Larry D. Lawson

Inhibition of whole blood platelet-aggregation by compounds in garlic clove extracts and commercial garlic products

The inhibitory effects of adenosine and 16 quantitatively determined organosulfur compounds derived from garlic cloves or commercial garlic preparations on collagen stimulated in vitro platelet aggregation in whole blood were determined. An estimation of the anti-aggregatory activity of several brands of the major types of commercial garlic preparations was determined from the activities of the individual compounds present in each sample. In platelet rich plasma (PRP) most of the anti-aggregatory activity of garlic clove homogenates was due to adenosine; however, in whole blood neither adenosine nor the polar fraction had any effect and all of the anti-aggregatory activity was due to allicin and other thiosulfinates. Allicin was equally active in whole blood and PRP. Among brands there was a several-fold variation in content of the organosulfur compounds and activity for all types of garlic products tested. The best garlic powder tablets were equally as active as clove homogenates whereas steam-distilled oils were 35% as active and oil-macerates (due to low content) only 12% as active. A garlic product aged many months in aqueous alcohol had no activity. For steam-distilled oils, most of the activity was due to diallyl trisulfide. For the oil-macerates, most of the activity was due largely to the vinyl dithiins. Ajoene, an exclusive component of the oil-macerates, had highest specific activity of all the compounds tested but, because of its low concentration, had only 13% of the activity of diallyl trisulfide and 3% of the activity of allicin. Compounds which may be active in vivo are discussed.

Triacylglycerol structure of plant and fungal oils containing ψ-linolenic acid

The triacylglycerol stereospecific structure was determined for the major plant oils containing ψ-linolenic acid (GLA): evening primrose oil (EPO), black currant oil (BCO), borage oil (BO), andMucor javanicus fungal oil (MJO). It was found that GLA, although not α-linolenic acid, resisted pancreatic lipase hydrolysis. Therefore, the 2-position analysis was determined using phospholipase C-generated 1,2-diacylglycerol and phospholipase A2-generated lysophosphatidylcholine. GLA was found to be concentrated in the 3-position of EPO and BCO, the 2-position of BO, and the 2- and 3-positions of MJO. In BCO, octadecatetraenoic acid (n−3), also a †-6 fatty acid, was distributed similarly to GLA, but α-linolenic acid was found predominantly in the 1-position. Linoleic acid was nearly evenly distributed in all positions of EPO and BCO but was concentrated in the 1-position of BO and the 2-position of MJO. Both palmitic and stearic acids were found predominantly in the 1-position of all of the oils. The results demonstrate similarities and differences in the positional distribution of fatty acids in GLA-containing oils.

β-Oxidation of the coenzyme a esters of elaidic, oleic, and stearic acids and their full-cycle intermediates by rat heart mitochondria

beta-Oxidation rates for the CoA esters of elaidic, oleic and stearic acids and their full-cycle beta-oxidation intermediates and for the carnitine esters of oleic and elaidic acids were compared over a wide range of substrate and albumin concentrations in rat heart mitochondria. The esters of elaidic acid were oxidized at about half the rate of the oleic acid esters, while stearoyl-CoA was oxidized equally as rapid as oleoyl-CoA. The full-cycle beta-oxidation intermediates of elaidoyl-CoA (trans-16 : 1 delta 7, -14 : 1 delta 5, and -12 : 1 delta 3) were found to be oxidized at rates nearly equal to those for the corresponding intermediates of oleoyl-CoA. Therefore, after the first cycle of beta-oxidation, oleoyl-CoA and elaidoyl-CoA are oxidized at nearly equal rates. The activity of fatty acyl-CoA dehydrogenase was higher with elaidoyl-CoA and its full-cycle intermediates as substrates than with the corresponding cisisomers. It was concluded that the slower oxidation rate of elaidic acid is not due to slower oxidation of any of its full-cycle beta-oxidation intermediates, nor to slower activity of fatty acyl-CoA dehydrogenase, nor to outer mitochondrial carnitine acyltransferase. Possible explanations to account for the slower oxidation rate of elaidic acid are discussed.

β-oxidation of the coenzyme A esters of vaccenic, elaidic, and petroselaidic acids by rat heart mitochondria

Rates of β-oxidation of the coenzyme A esters of vaccenic, elaidic, and petroselaidic acids as well as their respectivecis isomers by rat heart mitochondria were measured and compared. At all concentrations studied, vaccenoyl-CoA was oxidized more rapidly than elaidoyl-CoA, but more slowly than oleoyl-CoA except at high substrate concentrations. Alltrans octadecenoyl-CoA esters were oxidized at a slower rate than their respectivecis or saturated isomers. Oxidation rates decreased as the double bond approached the carboxyl-end.

Oxidation of fatty acid by heart mitochondria of chickens with endogenous hyperlipidemia

Abstract The lipid composition of blood plasma and heart, and fatty acid oxidation rates of heart mitochondria in layers, hereditary nonlaying hens, and roosters were determined. The plasma cholesterol levels were normal in layers and roosters (100–130 mg/dl) whereas nonlayers were hypercholesterolemic (640 mg/dl). Plasma triglyceride levels were also strikingly different between layers, nonlayers, and roosters, 850, 5300 and 152 (mg/dl) respectively. A moderate elevation of phospholipid level was also noted in nonlayers. Unlike plasma, no significant difference was found in cholesterol and phospholipid content of the heart between layers and nonlayers. The lipid content of rooster hearts was lower in all three lipid classes than hens. The fatty acid oxidation rate in heart mitochondria revealed that nonlayers catabolized both oleic and stearic acids at significantly faster rates than layers. Roosters exhibited the slowest fatty acid oxidation rates. Oleic acid was oxidized at a significantly higher rate than stearic acid in all chickens examined.