L(-1) could remarkably increase the protein expression of cardiomyocyte Akt (P < 0.05), while succinic acid at the concentration of 200 mg x L(-1) had no obvious effect on the protein expression of cardiomyocyte Akt. Therefore, this study demonstrated that succinic acid could inhibit necrosis and apoptosis caused by cardiomyocyte hypoxia/reoxygenation by activating Akt phosphorylation.

Effects of cytochrome P450 isozymes on aristolochic acid renal cytotoxicity / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effect of cytochrome P450 isozymes on aristolochic acid induced cytotoxicity on renal proximal tubular epithelial cell (cell line HK-2).</p><p><b>METHOD</b>Human renal tubular cells (cell line HK-2), were treated with aristolochic acid (AA) alone or in combination with cytochrome P450 isozymes inhibitors, including alpha-naphthoflavone (CYP450 1A1 and 1 A2 inhibitors), ketoconazole (CYP450 3A4 inhibitor), sodium diethyldithiocarbamate (CYP450 2A6 and 2E1 inhibitors), quinidine (CYP450 2D inhibitor), alpha-lipoic acid (NADPH: P450 reductase inhibitor), sulfaphenazole (CYP450 2C inhibitor) in the presence or absence of liver microsome(S9). The inhibition of cell proliferation rate was studied by MTT assay and the lactate dehydrogenase release rate was determined with continuous monitoring method.</p><p><b>RESULT</b>AA inhibits cell proliferation and promotes the release of LDH over the range of 12.5-100 mg x L(-1), in a dose-dependent manner. Addition of S9 into the culture system reduced AA cytotoxicity, with the cell proliferation inhibition reducing and the release of LDH decreasing (AA + S9 group vs the same concentration of AA alone group, P < 0.05). In the absence of S9, ketoconazole or alpha-naphthoflavone has no obvious effect on AA cytotoxicity, however,under the conditions of adding S9, ketoconazole or alpha-naphthoflavone enhances AA cytotoxicity. Other inhibitors of CYP450 isozymes has no distinct effect on AA cytotoxicity.</p><p><b>CONCLUSION</b>The microsomal enzyme of Liver can reduce the AA cytotoxicity, and CYP450 3A, CYP450 1A may be the major cytochrome P450 isozymes which impact AA cytotoxicity.</p>