Determination of Biologically Relevant Vitamin D Metabolites in a Mouse Model of Non Melanoma Skin Cancer

Food, Agricultural, and Environmental Sciences (FAES): 1st Place (The Ohio State University Edward F. Hayes Graduate Research Forum)Background: Vitamin D has received recent attention as a nutrient in which a large portion of Americans may be deficient. Vitamin D is a unique “essential” nutrient in that it can be produced endogenously in the skin via UVB irradiation of 7-dehydrocholesterol, or taken in from the diet. Although it is well established that vitamin D plays a role in bone health, a growing body of evidence suggests that it may also have a role in chronic diseases, including several types of cancer. Vitamin D is not naturally present in many foods although some foods including dairy products and ready to eat cereals are fortified. Some researchers recommend that individuals receive approximately 5 to 15 minutes of unprotected sun exposure several times a week in order to produce sufficient amounts of vitamin D, yet unprotected sun exposure is also a risk factor for skin cancer. Cell studies have demonstrated that 1,25-dihydroxyvitamin D, the active metabolite of vitamin D, has an inhibitory effect on skin cancer initiation, but cancerous cells lose sensitivity to the growth regulating properties of the compound. These recent reports indicate an important biological role of vitamin D metabolites in skin cancer development, but there have been no studies on the disease measuring these compounds in skin. This is primarily due to the challenging nature of this analysis and need for highly sensitive and sophisticated analytical instrumentation. Purpose/Rationale: Since vitamin D may have a role in the prevention of skin cancer, and the UVB exposure needed for endogenous synthesis of the vitamin is a risk factor for the disease, the effects of dietary vitamin D on the development of skin cancer is a critical area of investigation. However, before results can be translated to humans, appropriate animal models of skin cancer need to be investigated. The purpose of this research is to measure the levels of biologically relevant vitamin D metabolites in the skin and serum of mice fed escalating doses of vitamin D. Research Methods: To evaluate the effects of dietary vitamin D on non-melanoma skin cancer (NMSC), 150 Skh-1 hairless, but immunocompetent, mice were placed on diets with escalating doses of the vitamin for 29 weeks. The Skh-1 mouse is a well-recognized model of NMSC. Equal numbers of male and female mice were assigned to each dietary level of vitamin D (25, 150, 1000 IU). Within each dietary level, n=15 mice were exposed to UVB light three times per week for the last 25 weeks of the study, and n=10 mice were abstained from the treatment. The UVB exposure given to the mice was one minimal erythemic dose, which is equivalent to a light sunburn. Vitamin D metabolite levels will be measured in the serum and skin of the mice using high performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS), a sensitive and advanced analytical technique. The estimated levels of these compounds in the skin are quite low, thus extracts from skin samples will be derivatized with 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD), allowing more efficient and sensitive analysis of the vitamin D metabolites. Predicted Findings: We expect to see increased vitamin D metabolites in samples from mice supplemented with the nutrient. A dose-dependent increase in specific metabolites is also expected. Implications: The levels of vitamin D-related compounds in the tissues and serum of mice from this study will be correlated with previously evaluated cancer outcomes. This will be the first study of its kind to measure vitamin D metabolites in murine skin using HPLC-MS/MS in an effort to elucidate the influence of dietary vitamin D on NMSC.A five-year embargo was granted for this item

Heat Treatment of Soy Flour and Its Effects on β-glucosidase Activity

College of Food, Agricultural, and Environmental Sciences Undergraduate Research Forum, Second Place in Food Science CategoryIsoflavones, phytochemicals readily found in soy beans and soy products, have been associated with reduced risk of prostate cancer in mice. Such findings require translation to human prostate cancer patients and thus methods for delivering the isoflavones to the body. Previous work in our laboratory has focused on soy-almond bread. The majority of isoflavones in soy are not in a form easily absorbed by the body. However, isoflavones are converted to a bioactive form by β-glucosidase, an enzyme intrinsic to soy and almond. Previous studies in our lab have suggested that the extent of this conversion may be affected by the heat treatment of soy ingredients. In order to elucidate the role of heat treatment in increasing β-glucosidase activity, crude enzyme extracts from raw almonds and raw or heat treated soy flour-soy milk mixture were obtained using a sodium phosphate buffer at pH 5.0. The heat treatment consisted of roasting or steaming. Protein content was quantified using the Bradford and bicinchoninic acid methods, which indicated that almond and raw soy mixture contained the most protein, while the steamed contained the least. When the β-glucosidase activity of the extracts was measured using p-nitrophenol-β-D-glucopyranoside, almond extract showed the greatest activity, but interestingly, roasted and steamed extracts showed the next highest activity, followed by fermented and raw. It appears that water plays a key role in the mechanism of conversion of isoflavones into bioactive forms, while protein content is less relevant. Such finding is critical when tailoring foods to contain high levels of phytochemicals that are potentially more bioactive by either modifying the crops that provide the raw ingredients or the processing that leads to the desired outcome.Ohio Agricultural Research and Development Center, S.E.E.D.S. GrantCollege of Food, Agricultural, and Environmental Sciences Undergraduate Research GrantA five-year embargo was granted for this item

Chemical characterization and antioxidant potential of wild ganoderma species from Ghana

The chemical characterization and antioxidant potential of twelve wild strains of Ganoderma sp. from Ghana, nine (LS1-LS9) of which were found growing wild simultaneously on the same dying Delonix regia tree, were evaluated. Parameters evaluated included the nutritional value, composition in sugars, fatty acids, phenolic and other organic compounds and some vitamins and vitamin precursors. Antioxidant potential was evaluated by investigating reducing power, radical scavenging activity and lipid peroxidation inhibition using five in vitro assays. Protein, carbohydrate, fat, ash and energy contents ranged between 15.7-24.5 g/100 gdw, 73.31-81.90 g/100 g, 0.48-1.40 g/100 g, 0.68-2.12 g/100 g ash and 396.1-402.02 kcal/100 g, respectively. Fatty acids such as linoleic, oleic and palmitic acids were relatively abundant. Free sugars included rhamnose, fructose, mannitol, sucrose and trehalose. Total tocopherols, organic acids and phenolic compounds' content ranged between 741-3191 µg/100 g, 77-1003 mg/100 g and 7.6-489 µg/100 g, respectively. There were variations in the ß-glucans, ergosterol and vitamin D 2 contents. The three major minerals in decreasing order were K > P > S. Ganoderma sp. strain AM1 showed the highest antioxidant activity. This study reveals, for the first time, chemical characteristics of Ganoderma spp. which grew simultaneously on the same tree.The authors thank H.N.A. Wellington of University of Ghana for showing us the location of the LS1–9 samples and for aiding in the sample collection. The authors also thank the Foundation for Science and Technology (FCT, Lisbon, Portugal) and FEDER under Program PT2020 for financial support to CIMO (Pest-OE/AGR/UI0690/2015) and L. Barros (SFRH/BPD/107855/2015) grant. To POCI-01-0145-FEDER-006984 (LA LSRE-LCM), funded by FEDER, through POCI-COMPETE2020 and FCT. We also thank the Nutrient and Phytochemical Analytic Shared Resource, part of the OSU Comprehensive Cancer Center (NIH P30 CA016058), where ergosterol and vitamin D2 were analyzed, the OSU Food Innovation Center for financial support, and the OSU Center for Advanced Functional Foods Research and Entrepreneurship for in-kind support. Author Contributions: Mary Obodai designed the study and participated in the manuscript writing. Deborah L. Narh. Mensah and Nii Korley Kortei conducted bibliographic research, data organization and participated in the manuscript writing. Angela Fernandes, Lillian Barros and Isabel C. F. R. Ferreira performed all the chemical analysis, the statistics and participated in the manuscript writing. Deborah L. Narh Mensah, Matilda Dzomeku, Juanita Prempeh and Richard K. Takli collected all the samples. Matthew Teegarden and Steven J. Schwartz conducted analysis on bioactive compounds and edited manuscript. Mary Obodai, Deborah L. Narh. Mensah, Nii Korley Kortei and Isabel C.F.R. Ferreira revised the manuscript writing.info:eu-repo/semantics/publishedVersio

The Relevance of Marine Chemical Ecology to Plankton and Ecosystem Function: An Emerging Field

Marine chemical ecology comprises the study of the production and interaction of bioactive molecules affecting organism behavior and function. Here we focus on bioactive compounds and interactions associated with phytoplankton, particularly bloom-forming diatoms, prymnesiophytes and dinoflagellates. Planktonic bioactive metabolites are structurally and functionally diverse and some may have multiple simultaneous functions including roles in chemical defense (antipredator, allelopathic and antibacterial compounds), and/or cell-to-cell signaling (e.g., polyunsaturated aldehydes (PUAs) of diatoms). Among inducible chemical defenses in response to grazing, there is high species-specific variability in the effects on grazers, ranging from severe physical incapacitation and/or death to no apparent physiological response, depending on predator susceptibility and detoxification capability. Most bioactive compounds are present in very low concentrations, in both the producing organism and the surrounding aqueous medium. Furthermore, bioactivity may be subject to synergistic interactions with other natural and anthropogenic environmental toxicants. Most, if not all phycotoxins are classic secondary metabolites, but many other bioactive metabolites are simple molecules derived from primary metabolism (e.g., PUAs in diatoms, dimethylsulfoniopropionate (DMSP) in prymnesiophytes). Producing cells do not seem to suffer physiological impact due to their synthesis. Functional genome sequence data and gene expression analysis will provide insights into regulatory and metabolic pathways in producer organisms, as well as identification of mechanisms of action in target organisms. Understanding chemical ecological responses to environmental triggers and chemically-mediated species interactions will help define crucial chemical and molecular processes that help maintain biodiversity and ecosystem functionality

Stilbenoids remodel the DNA methylation patterns in breast cancer cells and inhibit oncogenic NOTCH signaling through epigenetic regulation of MAML2 transcriptional activity

DNA hypomethylation was previously implicated in cancer progression and metastasis. The purpose of this study was to examine whether stilbenoids, resveratrol and pterostilbene thought to exert anticancer effects, target genes with oncogenic function for de novo methylation and silencing, leading to inactivation of related signaling pathways. Following Illumina 450K, genome-wide DNA methylation analysis reveals that stilbenoids alter DNA methylation patterns in breast cancer cells. On average, 75% of differentially methylated genes have increased methylation, and these genes are enriched for oncogenic functions, including NOTCH signaling pathway. MAML2, a coactivator of NOTCH targets, is methylated at the enhancer region and transcriptionally silenced in response to stilbenoids, possibly explaining the downregulation of NOTCH target genes. The increased DNA methylation at MAML2 enhancer coincides with increased occupancy of repressive histone marks and decrease in activating marks. This condensed chromatin structure is associated with binding of DNMT3B and decreased occupancy of OCT1 transcription factor at MAML2 enhancer, suggesting a role of DNMT3B in increasing methylation of MAML2 after stilbenoid treatment. Our results deliver a novel insight into epigenetic regulation of oncogenic signals in cancer and provide support for epigenetic-targeting strategies as an effective anticancer approach