The environmental carcinogens classified as heterocyclic amines (HCA’s) and the tobacco-specific nitrosamine NNK generally require internal enzymatic activation. This activation occurs via cytochrome P450 (CYP) enzymes and leads to metabolites that bind to human DNA which may in turn cause mutations which may then in turn lead to carcinogenesis. Certain nonnutritive plant compounds termed phytochemicals may protect against HCA and NNK-induced mutagenesis and carcinogenesis. We investigated the potential protective effects of five different phytochemicals of the flavonoid class which naturally occur in citrus. These flavonoids were diosmin, naringin. naringenin, rutin, and quercetin. Our results suggest that naringenin and quercetin were the strongest inhibitors of the metabolic activation of NNK, while diosmin, naringin, naringenin, and rutin each demonstrated protective effects toward HCA-induced mutagenesis.
","abstract_html":"<p>The environmental carcinogens classified as heterocyclic amines (HCA’s) and the tobacco-specific nitrosamine NNK generally require internal enzymatic activation. This activation occurs via cytochrome P450 (CYP) enzymes and leads to metabolites that bind to human DNA which may in turn cause mutations which may then in turn lead to carcinogenesis. Certain nonnutritive plant compounds termed phytochemicals may protect against HCA and NNK-induced mutagenesis and carcinogenesis. We investigated the potential protective effects of five different phytochemicals of the flavonoid class which naturally occur in citrus. These flavonoids were diosmin, naringin. naringenin, rutin, and quercetin. Our results suggest that naringenin and quercetin were the strongest inhibitors of the metabolic activation of NNK, while diosmin, naringin, naringenin, and rutin each demonstrated protective effects toward HCA-induced mutagenesis.</p>","abstract_has_math":false,"creators":["Bear, Wayne L."],"institution":null,"degree_name":"Master of Science (MS)","degree_level":"Thesis","degree_discipline":"Pharmacology","degree_department":null,"school":null,"contributors":["Robert W. Teel","Raymond G. Hall","Marvin Peters"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2002,"date_issued":"2002-03-01T08:00:00Z","date_published":"2002-03-01T08:00:00Z","updated_at":"2026-07-24T02:53:44Z","subjects":["Chemical Actions and Uses","Pharmacology","Carcinogens, Environmental -- immunology; Bioflavonoids -- pharmacokinetics; Antioxidants -- chemistry; Anticarcinogenic Agents -- pharmacology; Flavones -- pharmacology; Enzyme Inhibitors -- pharmacology. Phytotherapy; Citrus -- chemistry."],"languages":["English"],"rights":["This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarsrepository.llu.edu/etd/1445","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Robert W. Teel","Raymond G. Hall","Marvin Peters"]},{"key":"dc:creator","label":"Author","values":["Bear, Wayne L."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Pharmacology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Chemical Actions and Uses","Pharmacology","Carcinogens, Environmental -- immunology; Bioflavonoids -- pharmacokinetics; Antioxidants -- chemistry; Anticarcinogenic Agents -- pharmacology; Flavones -- pharmacology; Enzyme Inhibitors -- pharmacology. Phytotherapy; Citrus -- chemistry."]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English"]},{"key":"dc:rights","label":"Dc Rights","values":["This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarsrepository.llu.edu/etd/1445"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The environmental carcinogens classified as heterocyclic amines (HCA’s) and the tobacco-specific nitrosamine NNK generally require internal enzymatic activation. This activation occurs via cytochrome P450 (CYP) enzymes and leads to metabolites that bind to human DNA which may in turn cause mutations which may then in turn lead to carcinogenesis. Certain nonnutritive plant compounds termed phytochemicals may protect against HCA and NNK-induced mutagenesis and carcinogenesis. We investigated the potential protective effects of five different phytochemicals of the flavonoid class which naturally occur in citrus. These flavonoids were diosmin, naringin. naringenin, rutin, and quercetin. Our results suggest that naringenin and quercetin were the strongest inhibitors of the metabolic activation of NNK, while diosmin, naringin, naringenin, and rutin each demonstrated protective effects toward HCA-induced mutagenesis.
"]},{"key":"dc:title","label":"Title","values":["Modulatory Effects of Citrus Flavonoids Towards the Metabolism and Mutagenicity of Environmental Carcinogens"]}]}],"canonical_facts":{"dc:contributor":["Robert W. Teel","Raymond G. Hall","Marvin Peters"],"dc:creator":["Bear, Wayne L."],"dc:description.abstract":["The environmental carcinogens classified as heterocyclic amines (HCA’s) and the tobacco-specific nitrosamine NNK generally require internal enzymatic activation. This activation occurs via cytochrome P450 (CYP) enzymes and leads to metabolites that bind to human DNA which may in turn cause mutations which may then in turn lead to carcinogenesis. Certain nonnutritive plant compounds termed phytochemicals may protect against HCA and NNK-induced mutagenesis and carcinogenesis. We investigated the potential protective effects of five different phytochemicals of the flavonoid class which naturally occur in citrus. These flavonoids were diosmin, naringin. naringenin, rutin, and quercetin. Our results suggest that naringenin and quercetin were the strongest inhibitors of the metabolic activation of NNK, while diosmin, naringin, naringenin, and rutin each demonstrated protective effects toward HCA-induced mutagenesis.
"],"dc:identifier":["https://scholarsrepository.llu.edu/etd/1445"],"dc:language":["English"],"dc:rights":["This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights."],"dc:subject":["Chemical Actions and Uses","Pharmacology","Carcinogens, Environmental -- immunology; Bioflavonoids -- pharmacokinetics; Antioxidants -- chemistry; Anticarcinogenic Agents -- pharmacology; Flavones -- pharmacology; Enzyme Inhibitors -- pharmacology. Phytotherapy; Citrus -- chemistry."],"dc:title":["Modulatory Effects of Citrus Flavonoids Towards the Metabolism and Mutagenicity of Environmental Carcinogens"],"thesis:degree_discipline":["Pharmacology"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T02:53:44Z"}