A high oleic sunflower oil fatty acid esters of plant sterols mixed with dietary diacylglycerol reduces plasma insulin and body fat accumulation in Psammomys obesus.

BACKGROUND: Metabolic syndrome is associated with subsequent development of cardiovascular diseases and type 2 diabetes. It is characterized by reduced response to insulin, central obesity, and dyslipidemia. Intake of plant sterols (PS) has been shown to confer a healthier lipid profile and ameliorate cardiovascular disease risk factors in experimental animals and humans. In this study we used an animal model of type 2 diabetes to assess the effects of a preparation of PS esterified to high oleic sunflower oil fatty acids mixed with dietary diacylglycerol (PS-HOSO) on diabetic related metabolic parameters. Psammomys obesus (P. obesus) were fed high energy (HE) diet supplemented by either PS-HOSO or control oil. Following 4.5 weeks of intervention, animals were divided into fasting and non-fasting modes prior to outcome measurements. Glucose and insulin levels as well as blood lipid profile, body weight, and fat accumulation were evaluated in fasting and non-fasting modes. RESULTS: P. obesus fed with a HE diet displayed a characteristic heterogeneity in their blood glucose and insulin levels with a subset group displaying type 2 diabetes symptoms. PS-HOSO treatment significantly reduced total cholesterol (24%, P < 0.001) and non-HDL cholesterol (34%, P < 0.01) compared to the control diet. Among fasting animals, body weight at end point and epididymal fat-to-liver weight ratio were significantly (P < 0.05 each) reduced (7% and 16%, respectively) compared to controls. Interestingly, fasting blood glucose levels were similar between groups, whereas plasma insulin level at end point was 44% lower in the PS-HOSO group compared to control group (P < 0.0001) CONCLUSION: PS-HOSO supplementation to diabetes-prone gerbils counteracts the increase in body weight and epididymal fat accumulation, and also results in a drop in circulating insulin levels. These effects are pointing out that PS-HOSO may serve as a functional ingredient for metabolic syndrome or diabetic sufferers, which not only influences body weight, but also prevents or reverses insulin resistance and hyperlipidemia.

Pregnancy outcome in the Psammomys obesus gerbil on low- and high-energy diets.

INTRODUCTION: Diabetes mellitus (DM) during pregnancy is associated with an increased risk for poor reproduction and a high rate of congenital malformations. The gerbil Psammomys obesus is a unique model for nutritionally induced Type 2 DM (T2DM) that enabled us to study the outcome of uncontrolled T2DM during pregnancy. METHODS: Female Psammomys on low-energy (LE) or high energy (HE) diet were studied. The blood glucose levels and weights of pregnant animals were determined. The offspring from the different groups were followed-up to weaning. RESULTS: Most of the HE-diet animals were diabetic (77%). There were no differences in the pregnancy rates in animals on both diets (32.7% in HE vs. 38.3% in LE). Pregnancy of the HE-diet group was longer than the LE-diet group (26.7 vs. 26.1 days), and litter average was reduced (2.7 vs. 3.0). At birth, the offspring of the HE-diet dams weighed less (5.2 vs. 7.2 g) and had smaller crown rump length (4.0 vs. 4.6 cm) These offspring also presented a 1-3 days delay in neuro-developmental parameters (first turn over, hair appearance, eye-opening and response to noise). However, from the fourth week of life they became diabetic, and from the third week they weighed more than the LE offspring. CONCLUSION: HE-diet caused diabetes, maternal complications and altered reproduction in Psammomys animals. The offspring of diabetic Psammomys presented birth weight and length changes as well as developmental delay.

The response to sex steroid hormones and vitamin D of cultured osteoblasts derived from ovariectomized mice with and without 17beta-estradiol pretreatment.

This study investigated whether 17beta-estradiol (E2) may have different effects on osteoblasts derived from estrogen-deficient ovariectomized (OVX) mice compared to sham-operated normal animals. We studied the specific effects of 17beta-estradiol on the differentiation and function of cultured osteoblasts derived from these groups of animals, with or without estrogen replacement treatment. One-month-old mice were ovariectomized or sham-operated, and treated (every second day) for 4 weeks with 0.5 mg/kg 17beta-estradiol or with vehicle alone. At the end of the experiment, bones were removed for primary osteoblast cultures or for morphological and chemical evaluation. In cells from untreated OVX animals, alkaline phosphatase (ALP) specific activity was reduced, while collagen production and mineralization were unchanged when compared to cells from controls. In vivo estrogen pretreatment of the OVX mice elevated ALP activity and mineralization of the cells, while collagen production was reduced. The addition of 17beta-estradiol to the culture medium increased ALP activity, collagen production, and mineralization by all cultured osteoblasts, except in those derived from sham-operated, estrogen-pretreated mice, where these features remained unchanged. Osteocalcin production was unchanged. Addition of testosterone or 1,25(OH)2D3 to the culture medium induced changes that differed among the groups depending on the source of the cultured cells. It seems that ovariectomy in mice prior to culture affected the phenotype of the cultured osteoblasts and their response to estradiol, testosterone, and 1,25(OH)2D3, depending on whether animals were pretreated with estradiol or not. These results imply that the animal's estrogen status prior to culture can influence the response to estrogens; this finding may have important implications for hormone replacement therapy (HRT) in postmenopausal women.