Experimental Hypercholesterolemia Research Articles

Accelerated Extracellular Nucleotide Metabolism in Brain Microvascular Endothelial Cells in Experimental Hypercholesterolemia

Hypercholesterolemia affects the neurovascular unit, including the cerebral blood vessel endothelium. Operation of this system, especially in the context of energy metabolism, is controlled by extracellular concentration of purines, regulated by ecto-enzymes, such as e-NTPDase-1/CD39, ecto-5′-NT/CD73, and eADA. We hypothesize that hypercholesterolemia, via modulation of the activity of nucleotide metabolism-regulating ecto-enzymes, deteriorates glycolytic efficiency and energy metabolism of endothelial cells, which may potentially contribute to development of neurodegenerative processes. We aimed to determine the effect of hypercholesterolemia on the concentration of purine nucleotides, glycolytic activity, and activity of ecto-enzymes in the murine brain microvascular endothelial cells (mBMECs). We used 3-month-old male LDLR−/−/Apo E−/− double knockout mice to model hypercholesterolemia and atherosclerosis. The age-matched wild-type C57/BL6 mice were a control group. The intracellular concentration of ATP and NAD and extracellular activity of the ecto-enzymes were measured by HPLC. The glycolytic function of mBMECs was assessed by means of the extracellular acidification rate (ECAR) using the glycolysis stress test. The results showed an increased activity of ecto-5′-NT and eADA in mBMECs of the hypercholesterolemic mice, but no differences in intracellular concentration of ATP, NAD, and ECAR between the hypercholesterolemic and control groups. The changed activity of ecto-5′-NT and eADA leads to increased purine nucleotides turnover and a shift in their concentration balance towards adenosine and inosine in the extracellular space. However, no changes in the energetic metabolism of the mBMECs are reported. Our results confirm the influence of hypercholesterolemia on regulation of purine nucleotides metabolism, which may impair the function of the cerebral vascular endothelium.Graphical abstractThe effect of hypercholesterolemia on the murine brain microvascular endothelial cells (mBMECs). An increased activity of ecto-5′-NT and eADA in mBMECs of the LDLR−/−/Apo E−/− mice leads to a shift in the concentration balance towards adenosine and inosine in the extracellular space with no differences in intracellular concentration of ATP. Figure was created with Biorender.com.

Dynamics of the Nitrergic System in Experimental Hypercholesterolemia

Hypercholesterolemia and atherosclerosis are still the main cause of mortality in Central Asia. Study of the molecular mechanisms of endothelial dysfunction with changes in the nitroergic system in experimental hypercholesterolemia. The experiments were carried out on 28 Chinchilla rabbits with an average weight of 2.5-3.0 kg. The action of drugs was studied in dynamics: the initial 3-month condition and after one month of drug administration. The results obtained were compared with those of the control and intact groups. The activity of the enzyme nitrate reductase in the blood serum on the 30th day of the introduction of exogenous cholesterol increases only 1.15 times, then on the 60th and 90th days of the introduction - 1.3 and 1.76 times. In the dynamics of hypercholesterolemia and atherosclerosis in the blood serum, there are noticeable disturbances in the NO-ergic system.

Investigation of the effects of atorvastatin and Lactobacillus acidophilus on some hormones and oxidative stress in experimental hypercholesterolemia

AimThe investigation of serum leptin, ghrelin, insulin, seratonin hormones, NO, total oxidant/antioxidant status and brain cannaboid 1 receptor protein and apoptotic cell levels in atorvastatin and Lactobacillus acidophilus administrated experimental hypercholesterolemia was aimed in the project. MethodsIn the study, 5 experimental groups were formed. Group 1 was fed with standard rat chow, and Group 2 was fed with 2% cholesterol added standard rat chow for 8 weeks. Group 3 was fed with 2% cholesterol feed and received atorvastatin (20 mg/kg/day) for the last 4 weeks. Group 4 was given L. acidophilus (2 ×108 cfu/kg/day). Group 5 was given atorvastatin and L. acidophilus probiotic in the last 4 weeks of the experiment period. After the experimental period, blood samples were taken from each rat. Rats were sacrificed and brain tissues were taken for analyzes. In sera samples, leptin, ghrelin, insulin, serotonin hormones and NO levels were measured with ELISA. In brain samples, cannabinoid 1 receptor proteins and apoptosis levels were measured by ELISA. Total oxidant and antioxidant levels were investigated with using Rel Assay Kits. ResultsThe addition of cholesterol to feeds increased the levels of serum cholesterol, insulin and leptin levels; on the other hand, reduced the levels of serotonin and ghrelin. In hypercholesterolemia, total oxidant and NO levels were increased, and total antioxidant levels were decreased. ConclusionThe results showed that administrations of L. acidophilus and atorvastatin might be recommended for treatment of hypercholesterolemia.

INFLUENCE OF CHOLESTEROL ENRICHED DIET ON GENES EXPRESSION ENCODING BONE MORPHOGENETIC PROTEIN-2 AND OSTEOCALCIN IN MOUSE MANDIBLE.

The aim: To evaluate the mRNA expression of the key regulators of osteogenesis - osteocalcin and BMP-2 in the mouse embryos mandible (17th day of pregnancy) which were borne by females on high-cholesterol diet for 30 days before fertilization and throughout pregnancy. Materials and methods: Experimental hypercholesterolemia (2%) was simulated by adding Cholesterol to the diet for 60 days. In experiment were used 40 mature female white mice that were randomly divided to control and experimental groups. The control group were fed with standard chow diet, the experimental group with diet with cholesterol enriched diet (with addition of 2 grams of Cholesterol per 100 grams of standard chow). The mandibles of mouse embryos (E-17) were examined by using molecular genetic methods. Results: In control group the relative level of BMP-2 mRNA / actin mRNA was 27.0«2.82, the relative level of and osteocalcin mRNA / actin mRNA was 30.5«6,28. In the jaws of animals in the experimental group with cholesterol enriched diet, the expression relative level of BMP-2 was 30.9«5.81 that is by 14,4% higher than in control group. Therefore, the expression level of оsteocalcin, on the contrary, decreased by 22.3% and was 23.7+5.31. Conclusions: Our study report influence of the cholesterol enriched diet (2%) on mRNA expression of BMP-2 and osteocalcin encoding genes. The embryos from mouse on cholesterol enriched diet (2%) had increased level of BMP-2 gene expression, however significantly decreased level of osteocalcin gene expression.

Metabolic and structural changes in the myocardium of rats with hypercholesterolemia after prolonged administration of simvastatin

BACKGROUND: The use of statins in cardiovascular pathologies in some cases is associated with the risk of developing statin-induced myopathy, the mechanisms of which are not fully understood. Only a few studies of molecular changes in the myocardium in statin myopathy are presented in the literature. However, the myocardium, as a type of muscle tissue, can also be involved in the pathological process. In this regard, in our opinion, it is advisable to analyze the biochemical changes in the rat myocardium against the background of the use of simvastatin.
 AIM: To analysis of the dynamics of changes in the end products of glycolysis and the isoform composition of the giant protein titin in the heart muscle in animals with experimental hypercholesterolemia on the background of long-term administration of simvastatin.
 MATERIALS AND METHODS: The study was carried out on outbred male rats divided into 3 groups: control group (35 individuals) intact animals; comparison group (35 animals) intact animals treated with simvastatin for two months; experimental group divided into: subgroup 1 (35 individuals) animals with induced alimentary hypercholesterolemia, subgroup 2 (35 individuals) animals with induced alimentary hypercholesterolemia, which were administered simvastatin for two months. During the experiment, the content of the giant sarcomere protein titin, as well as changes in the concentration of pyruvate and lactic acid in the myocardium of the animals of the studied groups were studied.
 RESULTS: In animals with a physiological course of metabolic processes, the administration of simvastatin caused the accumulation of lactic acid in the myocardium. Under conditions of alimentary hypercholesterolemia under the influence of simvastatin, a decrease in the elevated level of pyruvate and lactic acid was revealed, which is obviously due to a decrease in pathobiochemical shifts in energy metabolism. The determination of the isoform composition of titin made it possible to establish that the administration of simvastatin under conditions of alimentary hypercholesterolemia contributed to the appearance of early dystrophic changes in the myocardium, which is consistent with the results of earlier studies of impaired myocardial contractile activity under the influence of statins.
 CONCLUSIONS: The results obtained indicate the need for a more thorough study of statins in terms of their safe use in patients with cardiovascular pathology.

Effect of diet-induced hypercholesterolemia on metabolic processes in the heart, liver, and pancreas in rats

Aim. To analyze the biochemical changes in the cells of the heart muscle, liver and pancreas, as well as to establish their pathogenetic significance in diet-induced experimental hypercholesterolemia.
 Methods. The study was conducted on 65 outbred male rats. During the experiment, the animals were divided into groups: the first (control, n=30) animals that were kept on a general vivarium diet; the second (experimental, n=35) animals with diet-induced hypercholesterolemia for three months by keeping on a special diet. At the end of the experiment, the concentrations of pyruvic acid, lactate, reduced glutathione, the activity of glutathione reductase, and glutathione peroxidase were determined in the tissues by using biochemical methods. The Student's t-test was used for the experimental data of the samples after normality testing.
 Results. The analysis of energy metabolism indicators in animals with hypercholesterolemia relative to the control group revealed a lower level of pyruvic acid in the heart muscle (0.290.03 mmol/mg protein; p 0.05) and liver (0.250.02 mmol/mg protein; p 0.001). A significantly higher lactate level was recorded in all tissues, most pronounced in the liver (6.730.6 mmol/mg protein; p 0.001). The results obtained indicate the predominance of the anaerobic glycolysis in the tissues and the accumulation of incomplete-oxidation products. The study of the key glutathione-linked enzymes in animals with hypercholesterolemia relative to the control showed a lower activity of glutathione reductase in the pancreas 0.520.05 mmol/mg protein/min (p 0.001), as well as its higher activity in the liver 0.2970.03 mmol/mg protein/min (p 0.001) and heart 13.581.4 mmol/mg protein/min (p 0.001). The activity of glutathione peroxidase and reduced glutathione in all organs remained practically unchanged, or the differences were insignificant. This trend indicates a violation of the antioxidant defense system and oxidative stress.
 Conclusion. Changes in the metabolic link of adaptive-compensatory responses in the cells of the heart muscle, liver, and, most pronounced in the pancreas, indicate the role of the pancreas as a target organ in the pathogenesis of diet-induced hypercholesterolemia.

Efficacy of Chocolate on Hypercholestrolemic Rats

Chocolate comprises number of raw and processed foods produced from the seed of the tropical cocoa tree. Chocolate is produced from cocoa mass added with sugar and cocoa butter. Chocolate has been promoted for its health benefits, as it seems to possess substantial amount of antioxidant that reduces the formation of free radicals. Researchers concluded that chocolate containing higher amount of cocoa have higher procyanidins content, so higher antioxidant capacities. Evidence suggests that regular consumption of cocoa products containing flavanol may reduce the risk of cardiovascular diseases. Thus, the present study was carried out to assess the effect of chocolate on lipid profile of hypercholesterolemic rats. The rats were grouped under three categories; Triton 400mg was injected to experimental rats to make it hypercholesterolemia. Based on the objectives a cocoa rich chocolate sample was developed using cocoa seed, cocoa butter, sugar and lecithin and the experimental hypercholesterolemia rates were feed with chocolate sample for duration of 20 days, and the lipid profile was analysed at initial and at final days of supplementation. During the period of supplementation, the Cholesterol and LDL level were decreased gradually which may be due to the supplementation of chocolate. Significant reduction was observed at 5% level. Thus, it was concluded that in the present study there was a significant effect on lipid profile of chocolate supplemented with hypercholesterolemic rats.

EFFECT OF DIHYDROQUERCETIN ON HYPERCHOLESTERINEMIA

The article is devoted to the study of the natural flavonoid dihydroquercetin (0.0125 g per 1 kg of animal weight in daily diet) effect on the development of experimental hypercholesterolemia in rabbits “Chinchilla”. Dihydroquercetin was obtained by extraction with ethyl acetate from crushed Siberian larch (Larix sibirica Ledeb., 1833) wood chips with several cycles of subsequent recrystallization from water (purity 90–92%). Hypercholesterolemia was induced by an atherogenic diet: 0.35 g of cholesterol in the diet per 1 kg of animal weight. The duration of the experiment was two months. It was shown that the introduction of dihydroquercetin into the daily diet of rabbits with alimentary hypercholesterolemia does not significantly affect the level of total cholesterol, as well as the concentration of its atherogenic fractions of LDL and VLDL in the blood. Nevertheless, it was found that, in comparison with the model of hypercholesterolemia, this natural compound contributes to the maintenance of an increased concentration of HDL cholesterol, which has an antiatherogenic effect. Accordingly, this reduces the value of the blood atherogenic coefficient, which reflects the degree of risk of atherosclerosis. In general, the data obtained predetermines the need for further research using various approaches to modeling hypercholesterolemia and atherosclerosis in experimental animals.

4263 The cardioprotective effects of ramipril during the course of experimental hypercholesterolemia in rabbits

4263 The cardioprotective effects of ramipril during the course of experimental hypercholesterolemia in rabbits

Myocardial Oxygen Consumption In Rabbits Treated With Ramipril During The Course Of Experimental Hypercholesterolemia

Background and Aims: Angiotensin converting enzyme inhibitors (ACE-I) are widely used in therapy of CVD, due to their cardioprotective and vasculoprotective effects. However, the consensus of the effect of ACE-I on the control of myocardial oxygen consumption (MVO2) under the condition of endothelial dysfunction has not been reached yet. The aims of the study were to determine the influence of ramipril on MVO2 and oxidative stress biomarkers during the course of experimental hypercholesterolemia.

Antihypercholesterolemic, antioxidative and anti-inflammatory potential of an extract of the plant Tabernaemontana divaricata in experimental rats fed an atherogenic diet

Abstract The present study highlights the putative anti-atherogenic, antioxidative and anti-inflammatory potential of Tabernaemontana divaricata extract (ethanolic) in a Wistar rat model of experimental hypercholesterolemia. The rats were divided into Group I (control), Group II (atherogenic diet-fed, saline-treated) and Group III (atherogenic diet-fed, T. divaricata extract-treated [200 mg/kg/b.wt]). The levels of lipid profile parameters (total cholesterol, triglycerides, high-density, low-density and very low-density lipoprotein cholesterol and atherogenic index) and C-reactive protein (CRP) were investigated in serum samples. The levels of enzymatic and non-enzymatic antioxidants, malondialdehyde and nitric oxide (NO), and gene and protein expression levels of CRP, inducible nitric oxide synthase (iNOS) and tumor necrosis factor-α (TNF-α) and gene expression levels of interleukin-1β (IL-1β) were determined in liver tissue samples. Rats of Group II showed significantly heightened mean concentrations of CRP, and lower mean levels of lipid profile parameters, except high-density lipoprotein cholesterol, than control rats; Rats of Group II also exhibited significantly lower mean activities/levels of enzymatic and non-enzymatic antioxidants and heightened mean malondialdehyde and NO content compared to control animals. However, in Group III rats, the values were significantly improved, in contrast to Group II rats. Significantly higher gene expression of IL-1β and significantly higher gene and protein expression of CRP, iNOS and TNF-α occurred in liver samples from hypercholesterolemic rats compared to control rats. In liver samples from Group III rats, gene and protein expression was not markedly elevated. The T. divaricata extract thus exhibited anti-atherogenic potential in hypercholesterolemic Wistar rats due to its hypocholesterolemic, antioxidant and anti-inflammatory effects.

PECULIARITIES OF MORPHOLOGICAL CHANGES OF ENDOTHELIOCYTES AND REMODELING OF THE ARTERIES UNDER THE EXPERIMENTAL HYPERCHOLESTEROLEMIA

Introduction: Under the conditions of experimental hypercholesterolemia, endothelial dysfunction develops with the morphological marker which is an increase in the number of blood-circulating desquamated endothelial cells (DEC), but this situation needs to be clarified in the development of this pathology in the age aspect. The aim: To find out the features of remodeling of endothelial cells and arteries of the hind limbs in the rats of pre-repopductive and reproductive age with experimental hypercholesterolemia. Materials and methods: The experimental group consisted of 16 animals with biochemically confirmed hypercholesterolemia, which were divided into 2 groups: group 1 - 8 animals, aged 2-3 months, weighing 150-170 grams and group 2 - 8 rats aged from 11 to 11 months weighing 230-250 gram. The control group consisted of rats of the same age of 8 animals in each. Results: Hypercholesterolemia causes damage to the vascular endothelium of the arteries, which is characterized by an increase in the number of desquamated endothelial cells in the peripheral blood. The most circulating blood in desquamated endothelial cells was detected in 45 days of study in animals of reproductive age, where the number of desquamated endothelial cells increased by 2.56 times, and in animals of pre-reproductive age - 2.35 times. Morphological changes were characterized by thickening of the intima of the arteries of the femur, knee and tibia due to swelling of the endothelial cells, their desquamation and proliferative changes in places of preserved vascular endothelium. In response to the deposition of lipids and PAS-positive substrates, cellular reactions appeared as weak lymphocytic infiltration. In addition to hyperlastosis, fragmentation of elastic fibers was revealed. Correlation of intima contributed to the narrowing of vascular lumen. Lipids, xanthoma cells and sour mucopolysaccharides were accumulated in the inner membrane of the arteries. In addition to lymphocytic infiltrates, the amount of collagen fibers in adventitia increased. Conclusions: Under conditions of hypercholesterolemia the number of desquamated endothelial cells in the blood increases, and arterial remodeling is characterized by manifestations of hypertrophic-neoplastic remodeling in rats of pre-reproductive age, and in reproductive animals there were sclerotic and inflammatory changes.

ВЛИЯНИЕ ВЕЩЕСТВА НА ОСНОВЕ ФИБРОИНА ШЕЛКА НА ПОКАЗАТЕЛИ ЛИПИДНОГО ОБМЕНА У КРЫС С ЭКСПЕРИМЕНТАЛЬНОЙ ГИПЕРХОЛЕСТЕРИНЕМИЕЙ


 
 
 The article presents the results of a study on the effectiveness of a substance based on silk fibroin, obtained at the Institute of Chemistry and Polymer Physics of the Academy of Sciences of the Republic of Uzbekistan, in eliminating disorders of lipid metabolism in the body. In experiments in rats with experimental hypercholesterolemia, the substance was found to have a cholesterol-lowering property, which is manifested by a decrease in cholesterol level both in blood and in tissues. Studies on the mechanism of the hypocholesterolemic effect of the studied substance have shown its effects on the enterohepatic pathway of bile acids, which makes it possible to classify this substance as a group of bile acid sequestrants.
 
 

Short Oxoproline-Containing Peptides as Potential Pharmacological Means of Hypolipidemic and Antithrombotic Actions

The search and research of pharmacological agents that could combine lipid-lowering and antithrombotic effects on the human organism are one of the most urgent and important tasks of modern biological and medical research. The unique effects of the regulatory peptides of the oxoproline series (5-охо-Pro- His-Pro-NH2, 5-oxo-Pro-Trp-Pro, and 5-oxo-Pro-Arg-Pro or Pyr-His-Pro-NH2, Pyr-Trp-Pro, and Pyr- Arg-Pro) synthesized by the methods of classical peptide chemistry have been found in animals with experimental hypercholesterolemia. Repeated intranasal administration of these peptides to animals with developed hypercholesterolemia increased their anticoagulant, fibrinolytic and antiplatelet potential of the blood and simultaneously lowered increased concentrations of total cholesterol, low-density lipoprotein cholesterol, and triglycerides. In addition, they promoted normalization of blood glucose. A week after the last administration of these peptides, the hypocholesterolemic, normoglycemic and anticoagulant effects persisted. The relationship between the structure of the oxoproline-containing peptides and their functional properties is discussed. It is concluded that further studies of oxoproline-containing peptides are promising in the context of development of pharmacological agents, combining the antithrombotic activity with the improvement of lipid metabolism in the body.

AGE-RELATED MORPHOMETRIC CHARACTERISTICS OF REMODELING OF ARTERIAL BED OF HIND LIMBS IN WHITE RATS WITH EXPERIMENTAL HYPERCHOLESTEROLEMIA

Background. The human organism is constantly affected by metabolic risk factors. All of them for a long time are asymptomatic and often form in early childhood long before clinical manifestations. However, morphogenesis and morphofunctional features of age-related structural changes in blood vessels of different sites are poorly studied.Objective. To evaluate the morphometric characteristics of arterial bed remodeling of hind limbs in white rats of PRA and RA with experimentally induced hypercholesterolemia.Methods. The tissues biopsies from femoral, knee and shin areas were studied by means of histological and morphometric methods.Results. Experimental hypercholesterolemia caused remodeling of vessels with increasing thickness of medial and endothelial layer of vessels in the investigated parts of the rats’ body. In this case, the external diameter of vessels increased only in femoral area in the reproductive group of rats. In the group of pre-productive animals, the external diameter of the vessels studied was more or less unaffected. Thus, increased thickness of intima and media led to a decrease in arteries capacity. The depth of vascular lesions and the decrease in functional capacity of blood vessels were directly proportional to the duration of the experiment. In the group of reproductive rats, the changes in vascular bed were more evident.Conclusions. Objective study of the processes allows providing a scientific basis for further research and understanding of the pathomorphism of vascular diseases in humans.

Prebiotic and Synbiotic Modifications of Beta Oxidation and Lipogenic Gene Expression after Experimental Hypercholesterolemia in Rat Liver.

Background and aims: Non-alcoholic fatty liver disease (NAFLD) is characterized by the presence of fat in hepatocytes because of decreased β-oxidation and increased lipogenesis. Prebiotics, probiotics, and synbiotic have modulatory effects on intestinal microbiota and may influence the gut-liver axis. Our aim was to evaluate the effects of prebiotic, probiotics, and synbiotic on liver histopathology and gene expression related to β-oxidation and lipogenesis after hypercholesterolemia.Methods: Wistar male adult rats (n = 40) were submitted to hypercholesterolemic conditions (HPC) (60 days). On Day 30 of HPC, rats were subdivided in 5 groups: negative control (NC): without HPC + Gv (distilled water); positive control (PC): with HPC + Gv (distilled water); prebiotic (PRE): HPC + Gv with prebiotic (Fiber FOS®); probiotic (PRO): HPC + Gv with probiotic strains Gv (Probiatop®); and synbiotic (SYN): HPC + Gv with synbiotic (Simbioflora®). All rats were sacrificed on Day 30 post-treatment. Blood was collected to verify total serum cholesterol, and liver tissue was sampled to verify histopathological changes and gene expression. Gene expression related to ß-oxidation (PPAR-α and CPT-1) and lipogenesis (SREBP-1c, FAS and ME) was evaluated in liver tissue using RT-qPCR.Results: PC had higher cholesterol levels when compared to NC. PRE and SYN rats had lower cholesterol levels than PC. PC rats showed more histopathological changes than NC rats; PRE and SYN rats showed fewer alterations than PC rats. PPAR-α was expressed at higher levels in SYN and PC rats compared with PRE and PRO rats. CPT-1 expression was similar in all groups. SREBP-1c was expressed at higher levels in PC rats compared with NC rats; levels were lower in SYN rats compared with PRO rats; levels were lower in PRE rats compared with PC and PRO rats. FAS was expressed at lower levels in PRE rats compared with SYN rats. ME expression was lower in PC rats compared with NC rats.Conclusion: Prebiotic and synbiotic supplementation improve hepatic alterations related to hypercholesterolemia. These changes appear to be mediated by altered expression of genes related to β-oxidation and lipogenesis.

Comparative evaluation of the effects of ezetimibe and atorvastatin on serum lipid profile changes in experimental hypercholesterolemia in cat

Hyperlipidemia is defined as an elevation of one or more of the serum lipids, including cholesterol or triglycerides, or both of them. The aim of the present survey was comparative evaluation of the effects of ezetimibe and atorvastatin on serum lipid profile changes in cats. Twenty healthy male cats were randomly divided into four equal groups. Cholesterol powder (4 g/kg for 10 days) was administered to group A (control), atorvastatin (5 mg/kg) to group B, ezetimibe (2.5 mg/kg) to group C, and a combination of atorvastatin and ezetimibe to group D. Blood samples were collected four times, then serum triglycerides, total cholesterol, HDL-C, LDL-C, VLDL-C, BUN, creatinine, and uric acid levels were measured using standard commercial kits. Groups B and C and especially group D were more effective in lowering serum lipid profile compared with group A (p = 0.001). The highest reduction of total cholesterol, triglyceride, LDL-C, VLDL-C, and NEFA was in group D and the highest reduction of HDL-C was observed in group B (p = 0.001). BUN, creatinine, and uric acid levels were at normal range without any clinical findings. In conclusion, ezetimibe was more effective than atorvastatin in reducing cholesterol.

Effects of Karela (Bitter Melon; Momordica charantia) on genes of lipids and carbohydrates metabolism in experimental hypercholesterolemia: biochemical, molecular and histopathological study

BackgroundHypercholesterolemia is a serious diseases associated with type-2 diabetes, atherosclerosis, cardiovascular disorders and liver diseases. Humans seek for safe herbal medication such as karela (Momordica charantia/bitter melon) to treat such disorders to avoid side effect of pharmacotherapies widely used.MethodsForty male Wistar rats were divided into four equal groups; control group with free access to food and water, cholesterol administered group (40 mg/kg BW orally); karela administered group (5 g /kg BW orally) and mixture of cholesterol and karela. The treatments continued for 10 weeks. Karela was given for hypercholesterolemic rats after 6 weeks of cholesterol administration. Serum, liver and epididymal adipose tissues were taken for biochemical, histopathological and genetic assessments.ResultsHypercholesterolemia induced a decrease in serum superoxide dismutase (SOD), catalase, reduced glutathione (GSH) and an increase in malondialdehyde (MDA) levels that were ameliorated by karela administration. Hypercholesterolemia up regulated antioxidants mRNA expression and altered the expression of carbohydrate metabolism genes. In parallel, hypercholesterolemic groups showed significant changes in the expression of PPAR-alpha and gamma, lipolysis, lipogenesis and cholesterol metabolism such as carnitine palmitoyltransferase-1 (CPT-1). Acyl CoA oxidase (ACO), fatty acids synthase (FAS), sterol responsible element binding protein-1c (SREBP1c), 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoAR) and cholesterol 7α-hydroxylase (CYP7A1) at hepatic and adipose tissue levels. Interestingly, Karela ameliorated all altered genes confirming its hypocholesterolemic effect. Histopathological and immunohistochemical findings revealed that hypercholesterolemia induced hepatic tissue changes compared with control. These changes include cholesterol clefts, necrosis, karyolysis and sever congestion of portal blood vessel. Caspase-3 immunoreactivity showed positive expression in hepatic cells of hypercholesterolemic rats compared to control. All were counteracted and normalized after Karela administration to hypercholesterolemic group.ConclusionCurrent findings confirmed that karela is a potential supplement useful in treatment of hypercholesterolemia and its associated disorders and is good for human health.

Вплив корвітину на ліпідний спектр жовчі щурів з експериментальною гіперхолестеринемією

У роботі досліджено ліпідний спектр жовчі самців щурів із доксициклін-індукованою гіперхолестеринемією та при застосуванні корвітину в умовах експериментальної гіперхолестеринемії. Дослідження впливу корвітину (1 мг/кг, 7 днів) на ліпідний спектр жовчі в умовах доксициклінового навантаження (540 мг/кг, 5 днів) проводили на щурах-самцях масою 185–230 г (n=29). У гострих дослідах у тварин, що перебували під тіопенталовим наркозом (70 мг/кг), отримували жовч, у якій методом тонкошарової хроматографії, модифікованим у нашій лабораторії, визначали вміст фосфоліпідів, холестеролу та його етерів, вільних жирних кислот, тригліцеридів. Виявлено, що при доксициклін-індукованій гіперхолестеринемії в крові самців щурів зростає рівень загального холестеролу крові та зменшується концентрація вільного холестеролу жовчі. Корвітин усуває гіперхолестеринемічний ефект доксициклінового навантаження, знижуючи рівень загального холестеролу в крові й викликає істотне збільшення концентрації етерів холестеролу в жовчі самців щурів. В умовах доксициклін-індукованої гіперхолестеринемії в жовчі самців щурів знижується концентрація фосфоліпідів, а при застосуванні корвітину у тварин, що зазнали попереднього доксициклінового навантаження, уміст фосфоліпідів у печінковому секреті наближається до контрольних значень. Концентрація вільних жирних кислот у жовчі щурів із доксициклін-індукованою гіперхолестеринемією та при застосуванні корвітину виявляється істотно вищою, ніж у тварин контрольної групи.

黑豆黑米茯苓配方的降脂作用与成分分析

目的：观察黑豆黑米茯苓原粮配方的降脂效果与成分分析。方法：分光光度法测定降脂粉剂的成分。高血脂患者30例，服用上述降脂配方20天，检测使用降脂粉剂前后的血脂变化。实验性雌性小白鼠30只，分对照组(C)、高脂饲料喂养组(HFD)、高脂饲料加降脂粉剂喂养组(LLP)一周后，检测血脂的变化。结果：降脂粉剂异黄酮含量为3.8% (3.8% ± 0.5%)；高血脂患者的降脂有效率达96.7%，甘油三酯(TG)、总胆固醇(TC)有显著降低(p < 0.05)，低密度脂蛋白(LDL)轻度降低，高密度脂蛋白(HDL)轻度升高。高脂饲料加降脂粉剂喂养组小白鼠的TC比高脂饲料喂养组显著降低(p < 0.01)。结论：黑豆黑米茯苓配方降脂粉剂富含异黄酮，对高血脂患者和实验性高胆固醇小白鼠有明确的降脂效果，可以安全有效地用于降血脂治疗，其有效成分值得进一步研究。 Objective: To observe the lipid-lowering effect of black beans and black rice poria formula and analysis its effective components. Methods: Components analysis was done by spectrophotometry. 30 cases of patients with high blood lipids, taking the lipid-lowering formula powder for 20 days, with the detection of blood lipid changes before and after lipid-lowering powder taking. 30 experimental mouse, were randomly divided into control (C) group, high fat diet (HFD) group, high fat diet plus lipid-lowering powder (LLP) feeding group for a week, detecting the change of blood lipid. Result: The content of isoflavone was 3.8% (3.8% ± 0.5%) in the formula. In patients with hyperlipidemia, the total effective rate of the lipid-lowering powder was 96.7%, triglyceride (TG), total cholesterol (TC) decreased significantly (p < 0.05), low density lipoprotein (LDL) slightly decreased, high density lipoprotein (HDL) slightly elevated compared to that of the control. In mice experiments, TC of the high fat diet plus lipid-lowering food feeding group was significantly decreased (p < 0.01) compared with high fat diet group. Conclusion: The black bean black rice poria powder formulation is rich in isoflavone, has lipid-lowering effects in patients with hyperlipemia and experimental hypercholesterolemia mice, which can be safely and effectively used for lipid-lowering treatment. The effective components in the formula need further elucidation.