Grape proanthocyanidin inhibit pancreatic cancer cell growth in vitro and in vivo through induction of apoptosis and by targeting the PI3K/Akt pathway

Shikonin promotes autophagy in BXPC-3 human pancreatic cancer cells through the PI3K/Akt signaling pathway

The present study aimed to investigate the effect of shikonin on autophagy in BXPC-3 human pancreatic cancer cells and its underlying mechanism. Cell viability was assessed using the Cell Counting Kit-8 assay and the expression of light chain (LC) 3, p62, phosphoinositide 3-kinase (PI3K), Akt, phosphorylated (p)-PI3K and p-Akt was analyzed using western blot analysis. Following treatment with 1 μmol/l shikonin for 48 h and 2.5 and 5 μmol/l shikonin for 24 and 48 h, the viability of the BXPC-3 cells was found to be significantly reduced and the protein expression of LC3-II/LC3-I was observed to be increased, while the protein expression of p62, PI3K, Akt, p-PI3K and p-Akt was decreased. These findings suggest that shikonin promotes autophagy in BXPC-3 cells and that the underlying mechanism may be associated with the PI3K/Akt signaling pathway.

The effect of Cordyceps extract and a mixture of Ganoderma lucidum/Agaricus Blazi Murill extract on human endometrial cancer cell lines in vitro

Endometrial carcinoma is the most common gynaecological malignancy. Nevertheless there is a lack of curative therapies, especially for patients diagnosed with late stage, recurrent or aggressive disease, who have a poor prognosis. Cordyceps Sinensis, Ganoderma lucidum and Agaricus Blazi Murill are three fungi widely used in traditional Chinese medicine, and effects as adjuvants in tumour therapy have been demonstrated. However, the function and effects of these fungi in regard to endometrial cancer are not known. Three endometrial cancer cell lines, Ishikawa, Hec-1A and AN3-CA (derived from endometrial cancers grade I, II and III, respectively), were used to determine the effect of the fungi extracts on endometrial cancer cell function and to analyze the molecular mechanism. All fungi extracts had an inhibitory effect on cell viability and proliferation most probably exerted through induction of autophagy. Our data suggest that these fungi extracts may be used as adjuvants in endometrial tumour therapy.

Free radical scavenging, antioxidant and cancer chemoprevention by grape seed proanthocyanidin: an overview

A large number of investigations have demonstrated a broad spectrum of pharmacological and therapeutic benefits of grape seed proanthocyanidins (GSP) against oxidative stress and degenerative diseases including cardiovascular dysfunctions, acute and chronic stress, gastrointestinal distress, neurological disorders, pancreatitis, various stages of neoplastic processes and carcinogenesis including detoxification of carcinogenic metabolites. GSP exhibited potent free radical scavenging abilities in both in vitro and in vivo models. GSP exerted significant in vivo protection against structurally diverse drug and chemical-induced hepatotoxicity, cardiotoxicity, neurotoxicity, nephrotoxicity and spleentoxicity. GSP also protected against idarubicin and 4-hydroxyperoxy-cyclophosphamide-induced cytotoxicity toward human normal liver cells. GSP exhibited selective cytotoxicity toward selected human cancer cells, while enhancing the growth and viability of normal cells. GSP exhibited potent modulatory effects of pro-apoptotic and apoptotic regulatory bcl-XL, p53, c-myc, c-JUN, JNK-1 and CD36 genes. Long-term exposure to GSP may serve as a novel chemoprotectant against three stages of DMN-induced liver carcinogenesis and tumorigenesis including initiation, promotion and progression. GSP may selectively protect against oxidative stress, genomic integrity and cell death patterns in vivo. These results demonstrate that GSP may serve as a novel therapeutic intervention against carcinogenesis.

Urotensin II exerts antiapoptotic effect on NRK-52E cells through prostacyclin-mediated peroxisome proliferator-activated receptor alpha and Akt activation

Urotensin II (UII) is a cyclic vasoactive peptide which is mainly expressed in kidneys. Although elevated plasma UII levels are associated with renal impairment, the influence of UII on renal injury is unclear. In this study, we monitored the influence of UII on gentamicin-induced apoptosis in rat tubular cells (NRK-52E). We found that UII significantly reduced gentamicin-induced apoptosis and apoptotic signals. Blocking endogenous UII secretion caused cells to be more susceptible to gentamicin. In gentamicin-treated mice, UII also expressed protective effect on renal tubular cells. UII was also found to induce prostacyclin (PGI2) production, which caused peroxisomal proliferator-activated receptor α (PPARα) activation as revealed by both PGI2 synthase siRNA transfection and piroxicam treatment. Blockage of PPARα by siRNA transfection inhibited UII-induced Akt phosphorylation and the antiapoptotic effect of UII. Our results suggest that UII can protect renal tubular cells from gentamicin-induced apoptosis through PGI2-mediated PPARα and Akt activation.

Magnesium lithospermate B improves myocardial function and prevents simulated ischemia/reperfusion injury-induced H9c2 cardiomyocytes apoptosis through Akt-dependent pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Magnesium lithospermate B (MLB), an active polyphenol acid of Radix Salviae Miltiorrhizae (Danshen), showed a wide range of pharmacological activities in cardiovascular diseases. However, its role in protection against ischemia/reperfusion injury in H9c2 cardiomyocytes has not been elucidated. This study was aimed to investigate the protective effect and potential molecular mechanisms of MLB on apoptosis in H9c2 cardiomyocytes in vitro.

MATERIALS AND METHODS

We tested cell viability, shortening amplitude, necrosis, apoptosis, and the expression levels of Akt, phosphorylated Akt, Bcl-2 and Bax after 2-h simulated ischemia and 24-h simulated reperfusion in H9c2 cardiomyocytes. We further observed the contractile function in hearts after they were subjected to global 30-min ischemia and 180-min reperfusion.

RESULTS

Pretreatment with MLB markedly increased cell viability and while reducing evidence of necrosis and apoptosis in H9c2 cardiomyocytes. In addition, the expression of Bcl-2 and Bax protein was modulated. The results also showed that MLB significantly increased phosphorylation of Akt and that this phosphorylation can be partially inhibited by phosphoinositide 3-kinase/Akt inhibitor. Furthermore, MLB improved MI/R-induced myocardial contractile function.

CONCLUSION

Our results showed that MLB prevents I/R-induced myocardial damage by reducing necrosis and apoptosis in H9c2 cardiomyocytes and improving myocardial function in rat hearts.

PIMT prevents the apoptosis of endothelial cells in response to glycated low density lipoproteins and protective effects of grape seed procyanidin B2

Background

The development of diabetic angiopathy is associated with profound vascular endothelial cells (VEC) dysfunction and apoptosis. Glycated low density lipoproteins (gly-LDL) continuously produced in the setting of diabetic patients play an important role in causing VEC dysfunction and apoptosis. However, the underlying molecular mechanism remains largely elusive. Protein L-isoaspartyl methyltransferase (PIMT) is a widely expressed protein repair enzyme by multiple cell types of arterial wall including VEC. Our previous proteomic studies showed that the expression of PIMT was significantly decreased in the aorta of diabetic rats as compared with control rats and treatment with grape seed procyanidin extracts significantly increased the PIMT expression in diabetic rats. We hypothesized that PIMT plays a critical role in gly-LDL induced VEC apoptosis; grape seed procyanidin B2 (GSPB2) protect against gly-LDL induced VEC apoptosis through PIMT regulation.

Methods and Results

HUVEC transfected negative control and PIMT siRNA were treated with or without GSPB2 (10 µmol/L) for 48 h. Moreover, HUVEC of PIMT overexpression were stimulated by gly-LDL (50 µg/ml) in the presence or absence of GSPB2 (10 µmol/L) for 48 h. Our results showed that gly-LDL downregulated PIMT expression and PIMT overexpression or GSPB2 significantly attenuated gly-LDL induced VEC apoptosis. PIMT siRNA increased VEC apoptosis with up-regulation of p53, cytochrome c release, caspase-9 and caspase-3 activation. Mechanistically, overexpression of PIMT or GSPB2 increased the phosphorylation of ERK1/2 and GSK3β in the gly-LDL induced VEC.

Conclusion

In summary, our study identified PIMT as a key player responsible for gly-LDL induced VEC apoptosis and GSPB2 protect against gly-LDL induced VEC apoptosis by PIMT up-regulation. Targeting PIMT including use of GSPB2 could be turned into clinical application in the fighting against diabetic vascular complications.

Grape seeds: ripe for cancer chemoprevention

A wide variety of phytochemicals, mostly flavonoids or polyphenolics, have been shown to possess anticarcinogenic activities. Among these are the grape seed proanthocyanidins (GSPs), which are the active ingredients of grape seed extract (GSE). Substantial in vitro and preclinical in vivo studies have shown the chemopreventive efficacy of GSPs against various forms of cancers in different tumor models. In this issue of the journal, Derry and colleagues show that administration of GSE in the diet reduces azoxymethane-induced colon carcinogenesis in an A/J mouse model. The results of this innovative and comprehensive study indicate that inhibition of azoxymethane-induced colon cancer by dietary GSE is mediated through the induction of apoptosis that is associated with alterations in microRNA (miRNA) and cytokine expression profiles as well as β-catenin signaling. Notably, the demonstration that miRNA expression is affected by dietary GSE suggests a novel underlying mechanism for the chemopreventive action of GSE in colon cancer and, potentially, other cancers.

Crude aqueous extracts of Pluchea indica (L.) Less. inhibit proliferation and migration of cancer cells through induction of p53-dependent cell death

Background

Pluchea indica (L.) Less. (Asteraceae) is a perennial shrub plant with anti-inflammatory and antioxidant medicinal properties. However, the anti-cancer properties of its aqueous extracts have not been studied. The aim of this study was to investigate the anti-proliferation, anti-migration, and pro-apoptotic properties of crude aqueous extracts of P. indica leaf and root on human malignant glioma cancer cells and human cervical cancer cells, and the underlying molecular mechanism.

Methods

GBM8401 human glioma cells and HeLa cervical carcinoma cells were treated with various concentrations of crude aqueous extracts of P. indica leaf and root and cancer cell proliferation and viability were measured by cell growth curves, trypan blue exclusions, and the tetrazolium reduction assay. Effects of the crude aqueous extracts on focus formation, migration, and apoptosis of cancer cells were studied as well. The molecular mechanism that contributed to the anti-cancer activities of crude aqueous extracts of P. indica root was also examined using Western blotting analysis.

Results

Crude aqueous extracts of P. indica leaf and root suppressed proliferation, viability, and migration of GBM8401 and HeLa cells. Treatment with crude aqueous extracts of P. indica leaf and root for 48 hours resulted in a significant 75% and 70% inhibition on proliferation and viability of GBM8401 and HeLa cancer cells, respectively. Crude aqueous extracts of P. indica root inhibited focus formation and promoted apoptosis of HeLa cells. It was found that phosphorylated-p53 and p21 were induced in GBM8401 and HeLa cells treated with crude aqueous extracts of P. indica root. Expression of phosphorylated-AKT was decreased in HeLa cells treated with crude aqueous extracts of P. indica root.

Conclusion

The in vitro anti-cancer effects of crude aqueous extracts of P. indica leaf and root indicate that it has sufficient potential to warrant further examination and development as a new anti-cancer agent.