Phytochemical and Bioactive Potential of in vivo and in vitro Grown Plants of Centaurea ragusina L. - Detection of DNA/RNA Active Compounds in Plant Extracts via Thermal Denaturation and Circular Dichroism.

INTRODUCTION: The phytochemical composition and biological activity of non-volatile components of Centaurea ragusina L. has not been studied previously. OBJECTIVES: Our aim was to evaluate the phytochemical and bioactive potential (including interactions with polynucleotides) of C. ragusina L. depending on the origin of plant material (in vivo - leaves from natural habitats, ex vitro - leaves from plants acclimated from culture media, in vitro - leaves and calli from plants grown in culture media) and polarity of solvents used in extract preparation (80 and 96% ethanol and water combinations or single solvents). METHODOLOGY: The polyphenol composition was determined by spectrophotometric and HPLC analysis. Biological activity of extracts was evaluated by following methods: 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) methods for antioxidative activity, 2,3,5-triphenyl tetrazolium chloride (TTC) microdilution method for antibacterial activity, crystal-violet test for cytotoxic activity and thermal denaturation (TD) and circular dichroism (CD) for DNA/RNA interactions. RESULTS: Conditions for the most efficient polyphenol extraction were determined: the 80% ethanol/water solvent system was the most suitable for callus and leaf ex vitro samples and 80 or 96% ethanol for leaf in vivo samples. Significantly higher levels of chlorogenic acid and naringenin were detected in callus tissue than in vivo plant. Ethanolic extracts exhibited the significant antibacterial activity against Staphylococcus aureus ATCC 25923. DNA/RNA active compounds in plant extracts were detected by TD and CD methods. CONCLUSIONS: Callus tissue and ex vitro leaves represent a valuable source of polyphenols as in vivo leaves. TD and CD can be applied for detection of DNA/RNA active compounds in extracts from natural resources. Copyright © 2017 John Wiley & Sons, Ltd.

Tamoxifen in trimodal therapy with cytotoxic drugs and hyperthermia in vivo significantly enhance therapeutic efficacy against B16-F10 melanoma.

AIMS AND BACKGROUND: The aim of the study was to investigate whether use of the antiestrogen tamoxifen and heat treatment in combined therapy with the well-known anticancer drugs cisplatin, dacarbazine and cyclophosphamide enhances their therapeutic efficacy on mouse B16-F10 melanoma in vivo. The results of systemic melanoma therapy have been mostly disappointing. Therefore, there is still a great need for strategies that can improve existing chemotherapy options. METHODS AND STUDY DESIGN: The tumor model for the investigation of antitumor activity was a mouse B16-F10 melanoma transplanted into the footpad of C57BL/6 Zgr/Hr mice. Drugs were given intraperitoneally 15 min before the application of local hyperthermia, and tumor growth and mouse survival were followed. RESULTS: Hyperthermia alone determined a significant delay of tumor growth, but mouse survival was not affected. In bimodal combinations with hyperthermia, all the tested antitumor drugs significantly increased both tumor growth delay and mouse survival. Tamoxifen alone did not show any inhibitory effect on B16-F10 melanoma in vivo. However, in the trimodal therapy with a particular drug and hyperthermia, it potentiated the inhibitory effects of the respective bimodal treatments, especially that of cyclophosphamide and hyperthermia. CONCLUSIONS: Our results obtained on the mouse B16-F10 melanoma in vivo confirmed the enhanced therapeutic efficacy of the trimodal therapy tamoxifen, hyperthermia and anticancer drug combinations in melanoma treatment. Further studies should optimize the heat-drug time scheduling and drug doses that will result in the best possible therapeutic achievement for these trimodal therapy options.

Antitumor effect of Croatian propolis as a consequence of diverse sex-related dihydropyrimidine dehydrogenase (DPD) protein expression.

The aim of this study was to detect the antitumor properties of Croatian propolis in BALB/c male and female mice injected with 4T1 mammary carcinoma. Furthermore, the gender-dependence of this effect and the possible involvement of combined effect of propolis and 5-Fluorouracil (5FU) on dihydropyrimidine dehydrogenase (DPD) transcriptional and translational level, were determined. In combination with 5FU propolis treatment induced gender-related effects. The results of the study revealed that pretreatment of mice with propolis combined with 5FU treatment prolonged the suppressive effect of 5FU on tumor growth and reduced the number of metastasis only in male mice. Only males pretreated with propolis prior to 5FU administration had decreased DPD protein level indicating higher sensitivity to 5FU. Thus, benefitial effects of propolis in male tumor-bearing mice treated with 5FU might be explained by increased sensitivity to 5FU as the result of translationally downregulated DPD.