Antimetastatic and Antitumor Activities of Orally Administered NAX014 Compound in a Murine Model of HER2-Positive Breast Cancer.

The natural isoquinoline alkaloid Berberine (BBR) has been shown to possess several therapeutic effects, including anticancer activity. Different BBR derivatives have been designed and synthesized in order to obtain new compounds with enhanced anticancer efficacy. We previously showed that intraperitoneal (IP) administration of the BBR-derived NAX014 compound was able to counteract HER-2 overexpressing mammary tumors onset and progression in transgenic mice. However, the IP administration was found to induce organ toxicity at doses higher than 2.5 mg/Kg. In this study, we evaluated the effect of intragastric (IG) administration of 20 mg/kg of NAX014 on both safety and anticancer efficacy in HER-2/neu transgenic mice. Furthermore, cancer cell dissemination and migration, tumor cell senescence and immunological changes were examined. Our results demonstrated that IG NAX014 administration delayed the onset of mammary tumors with no negative effects on health and survival. NAX014 reduced HER-2 overexpressing BC cells migration in vitro and the frequency of lung metastasis in HER-2/neu transgenic mice. A statistically significant increase of senescence-associated p16 expression was observed in tumors from NAX014-treated mice, and the induction of cell senescence was observed in HER-2 overexpressing BC cells after in vitro treatment with NAX014. Although NAX014 did not modulate the presence of tumor-infiltrating lymphocytes, the level of circulating TNF-α and VEGF was found to be reduced in NAX014-treated mice. The overall results address the NAX014 compound as potential tool for therapeutic strategies against HER-2 overexpressing breast cancer.

Potential application of berberine in the treatment of Escherichia coli sepsis.

Gram-negative sepsis ranks as the leading cause of death in intensive care units. Despite the development of new antibiotics, mortality from gram-negative sepsis remains high. The present study aims to investigate the in vivo effects of berberine (BBR) administration on septic death induced by intraperitoneal Escherichia coli injection. The results showed that (i) single 5 mg/kg dose of BBR increases the survival of septic mice, (ii) BBR administration improves the antimicrobial efficacy of antibiotic drug, (iii) BBR pre-treatment prevents improvements of BBR therapy without affecting the pro-survival effects of antibiotic drug. The effects of BBR administration were associated with immunological alterations represented by changes in CD4+ and CD8+ lymphocytes population and IL-6 and TNF-α production. This study highlighted the benefits of berberine administration as antibiotic adjuvant in E. coli sepsis. Furthermore, information about berberine-induced immunological perturbations and their influence on host response to infection and therapy has been shown.

Inducers of Senescence, Toxic Compounds, and Senolytics: The Multiple Faces of Nrf2-Activating Phytochemicals in Cancer Adjuvant Therapy.

The reactivation of senescence in cancer and the subsequent clearance of senescent cells are suggested as therapeutic intervention in the eradication of cancer. Several natural compounds that activate Nrf2 (nuclear factor erythroid-derived 2-related factor 2) pathway, which is involved in complex cytoprotective responses, have been paradoxically shown to induce cell death or senescence in cancer. Promoting the cytoprotective Nrf2 pathway may be desirable for chemoprevention, but it might be detrimental in later stages and advanced cancers. However, senolytic activity shown by some Nrf2-activating compounds could be used to target senescent cancer cells (particularly in aged immune-depressed organisms) that escape immunosurveillance. We herein describe in vitro and in vivo effects of fifteen Nrf2-interacting natural compounds (tocotrienols, curcumin, epigallocatechin gallate, quercetin, genistein, resveratrol, silybin, phenethyl isothiocyanate, sulforaphane, triptolide, allicin, berberine, piperlongumine, fisetin, and phloretin) on cellular senescence and discuss their use in adjuvant cancer therapy. In light of available literature, it can be concluded that the meaning and the potential of adjuvant therapy with natural compounds in humans remain unclear, also taking into account the existence of few clinical trials mostly characterized by uncertain results. Further studies are needed to investigate the therapeutic potential of those compounds that display senolytic activity.

Supplementation with tocotrienols from Bixa orellana improves the in vivo efficacy of daptomycin against methicillin-resistant Staphylococcus aureus in a mouse model of infected wound.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of skin and soft-tissue infection worldwide. An adequate immune response acts as a first line of defence against infections and therefore plays an essential role in the maintenance of health. Tocotrienols (T3s), the lesser known isomers of vitamin E, possess many biological properties and have been recognized as immunomodulators. PURPOSE: The aim of this study was to investigate whether the in vivo supplementation with a mixture of 87.1% δ- and 12.9% γ-T3s extract from seeds of Bixa orellana, (T3s) could be effective in increasing the effect of daptomycin (DAP) in a mouse model of wound infection due to MRSA. STUDY DESIGN/METHODS: Bacteria were inoculated onto full-thickness wound on the dorsal side of BALB/c mice at 5 × 106 CFU per mouse. Mice were randomized into five groups: an uninfected group, an infected-untreated group, a T3s-pretreated group with no antibiotics given after challenge, a T3s-pretreated group plus DAP given after challenge, a group only given DAP after challenge. Main outcome measures were: bacterial load on the wounds, analysis of Natural Killer (NK) cytotoxicity, immunological phenotype and markers of tissue repair. RESULTS: Our results showed that bacterial load in wounds from mice receiving T3s or DAP alone was 1- or 3-log10 lower, respectively, compared with the infected-untreated group. T3s plus daptomycin showed the highest efficacy, achieving a 4-log10 decrease in bacterial load. This higher antimicrobial effect was associated with increased levels of NK cytotoxicity and markers of wound repair. CONCLUSION: These data suggest that treatment with T3s may be useful for the management of infected wounds as immune adjuvants in combination with DAP.

Changes in Zn homeostasis during long term culture of primary endothelial cells and effects of Zn on endothelial cell senescence.

Endothelial cell senescence and Zn nutritional status influence cardiovascular disease. The influence of Zn appears dichotomous, hence it is imperative to understand the relationship with cellular senescence to improve knowledge about the molecular and cellular basis of the disease. Here we aimed to determine: 1) the impact of chronic exposure to a moderately high dose of Zn on senescence of endothelial cells; 2) the changes in Zn homeostasis during the lifespan of primary cultured endothelial cells; and 3) the susceptibility of proliferating and senescent endothelial cells to cell death after short term exposure to increasing doses of Zn and of the Zn chelator TPEN. Chronic exposure to Zn accelerated senescence and untreated cells at later passages, where doubling time had increased, displayed relocation of labile Zn and altered expression of genes involved in the response to Zn toxicity, including SLC30A1, SLC39A6, SLC30A5, SLC30A10 and metallothioneins, indicating that senescent cells have altered zinc homeostasis. Most Zn-dependent genes that were expressed differently between early and late passages were correlated with changes in the expression of anti-apoptotic genes. Short-term treatment with a high dose of Zn leads to cell death, but only in the population of cells at both earlier and later passages that had already entered senescence. In contrast, Zn depletion led to death of cells at earlier but not later passages, which suggests that there are sub-populations of senescent cells that are resistant to Zn depletion. This resistant senescent cell population may accumulate under conditions of Zn deficiency and contribute to vascular pathology.

Role of Daptomycin on Burn Wound Healing in an Animal Methicillin-Resistant Staphylococcus aureus Infection Model.

Prolonged hospitalization and antibiotic therapy are risk factors for the development of methicillin-resistant Staphylococcus aureus (MRSA) infections in thermal burn patients. We used a rat model to study the in vivo efficacy of daptomycin in the treatment of burn wound infections by S. aureus, and we evaluated the wound healing process through morphological and immunohistochemical analysis. A copper bar heated in boiling water was applied on a paraspinal site of each rat, resulting in two full-thickness burns. A small gauze was placed over each burn and inoculated with 5 × 107 CFU of S. aureus ATCC 43300. The study included two uninfected control groups with and without daptomycin treatment, an infected control group that did not receive any treatment, and two infected groups treated, respectively, with intraperitoneal daptomycin and teicoplanin. The main outcome measures were quantitative culture, histological evaluation of tissue repair, and immunohistochemical expression of wound healing markers: epidermal growth factor receptor (EGFR) and fibroblast growth factor 2 (FGF-2). The highest inhibition of infection was achieved in the group that received daptomycin, which reduced the bacterial load from 107 CFU/ml to about 103 CFU/g (P < 0.01). The groups treated with daptomycin showed better overall healing with epithelialization and significantly higher collagen scores than the other groups, and these findings were also confirmed by immunohistochemical data. In conclusion, our results support the hypothesis that daptomycin is an important modulator of wound repair by possibly reducing hypertrophic burn scar formation.

Colistin enhances therapeutic efficacy of daptomycin or teicoplanin in a murine model of multiresistant Acinetobacter baumannii sepsis.

We investigated the efficacy of colistin combined with teicoplanin or daptomycin in an experimental mouse model of multiresistant Acinetobacter baumannii infection. Animal received intraperitoneally 1ml saline containing 2×1010CFU of A. baumannii. Colistin, daptomycin, teicoplanin, and colistin plus daptomycin or teicoplanin were given by intraperitoneal administration 2h after bacterial challenge. A control group received sodium chloride solution. In the in vitro study A. baumannii showed to be susceptible only to colistin with MIC of 2mg/l. In the in vivo study, colistin alone showed a good antimicrobial efficacy. When combined with teicoplanin or daptomycin, colistin produced the lowest bacterial and the best survival rates. In immunological studies, when colistin was associated to daptomycin or teicoplanin, both the number and the cytotoxic activity of NK cells increased. In conclusion, colistin combined with teicoplanin or daptomycin may improve the therapy of multiresistant A. baumannii infection.

Modulators of cellular senescence: mechanisms, promises, and challenges from in vitro studies with dietary bioactive compounds.

Cellular senescence is considered an important mechanism to prevent malignant transformation of potentially mutated cells but, persistence of senescent cells within tissues alters microenvironment in ways that can promote cancer and aging phenotype thus underlining pathophysiologic processes of different age-related diseases. Coincident with this increased knowledge, understanding and finding modulators of the dynamics that control senescent-cell formation, fate and subsequent effect on tissue function has gained critical interest in experimental gerontology and cancer research. The purpose of this review is to discuss the evidence that various dietary bioactive compounds can modulate cellular senescence in vitro and to summarize findings and mechanisms that might be useful for the development of health-promoting nutraceuticals. An overview of cellular senescence and its impact in aging and cancer is described along with the strategies and pathways that are currently being investigated to target cellular senescence. Particular emphasis is given to the mechanisms by which bioactive dietary factors (i.e., most polyphenols) can delay or induce cellular senescence in vitro and how this knowledge could be used to explain the opposite effects shown in cancer lines and primary cells by some of these compounds. In addition, the problems to translate findings from modulation of cellular senescence in vitro into experimental treatments or clinical trials able to prevent or counteract age-related diseases are briefly described. The information herein provided might be useful to design further research in the field as well as to develop new nutraceuticals to be tested in experimental models and clinical trials.

Effect of annatto-tocotrienols supplementation on the development of mammary tumors in HER-2/neu transgenic mice.

Tocotrienols (T3), the lesser known isomers of vitamin E, have been reported to possess anticancer activity both in in vitro and in vivo experimental models of rodents transplanted with parental tumors or treated with carcinogens. We investigated the effects of dietary supplementation with annatto-T3 (90% δ-T3 and 10% γ-T3) on the spontaneous development of mammary tumors in HER-2/neu transgenic mice. Underlying mechanisms of the antitumor effect were evaluated by studying apoptosis, senescent-like growth arrest, immune modulation, oxidative effect and the expression of HER-2/neu in tumoral mammary glands of transgenic mice and in vitro in human and mice tumor cell lines. Annatto-T3 supplementation delayed the development of mammary tumors, reducing the number and size of mammary tumor masses and those of lung metastases. In annatto-T3-supplemented mice, both apoptosis and senescent-like growth arrest of tumor cells were increased in mammary glands while no immune modulation was observed. In vitro, a dose-dependent inhibition of cell growth, increased apoptosis and senescent-like growth arrest and a time-dependent accumulation of reactive oxygen species were observed in tumor cells treated with annatto-T3 or purified δ-T3. Annatto-T3 reduced both HER-2/neu mRNA and p185(HER-2/neu) protein in tumors and in tumor cell lines. The results show that the antitumor effect of annatto-T3 supplementation in HER-2/neu transgenic mice is mainly related to the direct induction of oxidative stress, senescent-like growth arrest and apoptosis of tumor cells rather than to an immune modulation.