The location of pacemakers in the uteri of pregnant guinea pigs and rats.

The pregnant uterus is a smooth muscle organ whose pattern of contraction is dictated by the propagation of electrical impulses. Such electrical activity may originate from one or more pacemakers, but the location of these sites has not yet been determined. To detect the location of the pacemaker in the gravid uterus, two approaches were used: 1) determine the site from where the contraction started using isolated uteri from the pregnant guinea pig, and videotape their contractions; and 2) record, in isolated uteri from pregnant term rats, with 240 extracellular electrodes simultaneously, and determine where the electrical bursts started. In both the contractile and electrophysiological experiments, there was not a single, specific pacemaker area. However, most contractions (guinea pig 87%) and bursts (rat 76%) started close to the mesometrial border (mean 2.7 ± 4.0 mm SD in guinea pigs and 1.3 ± 1.4 mm in rats). In addition, in the rat, most sites of initiations were located closer to the ovarial end of the horn (mean distance from the ovarial end 6.0 ± 6.2 mm SD), whereas such an orientation was not seen in the guinea pig. In both guinea pig and rat uteri at term, there is not one specific pacemaker area. Rather, contractile and electrical activity may arise from any site, with the majority starting close to the mesometrial border. Furthermore, in the rat, most activities started at the ovarial end of the horn. This may suggest a slightly different pattern of contraction in both species.

Short-term effects of oral administration of Pistacia lentiscus oil on tissue-specific toxicity and drug metabolizing enzymes in mice.

BACKGROUND: Pistacia lentiscus (Anacardiaceae) is a flowering plant traditionally used in the treatment of various skin, respiratory, and gastrointestinal disorders. The aim of this study was to assess whether Pistacia lentiscus oil has any short term toxic effects in vivo and in vitro. METHODS: Pistacia lentiscus oil (100µl) was administered orally into mice for 5 days. RESULTS: Measurements of body weight did not show any weight loss. Serum concentration of LDH did not show any significant statistical difference when compared to control mice. Similarly, blood, kidney or liver function tests showed no toxicity with Pistacia lentiscus oil when compared to the control group. Examination of gastrointestinal tissues sections revealed similar structural features with no difference in cell proliferation. In this context, pharmacological dilutions of Pistacia lentiscus oil (10(-6) - 10(-3)) did not affect the viability (cell death and proliferation) of mouse gastric stem cells, human colorectal cancer cells HT29, human hepatoma cells HepG2. However, it appears that at the dose and time point studied, Pistacia lentiscus oil treatment has targeted various cytochrome P450s and has specifically inhibited the activities and the expression of CYP2E1, CYP3A4, CYP1A1 and CYP1A2 differentially in different tissues. Our results also demonstrate that there is no appreciable effect of Pistacia lentiscus oil on the GSH-dependent redox homoeostasis and detoxification mechanism in the tissues. CONCLUSION: These data suggest a good safety profile of short term oral use of Pistacia lentiscus oil as a monotherapy in the treatment of various skin, respiratory, and gastrointestinal disorders. However, due to its inhibitory effect of various cytochrome P450s and mainly CYP3A4, this might have implications on the bioavailability and metabolism of drugs taken in combination with Pistacia lentiscus oil. More attention is needed when Pistacia lentiscus oil is intended to be uses in combination with other pharmacological agents in order to avoid potential drug-drug interaction leading to toxicity. This study will help in safer use of Pistacia lentiscus oil for therapeutic purpose.

Frondoside a suppressive effects on lung cancer survival, tumor growth, angiogenesis, invasion, and metastasis.

A major challenge for oncologists and pharmacologists is to develop less toxic drugs that will improve the survival of lung cancer patients. Frondoside A is a triterpenoid glycoside isolated from the sea cucumber, Cucumaria frondosa and was shown to be a highly safe compound. We investigated the impact of Frondoside A on survival, migration and invasion in vitro, and on tumor growth, metastasis and angiogenesis in vivo alone and in combination with cisplatin. Frondoside A caused concentration-dependent reduction in viability of LNM35, A549, NCI-H460-Luc2, MDA-MB-435, MCF-7, and HepG2 over 24 hours through a caspase 3/7-dependent cell death pathway. The IC50 concentrations (producing half-maximal inhibition) at 24 h were between 1.7 and 2.5 µM of Frondoside A. In addition, Frondoside A induced a time- and concentration-dependent inhibition of cell migration, invasion and angiogenesis in vitro. Frondoside A (0.01 and 1 mg/kg/day i.p. for 25 days) significantly decreased the growth, the angiogenesis and lymph node metastasis of LNM35 tumor xenografts in athymic mice, without obvious toxic side-effects. Frondoside A (0.1-0.5 µM) also significantly prevented basal and bFGF induced angiogenesis in the CAM angiogenesis assay. Moreover, Frondoside A enhanced the inhibition of lung tumor growth induced by the chemotherapeutic agent cisplatin. These findings identify Frondoside A as a promising novel therapeutic agent for lung cancer.

Thymoquinone as an anticancer agent: evidence from inhibition of cancer cells viability and invasion in vitro and tumor growth in vivo.

Phytochemical compounds are emerging as a new generation of anticancer agents with limited toxicity in cancer patients. The purpose of this study was to investigate the potential impact of thymoquinone (TQ), the major constituent of black seed, on survival, invasion of cancer cells in vitro, and tumor growth in vivo. Exposure of cells derived from lung (LNM35), liver (HepG2), colon (HT29), melanoma (MDA-MB-435), and breast (MDA-MB-231 and MCF-7) tumors to increasing TQ concentrations resulted in a significant inhibition of viability through the inhibition of Akt phosphorylation leading to DNA damage and activation of the mitochondrial-signaling proapoptotic pathway. We provide evidence that TQ at non-toxic concentrations inhibited the invasive potential of LNM35, MDA-MB-231, and MDA-MB231-1833 cancer cells. Moreover, we demonstrate that TQ synergizes with DNA-damaging agent cisplatin to inhibit cellular viability. The anticancer activity of thymoquinone was also investigated in athymic mice inoculated with the LNM35 lung cells. Administration of TQ (10 mg/kg/i.p.) for 18 days inhibited the LNM35 tumor growth by 39% (P < 0.05). Tumor growth inhibition was associated with significant increase in the activated caspase-3. The in silico target identification suggests several potential targets of TQ mainly HDAC2 proteins and the 15-hydroxyprostaglandin dehydrogenase. In this context, we demonstrated that TQ treatment resulted in a significant inhibition of HDAC2 proteins. In view of the available experimental findings, we contend that thymoquinone and/or its analogues may have clinical potential as an anticancer agent alone or in combination with chemotherapeutic drugs such as cisplatin.

Inhibition of cell survival, invasion, tumor growth and histone deacetylase activity by the dietary flavonoid luteolin in human epithelioid cancer cells.

Phytochemical compounds and histone deacetylase (HDAC) inhibitors are emerging as a new generation of anticancer agents with limited toxicity in cancer patients. We investigated the impact of luteolin, a dietary flavonoid, on survival, migration, invasion of cancer cells in vitro, and tumor growth in vivo. Luteolin (25-200µM) decreased the viability of human cancer cell lines originating from the lung (LNM35), colon (HT29), liver (HepG2) and breast (MCF7/6 and MDA-MB231-1833). Luteolin effectively increased the sub-G1 (apoptotic) fraction of cells through caspase-3 and -7 dependent pathways. We provide evidence that luteolin at sub-lethal/non-toxic concentrations inhibited the invasive potential of LNM35, MCF-7/6 and MDA-MB231-1833 cancer cells using Matrigel as well as the chick heart and Oris invasion assays. Moreover, we demonstrate for the first time that luteolin is a potent HDAC inhibitor that potentiates the cytotoxicity of cisplatin in LNM35 cells and decreases the growth of LNM35 tumor xenografts in athymic mice after intraperitoneal injection (20mg/kg/day for 18days) Thus, luteolin, in combination with standard anticancer drugs such as cisplatin, may be a promising HDAC inhibitor for the treatment of lung cancer.