title: Bixin and norbixin have opposite effects on glycemia, lipidemia, and oxidative stress in streptozotocin-induced diabetic rats.
abstract: The present study investigated the effects of oral administration of annatto carotenoids (bixin (BIX) and norbixin (NBIX)) on glucose levels, lipid profiles, and oxidative stress parameters in streptozotocin (STZ)-induced diabetic rats. Animals were treated for 30 days in the following groups: nondiabetic control, diabetic vehicle, diabetic 10 mg/kg BIX, diabetic 100 mg/kg BIX, diabetic 10 mg/kg NBIX, diabetic 100 mg/kg NBIX, diabetic metformin, and diabetic insulin. Blood glucose, LDL cholesterol, and triglyceride levels were reduced in the diabetic rats treated with BIX. BIX treatment prevented protein oxidation and nitric oxide production and restored superoxide dismutase activity. NBIX treatment did not change most parameters assessed, and at the highest dose, it increased LDL cholesterol and triglycerides levels and showed prooxidant action (increased protein oxidation and nitric oxide levels). These findings suggested that BIX could have an antihyperglycemic effect, improve lipid profiles, and protect against damage induced by oxidative stress in the diabetic state. Because NBIX is a water-soluble analog of BIX, we propose that lipophilicity is crucial for the protective effect of annatto carotenoids against streptozotocin-induced diabetes.
authors.affiliation: Graduate Program on Pharmacology, Center of Health Sciences, Federal University of Santa Maria, 97105-900 Santa Maria, RS, Brazil ; Integrated Center for Laboratory Analysis Development (NIDAL), Department of Alimentary Technology and Science, Center of Rural Sciences, Federal University of Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Miguel
authors.identifier: 0000-0002-8919-0351
authors.initials: M
authors.lastname: Roehrs
authors.affiliation: Integrated Center for Laboratory Analysis Development (NIDAL), Department of Alimentary Technology and Science, Center of Rural Sciences, Federal University of Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Cassieli Gehlen
authors.identifier: 0000-0002-4735-9083
authors.initials: CG
authors.lastname: Figueiredo
authors.affiliation: Integrated Center for Laboratory Analysis Development (NIDAL), Department of Alimentary Technology and Science, Center of Rural Sciences, Federal University of Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Mariane Magalhães
authors.initials: MM
authors.lastname: Zanchi
authors.affiliation: Graduate Program on Pharmacology, Center of Health Sciences, Federal University of Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Guilherme Vargas
authors.initials: GV
authors.lastname: Bochi
authors.affiliation: Graduate Program on Pharmacology, Center of Health Sciences, Federal University of Santa Maria, 97105-900 Santa Maria, RS, Brazil ; Department of Clinical and Toxicological Analysis, Center of Health Sciences, Federal University of Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Rafael Noal
authors.identifier: 0000-0003-4379-4229
authors.initials: RN
authors.lastname: Moresco
authors.affiliation: Graduate Program on Pharmacology, Center of Health Sciences, Federal University of Santa Maria, 97105-900 Santa Maria, RS, Brazil ; Integrated Center for Laboratory Analysis Development (NIDAL), Department of Alimentary Technology and Science, Center of Rural Sciences, Federal University of Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Andréia
authors.identifier: 0000-0002-5793-9671
authors.initials: A
authors.lastname: Quatrin
authors.affiliation: Graduate Program on Pharmacology, Center of Health Sciences, Federal University of Santa Maria, 97105-900 Santa Maria, RS, Brazil ; Integrated Center for Laboratory Analysis Development (NIDAL), Department of Alimentary Technology and Science, Center of Rural Sciences, Federal University of Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Somacal
authors.affiliation: Integrated Center for Laboratory Analysis Development (NIDAL), Department of Alimentary Technology and Science, Center of Rural Sciences, Federal University of Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Lisiane
authors.identifier: 0000-0002-4733-6383
authors.initials: L
authors.lastname: Conte
authors.affiliation: Graduate Program on Pharmacology, Center of Health Sciences, Federal University of Santa Maria, 97105-900 Santa Maria, RS, Brazil ; Integrated Center for Laboratory Analysis Development (NIDAL), Department of Alimentary Technology and Science, Center of Rural Sciences, Federal University of Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Tatiana
authors.identifier: 0000-0003-0168-3416
authors.initials: T
authors.lastname: Emanuelli