Capacidade antioxidante total de óleos vegetais comestíveis: determinantes químicos e sua relação com a qualidade dos óleos

Chemical Composition and Antifungal In Vitro and In Silico, Antioxidant, and Anticholinesterase Activities of Extracts and Constituents of Ouratea fieldingiana (DC.) Baill

Ouratea fieldingiana (Gardner) Engl is popularly used for wound healing. This study describes the main chemical compounds present in extracts of O. fieldingiana and evaluates their biological potential by investigating antifungal, antioxidant, and anticholinesterase activities. The action mechanism of main antifungal compound was investigated by molecular docking using the enzyme sterol 14-α demethylase, CYP51, required for ergosterol biosynthesis. The seeds and leaves were extracted with ethanol in a Soxhlet apparatus and by maceration, respectively. Both extracts were subjected to silica gel column chromatography for isolation of main constituents, followed by purification in sephadex. The structures of compounds were established by ¹H and ¹³C-NMR spectroscopy and identified by comparison with literature data as amentoflavone and kaempferol 3-O-rutinoside, respectively. The antioxidant activities of the extracts were determined by the DPPH and ABTS free radical inhibition methods. In general, the extracts with the highest antioxidant activity corresponded to those with higher content of phenolic compounds and flavonoids. The ethanol extracts and two isolated compounds presented relevant antifungal activity against several Candida strains. The in silico findings revealed that the compound amentoflavone coupled with the CYP450 protein due to the low energy stabilization (-9.39 kcal/mol), indicating a possible mechanism of action by inhibition of the ergosterol biosynthesis of Candida fungi.

Elevated Serum Retinol and Low Beta-Carotene but not Alpha-Tocopherol Concentrations Are Associated with Dyslipidemia in Brazilian Adolescents

The purpose of this study was to investigate the status of retinol, beta-carotene, and alpha-tocopherol serum concentrations in adolescents with dyslipidemia. A case series dyslipidemia study was conducted, with an attached control group, including 104 adolescents of public schools in Recife during the months of March/April 2013. Retinol, beta-carotene and alpha-tocopherol serum concentrations were analysed by high efficiency liquid chromatography. Sociodemographic, anthropometric, clinical and biochemical variables were analysed. Dyslipidemic adolescents had high serum concentrations of both retinol (p=0.007) and beta-carotene/apolipoprotein A-I ratio (p=0.034); they also had low concentrations of beta-carotene/total cholesterol (p<0.0001) and beta-carotene/apolipoprotein B ratios (p=0.033) when compared to the controls. The alpha-tocopherol serum status was not associated with dyslipidemia. Overweight, abdominal obesity, lipid profile markers, and systolic and diastolic blood pressures were more prevalent in dyslipidemic adolescents. The findings show an association between vitamin A and dyslipidemia in adolescents. However, additional investigations of this risk group are necessary to clarify the mechanisms of action of this nutrient in the pathogenesis of this syndrome, aiming at reducing cardiometabolic risks as of earlier ages.