90 research outputs found

    Garlic's ability to prevent in vitro Cu(2+)-induced lipoprotein oxidation in human serum is preserved in heated garlic: effect unrelated to Cu(2+)-chelation

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    BACKGROUND: It has been shown that several extracts and compounds derived from garlic are able to inhibit Cu(2+)-induced low density lipoprotein oxidation. In this work we explored if the ability of aqueous garlic extract to prevent in vitro Cu(2+)-induced lipoprotein oxidation in human serum is affected by heating (a) aqueous garlic extracts or (b) garlic cloves. In the first case, aqueous extract of raw garlic and garlic powder were studied. In the second case, aqueous extract of boiled garlic cloves, microwave-treated garlic cloves, and pickled garlic were studied. It was also studied if the above mentioned preparations were able to chelate Cu(2+). METHODS: Cu(2+)-induced lipoprotein oxidation in human serum was followed by the formation of conjugated dienes at 234 nm and 37°C by 240 min in a phosphate buffer 20 mM, pH 7.4. Blood serum and CuSO(4 )were added to a final concentration of 0.67% and 0.0125 mM, respectively. The lag time and the area under the curve from the oxidation curves were obtained. The Cu(2+)-chelating properties of garlic extracts were assessed using an approach based upon restoring the activity of xanthine oxidase inhibited in the presence of 0.050 mM Cu(2+). The activity of xanthine oxidase was assessed by monitoring the production of superoxide anion at 560 nm and the formation of uric acid at 295 nm. Data were compared by parametric or non-parametric analysis of variance followed by a post hoc test. RESULTS: Extracts from garlic powder and raw garlic inhibited in a dose-dependent way Cu(2+)-induced lipoprotein oxidation. The heating of garlic extracts or garlic cloves was unable to alter significantly the increase in lag time and the decrease in the area under the curve observed with the unheated garlic extracts or raw garlic. In addition, it was found that the garlic extracts were unable to chelate Cu(2+). CONCLUSIONS: (a) the heating of aqueous extracts of raw garlic or garlic powder or the heating of garlic cloves by boiling, microwave or pickling do not affect garlic's ability to inhibit Cu(2+)-induced lipoprotein oxidation in human serum, and (b) this ability is not secondary to Cu(2+)-chelation

    QSAR of substituted morpholines with antioxidant and squalene synthase inhibitory activity

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    A quantitative structure-activity relationship (QSAR) study was performed for a series of antihyperlipidemic morpholine derivatives, exhibiting squalene synthase (SQS) inhibitory as well as antioxidant activity (inhibition of lipid peroxidation). Physico/stereo-chemical descriptors of low energy conformations of the compounds were calculated and a number of QSAR models with statistical significance and predictability were produced. The final models include chemical descriptors such as ELUMO, EHOMO-ELUMO gap, cLogP, electrostatic (FNSA1 and RNCS) as well as geometry (YZSHADOW/YZRECTANGLE) descriptors, indicating that electron affinity, along with molecular shape and electrostatic effects play a significant role in the compound's described activities. These models provide some insight on the molecular mechanism of action of these derivatives and assist in the prediction of action in vitro as well as the design of more potent derivatives in the search for effective antiatherosclerosis agents. © Springer Science+Business Media, LLC 2011

    EP2306 [2-(4-biphenyl)-4-methyl-octahydro-1,4-benzoxazin-2-ol, hydrobromide], a novel squalene synthase inhibitor, reduces atherosclerosis in the cholesterol-fed rabbit

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    EP2306 [2-(4-biphenyl)-4-methyl-octahydro-1,4-benzoxazin-2-ol, hydrobromide] inhibits squalene synthase and lipid biosynthesis and possesses antioxidant properties. We hypothesized that EP2306 can effectively modify circulating lipids and reduce atherosclerosis in the cholesterol-fed rabbit. Animals were fed a high-cholesterol diet for 4 weeks followed by 4 (phase 1 and 2) or 12 weeks (phase 3) of drug treatment while on high-cholesterol diet. In phase 1, the dose-effect relationship of EP2306 on lipids and atherosclerosis was established, and its most effective dose was determined (2 mg/kg). This dose reduced significantly total cholesterol (512 ± 96 mg/dl before versus 320 ± 124 mg/dl after treatment, p < 0.05) and atherosclerotic lesions compared with control animals. In phase 2, the effects of 2 mg/kg EP2306, 2.5 mg/kg simvastatin, and their combination were assessed. Although no significant effect on lipid parameters was observed, there was a significant reduction (35 ± 5%, p < 0.05) of atherosclerotic lesions in animals treated with EP2306, a similar reduction with simvastatin, and a further reduction (48 ± 7%, p < 0.05) when the two agents were combined. In animals treated for 12 weeks with the drugs (phase 3), only EP2306 significantly reduced atherosclerotic lesions by more than 50%, whereas simvastatin alone or in combination with EP2306 had no effect. Treatment with EP2306 did not adversely affect liver transaminases or cause any histopathological changes on various organs of the animals. In conclusion, we have shown that EP2306 inhibits atherosclerosis in vivo, indicating potential as a novel therapeutic agent for coronary artery disease and other atherosclerosis-related disorders. Copyright © 2007 by The American Society for Pharmacology and Experimental Therapeutics

    Antiatherosclerotic properties of EP2302, A novel squalene synthase inhibitor, in the cholesterol-fed rabbit

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    EP2302 is a novel nitric oxide donor compound that inhibits squalene synthase. We hypothesized that EP2302 can reduce atherosclerosis in the cholesterol-fed rabbit atherosclerosis model. Animals were fed a high-cholesterol (HC) diet for 4 weeks. Animals subsequently received drug or placebo for 4 (n = 15) or 12 weeks (n = 15) while on HC diet. A third group (n = 16) received drug or placebo for 4 weeks while on regular diet (regression group). No significant differences were observed in circulating lipids among any of the treatment groups at each time point during HC intake. The perimeter and area of the ascending aorta covered by lesions were significantly decreased in animals treated with 2 mg/kg EP2302 for 4 weeks (44% and 42% reduction, respectively). Moreover, a significant decrease in the perimeter of the ascending and descending aorta covered by lesions was observed in animals treated with 2 mg/kg EP2302 for 12 weeks (73% and 44% reduction, respectively) as well as in the regression group (61% and 65% reduction, respectively). Treatment with EP2302 did not cause any toxicity in animal vital organs. We have shown that EP2302 inhibits atherosclerosis in the cholesterol-fed rabbit and therefore may serve as a candidate drug to be tested in humans for atherosclerosis-related disorders. © 2008 by Lippincott Williams & Wilkins
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