Kaempferide-7-O-(4"-O-acetylrhamnosyl)-3-O-rutinoside reduces myocardial infarction size after coronary artery ligation in rats.

Kaempferide-7-O-(4"-O-acetylrhamnosyl)-3-O-rutinoside (A-F-B) is a novel flavonoid extracted from the leaves of Actinidia kolomikta. We recently reported that A-F-B administration could improve lipid profiles. A-F-B actions are associated with regulating the activities of PAP and HMG-CoA reductase in hepatic tissue. This study evaluated the effects of A-F-B on acute myocardial infarction (AMI) in rats. An AMI model was established by ligating the left anterior descending coronary artery. The myocardial infarct size (MIS), creatine kinase (CK-MB) activity, troponin T level, endothelial nitric oxide synthase (eNOS) activity, superoxide dismutase (SOD) activity, catalase activity, malondialdehyde (MDA) content, nitric oxide (NO) content were measured. The results showed that the groups treated with A-F-B showed a dose-dependent reduction in MIS. A-F-B markedly inhibited the elevation of the activity of CK-MB, troponin T level, and the content of MDA induced by AMI. A-F-B also showed a capacity to increase the activities of SOD, catalase, and eNOS. The NO content in A-F-B-treated groups also augmented. The findings suggest that A-F-B exerted cardioprotective effects against acute myocardial ischemic injury by regulating antioxidative enzymes activity and endothelial nitric oxide synthase activity.

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-1ß (IL-1ß) 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-1ß 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-1ß.

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.

Ginsenoside Rg2 Ameliorates Brain Injury After Intracerebral Hemorrhage in a Rat Model of Preeclampsia.

The incidence of maternal hemorrhagic stroke is elevated in women with preeclampsia during pregnancy. Panax ginseng is a traditional medicinal herb with numerous applications, and ginsenosides are the key bioactive compounds in Panax ginseng. This study aims to evaluate the effects of ginsenoside Rg2 on pregnancy outcomes and brain injury after intracerebral hemorrhage (ICH) in a rat model of preeclampsia. Preeclampsia was induced in rats by N(ω)-nitro-L-arginine methyl ester. Then, an ICH model was prepared by intrastriatal injection of bacterial collagenase. Ginsenoside Rg2 markedly elevated the survival ratio of fetuses. The placental and body weights were increased in the ginsenoside Rg2 group. Compared with the preeclampsia group, the Garcia test score of ginsenoside Rg2-treated rats was significantly increased. Ginsenoside Rg2 treatment ameliorated the ICH-induced augmentation of Evans blue extravasation, inhibited the ICH-induced elevation of brain water content, and reduced the interleukin-1ß and tumor necrosis factor-α levels in the hemorrhagic hemisphere after ICH in preeclampsia model rats. Furthermore, ginsenoside Rg2 treatment not only inhibited augmentation of TLR-4, MyD88, p-IκBα, and p-NF-κB expression but also abated the reduction of occludin and claudin-5 expression in the hemorrhagic hemisphere. The findings indicated that ginsenoside Rg2 improved pregnancy outcomes in a rat model of preeclampsia without decreasing the blood pressure and urine protein level. The findings also demonstrated that ginsenoside Rg2 ameliorated ICH-induced neurological disorder and blood-brain barrier dysfunction in an animal model of preeclampsia by regulating the TLR4/NF-κB signaling pathway.

Design, synthesis, and in-vivo evaluation of 4,5-diaryloxazole as novel nonsteroidal anti-inflammatory drug.

A series of 4,5-diaryloxazole analogs were designed and the interaction between oxaprozin and cyclooxygenase-2 studied by the docking method to improve the biological activity and reduce the gastrointestinal side effects of oxaprozin. Finally, 3-(4-(4-fluorophenyl)-5-(4-aminosulfonyl-3-fluorophenyl)-oxazole-2-yl) propanoic acid (NC-2142), the best candidate, was selected for synthesis and bioassay based on the screening result. NC-2142 could lower the tumefaction rates of back metatarsus in rats, as well as reduce the writhing times in mice. NC-2142 produced fewer gastric lesions than oxaprozin. After the aminosulfonyl group was introduced into the benzene ring of oxaprozin, its analgesic and anti-inflammatory activities remained unchanged, and it reduced the number of gastric lesions. This provided a feasible method for further structure modification and optimization of oxaprozin.

Ginsenoside Re Improves Isoproterenol-Induced Myocardial Fibrosis and Heart Failure in Rats.

Objective. Panax ginseng is used widely for treatment of cardiovascular disorders in China. Ginsenoside Re is the main chemical component of P. ginseng. We aimed to investigate the protective effect of ginsenoside Re on isoproterenol-induced myocardial fibrosis and heart failure in rats. Methods. A model of myocardial fibrosis and heart failure was established by once-daily subcutaneous injection of isoproterenol (5 mg/kg/day) to rats for 7 days. Simultaneously, rats were orally administrated ginsenoside Re (5 or 20 mg/kg) or vehicle daily for 4 weeks. Results. Isoproterenol enhanced the heart weight, myocardial fibrosis, and hydroxyproline content in rat hearts. Ginsenoside Re inhibited (at least in part) the isoproterenol-induced increase in heart weight, myocardial fibrosis, and hydroxyproline content. Compared with the isoproterenol group, treatment with ginsenoside Re ameliorated changes in left ventricular systolic pressure, left ventricular end diastolic pressure, and the positive and negative maximal values of the first derivative of left ventricular pressure. Ginsenoside Re administration also resulted in decreased expression of transforming growth factor (TGF)-ß1 in serum and decreased expression of Smad3 and collagen I in heart tissue. Conclusion. Ginsenoside Re can improve isoproterenol-induced myocardial fibrosis and heart failure by regulation of the TGF-ß1/Smad3 pathway.

Alprostadil attenuates myocardial ischemia/reperfusion injury by promoting antioxidant activity and eNOS activation in rats.

PURPOSE: To investigate the effect of alprostadil on myocardial ischemia/reperfusion (I/R) in rats. METHODS: Rats were subjected to myocardial ischemia for 30 min followed by 24h reperfusion. Alprostadil (4 or 8 µg/kg) was intravenously administered at the time of reperfusion and myocardial infarct size, levels of troponin T, and the activity of creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH) in the serum were measured. Antioxidative parameters, nitric oxide (NO) content and phosphorylated endothelial nitric oxide synthase 3 (p-eNOS) expression in the left ventricles were also measured. Histopathological examinations of the left ventricles were also performed. RESULTS: Alprostadil treatment significantly reduced myocardial infarct size, serum troponin T levels, and CK-MB and LDH activity (P<0.05). Furthermore, treatment with alprostadil significantly decreased malondialdehyde (MDA) content (P<0.05) and markedly reduced myonecrosis, edema and infiltration of inflammatory cells. Superoxide dismutase and catalase activities (P<0.05), NO level (P<0.01) and p-eNOS (P<0.05) were significantly increased in rats treated with alprostadil compared with control rats. CONCLUSION: These results indicate that alprostadil protects against myocardial I/R injury and that these protective effects are achieved, at least in part, via the promotion of antioxidant activity and activation of eNOS.

Ginsenoside Re Attenuates Isoproterenol-Induced Myocardial Injury in Rats.

Objective. Panax ginseng is widely used for treatment of cardiovascular disorders in China. Ginsenoside Re is the main chemical component of Panax ginseng. This study aimed to investigate the protective effect of Ginsenoside Re on isoproterenol-induced myocardial injury in rats. Methods. Male Wistar rats were orally given Ginsenoside Re (5, 20 mg/kg) daily for 7 days. Isoproterenol was subcutaneously injected into the rats for two consecutive days at a dosage of 20 mg/kg/day (on 6th and 7th day). Six hours after the last isoproterenol injection, troponin T level and creatine kinase-MB (CK-MB) activity were assayed. Histopathological examination of heart tissues was performed. The levels of malondialdehyde (MDA) and glutathione (GSH) in heart tissues were measured. The nuclear factor erythroid 2-related factor 2 (Nrf2) content in nucleus and the proteins of glutathione cysteine ligase catalytic subunit (GCLC) and glutathione cysteine ligase modulatory subunit (GCLM) in heart tissues were assayed by western blotting method. Results. Treatment with Ginsenoside Re at dose of 5, 20 mg/kg reduced troponin T level and CK-MB activity of rats subjected to isoproterenol. The cardioprotective effect of Ginsenoside Re was further confirmed by histopathological examination which showed that Ginsenoside Re attenuated the necrosis and inflammatory cells infiltration. Ginsenoside Re inhibited the increase of MDA content and the decrease of GSH in heart tissues. Moreover, the Nrf2 content in nucleus and the expressions of GCLC and GCLM were significantly increased in the animals treated with Ginsenoside Re. Conclusion. These findings suggested that Ginsenoside Re possesses the property to attenuate isoproterenol-induced myocardial ischemic injury by regulating the antioxidation function in cardiomyocytes.

[Effects of CASI on myocardial ischemia-reperfusion arrhythmia in rats].

OBJECTIVE: To observe the protective effect of compound acanthopanax senticosus injection (CASI) on myocardial ischemia-reperfusion arrhythmia in rats. METHOD: The myocardial ischemia-reperfusion model was induced by 30 min coronary occulusion and 60 min reperfusion in openchest anesthetized rats. The changes of arrhythmia with electrocardiogram lead II, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), the contents of malondialdehyde (MDA) and Ca2+ in myocardium were determined. RESULT: In rats treated by CASI (in a dosage of 25, 50 and 100 mg x kg(-1) femoral vein infusion at 30 min after coronary occulusion), the incidence of myocardial ischemia-reperfusion ventricular arrhythmias, for instance the ventricular tachycardia (VT) and ventricular fibrillation (Vf), was effectively prevented, the appearing time of arrhythmia was delayed and the duration of arrhythmia was shortened, while the elevated ST segment lowered as well. At the same time, the contents of myocardial Ca2+ and MDA were decreased significantly as well as the activities of myocardial SOD and GSH-Px increased markedly. CONCLUSION: CASI is of protective effect on myocardial ischemia-reperfusion arrhythmia, which may be related to scavenging the oxygen free radicals and Ca2+ overload formed during reperfusion.

Two New Triterpenoid Saponins from the Structural Modification of Pseudoginsenoside-F11 and their Cytotoxic Activities.

Two ginsenoside derivatives (1, 2) along with 2 known ginsenosides (3, 4) were isolated from the acid hydrolysis products of pseudoginsenoside-F11. Their structures were elucidated on the basis of spectroscopic analyses, including ID, 2D NMR and HR-ESI-MS. Among them, (12R, 20S, 24S)-20, 24; 12, 24-diepoxy-dammarane-3ß, 6α-diol (1) and (20R, 24R)-dammar-20, 24-epoxy-3ß, 6α, 12ß, 25-tetraol (2) were identified as new triterpenoid saponins. They were subjected to assay for cytotoxic activities against six human tumor cells lines.

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-1ß 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-1ß 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.

Simvastatin ameliorates low-dose streptozotocin-induced type 2 diabetic nephropathy in an experimental rat model.

The present study aims to study the possible renal protective effect of simvastatin in the development and progression of type 2 diabetic nephropathy. A rat model of T2DN was induced by high-fat diet together with single low-dose of streptozotocin. The diabetic rats were either given treatment or vehicle control for 13 weeks to develop nephropathy. At the end of treatment, parameters of renal function were determined. Kidney samples were collected for histological studies and generated homogenates for biochemical analysis. In T2DN rats, severe hyperglycemia was developed, FBG were markedly elevated. Diabetes induced significant alterations in renal structure, such as severe reduction of glomerular tufts, increase in Bowman's spaces, thickening of GBM. In addition, and SCr, UAER and BUN are elevated, accompanied with reduction in UCr and CCr, indicating obvious renal failure. On the other hand, endogenous antioxidants SOD, GSH-Px were reduced, whereas MDA was increased. However, treatment of T2DN rats with simvastatin restored renal changes in different aspects. Our results showed that STZ-induced T2DN could be attenuated by simvastatin. The renoprotective effects of simvastatin was indicated by improvements in kidney function parameters, and was attributed by its lipid-lowering effect as well as its anti-oxidative stress, anti-inflammatory properties without having noticeable influence on glycemic control. Simvastatin ameliorates low-dose Streptozotocin-induced type 2 diabetic nephropathy in an experimental rat model.

[Protective effect of ASS on myocardial ischemia-reperfusion injury in rats].

OBJECTIVE: To observe the protective effect of Acanthopanax senticosus saponins (ASS) on myocardial ischemia-reperfusion injury in rats. METHOD: The myocardial ischemia-reperfusion model was induced by 30 min left anterior descending coronary occlusion and 120 min reperfusion in rats. The changes of myocardial infarct size (MIS), the serum creatine phosphokinase (CK) and lactate dehydrogenase (LDH) activity, the serum lipid peroxidation (LPO) content and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity and plasma endothelin (ET), angiotensin II (Ang II), prostacycline (PGI2) and thromboxane A2 (TXA2) levels and myocardial free fatty acid (FFA) content of infarct and noninfarct area were determined. RESULT: In rats treated by ASS (in a dosage of 25, 50 and 100 mg x kg(-1) i.v. at 30 min after coronary occulusion), the MIS was significantly reduced, the serum CK and LDH activity, the plasma ET, Ang II and TXA2 level and myocardial FFA content declined, while plasma PGI2 level and PGI2/TXA2 was increased signficantly. In addition, serum LPO content declined, SOD and GSH-Px activity were increased markedly. CONCLUSION: ASS has protective effect on myocardial ischemia-reperfusion injury, which may be due to its function of improving free radicals and myocardial metabolism, decreasing plasma ET, Ang II and TXA2 levels and increasing plasma PGI2 level and PGI2/TXA2 ratio etc.

[Effects of ginsenoside-Rb on blood lipid metabolism and anti-oxidation in hyperlipidemia rats].

OBJECTIVE: To observe effects of ginsenoside-Rb (G-Rb) on total cholesterol, lipoprotein cholesterol metabolism and anti-oxidation in experimental hyperlipidemia rats. METHOD: Hyperlipidemia rats were respectively given G-Rb 50, 100, 200 mg x kg(-1) x d(-1) ig for twelve days. Total cholesterol, lipoprotein cholesterol and lipid peroxidation (LPO) contents, prostacycline (PGI2), thromboxane (TXA2), superoxide dismutase (SOD) and blood viscosity were measured. Fat accumulation in liver was also observed. RESULT: Triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-c) in serum, TXA2 in plasma, LPO in serum and liver, and blood viscosity were decreased significantly. High density lipoprotein cholesterol (HDLc) in serum, PGI2 in plasma and SOD in serum and liver were significantly increased by G-Rb (100, 200 mg x kg(-1)) in experimental hyperlipidemia rats. In addition, G-Rb could decrease TC/HDL-c, LDLc/HDL-c ratio, increase PGI2/TXA2 ratio and inhibit fat accumulation in liver. CONCLUSION: G-Rb could have anti-arteriosclerosis effect by improving cholesterol and lipoprotein-cholesterol metabolism, suppressing lipid peroxidation, increasing anti-oxidase activity and PGI2/TXA2 ratio.

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-ß1 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.

Synthesis and anti-cancer cell activity of pseudo-ginsenoside Rh2.

ß-d-Glucopyranoside,(3ß,12ß,20E)-12,25-dihydroxydammar-20(22)-en-3-yl (pseudo-ginsenoside Rh2) and its 20Z-isomer were synthesized from ginsenoside Rh2 under a mild condition, via a simple three-step called acetylation, elimination-addition and saponification. In addition, their activities were evaluated by eight different human tumor cells, compared with ginsenoside Rh2 group. Results indicated that the reaction in the side chain might greatly enhance the anti-proliferative activity of ginsenosides.

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.

Alprostadil attenuates myocardial ischemia/reperfusion injury by promoting antioxidant activity and eNOS activation in rats

Abstract Purpose: To investigate the effect of alprostadil on myocardial ischemia/reperfusion (I/R) in rats. Methods: Rats were subjected to myocardial ischemia for 30 min followed by 24h reperfusion. Alprostadil (4 or 8 μg/kg) was intravenously administered at the time of reperfusion and myocardial infarct size, levels of troponin T, and the activity of creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH) in the serum were measured. Antioxidative parameters, nitric oxide (NO) content and phosphorylated endothelial nitric oxide synthase 3 (p-eNOS) expression in the left ventricles were also measured. Histopathological examinations of the left ventricles were also performed. Results: Alprostadil treatment significantly reduced myocardial infarct size, serum troponin T levels, and CK-MB and LDH activity (P<0.05). Furthermore, treatment with alprostadil significantly decreased malondialdehyde (MDA) content (P<0.05) and markedly reduced myonecrosis, edema and infiltration of inflammatory cells. Superoxide dismutase and catalase activities (P<0.05), NO level (P<0.01) and p-eNOS (P<0.05) were significantly increased in rats treated with alprostadil compared with control rats. Conclusion: These results indicate that alprostadil protects against myocardial I/R injury and that these protective effects are achieved, at least in part, via the promotion of antioxidant activity and activation of eNOS.

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 3ß (GSK 3ß). Knockdown of GSK 3ß 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.

Identification and molecular cloning of a novel amphibian Bowman Birk-type trypsin inhibitor from the skin of the Hejiang Odorous Frog; Odorrana hejiangensis.

In this study, an amphibian (Odorrana hejiangensis) skin extract was fractionated by reverse phase HPLC and fractions were screened for trypsin inhibitory activity. Using this initial approach, a novel trypsin inhibitory peptide was detected with an apparent protonated molecular mass of 1804.83 Da, as determined by MALDI-TOF mass spectrometry. It was named Hejiang trypsin inhibitor (HJTI) in accordance. The primary structure of the biosynthetic precursor of HJTI was deduced from a cDNA sequence cloned from a skin-derived cDNA library. The primary structure of the encoded predicted mature active peptide was established as: GAPKGCWTKSYPPQPCS (non-protonated monoisotopic molecular mass--1802.81Da). On the basis of this unequivocal amino acid sequence, a synthetic replicate was synthesized by solid phase Fmoc chemistry. This replicate displayed a moderately potent trypsin inhibition with a K(i) of 388 nM. Bioinformatic analysis of the primary structure of this peptide indicated that it was a member of the Bowman-Birk family of protease inhibitors. The substitutions of Gln-14 and Ser-17 by Lys, resulted in an increase in cationicity and a small increase in potency to a K(i) value of 218nM. Neither HJTI nor its synthetic analog, possessed any significant antimicrobial activity.