Pyrroloquinoline quinone ameliorates diabetic cardiomyopathy by inhibiting the pyroptosis signaling pathway in C57BL/6 mice and AC16 cells.

PURPOSE: Diabetic cardiomyopathy (DCM), a common complication of diabetes mellitus and is characterized by myocardial hypertrophy and myocardial fibrosis. Pyrroloquinoline quinone (PQQ), a natural nutrient, exerts strong protection against various myocardial diseases. Pyroptosis, a type of inflammation-related programmed cell death, is vital to the development of DCM. However, the protective effects of PQQ against DCM and the associated mechanisms are not clear. This study aimed to investigate whether PQQ protected against DCM and to determine the underlying molecular mechanism. METHODS: Diabetes was induced in mice by intraperitoneal injection of streptozotocin, after which the mice were administered PQQ orally (10, 20, or 40 mg/kg body weight/day) for 12 weeks. AC16 human myocardial cells were divided into the following groups and treated accordingly: control (5.5 mmol/L glucose), high glucose (35 mmol/L glucose), and HG + PQQ groups (1 and 10 nmol/L PQQ). Cells were treated for 24 h. RESULTS: PQQ reduced myocardial hypertrophy and the area of myocardial fibrosis, which was accompanied by an increase in antioxidant function and a decrease in inflammatory cytokine levels. Moreover, myocardial hypertrophy-(ANP and BNP), myocardial fibrosis-(collagen I and TGF-ß1), and pyroptosis-related protein levels decreased in the PQQ treatment groups. Furthermore, PQQ abolished mitochondrial dysfunction and the activation of NF-κB/IκB, and decreased NLRP3 inflammation-mediated pyroptosis in AC16 cells under high-glucose conditions. CONCLUSION: PQQ improved DCM in diabetic mice by inhibiting NF-κB/NLRP3 inflammasome-mediated cell pyroptosis. Long-term dietary supplementation with PQQ may be greatly beneficial for the treatment of DCM. Diagram of the underlying mechanism of the effects of PQQ on DCM. PQQ inhibits ROS generation and NF-κB activation, which stimulates activation of the NLRP3 inflammasome and regulates the expression of caspase-1, IL-1ß, and IL-18. The up-regulated inflammatory cytokines trigger myocardial hypertrophy and cardiac fibrosis and promote the pathological process of DCM.

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.

Protective effect of Shenmai injection on doxorubicin-induced cardiotoxicity via regulation of inflammatory mediators.

BACKGROUND: Doxorubicin (DOX) is a chemotherapy drug for malignant tumors. The clinical application of DOX is limited due to its dosage relative cardiotoxicity. Oxidative damage and cardiac inflammation appear to be involved in DOX-related cardiotoxicity. Shenmai injection (SMI), which mainly consists of Panax ginsengC.A.Mey.and Ophiopogon japonicus (Thunb.) Ker Gawl, is widely used for the treatment of atherosclerotic coronary heart disease and viral myocarditis in China. In this study, we investigated the protective effect of Shenmai injection on doxorubicin-induced acute cardiac injury via the regulation of inflammatory mediators. METHODS: Male ICR mice were randomly divided into seven groups: control, DOX (10 mg/kg), SMI (5 g/kg), DOX with pretreatment with SMI (0.5 g/kg, 1.5 g/kg or 5 g/kg) and DOX with post-treatment with SMI (5 g/kg). Forty-eight hours after the last DOX administration, all mice were anesthetized for ultrasound echocardiography. Then, serum was collected for biochemical and inflammatory cytokine detection, and heart tissue was collected for histological and Western blot detection. RESULTS: A cumulative dose of DOX (10 mg/kg) induced acute cardiotoxicity in mice manifested by altered echocardiographic outcome, and increased tumor necrosis factor, interleukin 6 (IL-6), monocyte chemotactic protein 1, interferon-γ, and serum AST and LDH levels, as well as cardiac cytoplasmic vacuolation and myofibrillar disarrangement. DOX also caused the increase in the expression of IKK-α and iNOS and produced a large amount of NO, resulting in the accumulation of nitrotyrosine in the heart tissue. Pretreatment with SMI elicited a dose-dependent cardioprotective effect in DOX-dosed mice as evidenced by the normalization of serum inflammatory mediators, as well as improve dcardiac function and myofibril disarrangement. CONCLUSIONS: SMI could recover inflammatory cytokine levels and suppress the expression of IKK-α and iNOS in vivo, which was increased by DOX. Overall, there was evidence that SMI could ameliorate DOX-induced cardiotoxicity by inhibiting inflammation and recovering heart dysfunction.

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.

Potential accumulation of protopanaxadiol-type ginsenosides in six-months toxicokinetic study of SHENMAI injection in dogs.

SHENMAI injection (SMI), derived from famous Shen Mai San, is a herbal injection widely used in China. Ginsenosides are the major components of SMI. To monitor the exposure level of SMI during long-term treatment, a 6-month toxicokinetic experiment was performed. Twenty-four beagle dogs were dived into four groups (n = 6 in each group): a control group (0.9% NaCl solution) and three SMI groups (2, 6 or 3 mg/kg). The dogs were i.v. infused with vehicle or SMI daily for 180 d. Blood samples for analysis were collected at specific time points as follows: pre-dose (0 h); at 10, 30, and 60 min during infusion; and at 10, 30, 60, 90, 120, 240, and 300 min post-administration. Concentrations of ginsenosides Rb1, Rb2, Rc, Rd, Re, Rf, and Rg1 in the plasma were determined simultaneously by liquid chromatography-tandem mass spectrometry. Non-compartmental parameters were further calculated and analyzed. Significant differences were found between the kinetic behavior of 20(S)-protopanaxadiol-type (PPD-type) and 20(S)-protopanaxatriol-type (PPT-type) ginsenosides. Increasing in the exposure level of PPD-type ginsenosides was observed in dogs during the experiment. Therefore, PPD-type ginsenosides are closely related to the immunity modulation effect of SMI. Increased PPD-type ginsenoside exposure level may present potential toxicity and induce drug-drug interaction risks during SMI administration. As such, PPD-type ginsenoside accumulation must be carefully monitored in future SMI research.

One-month toxicokinetic study of SHENMAI injection in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: 'SHENMAI' injection (SMI) has been widely used in cardioprotection and modulation of the immune system because of its great efficacy. SMI primarily comprises the saponins from Panax ginseng and Ophiopogon japonicas. The profiles of saponins in SMI during long-term toxicokinetics remain unclear. MiR-146a possesses excellent sensitivity as a bio-marker in the innate immunity modification effect of SMI. AIM OF THE STUDY: Is to monitor the exposure level of SMI during a one-month toxicokinetic experiment, an analytical method involving ESI-LC-MS/MS technology was developed to determine 20 (S)-protopanaxadiol-type ginsenoside (Rb1, Rb2, Rc, Rd), 20 (S)-protopanaxatriol-type ginsenoside (Rg1, Re, Rf), oleanolic acid-type ginsenoside (Ro), and ophiopogonin D in rats. The levels of AST, CK, ALT, SOD, GSH-pX, MDA, miR-146a, and ECG were measured to explore the effects of SMI in cardiologic function and immune activity. RESULTS: Results show that the levels of AST, CK, and MDA decreased upon the administration of SMI. The level of miR-146a increased upon the administration of SMI dosage. During the administration of SMI, increasing exposure levels of 20 (S)-protopanaxadiol-type ginsenosides were also observed. CONCLUSION: The 20 (S)-protopanaxadiol-type ginsenosides were considered potential PK/TK markers because of their high exposure levels that continuously increased. Oxidative stress was slightly alleviated during the toxicokinetic study. Based on the level of miR-146a, negatively regulated innate immunity was observed. The regulation became more serious with increasing exposure levels of 20 (S)-protopanaxadiol-type ginsenosides. Negatively regulated innate immunity could be induced by long-term administration of SMI (>0.4g/kg).

Protective effect of Lycium barbarum polysaccharides against doxorubicin-induced testicular toxicity in rats.

The present study aimed to investigate whether Lycium barbarum polysaccharides (LBP) would protect against doxorubicin (DOX)-induced testicular toxicity. Male Sprague-Dawley rats were treated with distilled water (4 mL/kg) or LBP (200 mg/kg, p.o.) daily for 10 days and followed by saline (0.9 %, 10 mL/kg) or DOX (10 mg/kg) intravenous injection at day 7. Pretreatment with LBP ameliorated DOX-induced reduction in the testicular weights, sperm concentrations and percentage of motile sperms, as well as the increase in abnormal sperm rate. LBP administration to DOX-treated rats successfully reversed the changes in MDA and GHS-Px levels. Compared with the control, pretreatment with LBP significantly increased the plasma testosterone level in the LBP + DOX group. The histopathology examinations further confirmed that LBP effectively attenuated DOX-induced severe degenerative changes of seminiferous tubules. This study illustrated the capability of LBP in attenuating testicular oxidative stress and protecting testis-specific toxicity in DOX-exposed rats.

Stereospecific pharmacodynamics and chiral inversion of NG-nitro-arginine in the beagle dogs.

In the present study, we analyzed the stereospecific pharmacodynamics and inversion of N(G)-nitro-arginine by an intravenous blous injection of L-N(G)-nitro-arginine (L-NNA) or D-N(G)-nitro-arginine (D-NNA) (10 mg/kg) in beagle dogs. Significant pressor responses were observed for both substances, though a similar maximum response induced by L-NNA was reached at 120 min slower as compared with D-NNA. The rise in mean arterial pressure (MAP) of D-NNA dogs was also shown to be slower than the L-NNA group. Our data showed that D-NNA had no impact on MAP within 60 min after its injection. Plasma L-NNA started to appear after 45 min posterior to the i.v. bolus injection of D-NNA. This chiral inversion is unidirectional because no D-NNA was not produced from L-NNA. The pressor response in the D-NNA-injected dogs was well parallel to the plasma L-NNA concentration. Similar disposition of N(G)-nitro-arginine enantiomers and 4% of chiral inversion ratio from D-NNA to L-NNA was found in the beagle dogs. Given that D-amino acid oxidase (DAAO) is the essential enzyme in chiral inversion of D-NNA, we further compared the enzymatic activity of the renal DAAO between dogs and rats. Our data showed that dogs had a significantly lower enzymatic activity than rats, thus supported a lower inversion ratio of D-NNA in dogs.

Angelica sinensis: a novel adjunct to prevent doxorubicin-induced chronic cardiotoxicity.

Doxorubicin is an anthracycline antibiotic agent used in the treatment of a variety of solid and haematopoietic tumours, but its use is limited by formation of metabolites that induce acute and chronic cardiac toxicities. Angelica sinensis has been widely used to treat cardiovascular and cerebrovascular diseases in China. In the present study, we used an in vivo mouse model to explore whether A. sinensis could protect against doxorubicin-induced chronic cardiotoxicity. Male ICR mice were treated with distilled water or water extraction of A. sinensis (15 g/kg, orally) daily for 4 weeks, followed by saline or doxorubicin (15 mg/kg, intravenously) treatments weekly. Cardiotoxicity was assessed by electrocardiograph, antioxidant activity in cardiac tissues, serum levels of creatine kinase, aspartate aminotransferase (AST) and histopathological change in cardiac tissues. A cumulative dose of doxorubicin (60 mg/kg) caused animal death and myocardial injury characterized by increased QT interval and decreased heart rate in electrocardiograph, decrease of heart antioxidant activity, increase of serum AST, as well as myocardial lesions. Pre-treatment with A. sinensis significantly reduced mortality and improved heart performance of the doxorubicin-treated mice as evidenced from normalization of antioxidative activity and serum AST, preventing loss of myofibrils as well as improving arrhythmias and conduction abnormalities. Furthermore, the in vitro cytotoxic study showed that A. sinensis did not compromise the antitumour activity of doxorubicin. These results suggested that A. sinensis elicited a typical cardioprotective effect on doxorubicin-related oxidative stress, and could be a novel adjunct in the combination with doxorubicin chemotherapy.

Nitric oxide inducing function and intracellular movement of chicken interleukin-18 in cultured cells.

To evaluate the characteristics of chicken interleukin-18 (ChIL-18) in different forms in vitro, the ChIL-18 full-length gene (ChIL-18-F) and the ChIL-18 presumed mature protein gene (ChIL-18-M) were cloned and inserted into the eukaryotic expression vector pCI, to construct recombinant pCI-ChIL-18-F and pCI-ChIL-18-M. The recombinant plasmids were then transferred into chicken splenic lymphocytes (CSLs). Western blot showed that ChIL-18-F, with a molecular weight of 23.0 kDa, was produced in CSLs transfected by pCI-ChIL-18-F; ChIL-18-M, with a molecular weight of 19.5 kDa, was produced in CSLs transfected by pCI-ChIL-18-M. The nitric oxide (NO) level in the transfected CSLs and the culture medium at different time points was further examined under confocal microscopy using 4,5-diaminofluorescein staining. The results showed that both pCI-ChIL-18-F and pCI-ChIL-18-M groups showed significant increase in intracellular and extracellular NO production compared with pCI transfected control cells. These results suggest that both ChIL-18-F and ChIL-18-M could stimulate NO secretion in CSLs. To characterize the intracellular distribution of ChIL-18, ChIL-18-F and ChIL-18-M were each fused to the enhanced green fluorescent protein gene, and expressed in Vero cells. The results showed that the ChIL-18-F tended to the membranous region in Vero cells, while ChIL-18-M did not. This indicates that the N-terminal 27 amino acid peptide helped ChIL-18 target to Vero cell membranes.