Evidences for the mechanism of Shenmai injection antagonizing doxorubicin-induced cardiotoxicity.

BACKGROUND: Doxorubicin (DOX) is a widely used antitumor drug. However, its clinical application is limited for its serious cardiotoxicity. The mechanism of DOX-induced cardiotoxicity is attributed to the increasing of cell stress in cardiomyocytes, then following autophagic and apoptotic responses. Our previous studies have demonstrated the protective effect of Shenmai injection (SMI) on DOX-induced cardiotoxicity via regulation of inflammatory mediators for releasing cell stress. PURPOSE: To further investigate whether SMI attenuates the DOX-induced cell stress in cardiomyocytes, we explored the mechanism underlying cell stress as related to Jun N-terminal kinase (JNK) activity and the regulation of autophagic flux to determine the mechanism by which SMI antagonizes DOX-induced cardiotoxicity. STUDY DESIGN: The DOX-induced cardiotoxicity model of autophagic cell death was established in vitro to disclose the protected effects of SMI on oxidative stress, autophagic flux and JNK signaling pathway. Then the autophagic mechanism of SMI antagonizing DOX cardiotoxicity was validated in vivo. RESULTS: SMI was able to reduce the DOX-induced cardiomyocyte apoptosis associated with inhibition of activation of the JNK pathway and the accumulation of reactive oxygen species (ROS). Besides, SMI antagonized DOX cardiotoxicity, regulated cardiomyocytes homeostasis by restoring DOX-induced cardiomyocytes autophagy. Under specific circumstances, SMI depressed autophagic process by reducing the Beclin 1-Bcl-2 complex dissociation which was activated by DOX via stimulating the JNK signaling pathway. At the same time, SMI regulated lysosomal pH to restore the autophagic flux which was blocked by DOX in cardiomyocytes. CONCLUSION: SMI regulates cardiomyocytes apoptosis and autophagy by controlling JNK signaling pathway, blocking DOX-induced apoptotic pathway and autophagy formation. SMI was also found to play a key role in restoring autophagic flux for counteracting DOX-damaged cardiomyocyte homeostasis.

Simultaneous determination and pharmacokinetics of eight ginsenosides by LC-MS/MS after intravenously infusion of 'SHENMAI' injection in dogs.

SHENMAI injection, a prescription comprised of Panax ginseng and Ophiopogon japonicas, is being extensively applied in the field of cardio-protection and immune-modulation in China. Ginsenosides are the main active components in SHENMAI injection. In order to capture and analyze the pharmacokinetic profile of major ginsenosides of SHENMAI injection in Beagle dogs, liquid chromatography equipped with electro-spray ionization and tandem mass spectrometry method was applied in simultaneous determination for protopanaxatriol type ginsenoside (Re, Rf, Rg1), protopanaxadiol type ginsenoside (Rb2, Rb1, Rd, Rc) and oleanolic acid type ginsenoside (Ro). A C18 column (150 × 2.1mm, 5µm) and a linear gradient program were used to achieve chromatographic separation, with 0.02% acetic acid solution and acetonitrile. I.S. and ginsenosides were detected by LC-MS/MS in selective reaction mode. Good linearity spanning 5- 1500ng/mL was achieved with the R2 values higher than 0.99 for all analytes. Limit of quantification of all analytes were 3ng/mL. Intra- and inter-day precisions ranges from 0.47 to15.68 % and accuracies were within the range of 85.27-117.57%. Validated analyzing method was then used in the pharmacokinetic experiment for SMI in dogs. The results showed that the pharmacokinetic profile of protopanaxadiol, protopanaxatriol and oleanolic acid type ginsenoside were significant difference in dogs. Protopanaxadiol type ginsenosides exhibited an extremely higher level of exposure and a much slower elimination process. Whereas protopanaxatriol type ginsenosides were quickly eliminated. We concluded that 20 (S) - protopanaxadiol type ginseno sides could be a potential pharmacokinetic marker of SHENMAI injection.

Cryptotanshinone induces inhibition of breast tumor growth by cytotoxic CD4+ T cells through the JAK2/STAT4/ perforin pathway.

Cryptotanshinone (CPT), is a quinoid diterpene isolated from the root of the Asian medicinal plant, Salvia miotiorrhiza bunge. Numerous researchers have found that it could work as a potent antitumor agent to inhibit tumor growth in vitro, buith there has been much less emphasis on its in vivo role against breast tumors. Using a mouse tumor model of MCF7 cells, we showed that CPT strongly inhibited MCF7 cell growth in vivo with polarization of immune reactions toward Th1-type responses, stimulation of naive CD4+ T cell proliferation, and also increased IFN-γ and perforin production of CD4+ T cells in response to tumor-activated splenocytes. Furthermore, data revealed that the cytotoxic activity of CD4+ T cells induced by CPT was markedly abrogated by concanamycin A(CMA), a perforin inhibitor, but not IFN-γ Ab. On the other hand, after depletion of CD4+ T cells or blocked perforin with CMA in a tumor-bearing model, CPT could not effectively suppress tumor growth, but this phenomenon could be reversed by injecting naive CD4+ T cells. Thus, our results suggested that CPT mainly inhibited breast tumor growth through inducing cytotoxic CD4+ T cells to secrete perforin. We further found that CPT enhanced perforin production of CD4+ T cells by up-regulating JAK2 and STAT4 phosphorylation. These findings suggest a novel potential therapeutic role for CPT in tumor therapy, and demonstrate that CPT performs its antitumor functions through cytotoxic CD4+ T cells.