Effects of short- and long-term treatments of sardine (Sardina pilchardus) protein hydrolysates on blood lipid concentrations and antioxidant status, in rats fed cholesterol-enriched diets

Hypercholesterolemia is a major risk factor of cardiovascular diseases (CVD). A limited number of experimental studies have shown that sardine protein hydrolysates (SPH) could be a very useful natural compound to prevent hy-percholesterolemia by both improving the lipoprotein profile and modula-ting oxidative stress. In the present study, the effect of short and long term treatments with SPH were examined on serum lipid contents, lipid peroxida-tion and antioxidant enzymes activities in rats fed cholesterol-enriched diet. At day 0, rats were divided into five groups. The group of day 0 was the stan-dard group, and the four remaining groups were divided into two parts of two groups each consuming for 14 or 28 days an hypercholesterolemic diet, and treated (HC-SPH) or not (HC) by gavage with SPH. Compared with day 0, serum TC contents were increased at day 14 and remained unchanged at day 28 in HC-SPH group. These values were decreased in HC-SPH versus HC. Liver and heart TBARS concentrations were increased at day 14 then diminished at day 28 in HC-SPH group. Liver and heart SOD and CAT activities were decrea-sed at short term then remained unchanged at long term in HC-SPH group. In addition, these activities were enhanced in HC-SPH versus HC. In conclusion, these results indicate the potential effects of short and long term treatments of SPH to improved cholesterolemia and reduced radical attack in rats fed high-cholesterol diets.

Abstract P278: Coronary Microvascular Dysfunction Is Associated With Augumented Autophagy-lysosomal Signaling In Mice With Hypercholesterolemic Diet

Accumulating evidence indicates coronary microvascular dysfunction (CMD) contributes to myocardial ischemia with or without epicardial coronary atherosclerosis. However, it remains unknown which molecular pathway is associated with compromised coronary microvascular function preceding the development of myocardial ischemic injury. Recent studies suggest that autophagy-lysosomal signaling pathway is involved in the regulation of endothelial homeostasis under various metabolic stresses such as hypercholesterolemia. In this study, the early effects of hypercholesterolemia on the function and integrity of coronary microcirculation were studied in mice and the expressions of various molecular markers of autophagy-lysosome pathway were also determined in the coronary circulation. Mice were fed a hypercholesterolemic paigen diet (PD) for 8 weeks and coronary microvascular function was determined by measuring coronary flow reserve (CFR) under baseline and hyperemic conditions. The effects of PD on cardiac function or remodeling were also assessed by echocardiograph or immunohistochemistry studies. In PD-fed hypercholesterolemic mice, hyperemia-induced increase in CFR was significantly abrogated compared to that in normal chow diet-fed (ND) control mice (PD: 1.583±0.4193 vs. ND: 3.087±0.586) (n=7-8). The diet-induced hypercholesterolemia did not lead to cardiac dysfunction (EF%, PD: 59.870±7.549 vs ND: 64.040±9.088) or hypertrophic remodeling (LV mass (mg), PD: 92.240±14.410 vs ND: 96.030±25.07). PD increased mild cardiac inflammation and fibrosis but did not resulted in rarefaction in the myocardium. In small coronary arterial wall, PD induced endothelial inflammasome activation and inflammation, which was accompanied by upregulation of autophagy and lysosome signaling pathway. In conclusion, hypercholesterolemic diet induces CMD without alterations in cardiac function or remodeling. These alterations in coronary microvascular function represent the early effects of diet-induced hypercholesterolemia, which may be ameliorated with activation of autophagy and lysosome signaling pathways.

Effect of Aspirin on Experimental Atherosclerosis in Rabbits Submitted to Hypercholesterolemic Diet

Aspirin, besides its antithrombotic activity, has also been quoted for protective effect reducing new coronary lesions. Objective: Considering the growing interest in the study of drugs that prevent the progression of atherosclerotic lesion, the objective of this study was to determine the effect of aspirin in experimental atherogenesis induced in rabbits fed with cholesterol rich diets. Method: Thirty adult, New Zealand white male rabbits, with 3.4 kg of body weight were submitted to a 1.5% cholesterol-rich-diet for 9 weeks. Aspirin was triturated, mixed with chloroform and incorporated to the normal chow. The drug was given to the rabbits every day in portions of 20 g of chow with 100 mg of aspirin. The rabbits were divided in 3 groups as follows: A) Cholesterol-rich-diet (n=10); B) Cholesterol-rich-diet plus aspirin (n=10) and C) Normal chow (n=10). Blood samples were collected before starting the diet, at 5 weeks and at sacrifice (9 weeks) for determination of total cholesterol, triglycerides, enzymes and hematological tests. After sacrifice, staining of the aorta was done by Sudan III for visualization of sudanophillic plaques. The percentual of aorta couvered with lipidic deposits were determined by computerized planimetry. Results: Total cholesterol (mg/dl) was per group: A- TO=52, T5=424 and T9=1.483; B- TO=32, T5=755 and T9=1.436; C- TO=41, T5=22 and T9=27. Planimetry data did not differ among groups A (23.3%) and B (27.3%). Scanning microscopy – the interpretation of the document images in three groups showed insignificant platelet deposition in all aortic segments both in groups B and C. Conclusion: This experiment enhances the theoretic basis for the protective effect of aspirin as an antiaggregant factor in the experimental aortic atherosclerotic lesion.

Beneficial Role of Mushroom in Recovering Complications of Hypercholesterolemia

Mushrooms are considered as a valuable source of important nutrients having hepatoprotective and anti-hyperlipidemic actions. Present experimental research was done to explore the beneficial role of mushroom on health in hypercholesterolemia. Total thirty Swiss albino mice were taken and randomly divided into three groups: control A, group B and group C. Each group consisted of ten mice. The control A group was fed with normal mice pellet and fresh water. Group B was fed with hypercholesterolemic diet and group C was supplied hypercholesterolemic diet with mushroom powder (500g/kg/mice body weight) for 60 days. After the experimental tenure, mice of each group were sacrificed ethically and the samples (liver and blood) were collected for gross, histological study and lipid profile analysis. Increased liver weight, pale and hemorrhagic liver in gross observation along with some histological changes including dilation and congestion of central and portal vein, fat accumulation in hepatocyte and marked lymphocytic infiltration were found in group B, while mushroom supplementation recovered this gross and histological changes and reduced liver weight in group C. Just mild congestion and dilation was in the portal vein of group C. In lipid profile analysis, total cholesterol (TC), triglyceride (TG) and low density lipoprotein (LDL) level significantly reduced respectively by 10%, 38% and 17% in group C than group B. High density lipoprotein (HDL) level also significantly increased by 20% in group C compared to group B. Therefore, it can be concluded that mushrooms might have potentially beneficial actions in recovering of some complications in hypercholesterolemia.

Effects of high rosuvastatin doses on hepatocyte mitochondria of hypercholesterolemic mice

Statins are the cornerstone of therapy for individuals with hyperlipidemia. The aim of this study was to analyze the undesirable effects of mild, moderate and high doses of rosuvastatin in CD-1 male mice who received a cholesterol-rich diet, focusing on the morphological and functional changes on hepatocyte mitochondria. In a mouse model we studied the combined administration of a cholesterol-rich diet along with mild and moderate doses of rosuvastatin (1, 2.5 or 5 mg/kg/day) during several days. After the animals were sacrificed, liver mitochondria were isolated for microscopic studies and to analyze the respiratory function. The respiratory control (state-3/state-4) was evaluated in mice who received high doses of rosuvastatin. Rosuvastatin doses higher than 20 mg/kg/day induced premature death in mice with a hypercholesterolemic diet, but not in mice with a cholesterol-free diet. Doses from 2.5 to 5 mg/kg/day also induced morphological and functional alterations in mitochondria but these hypercholesterolemic animals survived longer. Giving 1 mg/kg/day, which is close to the maximal therapeutic dose for humans, did not affect mitochondrial architecture or respiratory function after two months of treatment. We analyzed the effect of rosuvastatin on hepatic tissue because it is where statins are mainly accumulated and it is the main site of endogenous cholesterol synthesis. Our results contribute to understand the side effects of rosuvastatin in hypercholesterolemic mice, effects that could also affect humans who are intolerant to statins.

Protective Effect of Yerba Mate on Rats Fed on High Cholesterol Diet- An Experimental Study

Introduction: Yerba mate tea, a concoction made from the leaf extracts of the tree Ilex paraguariensis, is a broadly consumed non alcoholic beverage in Latin America which is gaining rapid introduction into the world market. Aim: To explore the influence of Yerba Mate (Ilex paraguariensis) powder and beverage on induced hypercholesterolemic rats. Materials and Methods: The experiment was carried out for a duration of one year from February 2020 to January 2021 at University of Ha’il, Ha’il, Saudi Arabia, on 48 male Albino rats divided into six subgroups; Control (-) group: group fed a basal diet. Rats in the other five groups fed on basal diet containing 2% cholesterol+0.25% bile salts for two weeks to induce hypercholesterolemia. Then those rats were subdivided into: control(+)group:groupthatremainedhypercholesterolemic.Yerba Mate Powdered (YMP) 15% group: fed on hypercholesterolemic diet+YMP15%; YMP 10% Group: fed on hypercholesterolemic diet+YMP10%; Yerba Mate Beverage (YMB) 15% group: fed on a hypercholesterolemic diet+YMB 15%; and YMB 10% group: fed on a hypercholesterolemic diet+YMB 10%. Results: It was found that, with increasing the amount of Yerba Mate powder or beverage, the total cholesterol, triglycerides, Low Density Lipoprotein-Cholesterol (LDL-C), Aspartate Transaminase (ALT), Alanine Transaminase (ALT), urea nitrogen and glucose levels decreased significantly (p<0.05) and the best result belonged to the group of rats that fed on Yerba Mate 15% powder. Conclusion: It can be concluded that, supplementation with high percentage of Yerba Mate powder (15%) exerts a positive impact on the lipid profile and other biochemical parameters in hypercholesterolemic rats.

Potential benefits of antihypertensive therapy in NAFLD: results from an experimental model

Background and introduction Non-alcoholic fatty liver disease (NAFLD) is considered as the most frequent cause of chronic hepatic disease in adults. It is strictly correlated with insulin resistance. The renin-angiotensin system (RAS) has been correlated to the whole basic physiopathogenic mechanism of NAFLD in experimental models. Systemic arterial hypertension has been suggested to be associated with NAFLD in approximately 40% of the cases, and NAFLD has been independently associated with an increased risk of arterial hypertension in observational studies. Therefore, we can infer that treating arterial hypertension in NAFLD carriers will often be necessary and that the potential beneficial effects of the antihypertensive might, in this context, influence the choice of the respective drug. Purpose We aimed to evaluate the effects of the renin-angiotensin system blockade with angiotensin-converting enzyme inhibitor ramipril and angiotensin 2 type 1 receptor antagonist olmesartan, both used preventively, in NAFLD induced in rabbits fed a hypercholesterolemic diet and compared the results between the groups. Methods Forty-one rabbits were divided into four groups (normal, control, olmesartan and ramipril). The control, olmesartan and ramipril group were fed a hypercholesterolemic diet. Animals from olmesartan group were treated with olmesartan 1mg/kg/day and animals from ramipril group with ramipril 0.35 mg/kg/day. At the end of the 8th week, all rabbits underwent segmental hepatic resection and were euthanised. Blood samples were collected to determine glucose, creatinine, total cholesterol, triglycerides, high-density lipoprotein cholesterol, and aminotransferase levels at baseline and euthanasia. Haematoxylin and eosin and Gomori trichrome stained slides were analysed based on the histological scoring system for NAFLD. Results The comparison between two groups (olmesartan with placebo and ramipril with placebo) showed that olmesartan and ramipril significantly diminished the development of steatosis (p=0.015, p=0.032), lobular inflammation (p&lt;0.001, p=0.006), hepatocellular ballooning (p&lt;0.001, p=0.023) and fibrosis (p=0.001, p=0.02). Based on NAFLD activity score, olmesartan and ramipril significantly reduced the development of nonalcoholic steatohepatitis (p&lt;0.001, p=0.003). The comparison between olmesartan and ramipril showed that results were similar in all histological parameters evaluated (p=1, p=0.454, p=0.454, p=0.195, p=0.078). Conclusion(s) The preventive use of olmesartan and ramipril attenuates similarly, the development of hepatic steatosis, lobular inflammation, hepatocellular ballooning and fibrosis in hypercholesterolemic rabbits and based on NAFLD activity score both significantly reduced the development of nonalcoholic steatohepatitis. Funding Acknowledgement Type of funding source: None

High Cholesterol Diet Exacerbates Blood-Brain Barrier Disruption in LDLr–/– Mice: Impact on Cognitive Function

Background: Evidence has revealed an association between familial hypercholesterolemia and cognitive impairment. In this regard, a connection between cognitive deficits and hippocampal blood-brain barrier (BBB) breakdown was found in low-density lipoprotein receptor knockout mice (LDLr–/–), a mouse model of familial hypercholesterolemia. Objective: Herein we investigated the impact of a hypercholesterolemic diet on cognition and BBB function in C57BL/6 wild-type and LDLr–/–mice. Methods: Animals were fed with normal or high cholesterol diets for 30 days. Thus, wild-type and LDLr–/–mice were submitted to memory paradigms. Additionally, BBB integrity was evaluated in the mice’s prefrontal cortices and hippocampi. Results: A tenfold elevation in plasma cholesterol levels of LDLr–/–mice was observed after a hypercholesterolemic diet, while in wild-type mice, the hypercholesterolemic diet exposure increased plasma cholesterol levels only moderately and did not induce cognitive impairment. LDLr–/–mice presented memory impairment regardless of the diet. We observed BBB disruption as an increased permeability to sodium fluorescein in the prefrontal cortices and hippocampi and a decrease on hippocampal claudin-5 and occludin mRNA levels in both wild-type and LDLr–/–mice treated with a hypercholesterolemic diet. The LDLr–/–mice fed with a regular diet already presented BBB dysfunction. The BBB-increased leakage in the hippocampi of LDLr–/–mice was related to high microvessel content and intense astrogliosis, which did not occur in the control mice. Conclusion: Therefore, LDLr–/–mice seem to be more susceptible to cognitive impairments and BBB damage induced by exposure to a high cholesterol diet. Finally, BBB disruption appears to be a relevant event in hypercholesterolemia-induced brain alterations.

Detection of myenteric plexus neurons in dyslipidemic, smoking, and diabetic rats treated with carqueja

The plant species Baccharis trimera presents antioxidants that may have neuroprotective effects on the neurons of the myenteric plexus. Thus, the aim of the present study was to investigate possible quantitative alterations in the myenteric plexus neurons and in the glycemic and lipid profile of 25 rats with 90 days old, exposed to smoking, a hypercholesterolemic diet, and with diabetes mellitus induced by streptozotocin during four weeks, and then treated with different doses of carqueja extract for two weeks. The myenteric plexus neurons were stained with basic Giemsa and using the NADPH-diaphorase histochemistry protocol. In the study conditions, there was a significant reduction in the number of total neurons between the groups treated with carqueja and the positive control, stained with the Giemsa. In contrast, there was no significant difference in the number of neurons of the inhibitory subpopulation between the groups treated with carqueja and the negative control, evidenced by the NADPH-diaphorase histochemistry. At the 30mg/kg dose there was a reduction in the cholesterol and triglyceride levels. Based on the results, Baccharis trimera presented no neuroprotective or hypoglycemic effect, although the nitric subpopulation has proven more resistant to the deleterious effects of diabetes, smoking, and the hypercholesterolemic diet.

Early myocardial injury biomarkers in diabetic hyperlipidemic rats: Impact of 10-dehydrogingerdione and vitamin D3

Hyperlipidemia represents a major risk factor for cardiovascular diseases leading to myocardial injury. The present study aimed to illustrate the myocardial injury induced in a diabetic hyperlipidemic rat model and the effect of vitamin D3, 10-DHGD intake either individually or in combination form. Male albino rats were selected for the study, received alloxan, hypercholesterolemic diet, and categorized into four groups. The first one (DHC), received hypercholesterolemic diet only and referred to as control. The remaining groups (2, 3, 4) received vitamin D3, 10-DHGD, and combination of both, respectively. Certain biomarkers that were selected for MI evaluation included blood glucose, lipogram pattern, Copeptin, C-reactive protein, myeloperoxidase, heart fatty acid-binding protein, and histopathological changes in myocardium and aorta. Vitamin D3 and 10-DHGD intake induced significant hypoglycemic, hypolipidemic effects, decreased inflammation, and MI biomarkers. Decreased myocardial vacuoles, foam cells, and intimal lesions were also observed compared to DHC. Their combination intake induced more marked reduction in all biomarkers and showed a histopathological pattern similar to normal features of myocardium and aorta. Our findings suggest the therapeutic roles of vitamin D3, 10-DHGD, and their combination against myocardial injury in diabetic hyperlipidemic rats. Impact statement Hyperlipidemia represents a major risk factor for cardiovascular diseases leading to myocardial injury (MI). The present study aimed to illustrate the pattern of myocardial injury induced in diabetic hyperlipidemic rat model and the effect of vitamin D3, 10-dehydrogingerdione (10-DHGD) intake either individually or in combination form.