Evaluation of hydroxyl radical-scavenging property of garlic.

Garlic has been reported to provide protection against hypercholesterolemic atherosclerosis and ischemia-reperfusion-induced arrhythmias and infarction. Oxygen free radicals (OFRs) have been implicated as causative factors in these diseases and antioxidants have been shown to be effective against these conditions. The effectiveness of garlic in these disease states could be due to its ability to scavenge OFRs. However, the OFR-scavenging activity of garlic is not known. Also it is not known if its activity is affected by cooking. We therefore investigated, using high pressure liquid chromatography, the ability of garlic extract (heated or unheated) to scavenge exogenously generated hydroxyl radical (.OH). .OH was generated by photolysis of H2O2 (1.2-10 mumoles/ml) with ultraviolet (UV) light and was trapped with salicylic acid (500 nmoles/ml). H2O2 produced .OH in a concentration-dependent manner as estimated by .OH adduct products 2,3-dihydroxybenzoic acid (DHBA) and 2,5-DHBA. Garlic extract (5-100 microliters/ml) produced an inhibition (30-100%) of 2,3-DHBA and 2,5-DHBA generated by photolysis of H2O2 (5.00 pmoles/ml) in a concentration-dependent manner. Its activity is reduced by 10% approximately when heated to 100 degrees C for 20, 40 or 60 min. The extent of reduction in activity was similar for the three heating periods. Garlic extract prevented the .OH-induced formation of malondialdehyde in the rabbit liver homogenate in a concentration-dependent manner. It alone did not affect the MDA levels in the absence of .OH. These results indicate that garlic extract is a powerful scavenger of .OH and that heating reduces its activity slightly.

Antioxidant activity of allicin, an active principle in garlic.

Garlic has been claimed to be effective against diseases, in the pathophysiology of which oxygen free radicals (OFRs) have been implicated. Effectiveness of garlic could be due to its ability to scavenge OFRs. However, its antioxidant activity is not known. We investigated the ability of allicin (active ingredient of garlic) contained in the commercial preparation Garlicin to scavenge hydroxyl radicals (.OH) using high pressure liquid chromatographic (HPLC) method. .OH was generated by photolysis of H2O2 (1.25-10 mumoles/ml) with ultraviolet light and was trapped with salicylic acid which is hydroxylated to produce .OH adduct products 2,3- and 2,5-dihydroxybenzoic acid (DHBA). H2O2 produced a concentration-dependent .OH as estimated by .OH adduct products 2,3-DHBA and 2,5-DHBA. Allicin equivalent in Garlicin (1.8, 3.6, 7.2, 14.4, 21.6, 28.8 and 36 micrograms) produced concentration-dependent decreases in the formation of 2,3-DHBA and 2,5-DHBA. The inhibition of formation of 2,3-DHBA and 2,5-DHBA with 1.8 micrograms/ml was 32.36% and 43.2% respectively while with 36.0 micrograms/ml the inhibition was approximately 94.0% and 90.0% respectively. The decrease in .OH adduct products was due to scavenging of .OH and not by scavenging of formed .OH adduct products. Allicin prevented the lipid peroxidation of liver homogenate in a concentration-dependent manner. These results suggest that allicin scavenges .OH and Garlicin has antioxidant activity.

Haemoglobin Hammersmith precludes monitoring with conventional pulse oximetry.

We report a case of a 15-yr-old North American Indian female with haemoglobin Hammersmith, scheduled for elective tonsillectomy, whose arterial oxygen saturation could not be reliably monitored perioperatively because of technical limitations of conventional dual wavelength pulse oximetry. The patient was chronically icteric. She had an atrial septal defect with a small L-->R shunt demonstrated by echocardiography. On arrival in the operating room pulse oximetry (Nellcor-Model N100) demonstrated a saturation of 45% whilst breathing room air. Her oxygen saturation increased to 60% whilst breathing 100% oxygen via a face mask. An arterial blood gas performed whilst breathing 100% oxygen revealed a PaO2 of 418 mmHg. Tonsillectomy was completed uneventfully under general anaesthesia. The pulse oximeter did not provide any clinically useful information throughout the case. In conclusion, conventional dual wavelength pulse oximeters cannot give an accurate estimate of oxygenation in patients with haemoglobin Hammersmith. Assessment of oxygenation in these patients requires alternative monitoring techniques.

Hydroxyl radical-scavenging property of indomethacin.

The ability of indomethacin to scavenge hydroxyl radical (.OH) using high pressure liquid chromatography (HPLC) was investigated. .OH radical was generated by photolysis of H2O2 (1.5-10 mmoles/L) with UV light and was trapped with salicyclic acid (500 nmoles). H2O2 produced .OH in a concentration-dependent manner as estimated by .OH adduct products 2,3- and 2,5-dihydroxybenzoic acid (DHBA). Indomethacin in increasing concentrations (5-600 mumoles/L) produced increasing inhibition of generation of 2,3-DHBA (7-67%) and of 2,5-DHBA (7-77%). The results indicate that indomethacin scavenges .OH in a concentration-dependent manner.

Evaluation of hydroxyl radical-scavenging property of purpurogallin using high pressure liquid chromatography.

Purpurogallin (PPG) has been used as an additive to edible and non-edible oils or fats to retard oxidation. Its antioxidant mechanism is not known. We investigated the ability of PPG to scavenge exogenously generated hydroxyl radicals (.OH) using a sensitive high pressure liquid chromatographic (HPLC) method. .OH was generated by photolysis of H2O2 (1.25-10 mumoles) with UV light and was trapped with salicylic acid (500 nmoles). Salicylic acid is hydroxylated to produce .OH adduct products 2,3- and 2,5-dihydroxybenzoic acid (DHBA). H2O2 produced concentration-dependent .OH as estimated by generation of 2,3- and 2,5-DHBA. PPG (100, 200, 300, 400, 500, and 600 nmoles) produced concentration-dependent decreases in .OH adduct products (approximately 70% inhibition with 600 nmoles of PPG). It did not affect the peak of standard 2,3- and 2,5-DHBA indicating that the decrease in the adduct product generated by H2O2 is due to scavenging of .OH. These results indicate that photolysis of H2O2 by UV light produces .OH and that PPG scavenges .OH.

Diurnal rhythms of cortisol, ACTH, and beta-endorphin levels in neonates and adults.

To determine whether a diurnal rhythm exists in neonates admitted to neonatal intensive care units where there is continuous artificial lighting and periodic nursing and medical care, plasma cortisol, adrenocorticotropin (ACTH), and beta-endorphin concentrations were measured in two groups of infants and in adult human volunteers. As expected, a diurnal rhythm was seen in adults. A diurnal rhythm was also found for cortisol and endorphin levels in neonates (3 to 4 days postnatally) with minimal stress and in infants who were clinically severely stressed. There was not a significant difference between the morning and afternoon concentrations of ACTH in these infants, but the afternoon concentrations were lower than the morning's, as would be expected. We found that a diurnal rhythm does exist in neonates within the first few days of postnatal life and that the continuous lighting and medical and nursing interventions do not interfere with this rhythm.

Regulation of carnosine metabolism: the subcellular localization of carnosinase in liver.

We studied the subcellular localization of carnosinase (EC 3.4.13.3) in rat liver. The liver homogenate was fractionated by differential centrifugation into a nuclear (N), a mitochondrial (M), a lysosomal (L), a microsomal (P) and a soluble (S) fraction. The purity of different subcellular fractions was established by using different markers. The carnosinase activity in different fractions was measured by fluorometric determination of L-histidine produced using carnosine as a substrate. The intracellular distribution of carnosinase was very similar to that of lactate dehydrogenase with the highest relative specific activity of enzyme being observed in the soluble fraction. These results indicate that carnosinase enzyme is primarily located in the soluble (cytoplasmic) fraction of rat liver.

Evaluation and assessment of high sensitivity thyrotropin methods as an index for thyroid function.

We report the evaluation of four new commercially available sensitive assay kits for determination of thyrotropin (TSH) and their clinical utility in normal subjects and patients with thyroidal and non-thyroidal illnesses. The sensitivity for the reliable detection of serum TSH by these methods ranged from 0.1-0.4 mU/L and their decreasing order was : NML greater than Serono greater than Abbott EIA greater than Hybritech. The coefficient of variation ranged from 2.0-5.8% for intra-assay and 2.3-8.6% for interassay at different concentration levels. Patients studied (n = 130) were assigned into four groups on the basis of the serum thyroxine value and their clinical findings. In total, there were 17 discrepancies (five with Hybritech, three with NML, five with Abbott EIA, and four with Serono) in making the correct diagnosis using these sensitive TSH methods as a single diagnostic test. These discrepancies were mainly in the same patients who were clinically euthyroid but had subnormal TSH values. There were no discrepancies in making the correct diagnosis for patients with hyperthyroidism or hypothyroidism using these sensitive TSH methods. Our observations indicate that the sensitive TSH methods are reliable in measuring subnormal levels and may be used to detect hyperthyroidism without affecting in any way their value in detecting hypothyroidism.

Aortic changes in cynomolgus monkeys fed high-fat diets (long-term study).

Two diets containing either a lard-corn oil mixture (LCO) or partially hydrogenated herring oil (PHHO) were fed to cynomolgus monkeys (Macaca fascicularis) for up to 30 months. Serum cholesterol values rose to 180 mg/dl in the LCO-group and to 260 mg/dl in the PHHO-group. Serum lipoprotein concentrations were normal in the LCO-group, but PHHO-fed monkeys had lower HDL- and higher LDL- and VLDL-proportions. Only one animal on the LCO-diet for 24 months developed a pre-atherosclerotic lesion in the aorta. The general absence of true atherosclerotic lesions in the presence of high serum cholesterol levels and abnormal serum lipoprotein proportions may be interpreted as being indicative of the low atherogenicity of the fats used. This finding points toward a specific fat-animal species interaction.

Effects of plant and animal lipids rich in docosenoic acids on the myocardium of Cynomolgus monkeys.

Cynomolgus monkeys (Macaca fascicularis) were fed diets containing 25% rapeseed oil (RSO), partially-hydrogenated herring oil (PHHO) or a 3:1 mixture of lard/corn oil as control (CON) for 4 months. The RSO contained approximately 25% of the fatty acids as erucic acid (cis-docos-13-enoic, 22:1w9) while the PHHO contained a similar concentration of mainly cetoleic acid (cis-docos-11-enoic, 22:1w11). The CON contained no 22:1 acids. The monkeys developed the expected myocardial lipidosis, somewhat more pronounced in the RSO than the PHHO group, but small foci of mononuclear cell infiltration, while infrequent, occurred in all three groups. Significant intergroup differences in biochemical or hematologic measurements of serum constituents were an increase in serum cholesterol concentration in the RSO group and an increase in serum glutamicoxaloacetic transaminase activity in both RSO and PHHO groups at certain intervals. The shorter proportion of M. fascicularis life span represented by this experiment may account for the absence of clear intergroup differences such as are reported in rats used in similar studies.

Comparison of 3-kit methods for determination of human chorionic somatomammotropin by radioimmunoassay.

1. Three commercially available kit procedures for human chorionic somatomammotropin (HCS) were investigated. 2. The comparison of the methods included procedure, accuracy, precision, sample requirement and time required for analyses. 3. While one kit gave significantly higher values and requires more time to obtain results, each of 3 procedures was concluded to provide clinically useful information.