Metabolic status in growing rats fed isocaloric diets with increased carbohydrate-to-fat ratio

Dietary supplementation of defatted kenaf (Hibiscus cannabinus L.) seed meal and its phenolics-saponins rich extract effectively attenuates diet-induced hypercholesterolemia in rats

Kenaf is one of the important commercial fiber crops worldwide and defatted kenaf seed meal (DKSM) is a secondary by-product from the kenaf industry. Thus, efforts to turn this low-cost agricultural waste into value-added functional food ingredients will definitely bring advantageous impacts to the community health, environment and economy. The present study was aimed to investigate the cardioprotective properties of DKSM and its phenolics-saponins rich extract (PSRE) in diet-induced hypercholesterolemic rat model. Hypercholesterolemia was induced in Sprague-Dawley rats via atherogenic diet feeding and dietary interventions were conducted by incorporating DKSM (15% and 30%) and equivalent levels of PSRE (2.3% and 4.6%, respectively, equivalent to the total content of phenolics and saponins in DKSM groups) into the atherogenic diets. After 10 weeks of DKSM and PSRE supplementation, the hepatosomatic index, hepatosteatosis, serum lipid profile, Castelli risk indexes as well as hepatic and renal functions of hypercholesterolemic rats were significantly improved (p < 0.05). Besides, the levels of hepatic Hmgcr and serum Pcsk9 were lowered, along with transcriptional upregulations of hepatic Cyp7a1, Abca1, Lcat, ApoA2 and ApoE (p < 0.05). The gene expression of hepatic Ldlr was marginally enhanced by DKSM supplementation (p > 0.05), but superiorly upregulated by PSRE (p < 0.05). The combined results showed that hypercholesterolemia and the atherogenic risk in rats were effectively attenuated by DKSM and PSRE supplementation, possibly via modulations of multiple vital processes in hepatic cholesterol metabolism. Furthermore, phenolics and saponins may be the bioactives conferring DKSM and PSRE with their anti-hypercholesterolemic properties. In conclusion, DKSM and PSRE are prospective cardioprotective functional food ingredients for hypercholesterolemic individuals.

Effects of Maternal Isocaloric Diet Containing Different Amounts of Soy Oil and Extra Virgin Olive Oil on Weight, Serum Glucose, and Lipid Profile of Female Mice Offspring

BACKGROUND

Health status of offspring is programmed by maternal diet throughout gestation and lactation. The present study investigates the lasting effects of maternal supplementation with different amounts of soy oil or extra virgin olive oil (EVOO) on weight and biochemical parameters during gestation and lactation of female mice offspring.

METHODS

Eight weeks old female C57BL/6 mice (n=40) were assigned through simple randomization into four isocaloric dietary groups (16% of calories as soy oil (LSO) or EVOO (LOO) and 45% of calories as soy oil (HSO) or EVOO (HOO)) during three weeks of gestation and lactation. After weaning (at 3 weeks), all offspring received a diet containing 16% of calories as soy oil and were sacrificed at 6 weeks. Two-way ANOVA was used to adjust for confounding variables and repeated measures test for weight gain trend. Statistical analyses were performed with the IBM SPSS package.

RESULTS

At birth and adolescence, the weight of offspring was significantly higher in the soy oil than the olive oil groups (P<0.001 and P<0.001, respectively). Adolescence weight was significantly higher in the offspring born to mothers fed with 16% oil than those with 45% oil (P=0.001). Serum glucose, triglyceride and total cholesterol were significantly higher in the LSO than LOO (P<0.001, P<0.001 and P<0.001), LSO than HSO (P<0.001, P=0.03 and P<0.001), and LOO than HOO (P<0.001, P<0.001 and P<0.001) dietary groups, respectively. Serum triglyceride and total cholesterol were significantly higher in the offspring of HSO than HOO fed mothers (P<0.001 and P<0.001, respectively).

CONCLUSION

A maternal diet containing EVOO has better effects on birth weight, as well as weight and serum biochemical parameters in offspring at adolescence.

Comparison of maternal isocaloric high carbohydrate and high fat diets on osteogenic and adipogenic genes expression in adolescent mice offspring

Background

Maternal high fat/high calorie diet leads to adiposity and bone fracture in offspring. However, the effects of macronutrient distribution in maternal isocaloric diet have not been studied. The present study was designed to test the hypothesis that maternal isocaloric pair-fed high-carbohydrate diet will increase osteoblastic and decrease osteoclastic and adipogenic gene expression compared with high-fat diet in adolescent mice offspring.

Methods

Virgin female C57BL/6 mice were impregnated and fed either the AIN 93G isocaloric pair-fed high-carbohydrate (LF-HCD) or a high fat (HF-LCD) diet from the time of vaginal plug confirmation until the offspring was weaned.

Results

After adjusting for the sex of offspring, osteoprotegrin (OPG) and Ctnnb1 (beta-catenin) genes expression were significantly reduced by 98 % and 97 % in the bone of offspring born from the HF-LCD compared with the LF-HCD-fed mothers (p < 0.001 and p < 0.001, respectively). Peroxisome proliferator-activated receptor gamma-2 (PPAR γ2) gene expression in the bone of offspring born from the HF-LCD was 7.1-folds higher than the LF-HCD-fed mothers (p = 0.004). In the retroperitoneal fat mass of offspring born from HF-LCD, AdipoQ and LPL genes expression were respectively up-regulated 15.8 and 4.2-folds compared with the LF-HCD-fed mothers (p < 0.001 and p = 0.03, respectively).

Conclusions

Maternal isocaloric pair-fed high-carbohydrate diet enhances osteoblastogenesis and inhibits adipogenesis compared with high-fat diet in adolescent mice offspring.

[High-fat diets and body composition over two generations. An experimental study]

INTRODUCTION AND OBJECTIVE

Despite recent findings reported on the nutritional factors that induce epigenetic changes, little information is available at early ages. This study analyzed in an experimental model, over two generations, potential changes in body composition and potential expression of epigenetic changes as the result of the intake of isoenergetic diets with different fat levels.

MATERIALS AND METHODS

At weaning, Wistar female rats were divided into two groups that were fed either a control diet (fat=7% w/w) or a high-fat diet (15% w/w). Rats were mated at 70 days (M(1)) and their pups (P(1)) were the first generation; P(1) rats were mated at 70 days (M(2)) and their pups (P(2)) represented the second generation. At weaning, mothers and pups (M(1), M(2) and P(1), P(2)) were measured body weight (W) and composition (% body fat, %BF), and total skeleton bone mineral content (BMC), expressed as %BMC, using chemical and DXA methods respectively.

RESULTS

At weaning, high-fat diet groups M(2) and P(2) showed significant increases in W and %BF (p<0.05); increased %BF values were already found in the M(1) and P(1) groups (p<0.001). By contrast, %BMC significantly decreased in M(2) and P(2) rats (p<0.001).

CONCLUSION

This study demonstrates the need to review certain eating habits to avoid perpetuation of unhealthy patterns generation after generation.

Fructose and NAFLD: metabolic implications and models of induction in rats

PURPOSE: The increase in fructose consumption is paralleled by a higher incidence of obesity worldwide. This monosaccharide is linked to metabolic syndrome, being associated with hypertriglyceridemia, hypertension, insulin resistance and diabetes mellitus. It is metabolized principally in the liver, where it can be converted into fatty acids, which are stored in the form of triglycerides leading to NAFLD. Several models of NAFLD use diets high in simple carbohydrates. Thus, this study aimed to describe the major metabolic changes caused by excessive consumption of fructose in humans and animals and to present liver abnormalities resulting from high intakes of fructose in different periods of consumption and experimental designs in Wistar rats. METHODS: Two groups of rats were fasted for 48 hours and reefed for 24 or 48 hours with a diet containing 63% fructose. Another group of rats was fed an diet with 63% fructose for 90 days. RESULTS: Refeeding for 24 hours caused accumulation of large amounts of fat, compromising 100% of the hepatocytes. The amount of liver fat in animals refed for 48 hours decreased, remaining mostly in zone 2 (medium-zonal). In liver plates of Wistar rats fed 63% fructose for 45, 60 and 90 days it's possible to see that there is an increase in hepatocytes with fat accumulation according to the increased time; hepatic steatosis, however, is mild, compromising about 20% of the hepatocytes. CONCLUSIONS: Fructose is highly lipogenic, however the induction of chronic models in NAFLD requires long periods of treatment. The acute supply for 24 or 48 hours, fasted rats can cause big changes, liver steatosis with macrovesicular in all lobular zones.

Nutrition and growth

Nutrition plays a fundamental role in determining the growth of individuals. An appropriate growth progression is considered a harbinger of adequate nutrient intake and good health. On the other hand growth deceleration with or without short stature may indicate inadequate nutrition, even when there is no body weight deficit for height. Nutritional growth retardation (NGR) is most prevalent in populations at risk of poverty. However in affluent communities patients with NGR are often referred to the specialist because of short stature and delayed sexual development. The diagnosis may be overlooked and/or be established after exhaustive evaluations, if the pattern of weight progression over time is not considered. Patients with so-called idiopathic short stature may present diminished nutrient intake and decreased IGF-I levels, however their nutritional status and body weight progression patterns are usually not addressed by pediatric endocrinologists. NGR patients may cease to gain appropriate weight and fail to grow in height, even without exhibiting body weight deficits for height. They adapt to decreased nutrient intake by decreasing growth progression and thereby achieve equilibrium by decreasing the nutrient demands. This occurs by diminishing their metabolic rates and erythrocyte Na+, K+- ATPase activity, however they may not present alterations in other clinical biochemical markers of malnutrition. Therefore accurate weights and heights plotted on the growth chart over time are necessary to detect NGR. Nutritional rehabilitation is accompanied with catch up growth, though it may be difficult to change the dietary habits of adolescents who exhibit NGR.

Energy expenditures & physical activity in rats with chronic suboptimal nutrition

BACKGROUND

Sub-optimally nourished rats show reduced growth, biochemical and physiological changes. However, no one has assessed metabolic rate adaptations in rats subjected to chronic suboptimal nutrition (CSN). In this study energy expenditure (EE; kcal/100 g body weight) and physical activity (PA; oscillations in weight/min/kg body weight) were assessed in rats subjected to three levels of CSN.

RESULTS

Body weight gain was diminished (76.7 +/- 12.0 and 61.6 +/- 11.0 g) in rats fed 70 and 60% of the ad-libitum fed controls which gained more weight (148.5 +/- 32.3 g). The rats fed 80% gained weight similarly to controls (136.3 +/- 10.5 g). Percent Fat-free body mass was reduced (143.8 +/- 8.7 and 142.0 +/- 7.6 g) in rats fed 70 and 60% of ad-libitum, but not in those fed 80% (200.8 +/- 17.5 g) as compared with controls (201.6 +/- 33.4 g). Body fat (g) decreased in rats fed 80% (19.7 +/- 5.3), 70% (15.3 +/- 3.5) and 60% (9.6 +/- 2.7) of ad-libitum in comparison to controls (26.0 +/- 6.7). EE and PA were also altered by CSN. The control rats increased their EE and PA during the dark periods by 1.4 +/- 0.8 and 1.7 +/- 1.1 respectively, as compared with light the period; whereas CSN rats fed 80 and 70% of ad-libitum energy intake had reduced EE and PA during the dark periods as compared with the light period EE(7.5 +/- 1.4 and 7.8 +/- 0.6 vs. 9.0 +/- 1.2 and 9.7 +/- 0.8; p < 0.05, respectively), PA(3.1 +/- 0.8 and 1.6 +/- 0.4 vs. 4.1 +/- 0.9 and 2.4 +/- 0.4; p < 0.05) and RQ (0.87 +/- 0.04 and 0.85 +/- 0.5; vs. 0.95 +/- 0.03 and 0.91 +/- 0.05 p < 0.05). In contrast, both light (7.1 +/- 1.4) and dark period (6.2 +/- 1.0) EE and PA (3.4 +/- 0.9 and 2.5 +/- 0.5 respectively) were reduced in rats fed 60% of ad-libitum energy intake.

CONCLUSION

CSN rats adapt to mild energy restriction by reducing body fat, EE and PA mainly during the dark period while growth proceeds and lean body mass is preserved. At higher levels of energy restrictions there is decreased growth, body fat and lean mass. Moreover EE and PA are also reduced during both light and dark periods.