D-limonene rich volatile oil from blood oranges inhibits angiogenesis, metastasis and cell death in human colon cancer cells.

Aims: To identify the chemical constituents of volatile oil from blood orange (Citrus sinensis (L) Osbeck) and understand the possible mechanisms of inhibition of colon cancer cell proliferation.

Main Methods: Volatile oil was obtained from blood oranges by hydro-distillation. Nineteen compounds were identified by GC-MS and d-limonene was found to be the major component.

Obacunone represses Salmonella pathogenicity islands 1 and 2 in an envZ-dependent fashion.

Obacunone belongs to a class of unique triterpenoids called limonoids, present in Citrus species. Previous studies from our laboratory suggested that obacunone possesses antivirulence activity and demonstrates inhibition of cell-cell signaling in Vibrio harveyi and Escherichia coli O157:H7. The present work sought to determine the effect of obacunone on the food-borne pathogen Salmonella enterica serovar Typhimurium LT2 by using a cDNA microarray.

Production system and storage temperature influence grapefruit vitamin C, limonoids, and carotenoids.

Concentrations of grapefruit (cv. 'Rio Red'; Citrus paradisi Macf.) bioactives grown under organic and conventional production systems were evaluated after storage at various temperatures.

Methyl nomilinate from citrus can modulate cell cycle regulators to induce cytotoxicity in human colon cancer (SW480) cells in vitro.

Limonoids are triterpenoids found in citrus and possess cancer preventive properties in in vitro and in vivo assays. Although several mechanisms for the chemopreventive properties of limonoids have been postulated, the specific mechanisms involved in the anti-cancer effects have not been explored. In the present study, limonoids, including methyl nomilinate, isoobacunoic acid, isolimonexic acid (ILNA), and limonexic acid (LNA), were purified, identified by LC-MS and NMR spectral data and evaluated for their biological effects on SW480 human colon adenocarcinoma cells.

The natural alkaloid berberine targets multiple pathways to induce cell death in cultured human colon cancer cells.

In the current paper, berberine, an isoquinoline alkaloid, was tested for its chemopreventive potential in colon cancer (SW480) cells. Berberine inhibited proliferation of colon cancer cells in a dose- and time-dependent manner. Interestingly, this compound exhibited minimum toxicity in normal cells at 200 μM.

Influence of extraction solvents on antioxidant activity and the content of bioactive compounds in non-pungent peppers.

Bioactive compounds in foods have been shown to maintain human health. However, the relative amounts of bioactive compounds and the variation in the amounts are still poorly understood. In this study, the efficacy of different extraction solvents (hexane, ethyl acetate, acetone, methanol, and a methanol:water mixture), as well as the levels of certain bioactive compounds in non-pungent pepper cultivars (TMH, TMJ, PA137, and B58) were investigated using high-performance liquid chromatography (HPLC).

Differential inhibition of human colon cancer cells by structurally similar flavonoids of citrus.

A number of studies in the recent years have evaluated the anti-proliferative activity of flavonoids. Although certain studies investigated the structure-activity based on the phenotypic assays, no study has correlated the flavonoids structure with the ability to alter gene/protein expression. Present study was focused to understand the structure-function relationship of citrus flavonoids in terms of their ability to alter the gene expression in the colon adenocarcinoma cells.

Underestimation of pyruvic acid concentrations by fructose and cysteine in 2,4-dinitrophenylhydrazine-mediated onion pungency test.

Onion pungency has been routinely measured by determining pyruvic acid concentration in onion juice by reacting with 2,4-dinitrophenylhydrazine (DNPH) since 1961. However, the absorbency of the color adduct of the reaction rapidly decreased in onion samples as compared to that of the pyruvic acid standards, resulting in underestimations of the pyruvic acid concentrations. By measuring the absorbency at 1 min, we have demonstrated that accuracy could be substantially improved.

Evaluation of chemopreventive and cytotoxic effect of lemon seed extracts on human breast cancer (MCF-7) cells.

Extracts from lemon seed were investigated for the radical scavenging activity and apoptotic effects in human breast adenocarcinoma (MCF-7) cells and non-malignant breast (MCF-12F) cells for the first time. Defatted seed powder was successively extracted with ethyl acetate (EtOAc), acetone, methanol (MeOH), and MeOH:water (80:20). The chemical constituents were identified and quantified by LC-MS and HPLC analysis, respectively.

One-step casting of Laemmli discontinued sodium dodecyl sulfate-polyacrylamide gel electrophoresis gel.

A modified Laemmli sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) protocol is described. The new method saves 30 min for gel casting without loss of the resolution power of Laemmli gel. In this method, both the upper and lower gels can be cast at the same time because the lower gel contains 10% glycerol, which generates higher density in the lower gel than in the upper gel.

Structure-function relationships of citrus limonoids on p38 MAP kinase activity in human aortic smooth muscle cells.

Limonoids, abundantly present in citrus fruits, have potential role in reducing risk of different type of cancer. In the present study, we hypothesized that seven structurally different limonoids would involve in inflammatory pathway via modulating p38 MAP kinase activity at various extent in vascular smooth muscle cells. Results demonstrated that the different functional groups containing limonoids had differential effects on the p38 MAP kinase activity in human aortic smooth muscle cells.

Optimization of flavanones extraction by modulating differential solvent densities and centrifuge temperatures.

Understanding the factors influencing flavonone extraction is critical for the knowledge in sample preparation. The present study was focused on the extraction parameters such as solvent, heat, centrifugal speed, centrifuge temperature, sample to solvent ratio, extraction cycles, sonication time, microwave time and their interactions on sample preparation. Flavanones were analyzed in a high performance liquid chromatography (HPLC) and later identified by liquid chromatography and mass spectrometry (LC-MS).

Improved consistency in DNPH-mediated pyruvic acid analysis of onion juice by modifying the sample processing order.

Onion pungency is commonly measured on absorbency of the wine pink color that results from adding NaOH to the heated mixture of dinitrophenylhydrazine (DNPH) and onion juice. However, significant variation exists among several modifications of the original Schwimmer and Weston (SW) method. We observed differences in pyruvic acid concentrations of 20%-30% between our automated method and a batch method with manual absorbency readings.

Obacunone and obacunone glucoside inhibit human colon cancer (SW480) cells by the induction of apoptosis.

Objectives: The study was aimed to purify obacunone and obacunone glucoside (OG) from seeds of Marsh White grapefruit and understand the mode of cytotoxicity of limonoids on colon cancer (SW480) cells.

Methodology: Both limonoids were purified using chromatographic techniques. The structures and purity of limonoids were confirmed by NMR and HPLC analysis, respectively.

A three-component gene expression system and its application for inducible flavonoid overproduction in transgenic Arabidopsis thaliana.

Inducible gene expression is a powerful tool to study and engineer genes whose overexpression could be detrimental for the host organisms. However, only limited systems have been adopted in plant biotechnology. We have developed an osmotically inducible system using three components of plant origin, RD29a (Responsive to Dehydration 29A) promoter, CBF3 (C-repeat Binding Factor 3) transcription factor and cpl1-2 (CTD phosphatase-like 1) mutation.

Citrus limonin and its glucoside inhibit colon adenocarcinoma cell proliferation through apoptosis.

The current study was an attempt to elucidate the mechanism of human colon cancer cell proliferation inhibition by limonin and limonin glucoside (LG) isolated from seeds of Citrus reticulata. The structures of purified compounds were confirmed by NMR and quantified using HPLC. These compounds of more than 95% purity were subjected to proliferation inhibition assay using human colon adenocarcinoma (SW480) cells.

Apoptosis mediated cytotoxicity of citrus obacunone in human pancreatic cancer cells.

Obacunone is one of the oxygenated triterpenoids found in rutaceae family. It has been demonstrated for various biological activities including inhibition of cancer cells proliferation and tumor. The current study is an attempt to understand the mode of cytotoxicity of obacunone using cultured pancreatic cancer (MDA Panc-28) cells.

AtCPL5, a novel Ser-2-specific RNA polymerase II C-terminal domain phosphatase, positively regulates ABA and drought responses in Arabidopsis.

Arabidopsis RNA polymerase II (RNAPII) C-terminal domain (CTD) phosphatases regulate stress-responsive gene expression and plant development via the dephosphorylation of serine (Ser) residues of the CTD. Some of these phosphatases (CTD phosphatase-like 1 (CPL1) to CPL3) negatively regulate ABA and stress responses. Here, we isolated AtCPL5, a cDNA encoding a protein containing two CTD phosphatase domains (CPDs).

Simultaneous separation and identification of limonoids from citrus using liquid chromatography-collision-induced dissociation mass spectra.

Limonoids are considered as potential cancer chemopreventive agents and are widely distributed in the Citrus genus as aglycones and glucosides. In the present study, reversed-phase HPLC coupled with CID mass spectra was developed for the simultaneous separation and identification of aglycones and glucosides of limonoids from citrus. Five aglycones such as limonin, deacetyl nomilin, ichangin, isolimonoic acid and nomilin were identified by positive ion CID MS/MS, whereas five glucosides, viz.

Citrus flavonoid represses Salmonella pathogenicity island 1 and motility in S. Typhimurium LT2.

Salmonellosis is one of the leading health problems worldwide. With the rise of drug resistance strains, it has become imperative to identify alternative strategies to counter bacterial infection. Natural products were used historically to identify novel compounds with various bioactivities.

Rapid simultaneous determination of amines and organic acids in citrus using high-performance liquid chromatography.

Rapid analytical method for the simultaneous separation and determination of amines and organic acids is a vital interest for quality control of citrus and their products. In the present study, a simultaneous high performance liquid chromatography (HPLC) method for the rapid separation of three amines and two organic acids was developed. Chromatographic separation of compounds was achieved using Xbridge C(18) column at ambient temperature, with an isocratic mobile phase of 3mM phosphoric acid at a flow rate of 1.

Citrus limonoids interfere with Vibrio harveyi cell-cell signalling and biofilm formation by modulating the response regulator LuxO.

Citrus limonoids are unique secondary metabolites, characterized by a triterpenoid skeleton with a furan ring. Studies have demonstrated beneficial health properties of limonoids. In addition, certain citrus limonoids play a role in plant defence against insect pests.

In vivo induction of phase II detoxifying enzymes, glutathione transferase and quinone reductase by citrus triterpenoids.

Background: Several cell culture and animal studies demonstrated that citrus bioactive compounds have protective effects against certain types of cancer. Among several classes of citrus bioactive compounds, limonoids were reported to prevent different types of cancer. Furthermore, the structures of citrus limonoids were reported to influence the activity of phase II detoxifying enzymes.

Berberine induces apoptosis in breast cancer cells (MCF-7) through mitochondrial-dependent pathway.

Bioactive compounds found in many plant species have been used in Chinese, Unani, and Indian ayurvedic medicine. Accumulative evidences in both in vitro and in vivo studies using berberine demonstrated anti-cancer and anti-inflammatory properties in different cancer cells. In the present study, a putative compound from commercial sample was purified by chromatographic techniques.

Zebrafish (Danio rerio) endomembrane antiporter similar to a yeast cation/H(+) transporter is required for neural crest development.

CAtion/H(+) eXchangers (CAXs) are integral membrane proteins that transport Ca(2+) or other cations by exchange with protons. While several yeast and plant CAX proteins have been characterized, no functional analysis of a vertebrate CAX homologue has yet been reported. In this study, we further characterize a CAX from yeast, VNX1, and initiate characterization of a zebrafish CAX (Cax1).