Transient Vasodilation in Mouse 4T1 Tumors after Intragastric and Intravenous Administration of Gold Nanoparticles.

Gold nanoparticles (AuNPs) are foreseen as a promising tool in nanomedicine, both as drug carriers and radiosensitizers. They have been also proposed as a potential anticancer drug due to the anti-angiogenic effect in tumor tissue. In this work we investigated the effect of citrate-coated AuNPs of nominal diameter 20 nm on the growth and metastatic potential of 4T1 cells originated from a mouse mammary gland tumor inoculated into the mammary fat pad of Balb/ccmdb mice. To evaluate whether AuNPs can prevent the tumor growth, one group of inoculated mice was intragastrically (i.g.) administered with 1 mg/kg of AuNPs daily from day 1 to day 14 after cancer cell implantation. To evaluate whether AuNPs can attenuate the tumor growth, the second group was intravenously (i.v.) administered with 1 or 5 mg/kg of AuNPs, twice on day 5 and day 14 after inoculation. We did not observe any anticancer activity of i.v. nor i.g. administered AuNPs, as they did not affect neither the primary tumor growth rate nor the number of lung metastases. Unexpectedly, both AuNP treatment regimens caused a marked vasodilating effect in the tumor tissue. As no change of potential angiogenic genes (Fgf2, Vegfa) nor inducible nitric oxygenase (Nos2) was observed, we proposed that the vasodilation was caused by AuNP-dependent decomposition of nitrosothiols and direct release of nitric oxide in the tumor tissue.

Apples: content of phenolic compounds vs. variety, part of apple and cultivation model, extraction of phenolic compounds, biological properties.

Apples are among the most popular fruits in the world. They are rich in phenolic compounds, pectin, sugar, macro- and microelements. Applying different extraction techniques it is possible to isolate a particular group of compounds or individual chemicals and then test their biological properties. Many reports point to the antioxidant, antimicrobial, anticancer and many other beneficial effects of apple components that may have potential applications in food, pharmaceutical and cosmetic industries. This paper summarizes and compiles information about apple phenolic compounds, their biological properties with particular emphasis on health-related aspects. The data are reviewed with regard to different apple varieties, part of apple, cultivation model and methods of extraction.

[Glycosylases [4Fe-4S] and the charge transfer in DNA]. / Glikozylazy [4Fe-4S] i przenoszenie ladunku w DNA.

Both the physical and chemical test results indicate that the DNA under different conditions can act as a narrow band semiconductor. The charge transfer along the DNA double strand molecule depends both on the nucleotide sequence and the distance, and is possible only in the case of an ideal paring of both strands. The charge transfer within DNA may be perturbed/modified by formation of protein complexes, e.g., related to the processes of DNA repair. On the other hand, redox potentials of metalloproteins are modulated by binding to DNA. Particularly interesting are [4Fe-4S] glycosylases, iron-sulfur cluster containing enzymes involved in DNA base excision repair. There exists a hypothesis that disturbance of charge transfer along DNA is a signal associated with the regulation of cellular response to damage of the double helix. In the following review, based on the work of J. Barton and coworkers, the question is discussed of whether the [4Fe-4S] cluster may participate in the process of finding the DNA damage by repair proteins through detection of electronic structure perturbations.