title: Naringenin prevents high glucose-induced mitochondria-mediated apoptosis involving AIF, Endo-G and caspases.
abstract: Oxidative stress is implicated in hyperglycemia-induced alterations in cell signaling pathways. We examined the toxicity of high glucose in primary rat hepatocytes and its amelioration by naringenin. Incubation of hepatocytes with 40 mM glucose for 1.5 h exhibited significant decrease in cell viability confirmed by MTT reduction and Alamar blue assay. At the same time primary rat hepatocytes exhibited significant decrease in mitochondrial membrane potential indicating organelle dysfunction. Enhanced translocation of Cyt-c from mitochondria to cytosol and AIF/Endo-G from mitochondria to nucleus, activation of caspase-9/3, DNA damage, and chromatin condensation were observed in glucose-stressed hepatocytes, indicating the involvement of mitochondrial pathway in high glucose-induced apoptosis. Transcript levels of antioxidant enzymes were significantly altered along with corresponding changes in their enzymatic activities. The level of intracellular antioxidant glutathione as well as superoxide dismutase, catalase, and glutathione peroxidase activities were observed to be significantly decreased in hepatocytes treated with high concentration of glucose. Naringenin, a flavanone, was effective in preventing loss of cell viability, reactive oxygen species generation, and decline in antioxidant defense. Translocation of AIF, Endo-G, and Cyt-c from mitochondria was also inhibited by naringenin in glucose-stressed cells. Messenger RNA expression of anti-apoptotic and apoptotic genes, externalization of phosphatidyl serine, DNA damage, chromatin condensation, and sub-diploid cell population were effectively altered by naringenin indicating its anti-apoptotic potential in vitro. Our data suggests that naringenin can prevent apoptosis induced by high glucose through scavenging of reactive oxygen species and modulation of mitochondria-mediated apoptotic pathway.
authors.affiliation: Herbal Research Section, CSIR-Indian Institute of Toxicology Research, Lucknow, 226001, India.
authors.forename: Radhika
authors.initials: R
authors.lastname: Kapoor
authors.forename: Fatima
authors.initials: F
authors.lastname: Rizvi
authors.forename: Poonam
authors.initials: P
authors.lastname: Kakkar
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D051033:Apoptosis Inducing Factor / Q000502:physiology*; D053148:Caspase 3 / Q000378:metabolism*; D053453:Caspase 9 / Q000378:metabolism*; D045304:Cytochromes c / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000502:physiology*; D004789:Enzyme Activation / Q000187:drug effects; D044950:Flavanones / Q000494:pharmacology*; D005947:Glucose / Q000494:pharmacology / Q000633:toxicity*; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D017208:Rats, Wistar
chemical_list: D000975:Antioxidants; D051033:Apoptosis Inducing Factor; D044950:Flavanones; D045304:Cytochromes c; D004706:Endodeoxyribonucleases; C052391:endonuclease G; D053148:Caspase 3; D053453:Caspase 9; C005273:naringenin; D005947:Glucose