Mauritian Endemic Medicinal Plant Extracts Induce G2/M Phase Cell Cycle Arrest and Growth Inhibition of Oesophageal Squamous Cell Carcinoma in Vitro.

Terrestrial plants have contributed massively to the development of modern oncologic drugs. Despite the wide acceptance of Mauritian endemic flowering plants in traditional medicine, scientific evidence of their chemotherapeutic potential is lacking. This study aimed to evaluate the in vitro tumor cytotoxicity of leaf extracts from five Mauritian endemic medicinal plants, namely Acalypha integrifolia Willd (Euphorbiaceae), Labourdonnaisia glauca Bojer (Sapotaceae), Dombeya acutangula Cav. subsp. rosea Friedmann (Malvaceae), Gaertnera psychotrioides (DC.) Baker (Rubiaceae), and Eugenia tinifolia Lam (Myrtaceae). The cytotoxicities of the extracts were determined against six human cancer cell lines, including cervical adenocarcinoma, colorectal carcinoma, oesophageal adenocarcinoma, and oesophageal squamous cell carcinoma. The potent extracts were further investigated using cell cycle analysis and reverse phase protein array (RPPA) analysis. The antioxidant properties and polyphenolic profile of the potent extracts were also evaluated. Gas chromatography mass spectrometry (GC-MS) analyses revealed the presence of (+)-catechin and gallocatechin in E. tinifolia and L. glauca, while gallic acid was detected in A. integrifolia. L. glauca, A. integrifolia, and E. tinifolia were highly selective towards human oesophageal squamous cell carcinoma (KYSE-30) cells. L. glauca and E. tinifolia arrested KYSE- 30 cells in the G2/M phase, in a concentration-dependent manner. RPPA analysis indicated that the extracts may partly exert their tumor growth-inhibitory activity by upregulating the intracellular level of 5'AMP-activated kinase (AMPK). The findings highlight the potent antiproliferative activity of three Mauritian endemic leaf extracts against oesophageal squamous cell carcinoma and calls for further investigation into their chemotherapeutic application.

[Endovascular implantation of iodine-125 seeds strand and portal vein stenting followed by transcatheter arterial chemoembolization combined therapy with sorafenib for hepatocellular carcinoma with main portal vein tumor thrombus].

OBJECTIVE: To compare the therapeutic effect of portal vein stenting and endovascular implantation of iodine-125 seeds strand followed by transcatheter arterial chemoembolization combined with or without sorafenib in patients for hepatocellular carcinoma (HCC) with main portal vein tumor thrombus (MPVTT). METHODS: A total of 53 patients with HCC complicated by MPVTT who received portal vein stenting and endovascular implantation of iodine-125 seeds strand followed by transcatheter arterial chemoembolization combined without (group A, n=38) or with (group B, n=15) sorafenib in Affiliated Yancheng Hospital of Southeast University Medical College during January 2010 and August 2015 were analyzed retropectively.Overal survival, progress free survival and procedure-related adverse event were compared between the two groups. RESULTS: The technical success rate was 100% for placement of (125)I seeds strand and stent in the obstructed main portal vein.No serious procedure-related adverse events occurred. Median survival time of group A and B were 12.1 and 14.8 months, respectively (P=0.037). Additionally, Median progress free survival time of group A and B were 2.8 and 4.0 months, respectively (P=0.002). CONCLUSIONS: Endovascular implantation of iodine-125 seeds strand and portal vein stenting followed by transcatheter arterial chemoembolization combined with sorafenib could improve the survival time, the progress free survival time of patients with HCC complicated by MPVTT.

Effects of atorvastatin combined with trimetazidine on myocardial injury and inflammatory mediator in unstable angina patients during perioperative of percutaneous coronary intervention.

OBJECTIVE: To investigate the effects of atorvastatin combined with trimetazidine on periprocedural myocardial injury and serum inflammatory mediators in unstable angina pectoris (UAP) patients following percutaneous coronary intervention (PCI) treatment. PATIENTS AND METHODS: 90 patients with UAP treated with conventional medications and PCI were recruited and were randomly divided into the control group and the experimental group. The control group had 42 patients were treated with atorvastatin alone, while the experimental group had 48 cases treated with atorvastatin combined with trimetazidine. All the patients were checked the preoperative 24h and postoperative 24h PCI concentrations of cardiac troponin I (cTnI), hypersensitive C-reactive protein (hs-CRP), tumor necrosis factor-α (TNF-α), serum interferon-γ (IFN-γ) and interlukin-10 (IL-10). RESULTS: At the pre-PCI stage, every serum factors was no significant difference. 24 hours after the PCI intervention, the occurence of abnormal cTnI level in the experimental group was remarkable reduced than the control group. In the experimental group, the serum levels of TNF-α and IFN-γ significantly decreased (p < 0.05); while IL-10 was increased. In the control group, all the mediators were increased significantly except the hs-CRP (p < 0.05). CONCLUSIONS: No unexpected symptom was found in patients with large dose atorvastatin combined with large dose trimetazidine. The administration of conventional medications together with the atorvastatin plus trimetazidine were able to reduce the prevalence of postoperative myocardial injury.

Fyn arrests swainsonine-induced apoptosis in 293T cells via Akt and its phosphorylation.

Swainsonine (SW), an extract from Astragalus membranaceus, represents a new class of compounds that inhibit growth and induce apoptosis in a cancer model. In this study, we demonstrated the effect of Fyn on SW-induced apoptosis in 293T cells. Western blotting was used to measure the expression of the apoptosis-related factors caspase-3, Bcl-2, Bax, and the key factor Akt (also known as protein kinase B). Apoptosis increased dramatically after treatment with SW. Unlike the control group, after transfection with Fyn, the expression of Bcl-2, in contrast to Bax, was markedly upregulated. The results also showed that the protein expression levels of Akt and phosphorylated Akt were markedly increased. Our results establish that Fyn can arrest SW-induced apoptosis via the activity of Akt and its effective phosphorylation in 293T cells.

Induction of the mammalian GRP78/BiP gene by Ca2+ depletion and formation of aberrant proteins: activation of the conserved stress-inducible grp core promoter element by the human nuclear factor YY1.

Previously, we have identified a constitutive nuclear factor, p70CORE, from HeLa cell nuclear extract which interacts specifically with the stress-inducible change region (SICR) of the grp78 promoter. Here we report that p70CORE is identical to YY1, a member of the GLI zinc finger family, by criteria of biochemical properties including apparent molecular weight, binding site homology, immunoreactivity, and affinity purification. Recombinant YY1 binds the double-stranded SICR with high specificity but has no affinity for its single-stranded form. In cotransfection studies, YY1 specifically enhanced the transcriptional activation of the grp78 promoter under a variety of stress conditions: depletion of the endoplasmic reticulum calcium stores, protein glycosylation block, and formation of aberrant proteins by azetidine treatment. In contrast, YY1 has minimal effect on the stress induction of the hsp70 promoter. YY1 enhancement of the grp78 stress response is dependent on its DNA-binding domain, with little effect on the basal expression of the promoter. The effect of YY1 transactivation may be mediated by the highly conserved grp78 core element. This is the first example of the ubiquitous factor YY1 involved in regulating inducible gene expression and its involvement in mediating stress signals generated from the endoplasmic reticulum to the nucleus.

Suppression of grp78 core promoter element-mediated stress induction by the dbpA and dbpB (YB-1) cold shock domain proteins.

The highly conserved grp78 core promoter element plays an important role in the induction of grp78 under diverse stress signals. Previous studies have established a functional region in the 3' half of the core (stress-inducible change region [SICR]) which exhibits stress-inducible changes in stressed nuclei. The human transcription factor YY1 is shown to bind the SICR and transactivate the core element under stress conditions. Here we report that expression library screening with the core element has identified two new core binding proteins, YB-1 and dbpA. Both proteins belong to the Y-box family of proteins characterized by an evolutionarily conserved DNA binding motif, the cold shock domain (CSD). In contrast to YY1, which binds only double-stranded SICR, the Y-box/CSD proteins much prefer the lower strand of the SICR. The Y-box proteins can repress the inducibility of the grp78 core element mediated by treatment of cells with A23187, thapsigargin, and tunicamycin. In gel shift assays, YY1 binding to the core element is inhibited by either YB-1 or dbpA. A yeast interaction trap screen using LexA-YY1 as a bait and a HeLa cell cDNA-acid patch fusion library identified YB-1 as a YY1-interacting protein. In cotransfection experiments, the Y-box proteins antagonize the YY1-mediated enhancement of transcription directed by the grp78 core in stressed cells. Thus, the CSD proteins may be part of the stress signal transduction mechanism in the mammalian system.

Effect of cyclin D1 overexpression on drug sensitivity in a human fibrosarcoma cell line.

BACKGROUND: Alterations in the expression of genes that control the cell cycle may be of critical importance in determining the sensitivity of cells and tumors to drugs (chemosensitivity) and radiation. Mutations and deletions of the p53 tumor suppressor gene in cell lines and tumors are associated with resistance to a variety of DNA-damaging agents. The effects of alterations in the cyclin genes and their products on drug action have not been studied. One of these genes, cyclin D1, is expressed in early G1 phase, and its protein product, together with the cyclin-dependent kinases CDK4 and CDK6, mediates the phosphorylation and functional inactivation of the retinoblastoma protein (pRb). Elevated levels of expression of cyclin D1 protein have been found in a variety of cancers, including breast cancer, head and neck cancer, non-small-cell lung cancer, and mantle cell lymphomas. PURPOSE: This study was conducted to investigate the effect of increased expression of cyclin D1 protein on the chemosensitivity profile of a human fibrosarcoma cell line. METHODS: Expression plasmids containing either the neomycin-resistance gene and the complementary DNA sequence encoding human cyclin D1 or the neomycin-resistance gene only (control) were transfected by lipofection into the human HT1080 fibrosarcoma cell line, and cell colonies resistant to the antibiotic neomycin (G418) were isolated. Cyclin D1 messenger RNA (mRNA) and protein levels were measured by ribonuclease protection and western blot analyses, respectively. Dihydrofolate reductase (DHFR) mRNA and protein levels were measured by northern blot and western blot analyses, respectively. The phosphorylation status of pRb was assessed by western blot analysis. Cell cycle analysis was performed by use of the technique of fluorescence-activated cell sorting. Cytotoxicity assays were carried out by use of the sulforhodamine blue assay. RESULTS: Of the 16 cyclin D1-transfected cell clones that were isolated, four were randomly selected for further study. Two cell clones expressed high levels of cyclin D1 mRNA and protein as compared with control cells transfected with plasmids containing the neomycin-resistance gene only. A relative increase in the phosphorylated form of pRb in cells expressing high versus low levels of cyclin D1 was also revealed by western blot analysis. There was an increased fraction of cells in the S and G2 phases of the cell cycle among cells expressing higher levels of cyclin D1. Transfectants with increased cyclin D1 expression also had increased DHFR mRNA and protein expression. Cytotoxicity assays revealed a statistically significant (P < .01) increase in resistance to methotrexate in cells expressing high levels of cyclin D1 compared with cells expressing lower levels. There was no difference in resistance to doxorubicin, paclitaxel (Taxol), and cytarabine. CONCLUSION: Alterations in the expression of cyclin D1 led to altered cell cycle distribution in a human sarcoma cell line. The associated increase in DHFR expression resulted in increased resistance to methotrexate but had no effect on other classes of anticancer agents. IMPLICATIONS: These results indicate that alterations in cell cycle genes may differ in their effects on cytotoxicity. It will be important to determine the effects of alterations of other cell cycle regulatory genes on the responses of cells to specific classes of drugs. Tumors with overexpression of cyclin D1 may be relatively refractory to methotrexate treatment.

Axonal sprouting in the hemisected adult rat spinal cord.

The morphological and biochemical changes were studied in adult Sprague-Dawley rats after hemisection at the L3 spinal cord level. After survival periods of one, two and three months, fluorescent tracers, FluoroGold or rhodamine B, were implanted into the dorsal white columns of these rats at the positions of the corticospinal tract below the lesion. Following uptake of the tracer, the rats were killed and the motor cortices and spinal cords of both control and hemisected rats were analysed for positively labelled neurons. The highest number of labelled cells were found two months after hemisection. They were present in both sides of the cortices, particularly in the contralateral cortex, and also in the gray matter of the spinal cord above the hemisection. A few rats which were subjected to complete transection of the spinal cord also showed labelling of neurons in the motor cortex two months after lesion. The Protargol silver technique and the [3H]choline uptake study confirmed the presence of nerve fibres traversing the lesion site in the hemisected spinal cord. Furthermore, when the rats that had been hemisected two months earlier were subjected to a second cut at the same site, chromatolytic neurons were observed in the spinal cord as well as in the motor cortices of both sides. The hemisected rats demonstrated limited recovery in limb movement. The evidence of this study clearly shows that sprouting of nerve fibres has occurred in the lesioned adult rat spinal cord.

Leucovorin enhances cytotoxicity of trimetrexate/fluorouracil, but not methotrexate/fluorouracil, in CCRF-CEM cells.

BACKGROUND: Increased response rates in studies of patients with colon cancer have indicated that the cytotoxic effects of fluorouracil (5-FU) are potentiated by leucovorin (LV) and by methotrexate (MTX). However, preliminary studies using a sequential combination of MTX, LV, and 5-FU showed no additional potentiation. PURPOSE: We hypothesized that the lack of additional cell kill with this combination could be due to competition of LV with MTX for cellular uptake and reduced folate polyglutamylation. We have tested this possibility by comparing the cytotoxicity of drug combinations containing MTX with that of drug combinations containing trimetrexate (TMTX), an antifolate that does not compete with LV for uptake or polyglutamylation. METHODS: Human lymphocytic leukemia CCRF-CEM cells were exposed to MTX or TMTX for 24 hours and to 5-FU during the last 4 hours of antifolate exposure. LV was administered 30 minutes before 5-FU. RESULTS: After 20 hours of exposure to TMTX or MTX, intracellular levels of phosphoribosyl pyrophosphate were elevated to a similar degree, and these levels did not decrease after a 30-minute exposure to LV. No additional cell kill was observed when LV was added to the MTX/5-FU combination, but cytotoxicity was enhanced when LV was added to the TMTX/5-FU combination. CONCLUSIONS: This study supports the hypothesis that the lack of additional cell kill when high-dose LV is added to the MTX/5-FU combination may be due to competition of MTX with LV for cellular uptake and/or competition of MTX or its polyglutamates with polyglutamylation of reduced folates. Inasmuch as TMTX does not compete with LV and reduced folates for uptake and polyglutamylation, the synergy obtained with the combination of TMTX plus 5-FU and high-dose LV further supports this hypothesis.

Mechanisms of natural resistance to antifolates in human soft tissue sarcomas.

Efforts to use fresh human sarcoma cells for evaluating antifolate resistance with an in situ thymidylate synthesis assay using 5-[3H] deoxyuridine were unsuccessful because of low thymidylate synthesis activity in enzymatically disaggregated tumors. By incubating tumor cell suspensions in supplemented RPMI-1640 medium with 10% fetal bovine serum for 3 days, activity of the in situ thymidylate synthesis assay markedly increased (1.42 versus 0.03 pmol/h/10(7) cells), thus allowing 75% of samples to be evaluated for antifolate sensitivity. By criteria developed with a methotrexate-resistant and -sensitive cell line, this assay indicated that most sarcomas are naturally resistant to methotrexate (12 of 15). Natural resistance to 10-ethyl-10-deazaaminopterin and trimetrexate was also observed in 60% of the samples (nine of 15, respectively). The results from the 3-day in situ assay were confirmed by specific tests for resistance mechanisms in most sarcoma samples. The resistance mechanisms detected were impaired polyglutamylation, an increased level of dihydrofolate reductase, and amplification of this gene. These results encourage further exploration of this assay to predict response to antifolates in individual patients and to evaluate efficacy of new antifolates as candidates for clinical trial.

Effects of ginsenosides, lectins and Momordica charantia insulin-like peptide on corticosterone production by isolated rat adrenal cells.

Ginsenosides Rb1, Rb2, Rc and Rg1 inhibited steroidogenesis induced by a maximally active dose of corticotropin in isolated rat adrenal cells. The galactose-binding lectins from Momordica charantia seeds and Trichosanthes kirilowii tubers and mannose-binding concanavalin A did not affect basal corticosterone production. The lectins potentiated steroidogenesis induced by a submaximal dose of corticotropin but were without effect on steroidogenesis induced by a maximally active dose of corticotropin. Momordica charantia insulin-like peptide did not affect steroidogenesis.

Abortifacient activity in leaves, roots and seeds of Phytolacca acinosa.

Fresh leaves, roots and seeds of Phytolacca acinosa were individually extracted with 0.9% saline and cold acetone was added to the supernatants. The resultant precipitates were dialyzed against distilled water and lyophilized to form acetone powders (AP). The relative potencies of abortifacient activity of the APs were: seed greater than root greater than leaf. The abortifacient activity in these APs was susceptible to destruction by heat and pepsin.

Isolation and characterization of an abortifacient protein, momorcochin, from root tubers of Momordica cochinchinensis (family cucurbitaceae).

A glycoprotein with a molecular weight of 32,000 as estimated by SDS-polyacrylamide gel electrophoresis, and characterized by an abundance of Asp and Glu residues and an absence of Cys residues in its amino acid analysis, was isolated from fresh root tubers of Momordica cochinchinensis using a procedure that involved acetone precipitation, ammonium sulfate precipitation, ion exchange chromatography on DEAE Sepharose CL-6B and gel filtration on Sephadex G-75. The protein was capable of inducing mid-term abortion in mice. The characteristics of this protein were compared and contrasted with those of the abortifacient proteins isolated from other plants of the Cucurbitaceae family.

Beta-trichosanthin: a new abortifacient protein from the Chinese drug, wangua, Trichosanthes cucumeroides.

beta-Trichosanthin was a new abortifacient protein purified from the Chinese drug, Wangua, root tubers of Trichosanthes cucumeroides (Cucurbitaceae). The purification procedure involved acetone fractionation, ammonium sulfate precipitation, ion-exchange chromatography on CM-Sepharose and preparative agarose electrophoresis. Homogeneity of beta-trichosanthin was demonstrated in immunoelectrophoresis, agarose electrophoresis and SDS-polyacrylamide gel electrophoresis. It had a molecular weight of 28,000 and no cysteine in its molecule. It differed from trichosanthin, a known abortifacient protein isolated from a related Chinese drug, Tianhuafen, root tubers of Trichosanthes kirilowii (Cucurbitaceae), in molecular weight, carbohydrate content, charge and amino acid composition. beta-Trichosanthin was, however, immunochemically identical to trichosanthin and was about twice as potent as trichosanthin in inducing mid-term abortion in mice.

Isolation and characterization of an immunosuppressive protein from Trichosanthes kirilowii root tubers.

An immunosuppressive protein was isolated from Trichosanthes kirilowii root tubers by a procedure involving acetone fractionation and ion exchange chromatography on CM-Sepharose. Homogeneity of the protein was demonstrated in immunoelectrophoresis, SDS-polyacrylamide gel electrophoresis, gel filtration, high performance liquid chromatography and a single NH2-terminal sequence. The protein had a molecular weight of 26,000, aspartic acid as the NH2-terminal amino acid and no cysteine or carbohydrates in its molecule. It inhibited ConA-induced transformation in lymphocytes isolated from spleens of CBA mice. The protein was also potent in inducing mid-term abortion in mice.

Acid-ethanol extractable compounds from fruits and seeds of the bitter gourd Momordica charantia: effects on lipid metabolism in isolated rat adipocytes.

Fruits and seeds of the bitter gourd Momordica charantia (Family Cucurbitaceae) were extracted with acidic ethanol. The extract was adjusted to pH 3 and proteins and peptides were precipitated by addition of a copious volume of acetone. The precipitate was dissolved, dialyzed and lyophilized. The resulting material, designated "p-fraction" was tested for antilipolytic and lipogenic activities. Seed "p-fraction" was further chromatographed on fetuin agarose to yield an unadsorbed fraction (F) which could be fractionated by gel filtration on Sephadex G-10 to give an unretarded fraction (F1) and a retarded fraction (F2). Fruit "p-fraction" exhibited antilipolytic activity in hamster adipocytes and stimulated 3H-glucose incorporation into lipids. F1, a saponin containing fraction, inhibited both lipolysis and 3H-glucose incorporation into lipids. F2 enhanced 3H-glucose incorporation into lipid. The results are indicative of the presence of compounds with insulinomimetic activities in M. charantia fruits and seeds.

Effects of alpha-momorcharin, beta-momorcharin and alpha-trichosanthin on lipogenesis and testicular and adrenal steroidogenesis in vitro and plasma-glucose levels in vivo.

The effects of alpha-momorcharin, beta-momorcharin and alpha-trichosanthin on lipogenesis in isolated rat adipocytes were examined. None of the three abortifacient proteins possessed lipogenic activity. The plant proteins did not affect the plasma-glucose level in fasting mice nor did they affect luteinizing hormone-induced testosterone production in isolated rat Leydig cells or corticotropin-induced corticosterone production in isolated rat adrenal decapsular cells by the end of a 2-h incubation period. The results suggest that the functions of adipocytes, adrenal decapsular cells, Leydig cells and pancreatic beta cells were not greatly affected after short-term exposure to the abortifacient proteins.