Phenethyl isothiocyanate inhibits hypoxia-induced accumulation of HIF-1α and VEGF expression in human glioma cells

Phenethyl isothiocyanate (PEITC), a natural dietary isothiocyanate, inhibits angiogenesis but the molecular mechanisms that underlie this effect are not known. In this study, under hypoxic conditions (1% O₂), we examined the effect of PEITC on the intracellular level of the hypoxia inducible factor (HIF-1α) and extracellular level of the vascular endothelial growth factor (VEGF) in a variety of human cancer cell lines. Surprisingly, we observed that PEITC suppressed the HIF-1α accumulation during hypoxia in human glioma U87, human prostate cancer DU145, colon cancer HCT116, liver cancer HepG2, and breast cancer SkBr3 cells. PEITC treatment also significantly reduced the hypoxia-induced secretion of VEGF. Suppression of HIF-1α accumulation during treatment with PEITC in hypoxia was related to PI3K and MAPK pathways. Taken together, these results suggest that PEITC inhibits the HIF-1α expression through inhibiting the PI3K and MAPK signalling pathway and provide a new insight into a potential mechanism of the anticancer properties of PEITC.     

AKT signalling and mitochondrial pathways are involved in mushroom polysaccharide-induced apoptosis and G1 or S phase arrest in human hepatoma cells

This study describes molecular mechanisms for inhibiting tumour cell proliferation using polysaccharides from medicinal mushrooms in human hepatoma cells. The results show that regarding cell cycle-related proteins, three types of polysaccharides significantly enhance the expression of p27^Kip in HepG2 and Bel-7404 cells, while suppressing the activity of cyclin D1/CDK4 and/or cyclin E/CDK2. Considering apoptosis-related factors, the polysaccharides suppressed AKT activity through the inhibition of AKT phosphorylation at Thr³⁰⁸ and/or Ser⁴⁷³. The growth of HepG2 and Bel-7404 cells was suppressed by the up-regulation of a subunit of PI3K and phospho-PTEN, which are modulators of AKT activity. The polysaccharides also activated the mitochondria-mediated apoptosis pathway by stimulating the activation of Bcl-2 family proteins to release cytochrome c and Smac and cleave caspase-9 and caspase-3 in HepG2 and Bel-7404 cells. These factors have a potent effect on cell cycle arrest in G₁ and/or S phase and induce apoptosis in HepG2 and Bel-7404 cells.     

Induction of apoptosis in HeLa cells by ethanolic extract of Corallina pilulifera

Marine organisms are rich sources of new, biologically active compounds. Seaweeds have traditionally been used as food, but have also been used as folk medicine, particularly by coastal peoples. Recently, much attention has been paid to the anticancer activity of seaweed. Thus, we have screened organic extracts of seaweeds for their anticancer activity against human cell lines, and selected Corallina pilulifera as a candidate for use in treatment. The ethanolic extracts of Corallina pilulifera (EECP) showed cytotoxic activity against human cervical adenocarcinoma cell line, HeLa. The IC₅₀ of EECP against the HeLa cells was 250 μg/ml. Treatment of HeLa cells with various concentrations of EECP resulted in growth inhibition and induction of apoptosis in a dose-dependent manner. In Western blot analysis, apoptosis in the HeLa cells was associated with the release of cytochrome C from mitochondria into the cytosol, activation of caspase-3 and caspase-8, and proteolytic cleavage of PARP (poly (ADP-ribose) polymerase). These results strongly suggest that EECP may be a potential candidate in the field of anticancer drug discovery.     

Cancer preventive effect of Thai rat-tailed radish (Raphanus sativus L. var. caudatus Alef)

The cancer preventive effect of Raphanus sativus L. var. caudatus Alef (Thai rat-tailed radish) extract was evaluated against the HCT116 colon cancer cell line. HPLC and GC–MS were used to identify the phytoconstituents in Thai rat-tailed radish extract. Thai rat-tailed radish extract showed high cytotoxicity against HCT116 with an IC₅₀ at 9.42 ± 0.46 μg/ml. Apoptosis induced by Thai rat-tailed radish extract was confirmed (a) by DAPI staining which demonstrated nuclei morphological changes, chromatin condensation and nuclear fragmentation and (b) by Annexin V/PI flow cytometry. GC–MS analysis of Thai rat-tailed radish extract revealed two isothiocyanates; sulforaphane and sulforaphene, whose cytotoxicity and apoptosis induction effect were evident, giving Thai rat-tailed radish extract its anticancer attributes. This is the first report on the cancer preventive effect of Thai rat-tailed radish extract against HCT116 colon cancer cell line, through apoptosis induction.     

Apoptosis-mediated proliferation inhibition of human colon cancer cells by volatile principles of Citrus aurantifolia

Fruits of Citrus aurantifolia were subjected to hydro-distillation using Clevenger type apparatus to obtain volatile oil. Chemical composition of volatile oil was analysed by GC–MS. Twenty-two compounds representing more than 89.5% of the volatile oil were identified. d-limonene (30.13%) and d-dihydrocarvone (30.47%) were found to be the major compounds in the lime volatile oil. This oil showed 78% inhibition of human colon cancer cells (SW-480) with 100 μg/ml concentration at 48 h. Lime volatile oil showed DNA fragmentation and induction of caspase-3 up to 1.8 and 2- folds after 24 h and 48 h, respectively, which may be due to the involvement of apoptosis. Analysis of apoptosis-related protein expression further confirmed apoptosis induction by lime volatile oil. The above results suggested that lime volatile oil has potential benefits in colon cancer prevention. This is the first report, showing the possible mechanism of antiproliferative effect of lime volatile oil for the prevention of colon cancer in cell culture models.     

Curcumin based nanomedicines as efficient nanoplatform for treatment of cancer: New developments in reversing cancer drug resistance,rapid internalization,and improved anticancer efficacy

BackgroundCancer is a group of diseases involving an abnormal growth of cells which tend to proliferate in an uncontrolled fashion and in some cases metastasize to the surrounding tissues (malignancy). Resistance to chemotherapy is typically intrinsic (heterogeneity); however, acquired resistance has also become prevelant due to multiple factors including expression of energy-dependent transporters causing expulsion of internalized drug contents extracellular, insensitivity of tumor cells to drug-induced apoptosis, and induction of drug-detoxifying mechanisms. Curcumin (CUR) has gained widespread recognition due to remarkable anticancer, anti-mutagenic, and anti-metastasizing potentials via downregulation of proliferation of cancer cells and induction of apoptosis. Nevertheless, pharmaceutical significance and therapeutic feasibility of CUR is restricted due to intrinsic physicochemical characteristics including poor aqueous solubility, inadequate biological stability, low bioavailability, and short half-life.Scope and approachOwing to these pharmaceutical limitations of CUR, nanodelivery systems have attained remarkable fascination in the recent years. Therefore, this review was aimed to overview and critically ponders recent developments in improving anticancer viability of CUR.Key findings and conclusionCritical analysis of the literature revealed that nanodelivery systems showed promising efficiency in achieving tumor specific targetability, maximizing internalization of drugs into cancer cells, mitigating tumor metastasis, as well as improving anticancer efficacy of CUR. Moreover, nanocarrier-mediated improved pharmacokinetics, drug accumulation, induced promising cytotoxicity, and enhanced anticancer efficacy by suppressing Egr-1 induction, Mitogen-activated protein kinase (MAPK) pathway, and protein tyrosine kinase (PTK) cascades while mitigating the progression of tumor, have also been discussed.     

Antitumour properties of the leaf essential oil of Xylopia frutescens Aubl. (Annonaceae)

The aim of this study was to investigate the chemical composition and anticancer effect of the leaf essential oil of Xylopia frutescens in experimental models. The chemical composition of the essential oil was analysed by GC/FID and GC/MS. In vitro cytotoxic activity of the essential oil was determined on cultured tumour cells. In vivo antitumour activity was assessed in Sarcoma 180-bearing mice. The major compounds identified were (E)-caryophyllene (31.48%), bicyclogermacrene (15.13%), germacrene D (9.66%), δ-cadinene (5.44%), viridiflorene (5.09%) and α-copaene (4.35%). In vitro study of the essential oil displayed cytotoxicity on tumour cell lines and showed IC₅₀ values ranging from 24.6 to 40.0 μg/ml for the NCI-H358M and PC-3M cell lines, respectively. In the in vivo antitumour study, tumour growth inhibition rates were 31.0–37.5%. In summary, the essential oil was dominated by sesquiterpene constituents and has some interesting anticancer activity.     

Control of specific growth rate to enhance the production of a novel disintegrin,saxatilin, in recombinant Pichia pastoris

The methylotrophic yeast Pichia pastoris is one of the best hosts for the production of foreign proteins because of the presence of a strong alcohol oxidase 1 (AOX1) promoter that can be induced by methanol. Feeding the yeast, methanol induces protein production and provides an energy source for the host cells. However, excessive levels of methanol inhibit the growth of host cells, and insufficient methanol levels lead to poor growth and protein production. We have used various methanol feeding strategies to enhance the production of saxatilin. Saxatilin is a novel snake venom-derived disintegrin that inhibits tumor angiogenesis and metastasis and has been shown to suppress ovarian cancer cell invasion. A two-step increase feeding strategy to control the specific growth rate led to the best results in terms of specific protein production rates and final saxatilin amounts within the limited fermentation time.     

Neferine from Nelumbo nucifera induces autophagy through the inhibition of PI3K/Akt/mTOR pathway and ROS hyper generation in A549 cells

Previously we have reported that neferine from the medicinal plant Nelumbo nucifera, inhibited cancer cell proliferation by inducing apoptosis. The present study was focused on the action mechanism of neferine in inducing autophagy in lung cancer cells. Neferine markedly inhibited A549 cell proliferation in a dose dependent manner. Acidic vesicular accumulation was observed in neferine treated cells as an indication of autophagy. Neferine could induce the conversion of LC3B-I to LC3B-II without affecting the expression levels of PI3KCIII and Beclin1. It has been observed that neferine mediated autophagy is dependent on inhibition of PI3K/Akt/mTOR signaling by neferine. Neferine treatment could also lead to the ROS hypergeneration and depletion of cellular antioxidant, GSH. The results demonstrate that neferine-induced autophagy is mediated through ROS hypergeneration and mTOR inhibition. Taken together, the present study unveils a novel mechanism of action of neferine on lung cancer cells in the induction of autophagy.     

Inhibition effect of procyanidins from lotus seedpod on mouse B16 melanoma invivo and in vitro

Significant growth inhibition effects of procyanidins from lotus (Nelumbo nucifera Gaertn.) seedpod (LSPCs) on mouse melanoma B16 were found both in vivo and in vitro. In vivo treatment with LSPCs inhibited tumour growth in C₅₇BL/6 J mice by 55.3% in terms of average tumour weight. LSPCs can significantly (P < 0.05) decrease lipid peroxidation (LPO) levels and increase the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in liver tissue. In vitro assay of anti-cancer activities suggested that LSPCs (25–100 μg/ml) possessed cytotoxicities against mouse melanoma B16 in a dose-dependent mode. Furthermore, LSPCs had significant (P < 0.05) stimulatory effects on mouse splenocyte proliferation. The prevention of tumour growth was exerted through diverse mechanisms, including cell-cycle arrest, induction of tumour cell death by apoptosis and increase of Ca²⁺ ions, together with stimulation of antioxidant enzyme activities and immunomodulatory activities.     

Hibiscus sabdariffa leaf induces apoptosis of human prostate cancer cells in vitro and in vivo

Hibiscus sabdariffa leaf, the edible part of H. sabdariffa Linne, is usually ignored and discarded. The object of the study was to examine the anticancer properties of H.sabdariffa L. leaf extract (HLE). First, HLE was demonstrated to be rich in polyphenols, including catechin and ellagic acid (EA). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) data showed that among three kinds of human prostate cancer (CaP) cells, androgen-dependent LNCaP cells were the most susceptible to HLE. HLE and its purified compound EA were evaluated for apoptotic activities. Molecular data showed the effect of HLE in LNCaP cells might be mediated via both intrinsic and extrinsic apoptotic pathways. Finally, HLE inhibited the growth of LNCaP cells in xenograft tumour studies. As a result, our data presented the first evidence of HLE as an apoptosis inducer in LNCaP cells, and these findings may open interesting perspectives to the strategy in human CaP treatment.     

Partial characterization of a chymotrypsin-like protease in the larger grain borer (Prostephanus truncatus (Horn)) in relation to activity of Hyptis suaveolens (L.) trypsin inhibitor

Hyptis suaveolens trypsin inhibitor (HSTI) inhibits, in vitro, most of the trypsin-like serine proteases present in the gut of Prostephanus truncatus (Horn), the larger grain borer. In order to measure its in vivo effectiveness, different doses of the purified HSTI were incorporated into artificial seeds to measure their effects on the growth of P. truncatus larvae and pupae. Results showed that this protease inhibitor had no significant effect in vivo. Consequently, we investigated, identified, and partially characterized an inhibitor-insensitive protease that could explain the growth of P. truncatus on diet containing HSTI. This protease had an apparent molecular mass of 31 kDa, an optimum pH of 7.0, and an activity range extending from pH 6.0 to 8.0, which would allow activity in the gut of P. truncatus. This enzyme could be one of the physiological mechanisms in P. truncatus that allow the species to avoid the adverse effects of trypsin-like protease inhibitors present in the normal diet.     

Effects of hydrogen peroxide and l-tryptophan on antioxidative potential,apoptosis, and mammalian target of rapamycin signaling in bovine intestinal epithelial cells

Amino acids are primarily absorbed in the ruminant small intestine, and the small intestine is a target organ prone to oxidative stress, causing intestinal disfunction. Previous study suggested that l-Trp could benefit intestinal function and production performance. This study aimed to explore the effects of l-Trp on hydrogen peroxide (H₂O₂)-induced oxidative injury in bovine intestinal epithelial cells (BIEC) and the potential mechanism. The effects of l-Trp on cell apoptosis, antioxidative capacity, AA transporters, and the mammalian target of rapamycin (mTOR) signaling pathway were evaluated in BIEC treated with 0.8 mM l-Trp for 2 hours combined with or without H₂O₂ induction. In addition, to explore whether the effects of 0.8 mM l-Trp on oxidative stress were related to mTOR, an mTOR-specific inhibitor was used. The percentage of apoptosis was measured using flow cytometry. The relative gene abundance and protein expression in BIEC were determined using real-time PCR and Western blot assay, respectively. Results showed l-Trp at 0.4 and 0.8 mM enhanced the cell viability, and it was inhibited by l-Trp at 6.4 mM. l-Tryptophan at 0.4, 0.8, and 1.6 mM remarkably decreased the percentage of apoptosis and enhanced antioxidative capacity in H₂O₂-mediated BIEC. Moreover, l-Trp at 0.8 mM increased the relative gene abundance and protein expression of antioxidative enzymes and AA transporters, and the mTOR signaling pathway. The mTOR inhibitor lowered the protein expression of large neutral amino acid transporter 1, but the inhibition of mTOR did not alter the activities of catalase and superoxide dismutase or protein expression of alanine-serine-cysteine transporter 2 with or without H₂O₂ induction. l-Tryptophan increased catalase and superoxide dismutase activities in H₂O₂-mediated BIEC, although not with a present mTOR inhibitor. l-Tryptophan increased the protein expression of large neutral amino acid transporter 1 and alanine-serine-cysteine transporter 2 in H₂O₂-mediated BIEC with or without the presence of an mTOR inhibitor. The present work suggested that l-Trp supplementation could alleviate oxidative injury in BIEC by promoting antioxidative capacity and inhibiting apoptosis, and the mTOR signal played vital roles in the alleviation.     

Regulation of lipid and glucose homeostasis by mango tree leaf extract is mediated by AMPK and PI3K/AKT signaling pathways

Ethanolic extract of Mangifera indica (mango) dose-dependently decreased serum glucose and triglyceride in KK-A^y mice. Our in vitro and in vivo investigations revealed that the effect of mango leave extract (ME) on glucose and lipid homeostasis is mediated, at least in part, through the PI3 K/AKT and AMPK signaling pathway. ME up-regulated the expression of PI3 K, AKT and GYS genes by 2.0-fold, 3.2-fold, and 2.7-fold, respectively, leading to a decrease in glucose level. On the other hand, ME up-regulated AMPK and altered lipid metabolism. ME also down-regulated ACC (2.8-fold), HSL (1.6-fold), FAS (1.8-fold) and PPAR-γ (4.0-fold). Finally, we determined that active metabolites of benzophenone C-glucosides, Iriflophenone 3-C-β-glucoside and Foliamangiferoside A from ME, may play a dominant role in this integrated regulation of sugar and lipid homeostasis.     

Involvement of AMPK/mTOR/HIF-1α in anticancer control of quercetin in hypoxic MCF-7 cells

Quercetin has been reported to possess therapeutic effects in the treatment of cancers. In this study, the molecular action of quercetin, with emphasis on its ability to control the intracellular signaling cascades of hypoxia inducible factor-1α (HIF-1α), mammalian target of rapamycin (mTOR), and AMP-activated protein kinase (AMPK), responsible for survival or induction of apoptosis in hypoxic MCF-7 cells, was investigated. The effects of quercetin on apoptosis in relation to its ability to prevent HIF-1α induction were investigated. The involvement of HIF-1α reduction in quercetin-based cancer control was clearly shown in conditions of mTOR inhibition by rapamycin, an mTOR inhibitor. Surprisingly, quercetin induced an AMPK-suppressed state in a CoCl₂-induced hypoxic condition. It is speculated that quercetin is capable of inhibiting AMPK to decrease HIF-1α, which is a critical survival factor in hypoxia. A complex control of HIF-1α, mTOR, and AMPK is necessary in inducing apoptosis of MCF-7 breast cancer cells under hypoxia.     

Anti‐inflammatory and anticancer activities of water‐soluble peptide extracts of buffalo and cow milk Cheddar cheeses

This article aimed to assess the anti‐inflammatory and anticancer potential of water‐soluble peptide (WSP) extracts from buffalo and cow milk Cheddar cheeses. Anti‐inflammatory activity was evaluated on the basis of nitric oxide (NO) production in lipopolysaccharide‐stimulated macrophage (RAW‐264.7) cells. A cell viability assay, cell cycle arrest and apoptosis were performed to explore anticancer activity in a colon cancer model (HT‐29). The WSP extracts of both Cheddar cheeses effectively inhibited NO production in activated macrophages. Maximum growth inhibition was observed in the HT‐29 cells at concentrations of 400 and 500 μg/mL. A significant increase in cell population at G₀/G₁ phase of the cell cycle was observed. Moreover, the WSP extracts also induced extensive apoptosis in colon cancer cells.     

Anthocyanin-rich Mulberry extract inhibit the gastric cancer cell growth in vitro and xenograft mice by inducing signals of p38/p53 and c-jun

Anthocyanins have been well characterized by various bioactive properties. In previous studies, Mulberry anthocyanins (MACs) have proven to prevent atherosclerosis and inhibit melanoma metastasis. Here, AGS cells demonstrated an increase in the distribution of hypodiploid phase (apoptotic peak) after treatment with MACs. Further investigation revealed that MACs exerted their influence by inducing intrinsic and extrinsic apoptosis through p38/p53 and p38/c-jun signaling pathways. In addition, the caspase-related protein, such as caspase-3, was activated from pro-caspase to cleaved-caspase by treating MACs to AGS cells. We also used the experimental AGS gastric cancer xenograft model to verify the inhibitory effect of MACs. These findings suggest that, by targeting p38/p53 and the c-jun pathways, MACs suppressed cell survival and tumorigenesis, but induced apoptotic death in AGS cells. MACs can potentially prevent the growth of AGS cells for ineffective conventional chemotherapy of gastric carcinoma.