PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Onions”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMedDate not supplied

Suspended onion particles and potential corneal injury in onion harvesters.

The authors suspected that suspended onion particles contributed to corneal ulcers in onion harvesters in southern Taiwan. In the present study, the authors used manikins to study suspended onion particles in fields in an effort to simulate typical conditions experienced by onion harvesters. An animal eye-exposure simulation study was also performed by the authors, who impacted suspended soil grains or onion particles onto the corneas of guinea pigs via aerosol generated from the Palas dispersion nozzle. The average size of 25.9 pm for suspended particles collected during the digging of onions was the largest one of those for various harvesting activities. Some onion skin flakes were found in samples obtained from gathering and packing activities; the typical flake size was approximately 3.5 x 2.5 mm2. The results of the animal study indicated that the size of soil grains has a demonstrable effect on the severity of corneal injury (p = .009). With respect to onion skin flakes, wind velocity was also associated significantly with the occurrence of corneal injury (p = .0004). A wind velocity threshold of 7 m/sec is recommended for the maintenance of safety, and if the wind speed exceeds this threshold level, workers should not engage in harvesting activities. Furthermore, use of appropriately designed goggles is necessary for the protection of onion harvesters who work in high-wind conditions.

Agricultural Workers' Diseases↗
PubMed1978

Exposure to onion taste in mother's milk leads to enhanced preference for onion diet among weanling rats.

Five mothers of 50 newborn rat pups were maintained on either standard lab chow or a diet composed of the same chow with onion powder added. Taste preference tests administered during weaning indicated that the pups whose mother was fed the onion chow showed a preference for onion diet, but that such preference dissipated across the five day testing period. A control group of pups who were exposed to any onion diet cues available through channels other than the mother's milk did not show a preference for onion diet. It was concluded that exposure to onion taste in mother's milk was responsible for an initial preference for onion diet.

Animal Feed↗
PubMed1998

Field Persistence Studies on Pendimethalin Residues in Onions and Soil after Herbicide Postemergence Application in Onion Cultivation.

Field studies were undertaken to evaluate the fate of pendimethalin residues in spring and dry onions, after postemergence application of the herbicide in a clay soil onion planting in central Greece, at rates of 1.32 and 2.0 kg of active ingredient (ai)/ha. Residues were determined with capillary GC-ECD after onion extraction with 2-propanol/toluene and extract cleanup in a AgNO(3-)coated alumina column; the recovery of pendimethalin from spiked onions was found to be 82-99% and the limit of determination 0.007 mg/kg. Pendimethalin residues were found to decline rapidly, and it was estimated that 7 days after the treatment only half of the initial concentrations remained for both the low recommended dose (LRD) and the high recommended dose (HRD) experiments. In all cases the residues in dry bulb onion were well below the lowest maximum residue limit (MRL) set by European countries, which is 0.05 mg/kg. Residues in spring onions at harvest time were also below this level when treated at the LRD and were only slightly above in case of the HRD. The pendimethalin concentration in planting soil for the investigated period declined with half-lives of 37 and 39 days for the LRD and the HRD experiments, respectively.

Journal Article↗
PubMed2003

Hypoglycaemic and antioxidant effects of onion, Allium cepa: dietary onion addition, antioxidant activity and hypoglycaemic effects on diabetic rats.

The purpose of the present study was to discover the relative potency of onion, Allium cepa, with respect to its hypoglycaemic and hypolipidaemic effects on the diabetic situation, and the association of these effects with the potential against oxidative stress. Male Wistar rats were divided into four groups. A normal control (group A), and a non-diabetic group (group B) were treated daily with 1 ml A. cepa solution (0.4 g A. cepa/rat). Groups C and D were made diabetic by an intraperitoneal injection of streptozotocin (STZ) (60 mg/kg body weight) in citrate buffer (pH 6.3). These animals (groups C and D) were the STZ diabetic control and STZ diabetic rats with onion intake, respectively. Onion increased the fasting serum high-density lipoprotein levels, and demonstrated alleviation of hyperglycaemia in STZ diabetic rats. The hypoglycaemic and hypolipidaemic actions of A. cepa were associated with antioxidant activity, since onion decreased superoxide dismutase activities while no increased lipid hydroperoxide and lipoperoxide concentrations were observed in diabetic rats treated with A. cepa.

Alanine Transaminase↗
PubMed1987

Antiasthmatic effects of onions. Inhibition of platelet-activating factor-induced bronchial obstruction by onion oils.

Lyophilized onion extract and ether extracts of onions were separated by chromatographic methods into several subfractions and tested for their effects on asthmatic reactions of guinea pigs to allergen, histamine, acetylcholine and platelet-activating factor (PAF) inhalation as well as on thromboxane biosynthesis of human platelets and lung fibroblasts. Onion oils are counteracting the bronchial obstruction due to PAF inhalation.

Allium↗
PubMed1996

Coat protein gene sequences of garlic and onion isolates of the onion yellow dwarf potyvirus (OYDV).

Partial genomic sequences from an unknown garlic potyvirus and from an onion isolate of the onion yellow dwarf potyvirus (OYDV) were obtained. Comparison of the deduced amino acid sequences showed a similarity of 88% between the respective viral coat proteins. The garlic potyvirus coat protein was expressed in E. coli cells, purified, and subjected to Western blot analysis using antibodies raised against different garlic-infecting viruses. The expression protein was consistently recognised by anti-OYDV antibodies and did not react with antibodies specific for leek yellow stripe potyvirus (LYSV), garlic common latent carlavirus (GCLV) and shallot latent carlavirus (SLV). Besides, the garlic potyvirus coat protein was obtained as a fusion protein and used as antigen to produce polyclonal antibodies. These antibodies reacted with purified OYDV virions, but failed to recognise LYSV particles. In the light of this evidence the garlic potyvirus was identified as the garlic strain of OYDV.

Amino Acid Sequence↗
PubMed1993

Acute and subacute toxicity tests of onion coat, natural colorant extracted from onion (Allium cepa L.), in (C57BL/6 x C3H)F1 mice.

The toxicity test of onion coat colorant (OC), a food colorant extracted from onion (Allium cepa L.), was undertaken using (C57BL/6 x C3H)F1 mice of both sexes for the safety assessment of this product. The acute toxicity test was performed by administration of OC suspended in corn oil by gavage at doses of 2500, 5000, 7500, and 10,000 mg/kg body weight to groups of 5 or 6 males and 6 or 7 females, maintained for 14 d. Six of 12 females dosed at 10,000 mg/kg body weight and 3 of 11 females dosed at 7500 mg/kg body weight were dead before the end of the study, indicating that the tolerated dose of OC was between 7500 and 5000 mg/kg body weight. The subacute toxicity test of OC was examined using 123 mice of both sexes (62 males and 61 females) by feeding a diet mixed with OC at concentrations of 5, 2.5, 1.25, 0.6, and 0.3% for 90 d. All mice tolerated these doses of OC well. The body weight gains of male and female mice were not affected by the treatment. Histopathological examinations showed that hyperplastic changes in the esophagus, forestomach, pancreas, cervix, and endometrium of mice were found in treated and control mice. However, their incidences were not related to the dose of OC. Moreover, only a spontaneous ovarian teratoma was found in an OC-treated mouse. These results suggest that OC has no acute and subacute toxic effects in mice.

Administration, Oral↗
PubMed1995

Pickled onion-induced asthma: a model of sulfite-sensitive asthma?

BACKGROUND: Asthma elicited by sulfite ingestion has been mainly described in steroid-dependent and in non-atopic asthmatics. We have studied a group of 18 young extrinsic asthmatics who presented with asthma attacks immediately after eating pickled onions. OBJECTIVE: The aim of this study is to ascertain if these asthma attacks are elicited by sulfites contained in pickled onions and the influence of the dose and pH of onions. METHODS: The bronchial hyperreactivity of the patients was assessed by a methacholine challenge test. Oral challenge tests were performed with sodium metabisulfite (MSB) diluted in lemon juice at pH 4.2 and at pH 3.3 (only in patients who did not react with pH 4.2). Two types of pickled onions, Spanish and Dutch pickled onions, were used for oral challenge in seven of the patients. The Monier-Williams method was used to measure the SO2 concentration in pickled onions. RESULTS: The oral provocation test with MBS, pH 4.2, elicited a positive response in six patients (33.3%) and the test at pH 3.3 was positive in three out of 12. No significant difference in PD20 values was found between these groups. Three of the seven patients challenged with Spanish pickled onions had a positive reaction but had no reaction with Dutch pickled onions. The SO2 concentration in Spanish pickled onions varied between 765 and 1182 ppm while in Dutch pickled onions were 200 ppm; this exceeded the permitted level (100 ppm). SO2 release in Spanish pickled onion samples was nearly 2.5 times higher when the pH of the sample decreased from 4.2 to 3.3. CONCLUSION: High levels of SO2 in Spanish pickled onions, and their low pH (3.3) would be the responsible factors of the asthmatic outbreaks after ingestion of Spanish pickled onions by these patients.

Adolescent↗
PubMed1998

Heinz body formation in cats fed baby food containing onion powder.

OBJECTIVE: To determine whether cats fed baby food with onion powder develop Heinz bodies and anemia and to establish a dose-response relation between dietary onion powder content and Heinz body formation. DESIGN: Prospective study. ANIMALS: 42 healthy, adult, specific-pathogen-free cats. PROCEDURE: Commercial baby food with and without onion powder was fed to 2 groups of 6 cats for 5 weeks. Heinz body percentage, PCV, reticulocyte percentage, turbidity index, and methemoglobin and reduced glutathione concentrations were determined twice weekly and then weekly for 4 weeks following removal of the diet. For the dose-response study, 5 groups of 6 cats were fed a canned diet for 2 months that contained 0, 0.3, 0.75, 1.5, or 2.5% onion powder. Heinz body percentage, PCV, and reticulocyte percentage were determined twice weekly. RESULTS: Compared with cats fed baby food without onion powder, cats ingesting baby food with onion powder had significantly higher Heinz body percentages that peaked at 33 to 53%. Methemoglobin concentration also significantly increased but did not exceed 1.2%. Glutathione concentration, PCV, and food intake did not differ between the 2 groups. Rate and degree of Heinz body formation differed significantly between various onion powder concentrations fed. Compared with 0% onion powder, the diet with 2.5% onion powder caused a significant decrease in PCV and an increased punctate reticulocyte percentage. CLINICAL IMPLICATIONS: Baby food or other foods containing similar amounts of onion powder should be avoided for use in cats because of Heinz body formation and the potential for development of anemia, particularly with high food intake. Cats with diseases associated with oxidative stress may develop additive hemoglobin damage when fed baby food containing onion powder.

Anemia, Hemolytic↗
PubMed2002

Onions--a global benefit to health.

Onion (Allium cepa L.) is botanically included in the Liliaceae and species are found across a wide range of latitudes and altitudes in Europe, Asia, N. America and Africa. World onion production has increased by at least 25% over the past 10 years with current production being around 44 million tonnes making it the second most important horticultural crop after tomatoes. Because of their storage characteristics and durability for shipping, onions have always been traded more widely than most vegetables. Onions are versatile and are often used as an ingredient in many dishes and are accepted by almost all traditions and cultures. Onion consumption is increasing significantly, particularly in the USA and this is partly because of heavy promotion that links flavour and health. Onions are rich in two chemical groups that have perceived benefits to human health. These are the flavonoids and the alk(en)yl cysteine sulphoxides (ACSOs). Two flavonoid subgroups are found in onion, the anthocyanins, which impart a red/purple colour to some varieties and flavanols such as quercetin and its derivatives responsible for the yellow and brown skins of many other varieties. The ACSOs are the flavour precursors, which, when cleaved by the enzyme alliinase, generate the characteristic odour and taste of onion. The downstream products are a complex mixture of compounds which include thiosulphinates, thiosulphonates, mono-, di- and tri-sulphides. Compounds from onion have been reported to have a range of health benefits which include anticarcinogenic properties, antiplatelet activity, antithrombotic activity, antiasthmatic and antibiotic effects. Here we review the agronomy of the onion crop, the biochemistry of the health compounds and report on recent clinical data obtained using extracts from this species. Where appropriate we have compared the data with that obtained from garlic (Allium sativum L.) for which more information is widely available.

Flavonoids↗
PubMed1997

Influence of dietary capsaicin and onion on the metabolic abnormalities associated with streptozotocin induced diabetes mellitus.

Effect of feeding 15 mg% capsaicin diet or 3% freeze dried onion powder containing diet were examined in albino rats rendered diabetic with streptozotocin injection. Diabetic rats maintained on onion diet for 8 weeks excreted comparatively less amounts of albumin, urea, creatinine and inorganic phosphorus. Dietary onion also partially reversed the abnormalities in plasma albumin, urea, creatinine and inorganic phosphorus in diabetic animals. Onion also produced a significant reduction in hyperglycemic status of diabetic animals. Diabetic rats maintained on onion diet had a lowered relative liver weight at the end of the study compared to diabetic control group. Diabetic rats fed onion diet also exhibited lowered lipid peroxides in circulation and in urine when compared to diabetic control group. Blood cholesterol was lowered significantly by dietary onion in diabetic animals. Cholesterol decrease was exclusively from LDL-VLDL fraction. Significant decrease in blood phospholipids and triglycerides also brought about by dietary onion. Hepatic cholesterol, triglycerides, phospholipids which were elevated under diabetic condition were countered significantly by dietary onion. Dietary capsaicin did not have any significant influence on any of the parameters tested in diabetic rats. Thus, the study reveals that onion feeding improves the metabolic status in diabetic condition, probably because of its hypoglycemic as well as hypocholesterolemic effect.

Animals↗
PubMed2003

Temporal aspects of onion-induced antiplatelet activity.

Organosulfur compounds in onion extracts are formed following the lysis of the S-alk(en)yl-L-cysteine sulfoxides by alliinase. These compounds inhibit the aggregation of human blood platelets and offer the potential for positive cardiovascular health benefits. An experiment was designed to examine temporal and temperature effects on onion-induced antiplatelet activity. Platelet aggregation is induced by various agonists, including ADP, collagen, and thrombin. Unexpectedly, all freshly-juiced onion extracts (ca. 5 minutes post-juicing) appeared to exhibit both an agonist-free aggregation peak (AFP) and a platelet inhibitory peak (PIP) characteristic of inhibition of platelet aggregation. The AFP was minimal by 30 minutes and dissipated in all treatments by 120 minutes, while the PIP increased as onion extracts aged and did not change after 30 minutes at 25 degrees C. This finding confirms the observation that the in vitro platelet inhibitory activity of onion organosulfur compounds is time dependent. Freshly-prepared onion extracts were incubated with the ADP scavenger enzyme apyrase (E.C. 3.6.1.5). AFPs were abolished in apyrase-treated extracts, suggesting that this response may have been due to free ADP in onion extracts, although an amount of ADP required to generate such a response would be unexpected in onion extracts. In addition, platelet aggregates were not observed in the AFP, suggesting this response may be associated with changes in light transmission through platelet rich plasma that are not associated with platelet aggregation. Artifacts of analysis are, therefore, possible when assessing onion-induced antiplatelet activity with freshly-juiced extracts. Temporal formation of platelet-inhibiting organosulfur compounds should be taken into account during both in vitro and in vivo assessment of onion-induced antiplatelet activity.

Humans↗
PubMed2003

Antihypertensive effects of onion on NO synthase inhibitor-induced hypertensive rats and spontaneously hypertensive rats.

This study was designed to show the effects of onion on blood pressure in N(G)-nitro-L-arginine methyl ester (L-NAME) induced-hypertensive rats and stroke prone spontaneously hypertensive rats (SHRSP) using dried onion at 5% in their diets. For the experiment with L-NAME induced-hypertensive rats, male 6-weeks-old Sprague-Dawley rats were given tap water containing L-NAME to deliver 50 mg/kg BW/day. In this experiment, we found distinct antihypertensive effects of onion on the L-NAME induced-hypertensive rats and the SHRSP. Dietary onion decreased the thiobarbituric acid reactive substances (TBARS) in plasma in these hypertensive rats. Also, onion increased the nitrate/nitrite (products of nitric oxide (NO)) excreted in urine and the NO synthase (NOS) activity in the kidneys in SHRSP. These results suggested that the increased NO caused by the greater NOS activity, and additionally by the increased saving of NO by the antioxidative activity of onion, was one of the cause of the antihypertensive effect of onion in SHRSP. In the L-NAME induced hypertensive rats, onion did not significantly block the inhibition of NOS activity by L-NAME, and decreased nitrate/nitrite excretion in urine was not restored. The mechanism of the antihypertensive effect of onion probably involves increased saving of NO by antioxidative activity of onion in L-NAME induced-hypertensive rats.

Animals↗
PubMed2002

Transfer of a male-sterility-inducing cytoplasm from onion to leek ( Allium ampeloprasum).

Two interspecific triploid (AAC) hybrids (84/1-94 and 99/1-94) from crosses between onion [ Allium cepa (2 n=2 x=16, CC)] and leek [ A. ampeloprasum (2 n=4 x=32, AAAA)] were backcrossed to leek in order to transfer a male-sterility-inducing cytoplasm from onion that would enable the production of hybrid leek. GISH evaluations of meiosis in the interspecific hybrids revealed irregularities due to univalent onion chromosomes producing micronuclei from onion chromatin, whereas the pairing of the two sets of leek chromosomes was nearly normal. Attempts to use colchicine to double the chromosome number of the hybrids failed. Backcrosses of 84/1-94 to leek as the pollen parent were not successful. The first backcross of 99/1-94 to tetraploid leek produced 11 BC(1) plants with chromosome numbers between 38 and 41. Identification of parental chromosomes by GISH showed that all eight onion chromosomes and 30-33 leek chromosomes were transmitted to the backcross progenies due to unreduced egg cells. Onion chromosomes were eliminated during the second backcross. Southern hybridization confirmed the transfer of the T-cytoplasm like source of CMS from onion to the BC(2) progenies. After the third backcross to leek, 158 plants were obtained with varying numbers of onion chromosomes and some intergenomic recombinant chromosomes. Alloplasmic leek plants without onion chromatin were selected for further characterization of male sterility and quality traits.

Journal Article↗
PubMed1995

Antibacterial, antidermatophytic and antitoxigenic activities of onion (Allium cepa L.) oil.

The inhibitory effect of onion oil against the growth of various isolates of bacteria representing Gram-positive (4 isolates) and Gram-negative (4 isolates) species were studied. Results show that onion oil was highly active against all Gram-positive bacteria tested and only one isolate (Klebsiella pneumoniae) of Gram-negative bacteria. The inhibitory effect of onion oil against nine different species of dermatophytic fungi were also studied. Onion oil (200 ppm) completely inhibited the growth of Microsporum canis, M. gypseum and Trichophyton simii while the growth of both, Chrysosporium queenslandicum and Trichophyton mentagrophytes was completely inhibited by 500 ppm of onion oil. The growth of four other species of dermatophytic fungi was gradually reduced by increasing the concentrations of onion oil. The inhibitory effect of onion oil was also tested against four toxigenic isolates of fungi. Onion oil at different concentrations (100, 200 and 500 ppm) tested gradually reduced fungal growth and aflatoxin production by Aspergillus flavus IMI 89,717 and A. parasiticus var. globosus IMI 120,920. Fungal growth and production of sterigmatocystin and rubratoxin A by A. versicolor IMI 16,139 and Penicillium rubrum IMI 136,127 were completely inhibited by the addition of 200 ppm onion oil.

Allium↗