Planta medica
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The dried rhizome of Panax notoginseng is a traditional Chinese herb extensively used for treatment of cardiovascular diseases and other ailments. Panax notoginseng saponins (PNS) are known as the major pharmacologically active constituents. The purpose of this study was to investigate the cardioprotective effects of PNS against doxorubicin-induced cardiotoxicity and its possible influence on the anti-tumor activity of doxorubicin. ⋯ Pretreatment with PNS significantly protected the mice from DOX-induced cardiotoxicity as evidenced from improved ventricular contractile function, lower levels of serum LDH, CK and CK-MB, minimal morphological changes in hearts, and normalization of myocardial superoxide dismutase, glutathione peroxidase and catalase activities. Additionally, IN VITRO cytotoxic studies demonstrated that PNS did not compromise the inhibitory effect of doxorubicin on the proliferation of cancer cells. These results imply the potentially clinical application of PNS to overcome the negative side effects of doxorubicin.
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Stem bromelain (EC 3.4.22.32) is a major cysteine proteinase, isolated from pineapple ( Ananas comosus) stem. Its main medicinal use is recognized as digestive, in vaccine formulation, antitumoral and skin debrider for the treatment of burns. To verify the identity of the principle in stem fractions responsible for the antitumoral effect, we isolated bromelain to probe its pharmacological effects. ⋯ This antitumoral effect was superior to that of 5-FU, whose survival index was approximately 263 %, relative to the untreated control. Bromelain significantly reduced the number of lung metastasis induced by LLC transplantation, as observed with 5-FU. The antitumoral activity of bromelain against S-37 and EAT, which are tumor models sensitive to immune system mediators, and the unchanged tumor progression in the metastatic model suggests that the antimetastatic action results from a mechanism independent of the primary antitumoral effect.
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Naoxinqing (NXQ, a standardized extract of Diospyros kaki leaves) is a patented and approved drug of Traditional Chinese Medicine (TCM) used for the treatment of apoplexy syndrome for years in China, but its underlying mechanism remains to be further elucidated. The present study investigates the effects of NXQ against focal ischemia/reperfusion injury induced by middle cerebral artery occlusion (MCAO) in rats and against glutamate-induced cell injury of hippocampal neurons as well as against hypoxia injury of cortical neurons. Oral administrations of NXQ at 20, 40, 80 mg/kg/day for 7 days (3 days before MCAO and 4 days after MCAO) significantly reduced the lesion of the insulted brain hemisphere and improved the neurological behavior of the rats. ⋯ In primary rat cerebral cortical neuron cultures, pretreatment with 5 - 100 microg/mL NXQ also attenuates hypoxia-reoxygen induced neuron death and apoptosis in a dose-dependent manner. These results suggest that NXQ significantly protects the rats from MCAO ischemic injury in vivo and the hippocampal neurons from glutamate-induced excitotoxic injury as well as cortical neurons from hypoxia injury in vitro by synergistic mechanisms involving its antioxidative effects. NXQ:Naoxinqing CNS:central nervous system MCAO:middle cerebral artery occlusion I/R:ischemia and reperfusion.
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The phenolic glucoside gastrodin is the main component extracted from the rhizome of Gastrodia elata (Orchidaceae), a Chinese herbal medicine, which has long been used for treating dizziness, epilepsy, stroke and dementia. The present study aims to investigate the effect of gastrodin on hypoxia-induced neurotoxicity in cultured rat cortical neurons. Neuron survival and extracellular glutamate level were measured after an insult by hypoxia. ⋯ Further studies demonstrated that gastrodin prevented glutamate- and NMDA-induced neurotoxicity. In addition, gastrodin also inhibited the extracellular glutamate level induced by NMDA insult. These findings suggest that gastrodin has a neuroprotective action against hypoxia in the cultured cortical neuron, and the mechanism may involve a decreasing of the extracellular glutamate level.
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Multidrug resistance (MDR) constitutes the major obstacle to the successful treatment of cancer. In several cancer cells, MDR is thought to be mediated by the super-expression of P-glycoprotein (Pgp). Pgp extrudes drugs from the cells, therefore reducing their cytotoxicity, and its activity inhibition may reverse the MDR phenotype. ⋯ Of note, the P. amarus derivatives significantly potentiated 5 microM daunorubicin-induced cell death in Lucena-1 cells (P < 0.01) but not in K562 cells. After treatment only with P. amarus derivatives (100 microg/mL HE, 30 microg/mL LRF, 12.9 microg/mL NIRA, 43.2 microg/mL NIRT, 43 microg/mL PHYLLA or 41.6 microg/mL PHYLT), the Lucena-1 cellular viability was 83.7, 85.3, 101, 69.7, 75.6 or 88.7%, respectively, whereas the in the presence of daunorubincin, which was not cytotoxic PER SE, the cell viability decreased to 42.9, 42.2, 64.2, 35.4, 30.4 or 52.6%, respectively. Together, these results suggest a potential action of P. amarus derivatives as MDR reversing agents, mainly due to their ability to synergize with the action of conventional chemotherapeutics.