Effect of different commercial fat sources on brain, liver and blood lipid profiles of rats in growth phase

The possible antioxidative effects of ketogenic diet by modifying brain klotho expression: a rat model study

Objectives: The ketogenic diet (KD) has long been used as an alternative nonpharmacological therapy to manage pharmacoresistant epilepsy. The anticonvulsant mechanisms of KD have yet to be fully elucidated. The present study explored whether a KD could exert antioxidative effects by altering brain Klotho (Kl) gene expression.Methods: Thirty male rats were divided into three groups: the normal diet (ND) group received standard rat chow; the calorie-restricted diet (CRD) group was maintained at 90% of the calculated energy need; and the KD group received a diet composed of 8% protein, 2% carbohydrates, and 90% fat (per calorie macronutrient). The levels of β-hydroxybutyrate (BHB) in the serum, Kl gene expression in the brain, and Kl protein, malondialdehyde (MDA), and protein carbonyl (PC) levels in the serum and brain were evaluated by standard methods.Results: The serum BHB levels in the KD group were significantly greater than those in the ND and CRD groups (p < 0.001). The Kl expression in the brain was significantly greater in the KD group than in the ND group (p = 0.028). The brain MDA levels in the KD group were significantly lower than those in the ND group (p = 0.006). Elevated BHB was positively correlated with brain Kl expression (r = 0.668, p < 0.001). The brain MDA levels were negatively correlated with brain Kl expression (r = -0.531, p = 0.003) and serum BHB levels (r = 0.472, p = 0.020).Discussion: KD might exert antioxidative effects by increasing BHB and upregulating Kl in the brain. This could be considered a possible anticonvulsant mechanism of KD.

Evaluation of the toxicology, anti-lipase, and antioxidant effects of Callistemon citrinus in rats fed with a high fat-fructose diet

CONTEXT

Callistemon citrinus Skeels (Myrtaceae) exhibits many biological activities.

OBJECTIVE

This study analyzes for the first time, the toxicity, obesogenic, and antioxidant effects of C. citrinus in rats fed with a high fat-fructose diet (HFFD).

MATERIALS AND METHODS

Four studies using male Wistar rats were conducted: (a) 7 groups (n = 3): control (corn oil) and ethanol extract of C. citrinus leaf (single oral dose at 100-4000 mg/kg) for acute toxicity; (b) 2 groups (n = 8): control (corn oil) and C. citrinus (1000 mg/kg/day) for 28 days for subacute toxicity; (c) 3 groups (n = 4) with single oral dose of lipid emulsion: control (lipid emulsion), C. citrinus and orlistat (250 and 50 mg/kg, respectively) for lipid absorption; (d) 4 groups (n = 6): control (normal diet) and 3 groups fed with HFFD: HFFD only, C. citrinus and simvastatin (oral dose 250 and 3 mg/kg, respectively) for 13 weeks. Antioxidant enzymes and biomarkers were evaluated and inhibition of pancreatic lipase was determined in vitro.

RESULTS

Toxicological studies of C. citrinus showed no differences in biochemical parameters and lethal dose (LD₅₀) was higher than 4000 mg/kg. C. citrinus inhibited pancreatic lipase activity, with IC₅₀ of 392.00 µg/mL, and decreased lipid absorption by 70%. Additionally, it reduced the body weight 22%, restored the activities of antioxidant enzymes, and reduced the biomarkers of oxidative stress.

CONCLUSIONS

Callistemon citrinus showed an effect against oxidative stress by reducing biomarkers and induced antioxidant system, without toxic effects.

Non-Alcoholic Fatty Liver Disease, and the Underlying Altered Fatty Acid Metabolism, Reveals Brain Hypoperfusion and Contributes to the Cognitive Decline in APP/PS1 Mice

Non-alcoholic fatty liver disease (NAFLD), the leading cause of chronic liver disease, is associated with cognitive decline in middle-aged adults, but the mechanisms underlying this association are not clear. We hypothesized that NAFLD would unveil the appearance of brain hypoperfusion in association with altered plasma and brain lipid metabolism. To test our hypothesis, amyloid precursor protein/presenilin-1 (APP/PS1) transgenic mice were fed a standard diet or a high-fat, cholesterol and cholate diet, inducing NAFLD without obesity and hyperglycemia. The diet-induced NAFLD disturbed monounsaturated and polyunsaturated fatty acid (MUFAs, PUFAs) metabolism in the plasma, liver, and brain, and particularly reduced n-3 PUFAs levels. These alterations in lipid homeostasis were associated in the brain with an increased expression of Tnfα, Cox2, p21, and Nox2, reminiscent of brain inflammation, senescence, and oxidative stress. In addition, compared to wild-type (WT) mice, while brain perfusion was similar in APP/PS1 mice fed with a chow diet, NAFLD in APP/PS1 mice reveals cerebral hypoperfusion and furthered cognitive decline. NAFLD reduced plasma β₄₀- and β₄₂-amyloid levels and altered hepatic but not brain expression of genes involved in β-amyloid peptide production and clearance. Altogether, our results suggest that in a mouse model of Alzheimer disease (AD) diet-induced NAFLD contributes to the development and progression of brain abnormalities through unbalanced brain MUFAs and PUFAs metabolism and cerebral hypoperfusion, irrespective of brain amyloid pathology that may ultimately contribute to the pathogenesis of AD.