Triglyceride Lowering Activity Research Articles

Characterization of Green and Yellow Papaya (Carica papaya) for Anti-Diabetic Activity in Liver and Myoblast Cells and Wound-Healing Activity in Fibroblast Cells.

Obesity and diabetes, often characterized as "metabolic syndrome", have been recognized as two of the most important public health issues worldwide. The objective of the present research was to evaluate green and yellow papaya for anti-oxidation and anti-diabetic properties. Leaves, skin, pulp, and seed samples from papayas were freeze-dried and then extracted in water or 80% methanol. The extracts were used to determine total polyphenolic content and anti-oxidation activities, and to determine biological activities, including glucose uptake, Glut-2 expression, triglyceride reduction, and wound-healing activity. Our data demonstrated that methanol and water extracts of green and yellow papaya have similar concentrations of polyphenols in skin (10-20 mg/g dry powder), leaf (25-30 mg/g dry powder), and pulp (1-3 mg/g dry powder) fractions. However, both methanol and water extracts of seeds from yellow papaya have substantially higher concentrations of polyphenols compared to green papaya. Both water and methanol extracts of yellow papaya exhibited higher anti-oxidation activity compared to green papaya in skin (50-60%), pulp (200-300%), and seeds (10-800%). Old leaves also showed greater anti-oxidation activity (30-40%) compared to new leaves. Pulp extracts from both yellow and green papaya stimulated greater glucose uptake, but only pulp from green papaya stimulated glucose uptake in muscle cells. Similarly, pulp extract stimulated glucose transporter Glut-2 expression in liver cells. The skin, pulp, and seeds of green or yellow papaya showed triglyceride-lowering activity in liver cells by 60-80%, but samples taken from yellow papaya had a more potent effect. Seeds from both green and yellow papaya significantly stimulated the migration of fibroblasts in the wounded area by 2-2.5-fold compared to the untreated control. Consistent with these data, seeds from both green and yellow papaya also significantly stimulated collagen synthesis in fibroblast cells by almost 3-fold. In conclusion, our data indicate that different parts of papaya produce stimulatory effects on glucose uptake, Glut-2 expression, TG reduction, and wound-healing activities. This study concludes that different parts of the papaya can be beneficial for preventing diabetes and diabetes-related wound healing.

Uji Aktivitas Teh Celup Fraksi Metanol Rimpang Temu Mangga (Curcuma mangga Valeton and Zijp) sebagai Antihiperlipidemia

The high number of deaths from cardiovascular disease in the world makes cardiovascular drugs, such as antihyperlipidemic or dyslipidemia often used by patients in the whole world. Statins are first-line drugs that are often used, but have various side effects, such as myalgia, rhabdomyolysis, and are considered to trigger diabetes mellitus. Meanwhile, the use of traditional medicines such as the Temu mangga’s rhizome (Curcuma mangga Valeton and Zijp) is often used by the community as antihyperlipidemic therapy. The purpose of this study was to scientifically prove the antihyperlipidemic activity of teabags from the methanol fraction of Temu Mangga’s rhizome in reducing lipid profiles, namely total cholesterol, triglycerides, and LDL, as well as increasing HDL. This research method is experimental by measuring the parameters of total cholesterol, triglycerides, LDL, and HDL as well as the bodyweight of the test animals as additional parameters. The test group was divided into 3 doses, namely 0.35 mg, 0.7 mg, and 1.4 mg per 200 grams of test animals. The results showed that there was no significant difference between all groups, both in lipid profile and bodyweight of the test animals. However, a dose of 1.4 mg had better triglyceride lowering activity than the positive control, and the activity of the methanol fraction of the Temu Mangga’s rhizome was predicted to be similar to statins.

Oxygenated Water Inhibits Adipogenesis and Attenuates Hepatic Steatosis in High-Fat Diet-Induced Obese Mice

The expansion of adipose tissue mass is the primary characteristic of the process of becoming obesity, which causes chronic adipose inflammation and is closely associated with type 2 diabetes mellitus (T2DM). Adipocyte hypertrophy restricts oxygen availability, leading to microenvironmental hypoxia and adipose dysfunction. This study aimed at investigating the effects of oxygenated water (OW) on adipocyte differentiation (adipogenesis) and the metabolic function of mature adipocytes. The effects of OW on adipogenesis and the metabolic function of mature adipocytes were examined. Meanwhile, the in vivo metabolic effects of long-term OW consumption on diet-induced obesity (DIO) mice were investigated. OW inhibited adipogenesis and lipid accumulation through down-regulating critical adipogenic transcription factors and lipogenic enzymes. While body weight, blood and adipose parameters were not significantly improved by long-term OW consumption, transient circulatory triglyceride-lowering and glucose tolerance-improving effects were identified. Notably, hepatic lipid contents were significantly reduced, indicating that the DIO-induced hepatic steatosis was attenuated, despite no improvements in fibrosis and lipid contents in adipose tissue being observed in the OW-drinking DIO mice. The study provides evidence regarding OW’s effects on adipogenesis and mature adipocytes, and the corresponding molecular mechanisms. OW exhibits transient triglyceride-lowering and glucose tolerance-improving activity as well as hepatic steatosis-attenuating functions.

A Novel Acetyl-CoA Carboxylase 2 Selective Inhibitor Improves Whole-Body Insulin Resistance and Hyperglycemia in Diabetic Mice through Target-Dependent Pathways.

Excess intramyocellular lipid (IMCL) deposition in skeletal muscle is closely associated with insulin resistance. Pharmacological inhibition of acetyl-CoA carboxylase (ACC) 2 offers a promising approach to treat insulin resistance through stimulation of mitochondrial fatty acid oxidation (FAO) and reduction of IMCL deposition. Previously reported experimental ACC2 inhibitors exhibited plasma glucose-lowering effects in diabetic rodents. However, their antidiabetic action may be potentially biased by off-target effects on triglyceride metabolism or by neurologic side effects. In this study, we investigated a safety profile, target dependency of its action, and antidiabetic efficacy of compound 2e, a novel olefin derivative potent ACC2 selective inhibitor. Four-day administration of suprapharmacological dose of compound 2e did not exhibit any obvious side effects in Sprague-Dawley rats. In db/db mice, single administration of compound 2e led to significantly elevated FAO and reduced IMCL deposition in skeletal muscle. In ACC2 knockout mice, treatment with pharmacological doses of compound 2e did not reduce plasma triglyceride levels, whereas A-908292, a previously reported ACC2 inhibitor, caused a significant triglyceride reduction, showing that compound 2e was devoid of off-target triglyceride-lowering activity. Chronic treatment of db/db mice with compound 2e improved hyperglycemia but did not decrease plasma triglyceride levels. Additionally, compound 2e showed significant improvements of whole-body insulin resistance in the clamp study and insulin tolerance test. Collectively, compound 2e demonstrated a good safety profile and significant antidiabetic effects through inhibition of ACC2-dependent pathways. These findings provide further evidence that selective inhibition of ACC2 is an attractive strategy against insulin resistance and type 2 diabetes. SIGNIFICANCE STATEMENT: This study shows that pharmacological inhibition of acetyl-CoA carboxylase (ACC) 2 leads to significant improvements in whole-body glucose homeostasis, independently of off-target metabolic pathways and toxicity, which were observed in previously reported ACC2 inhibitors. These findings support the concept that ACC2-selective inhibitors will be a novel remedy for treatment of type 2 diabetes.

Tigliane Diterpenoids as a New Type of Antiadipogenic Agents Inhibit GRα-Dexras1 Axis in Adipocytes.

The phytochemical study of Euphorbia prolifera led to the isolation of two tiglianes (1 and 2) and 23 mysrinanes (3-25). Most of these isolates showed significant antiadipogenic activity in 3T3-L1 adipocyte without apparent cytotoxicity. Subsequent structural modification yielded 10 derivatives, among which 1a, the 5- O-acetyl derivative of 1, turned out to be the most active compound with improved triglyceride-lowering activity (EC50 for 1 and 1a: 0.61 and 0.32 μM, respectively) and reduced cytotoxicity (selectivity index for 1 and 1a: 28 and 312, respectively). The structure-activity relationship study revealed that the trans-fused 5/7/6 ring system in an angular shape was important to the activity. A mechanistic study indicated that 1 and 1a could inhibit the glucocorticoid receptor α-Dexras1 axis in adipocyte, leading to the retardation of cell differentiation at the early stage. These findings may provide a new type of lipid-lowering agents for future antiobesity drug development.

Screening of lactic acid bacteria with cholesterol-lowering and triglyceride-lowering activity in vitro and evaluation of probiotic function

To screen the lactic acid bacteria with cholesterol-lowering and triglyceride-lowering activity in vitro and evaluate their probiotic function. By plate separating, cholesterol-lowering and triglyceride-lowering activity in vitro were determined; and by evaluating the probiotic functions, including tolerances to simulated gastric and intestinal juice, the antibacterial spectrum, and the adhesion ability to Caco-2 cells, the probiotic strains with cholesterol-lowering and triglyceride-lowering activity in vitro were screened, and then were identified by phenotypical and physiological tests and 16Sr DNA. Finally, the cholesterol-lowering and triglyceride-lowering activity in vivo of the strains were evaluated using male Sprague-Dawley rats. Two strains L2-16 and L2-73 with stronger cholesterol-lowering and triglyceride-lowering activity in vitro, stronger tolerance to simulated gastric and intestinal juice and adhesion ability to Caco-2 cells, and wider antibacterial spectrum were screened from traditional Chinese fermented cucumber and were identified as Lactobacillus acidophilus and Enterococcus faecalis, respectively. Compared with a hyperlipidemia diet without lactic acid bacteria, the diet supplemented with Lactobacillus acidophilus L2-16 and Enterococcus faecalis L2-73 significantly reduced serum total cholesterol, triglycerides, and low-density lipoprotein cholesterol levels, and liver total cholesterol and triglyceride levels in rats (P < 0.05). Moreover, the diet supplemented with Lactobacillus acidophilus L2-16 and Enterococcus faecalis L2-73 significantly increased the fecal elimination of bile acids (P < 0.05). Lactobacillus acidophilus L2-16 and Enterococcus faecalis L2-73 may have application prospect in the production of some fermented foods such as fermented vegetables, milk, or meat, and probiotic preparations with the function to lower the serum lipid and liver lipid levels.

Design, synthesis and evaluation of novel thiazolidinedione derivatives as anti-hyperglycemic and anti-hyperlipidemic agents

A novel series of thiazolidine-2,4-diones was designed, synthesized and investigated for anti-diabetic activity. The (2,4-dioxo-1,3-thiazolidin-5-yl)methylphenylbenzamide derivatives contain an amide linkage between the central aryl ring and the hydrophobic tail. Structures of the compounds were confirmed by spectroscopic techniques fourier transform infrared spectroscopy, 1H-nuclear magnetic resonance and elemental (C, H, N) analysis. The synthesized compounds were evaluated for their in-vivo pharmacological activity (blood glucose and triglyceride lowering activity), where compounds thiazolidinediones-C and thiazolidinediones-E showed significant effects, comparable to the standard pioglitazone. Computational studies positively substantiated the nature and interaction of the designed compounds with peroxisome proliferator-activated receptor gamma.

Design, synthesis and biological evaluation of novel bergapten derivatives as potent lipid lowering agents

The aim of this study was to synthesize novel amide derivatives of bergapten and evaluate their lipid-lowering and triglyceride-lowering activities in mice. Amide derivatives of bergapten were synthesized by using lactone ring opening strategy in DMSO using NaOH as base followed by alkylation in presence of methyl iodide. The compounds were subjected to preliminary in vivo screening. Fenofibrate (30 mg/kg/day) was used as positive controls in this assay. The lipid lowering activity was evaluated using in vivo Triton model and Triton WR-1339 was used as positive control. Most of the synthesized analogs displayed remarkable plasma triglyceride-lowering activity. Compound 5 showed the best activity with (41%) triglyceride lowering activity. This compound also exhibited the most potent lipid lowering activity displaying 33%, 32% and 29% lowering in total cholesterol, phospholipids, and triglycerides, respectively. The other derivatives showed almost comparable activity with that of the parent molecule.

Evaluation of in vitro and in vivo biological activities of Cheilanthes albomarginata Clarke.

BackgroundThe Cheilanthes albomarginata Clarke (CA), a fern belonging to Pteridaceae family, is found mainly in India, Nepal, Pakistan and Bhutan at an altitude of 1300–2700 m. It grows mostly in the rock crevices on slopes. Juice from the rhizome of CA has been used to treat peptic ulcer. In this study, the biological activities (antioxidant, anti-inflammatory, anti-adipogenic and anti-obesity) of the extracts of CA were investigated. The total phenolic content of each extract was quantified. This is the first report regarding the study of biological activities on CA.MethodsIn the current study, the crude methanol and fractionated extract of the aerial part of CA were investigated for the antioxidant tests which were namely DPPH assay, hydrogen peroxide scavenging assay and nitrite scavenging assay. Their phenolic contents were measured by the Folin-Ciocalteu’s method.In vitro anti-inflammatory and anti-adipogenic assays were evaluated against the RAW 264.7 macrophage cells and 3 T3-L1 cells respectively. The crude methanol extract and phenolic fraction (combination of ethyl acetate and butanol fraction) were studied for the in vivo anti-obesity test using male Sprague Dawley rats.ResultsThe ethyl acetate fraction showed the strongest DPPH radical scavenging (82.54 ± 0.48%), hydrogen peroxide scavenging (3.41 ± 0.21 mg/ml) and nitrite scavenging activity (61.39%). The highest phenolic content was found in the ethyl acetate fraction followed by the butanol fraction. The ethyl acetate fraction showed the highest in vitro anti-inflammatory and anti-adipogenic activities. From the in vivo study on rats, the crude methanol extract and phenolic fraction showed plasma triglyceride lowering activity as well as reduction of weight of adipose tissue in high fat diet induced obese rats.ConclusionThe current study suggests that the ethyl acetate and butanol extracts of CA are potential source for antioxidant, anti-inflammatory and anti-adipogenic remedies. In addition to that the results of in vivo studies evidenced the possibility of CA as a source of anti-obesity drug remedies.

One-Step Production of Bioactive Proteins through Simultaneous PEGylation and Refolding

Production of protein therapeutics often involves in vitro refolding from bacterial inclusion bodies and subsequent PEGylation to improve protein stability and plasma half-life. Here, we devised a novel strategy for one-step production of site-specific mono-PEGylated proteins with good bioactivity and improved biostability by integrating PEGylation and protein refolding (IPPR). Using lysozyme and recombinant human fibroblast growth factor 21 (rhFGF21) as model proteins, we showed that both PEGylation and refolding of denatured proteins have been simultaneously accomplished by IPPR with high efficiency of refolding yield and bioconjugation. PEGylated rhFGF21 by IPPR has a similar capacity as the native rhFGF21 to stimulate glucose uptake in 3T3-L1 cells, but exhibits prolonged blood glucose and triglyceride lowering activity levels in the ob/ob diabetic mouse model. Hence, IPPR will significantly facilitate the generation of protein therapeutics.

Discovery of novel glitazones incorporated with phenylalanine and tyrosine: Synthesis, antidiabetic activity and structure–activity relationships

We report a series of new glitazones incorporated with phenylalanine and tyrosine. All the compounds were tested for their in vitro glucose uptake activity using rat-hemidiaphragm, both in presence and absence of insulin. Six of the most active compounds from the in vitro screening were taken forward for their in vivo triglyceride and glucose lowering activity against dexamethazone induced hyperlipidemia and insulin resistance in Wistar rats. The liver samples of rats that received the most active compounds, 23 and 24, in the in vivo studies, were subjected to histopathological examination to assess their short term hepatotoxicity. The investigations on the in vitro glucose uptake, in vivo triglyceride and glucose lowering activity are described here along with the quantitative structure–activity relationships.

Studies on the euglycemic and hypolipidemic potentials of the novel indole analogue of thiazolidinedione, DRF 2189.

Euglycemic and hypolipidemic activities of a novel indole analogue of thiazolidinedione, DRF 2189 (CAS 172647-53-9), have been evaluated in different animal models. Compared to troglitazone (CAS 97322-87-7), DRF 2189 exhibited interesting plasma glucose and triglyceride lowering activity in genetically diabetic and obese db/db mice. It also produced a significant reduction in plasma glucose, triglyceride, total cholesterol levels and improvement in oral glucose tolerance in another genetic mouse model, the ob/ob mice. In high-fat diet fed Sprague-Dawley rats, DRF 2189 treatment showed improvement in plasma lipid parameters. Like other thiazolidinediones, this compound also possesses peroxisome proliferator activated receptor gamma (PPAR gamma) transactivation potential. In anaesthetized rat experiment, DRF 2189 produced a transient fall in blood pressure without any change in the ECG pattern. It showed non-specific smooth muscle relaxant activity against acetylcholine, histamine and potassium chloride induced contractions in isolated guinea pig ileum. A twenty-eight-day toxicity study in Wistar rats did not show any signs of treatment related adverse effects. The overall antidiabetic and hypolipidemic activities of DRF 2189 are comparable with rosiglitazone (CAS 155141-29-0) and superior to troglitazone. In conclusion, results from these preclinical studies indicate that DRF 2189, a novel thiazolidinedione, has a marked potential for the management of type-2 diabetes.

Targeting Acyl-CoA:Diacylglycerol Acyltransferase 1 (DGAT1) with Small Molecule Inhibitors for the Treatment of Metabolic Diseases

Acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) is one of two known DGAT enzymes that catalyze the final step in triglyceride synthesis. Findings from genetically modified mice as well as pharmacological studies suggest that inhibition of DGAT1 is a promising strategy for the treatment of obesity and type 2 diabetes. Here we characterize a tool DGAT1 inhibitor compound, T863. We found that T863 is a potent inhibitor for both human and mouse DGAT1 in vitro, which acts on the acyl-CoA binding site of DGAT1 and inhibits DGAT1-mediated triacylglycerol formation in cells. In an acute lipid challenge model, oral administration of T863 significantly delayed fat absorption and resulted in lipid accumulation in the distal small intestine of mice, mimicking the effects of genetic ablation of DGAT1. In diet-induced obese mice, oral administration of T863 for 2 weeks caused weight loss, reduction in serum and liver triglycerides, and improved insulin sensitivity. In addition to the expected triglyceride-lowering activity, T863 also lowered serum cholesterol. Hepatic IRS2 protein was dramatically up-regulated in mice treated with T863, possibly contributing to improved insulin sensitivity. In differentiated 3T3-L1 adipocytes, T863 enhanced insulin-stimulated glucose uptake, suggesting a possible role for adipocytes to improve insulin sensitivity upon DGAT1 inhibition. These results reveal novel mechanistic insights into the insulin-sensitizing effects of DGAT1 inhibition in mouse models. Taken together, our study provides a comprehensive evaluation of a small molecule inhibitor for DGAT1 and suggests that pharmacological inhibition of DGAT1 holds promise in treating diverse metabolic disorders.

Hypolipidemic effect of dietary pea proteins: Impact on genes regulating hepatic lipid metabolism.

Controversial data on the lipid-lowering effect of dietary pea proteins have been provided and the mechanisms behind this effect are not completely understood. The aim of the study was to evaluate a possible hypolipidemic activity of a pea protein isolate and to determine whether pea proteins could affect the hepatic lipid metabolism through regulation of genes involved in cholesterol and fatty acid homeostasis. Rats were fed Nath's hypercholesterolemic diets for 28 days, the protein sources being casein or a pea protein isolate from Pisum sativum. After 14 and 28 days of dietary treatment, rats fed pea proteins had markedly lower plasma cholesterol and triglyceride levels than rats fed casein (p<0.05). Pea protein-fed rats displayed higher hepatic mRNA levels of LDL receptor versus those fed casein (p<0.05). Hepatic mRNA concentration of genes involved in fatty acids synthesis, such as fatty acid synthase and stearoyl-CoA desaturase, was lower in pea protein-fed rats than in rats fed casein (p<0.05). In conclusion, the present study demonstrates a marked cholesterol and triglyceride-lowering activity of pea proteins in rats. Moreover, pea proteins appear to affect cellular lipid homeostasis by upregulating genes involved in hepatic cholesterol uptake and by downregulating fatty acid synthesis genes.

Novel 2-aryl-naphtho[1,2- d]oxazole derivatives as potential PTP-1B inhibitors showing antihyperglycemic activities

A series of 2-aryl-naphtho[1,2- d]oxazole derivatives have been synthesized and evaluated for PTP-1B inhibitory activity. The compounds have been screened in vivo for antidiabetic activity under sucrose loaded model (SLM), sucrose-challenged streptozotocin-induced diabetic rat model (STZ-S) and db/db mice model. Compounds 8 and 12 have shown promising PTP-1B inhibitory activity, significant antidiabetic activity, moderate lipid and triglyceride lowering activity.

Effects of Dietary Soybean Peptides on Hepatic Production of Ketone Bodies and Secretion of Triglyceride by Perfused Rat Liver

Soybean protein isolate (SPI) was digested with protease to produce a peptides containing the low-molecular fraction (LD3) or a mixture of high- and low-molecular fractions (HD1). Rats were fed a diets containing SPI, LD3, or HD1 at a protein level equivalent to the 20% casein diet for 4 weeks. The serum triglyceride concentration was lower in rats fed SPI, LD3, and HD1 diets than in rats fed the casein diet, and the differences were significant for the cholesterol-enriched diet. The value for the LD3 group was the lowest among all groups for both the cholesterol-free and -enriched diets. The level of triglyceride in the post-perfused liver was significantly lower in the LD3 and HD1 groups and the SPI group than in the casein group irrespective of the presence of cholesterol in the diet. In the cholesterol-free diet, LD3 feeding as compared to casein feeding caused a reduction in triglyceride secretion from the liver to perfusate and an increment of hepatic ketone body production. The addition of cholesterol to the diets somewhat attenuated these effects of LD3. These results suggest that the low-molecular fraction in soybean peptides causes triglyceride-lowering activity through a reduction in triglyceride secretion from the liver to the blood circulation and the stimulation of fatty acid oxidation in the liver. There is a possibility that soybean peptides modulate triglyceride metabolism by changes in the hepatic contribution.

Serum glucose and triglyceride lowering activity of some novel glitazones against dexamethasone-induced hyperlipidemia and insulin resistance

<b>Objectives:</b> To study the serum glucose and triglyceride lowering activity of some novel glitazones against dexamethasone-induced hyperlipidemia and insulin resistance in rats.<br><b> Materials and Methods:</b> Serum glucose and triglyceride lowering activity of the test compounds and a standard, rosiglitazone, was tested at a dose of 10 mg/kg p.o. against dexamethasone-induced hyperlipidemia and insulin resistance in Sprague-Dawley (SD) rats. On day 11 of treatment, blood was collected for the estimation of serum glucose and triglyceride levels.<br><b> Results:</b> All the 14 compounds and rosiglitazone significantly (<i> P</i> < 0.05) decreased dexamethasone-induced elevation of serum glucose when compared to dexamethasone-alone-treated group. Among these compounds, compound 10 showed better antihyperglycemic activity than rosiglitazone. Compounds 7, 8 and 9 have shown significant (<i> P</i> < 0.05) serum triglyceride lowering activity than did rosiglitazone. Out of the 14 compounds tested, only compounds 7, 8 and 9 have shown both serum glucose and triglyceride lowering activity.<br><b> Conclusion:</b> The present study indicates that some of the newer glitazones show significant glucose and triglyceride lowering activity. In comparison to rosiglitazone, these glitazones show comparable serum glucose lowering and better triglyceride lowering activity.

Vascular lipases, inflammation and atherosclerosis

Members of the lipase family that include lipoprotein lipase, hepatic lipase and endothelial cell lipase play a central role in triglyceride and phospholipid hydrolysis. Because the site of action of these lipases is the endothelium, the endothelium is constantly exposed to products of lipolysis. These lipolysis products could elicit pro- or anti-inflammatory effects in endothelial as well as surrounding cells. These effects could be transient or long-term depending on the nutritional state. While lipolysis is per se anti-atherogenic due to its triglyceride lowering activity, it could also be pro-atherogenic due to prolonged exposure of endothelium to lipolysis products. In addition, lipoprotein lipase expressed in macrophages appears to be pro-atherogenic independent of plasma lipoproteins. In this review we summarize these pro- and anti-inflammatory consequences of lipolysis with respect to atherosclerosis.

Effects of Dietary Oyster Extract on Lipid Metabolism, Blood Pressure, and Blood Glucose in SD Rats, Hypertensive Rats, and Diabetic Rats

Oyster extract was prepared by hydrolysis of oyster protein with proteases, Aloase (a protease from Bacillus subtilis), and Pancitase (a protease from Aspergillus oryzae). Rats were fed a diet containing 20% casein (the control diet) or 15% casein and 5% oyster extract (the oyster extract diet) as the protein source. The oyster extract diet exerted a significant reduction in serum cholesterol and liver triglyceride concentrations as compared with the control diet in Sprague-Dawley (SD) rats fed cholesterol-supplemented diets for 4 weeks. The activities of cytosolic fatty acid synthase and glucose-6-phosphate dehydrogenase were significantly lower in the oyster extract group than in the control group in the liver of SD rats. Hepatic cholesterol and triglyceride concentrations were significantly lower in spontaneously hypertensive (SH) rats and Otsuka Long-Evans Tokushima Fatty (OLETF) rats, type 2 diabetic rats, fed the oyster extract diet, for 4 weeks and 4 months respectively, than in those fed the control diet in the cholesterol-free diet. Blood pressure was significantly lower in the oyster extract group than in the control group at the 2nd and 4th weeks after the beginning of feeding experimental diets in SH rats. These results suggest that oyster extract prepared by hydrolysis of oyster induces triglyceride-lowering activity in the liver through a decrease in hepatic lipogenesis in SD rats, and that it exerts the antihypertensive effect in SH rats.

Novel 2,3-Dihydrobenzofuran-2-carboxylic Acids: Highly Potent and Subtype-Selective PPARα Agonists with Potent Hypolipidemic Activity

The design and synthesis of a novel class of 2,3-dihydrobenzofuran-2-carboxylic acids as highly potent and subtype-selective PPARalpha agonists are reported. Systematic study of structure-activity relationships has identified several key structural elements within this class for maintaining the potency and subtype selectivity. Select compounds were evaluated in animal models of dyslipidemia using Syrian hamsters and male Beagle dogs, and all these compounds displayed excellent cholesterol- and triglyceride-lowering activity at dose levels that were much lower than the marketed weak PPARalpha agonist fenofibrate.