Part of the book: Toxicology Studies
Cancer is the second cause of mortality worldwide. Angiogenesis is an important process involved in the growth of primary tumors and metastasis. New approaches for controlling the cancer progression and invasiveness can be addressed by limiting the angiogenesis process. An increasingly large number of natural compounds are evaluated as angiogenesis inhibitors. The chorioallantoic membrane (CAM) assay represents an in vivo attractive experimental model for cancer and angiogenesis studies as prescreening to the murine models. Since the discovery of tumor angiogenesis, the CAM has been intensively used in cancer research. The advantages of this in vivo technique are in terms of low time-consuming, costs, and a lower number of sacrificed animals. Currently, a great number of natural compounds are being investigated for their effectiveness in controlling tumor angiogenesis. Potential reducing of angiogenesis has been investigated by our group for pentacyclic triterpenes, in various formulations, and differences in their mechanism were registered. This chapter aims to give an overview on a number of phytocompounds investigated using in vitro, murine models and the chorioallantoic membrane assay as well as to emphasize the use of CAM assay in the study of natural compounds with potential effects in malignancies.
Part of the book: Natural Products and Cancer Drug Discovery
Skin cancer is an increasingly frequent pathology, with a dangerous high percentage of malignant melanoma. The use of synthetic chemotherapy raises the problem of severe adverse effects and the development of resistance to treatment. Therefore, the use of natural therapies became the focus of numerous research groups due to their high efficacy and lower systemic adverse effects. Among natural products evaluated as therapeutical agents against skin cancer, betulinic acid was emphasized as a highly selective anti-melanoma agent and is currently undergoing phase II clinical trials as topical application. Several other pentacyclic triterpenes exhibit antiproliferative activities. This chapter aims to present the latest main discoveries in the class of pentacyclic triterenes with antitumor effect and the evolution of their preclinical trials. Furthermore, it includes reports on plant sources containing pentacyclic triterpenes, as well as the main possibilities of their water solubilization and cancer cell targeting. A review on recent data regarding mechanisms of action at cellular and molecular levels complements information on the outstanding medicinal potential of these compounds.
Part of the book: Unique Aspects of Anti-cancer Drug Development
The broad area of magnetic iron oxide nanoparticle (M-IONP) applications and their exclusive physico-chemical characteristics (superparamagnetic properties per se, solubility and stability in aqueous solutions, and high bioavailability in vivo) make these nanoparticles suitable candidates for biomedical uses. The most employed magnetic iron oxides in the biomedical field are magnetite and maghemite. Cancer represents a complex pathology that implies multiple mechanisms and signaling pathways, this complexity being responsible for the increased resistance to therapy and the lack of an effective curative treatment. A potential useful alternative was considered to be the use of magnetic iron nanoparticles. The M-IONPs proved to be effective as contrast agents in magnetic resonance imaging, as drug delivery carriers for different therapeutic agents, in magnetic cell separation assays, and are suitable to be engineered in terms of size, targeted delivery and substance release. Moreover, their in vivo administration was considered safe, and recent studies indicated their efficiency as anticancer agents. This chapter aims to furnish an overview regarding the physico-chemical properties of M-IONPs (mainly magnetite, maghemite and hematite), the synthesis methods and their in vitro biological impact on healthy and cancer cell lines, by describing their potential mechanism of action—enucleation, apoptosis or other mechanisms.
Part of the book: Iron Ores and Iron Oxide Materials