Dayuan Sui

Anti-proliferative effect of Juglone from Juglans mandshurica Maxim on human leukemia cell HL-60 by inducing apoptosis through the mitochondria-dependent pathway.

Induction of apoptosis in tumor cells has become the major focus of anti-tumor therapeutics development. Juglone, a major chemical constituent of Juglans mandshurica Maxim, possesses several bioactivities including anti-tumor. Here, for the first time, we studied the molecular mechanism of Juglone-induced apoptosis in human leukemia HL-60 cells. In the present study, HL-60 cells were incubated with Juglone at various concentrations. Occurrence of apoptosis was detected by Hoechst 33342 staining and flow cytometry. Expression of Bcl-2 and Bax mRNA was determined by quantitative polymerase chain reaction (qPCR). The results showed that Juglone inhibits the growth of human leukemia HL-60 cells in dose- and time-dependent manner. Topical morphological changes of apoptotic body formation after Juglone treatment were observed by Hoechst 33342 staining. The percentages of Annexin V-FITC-positive/PI negative cells were 7.81%, 35.46%, 49.11% and 66.02% with the concentrations of Juglone (0, 0.5, 1.0 and 1.5 microg/ml). Juglone could induce the mitochondrial membrane potential (DeltaPsim) loss, which preceded release of cytochrome c (Cyt c), Smac and apoptosis inducing factor (AIF) to cell cytoplasm. A marked increased of Bax mRNA and protein appeared with Juglone treatment, while an evidently decreased of Bcl-2 mRNA and protein appeared at the same time. These events paralleled with activation of caspase-9, -3 and PARP cleavage. And the apoptosis induced by Juglone was blocked by z-LEHD-fmk, a caspase-9 inhibitor. Those results of our studies demonstrated that Juglone-induced mitochondrial dysfunction in HL-60 cells trigger events responsible for mitochondrial-dependent apoptosis pathways and the elevated ratio of Bax/Bcl-2 was also probably involved in this effect.

Effect of ginsenoside Rb3 on myocardial injury and heart function impairment induced by isoproterenol in rats

The present study was designed to evaluate the effect of ginsenoside Rb3 on myocardial injury and heart function impairment induced by isoproterenol in rats. To induce myocardial ischemia, Sprague-Dawley rats were subcutaneously injected with isoproterenol (20mg/kg). Cardiac marker enzymes and antioxidative parameters in left ventricles were measured. Hemodynamic parameters were monitored and recorded as well. Histopathological examination of left ventricles was performed. It was found that the levels of creatine kinase and lactate dehydrogenase in isoproterenol-treated rats were significantly increased. The rats administrated with isoproterenol showed the declines in left ventricular systolic pressure, positive and negative maximal values of the first derivative of left ventricular pressure, and an elevation of left ventricular end diastolic pressure. Isoproterenol enhanced the content of malondialdehyde and decreased the activities of superoxide dismutase, catalase in left ventricles. Administration of ginsenoside Rb3 significantly ameliorated myocardial injury and heart function impairment induced by isoproterenol. The cardioprotective effect of ginsenoside Rb3 was further confirmed by histopathological examination. Ginsenoside Rb3 also alleviated the increase of malondialdehyde content and decrease of superoxide dismutase and catalase activities in left ventricles. The results indicated that ginsenoside Rb3 possesses the effect against isoproterenol-induced myocardial injury and heart function impairment, and that the mechanism of pharmacological action was related to the antioxidant activity of ginsenoside Rb3 at least in part.

20(S)-Protopanaxadiol Triggers Mitochondrial-Mediated Apoptosis in Human Lung Adenocarcinoma A549 Cells via Inhibiting the PI3K/Akt Signaling Pathway

20(S)-Protopanaxadiol (PPD), an aglycone saponin ginsenoside isolated from Panax quinquefolium L, has been shown to inhibit the growth and proliferation in several cancer lines. However, the underlying molecular mechanisms remain poorly understood. In this study, we investigated the apoptosis-induced effects and the mechanism of 20(S)-PPD on human lung adenocarcinoma A549 cells. 20(S)-PPD showed a potent antiproliferative activity against A549 cells by triggering apoptosis. 20(S)-PPD-induced apoptosis was characterized by a dose-dependent loss of the mitochondrial membrane, release of cytochrome c, second mitochondria-derived activator of caspase (Smac) and apoptosis-inducing factor (AIF), activation of caspase-9/-3, and cleavage of poly (ADP-ribose) polymerase (PARP). Caspase-dependence was indicated by the ability of the pan-caspase inhibitor z-VAD-fmk to attenuate 20(S)-PPD-induced apoptosis. After treatment with 20(S)-PPD, the proportion of A549 cells at the G0/G1 phase increased, while cells at the S and G2/M phases decreased. Furthermore, 20(S)-PPD also triggered down-regulation of phosphorylated Akt (Ser473/Thr308) and glycogen synthase kinase 3β (GSK 3β). Knockdown of GSK 3β with siRNA promoted the apoptotic effects of 20(S)-PPD. These results revealed an unexpected mechanism of action for this unique ginsenoside: triggering a mitochondrial-mediated, caspase-dependent apoptosis via down-regulation of the PI3K/Akt signaling pathway in A549 cells. Our findings encourage further studies of 20(S)-PPD as a promising chemopreventive agent against lung cancer.

Ginsenoside Rb3 inhibits angiotensin II-induced vascular smooth muscle cells proliferation.

This study was designed to examine the effect of ginsenoside Rb3 on angiotensin (Ang) II-induced proliferation of cultured rat vascular smooth muscle cells (VSMCs). VSMCs proliferation was evaluated by [3H]Thymidine incorporation. The cell cycle was examined by flow cytometry. The expression of mRNA of proto-oncogene c-myc, c-fos and c-jun was observed by RT-PCR. Ginsenoside Rb3 had no effects on VSMCs proliferation in physiological condition. Ang II significantly increased the proliferation of VSMCs and the expression of mRNA of proto-oncogene c-myc, c-fos and c-jun. Ginsenoside Rb3 markedly inhibited Ang II-induced VSMCs proliferation. Concomitantly, ginsenoside Rb3 decreased cell cycle progression from G(0)/G(1) to S phase. Furthermore, ginsenoside Rb3 significantly attenuated the expression of mRNA of proto-oncogene c-myc, c-fos and c-jun. This study showed that ginsenoside Rb3 inhibited Ang II-induced VSMCs proliferation, at least in part by inhibiting Ang II-induced G(0)/G(1) to S phase transition and attenuating the expression of mRNA of c-fos, c-jun and c-myc. The findings may explain the beneficial effects of ginsenoside Rb3 in cardiovascular diseases, and it will be useful to develop prevention and therapeutics of cardiovascular diseases.

Ginsenoside Rb3 ameliorates myocardial ischemia-reperfusion injury in rats

Context: Panax ginseng C. A. Mey (Araliaceae) has been widely used in clinic for treatment of cardiovascular diseases in China. Ginsenoside Rb3 is the main chemical component of Panax ginseng. Objective: The aim of this study was to evaluate the effect of ginsenoside Rb3 on myocardial ischemia-reperfusion injury in rats. Methods: Sprague–Dawley rats were orally treated with Rb3 (5, 10 or 20 mg/kg) daily for 3 days followed by subjecting to left anterior descending coronary artery ligation for 30 min and reperfusion for 24 h. Results: This study showed that ginsenoside Rb3 treatment resulted in a reduction in myocardial infarct size. Ginsenoside Rb3 significantly attenuated the changes of creatine kinase activity and lactate dehydrogenase activity. The cardioprotective effect of ginsenoside Rb3 was further confirmed by histopathological examination. Ginsenoside Rb3 alleviated the increase of malondialdehyde content and the decrease of superoxide dismutase activity in left ventricle. Treatment with ginsenoside Rb3 also decreased plasma endothelin and angiotensin II levels. Conclusion: These findings suggested that ginsenoside Rb3 possesses the effect against myocardial IR injury and the underlying mechanism is related to its antioxidant activity and microcirculatory improvement.

Protective effect of total flavonoids extracted from the leaves of Murraya paniculata (L.) Jack on diabetic nephropathy in rats.

This study was designed to evaluate the effects of total flavonoids extracted from the leaves of Murraya paniculata (L.) Jack (TFMP) on diabetic nephropathy. High fat diet and streptozotocin-induced diabetic rats were treated with the TFMP (35 or 70 mg/kg) for 13 weeks. Changes of renal function parameters were examined at the end of administration. Some kidneys were collected for histological and immunohistochemistry studies, the other ones for biochemical parameters analysis. TFMP significantly decreased the levels of serum blood urea nitrogen, serum creatinine, creatinine clearance, interleukin-6, urinary albumin, 24h-urinary albumin excretion rate, kidney weight to body weight ratio and fasting blood glucose in diabetic rats. Meanwhile, the levels of triglycerides, total and LDL cholesterols in the TFMP treated diabetic rats were lower and the high-density lipoprotein cholesterol level was higher than that in the diabetic rats. TFMP treatment significantly blocked the decrease of superoxide dismutase and glutathione peroxidase and increase of malondialdehyde levels in diabetic rats. Furthermore, the TFMP not only decreased the expression of TGF-β1 and CTGF protein, but also reduced diabetes-induced morphological alterations of the kidney. These results suggest that TFMP is a protective agent against renal damage in diabetic nephropathy.

Acanthopanax senticosides B ameliorates oxidative damage induced by hydrogen peroxide in cultured neonatal rat cardiomyocytes.

Acanthopanax senticosides B is a monomer of Acanthopanax senticosus saponins. Previous reports showed that Acanthopanax senticosus saponins exhibit antioxidant action and cardiac protection. However, whether Acanthopanax senticosides B has cardiac protection remains unknown. In this study, we investigated the effect of Acanthopanax senticosides B on oxidative damage induced by hydrogen peroxide (H(2)O(2)) of cardiomyocytes. As revealed from the results, when the cardiomyocytes were exposed to H(2)O(2) for designed time and concentration, the percentage of survival cells was down significantly, the activity of lactate dehydrogenase (LDH) and the content of cellular malondialdehyde (MDA) were increased markedly. These results indicated that the cells were subjected to oxidative damage. Treatment with Acanthopanax senticosides B prior to H(2)O(2) (100 microM) exposure can increase cell viability significantly, lessen H(2)O(2)-induced cardiomyocyte morphological change, and inhibit augmentation of LDH activity in culture media and cellular MDA content markedly. Our results demonstrated that Acanthopanax senticosides B (400 microg/ml and 200 microg/ml) can protect cells against oxidative injury of H(2)O(2) (100 microM). Furthermore, the activities of superoxide dismutase (SOD), glutathione peroxidase, catalase and the content of reduced glutathione (GSH) of cardiomyocytes were also raised by Acanthopanax senticosides B. Taken together, the study implicated that Acanthopanax senticosides B protects cardiomyocytes against oxidative-stress injury induced by H(2)O(2) through reduction of lipid peroxidation and enhancement of the activity of antioxidant defense.

Ginsenoside Rg3 Improves Cardiac Function after Myocardial Ischemia/Reperfusion via Attenuating Apoptosis and Inflammation.

Objectives. Ginsenoside Rg3 is one of the ginsenosides which are the main constituents isolated from Panax ginseng. Previous study demonstrated that ginsenoside Rg3 had a protective effect against myocardial ischemia/reperfusion- (I/R-) induced injury. Objective. This study was designed to evaluate the effect of ginsenoside Rg3 on cardiac function impairment induced by myocardial I/R in rats. Methods. Sprague-Dawley rats were subjected to myocardial I/R. Echocardiographic and hemodynamic parameters and histopathological examination were carried out. The expressions of P53, Bcl-2, Bax, and cleaved caspase-3 and the levels of TNF-α and IL-1β in the left ventricles were measured. Results. Ginsenoside Rg3 increased a left ventricular fractional shortening and left ventricular ejection fraction. Treatment with ginsenoside Rg3 also alleviated increases of left ventricular end diastolic pressure and decreases of left ventricular systolic pressure and ±dp/dt in myocardial I/R-rats. Ginsenoside Rg3 decreased apoptosis cells through inhibiting the activation of caspase-3. Ginsenoside Rg3 also caused significant reductions of the contents of TNF-α and IL-1β in left ventricles of myocardial I/R-rats. Conclusion. The findings suggested that ginsenoside Rg3 possessed the effect of improving myocardial I/R-induced cardiac function impairment and that the mechanism of pharmacological action of ginsenoside Rg3 was related to its properties of antiapoptosis and anti-inflammation.

Effect of ginsenoside Rh1 on myocardial injury and heart function in isoproterenol-induced cardiotoxicity in rats

The present study was designed to investigate the effect of ginsenoside Rh1 on myocardial injury and heart function in isoproterenol-induced cardiotoxicity in rats. Sprague–Dawley rats were subcutaneously injected with isoproterenol (20 mg/kg). Cardiac marker enzymes in serum, antioxidative parameters and inflammatory cytokines in left ventricles were measured. Hemodynamic parameters were monitored and recorded as well. Histopathological examination of left ventricles was performed. It was found that creatine kinase-MB (CK-MB) activity and troponin T level in isoproterenol-treated rats were significantly increased. Isoproterenol caused declines of left ventricular systolic pressure, positive and negative maximal values of the first derivative of left ventricular pressure, and an elevation of left ventricular end diastolic pressure. Isoproterenol enhanced the content of malondialdehyde (MDA), tumor necrosis-α (TNF-α), interleukin-1β (IL-1β) and decreased the activities of superoxide dismutase (SOD), catalase, and glutathione peroxidase (GSH-Px) in left ventricles. Ginsenoside Rh1 significantly ameliorated myocardial injury and heart function impairment induced by isoproterenol. The cardioprotective effect of ginsenoside Rh1 was further confirmed by histopathological examination. Ginsenoside Rh1 also partially inhibited the increase of MDA, TNF-α, IL-1β contents and the decrease of SOD, catalase, and GSH-Px activities in left ventricles. The results indicated that ginsenoside Rh1 possessed the effect against isoproterenol-induced cardiotoxicity, and that the mechanism of pharmacological action was related to regulating the activities of SOD, catalase, and GSH-Px and decreasing the contents of TNF-α and IL-1β.

Beneficial effects of 20(S)-protopanaxadiol on antitumor activity and toxicity of cyclophosphamide in tumor-bearing mice.

20(S)-protopanaxadiol (PPD) is an extract of Panax quinquefolius L. The aim of this study was to investigate the effect of PPD on the antitumor activity and toxicity of cyclophosphamide (CTX) in tumor-bearing mice. C57BL/6 mice bearing Lewis lung carcinoma cells were treated with PPD (50 mg/kg) alone, CTX (20 mg/kg) alone or PPD (50 mg/kg) in combination with CTX (20 mg/kg), respectively. The results showed that PPD alone has no significant antitumor activity but synergistically enhanced the antitumor activity of CTX. PPD significantly increased the peripheral white blood cell count, bone marrow cell count, interleukin-2 and interferon-γ in CTX-treated tumor-bearing mice. The lowered levels of spleen index, splenocyte proliferation and natural killer cell activity in tumor-bearing mice following CTX treatment were also increased by PPD administration. PPD may be a beneficial supplement during CTX chemotherapy for enhancing the antitumor efficacy and reducing the toxicity of CTX.