Kiwi Extract Research Articles

Kiwifruit allergy across Europe: Clinical manifestation and IgE recognition patterns to kiwifruit allergens

Kiwifruit is a common cause of food allergy. Symptoms range from mild to anaphylactic reactions. We sought to elucidate geographic differences across Europe regarding clinical patterns and sensitization to kiwifruit allergens. Factors associated with the severity of kiwifruit allergy were identified, and the diagnostic performance of specific kiwifruit allergens was investigated. This study was part of EuroPrevall, a multicenter European study investigating several aspects of food allergy. Three hundred eleven patients with kiwifruit allergy from 12 countries representing 4 climatic regions were included. Specific IgE to 6 allergens (Act d 1, Act d 2, Act d 5, Act d 8, Act d 9, and Act d 10) and kiwifruit extract were tested by using ImmunoCAP. Patients from Iceland were mainly sensitized to Act d 1 (32%), those from western/central and eastern Europe were mainly sensitized to Act d 8 (pathogenesis-related class 10 protein, 58% and 44%, respectively), and those from southern Europe were mainly sensitized to Act d 9 (profilin, 31%) and Act d 10 (nonspecific lipid transfer protein, 22%). Sensitization to Act d 1 and living in Iceland were independently and significantly associated with severe kiwifruit allergy (odds ratio, 3.98 [P = .003] and 5.60 [P < .001], respectively). Using a panel of 6 kiwifruit allergens in ImmunoCAP increased the diagnostic sensitivity to 65% compared with 20% for skin prick tests and 46% ImmunoCAP using kiwi extract. Kiwifruit allergen sensitization patterns differ across Europe. The use of specific kiwifruit allergens improved the diagnostic performance compared with kiwifruit extract. Sensitization to Act d 1 and living in Iceland are strong risk factors for severe kiwifruit allergy.

ANTIOXIDANT EFFECT OF KIWI PEEL METHANOLIC EXTRACT ON OXIDATIVE STABILITY OF SUNFLOWER OIL DURING STORAGE CONDITION

The Oxidation of lipids change organoleptical properties, Nutritional value and shelf life of oils, and produce undesirable compounds that are not safe for customer”s health. There is many methods for prevention of oxidation such synthetic antioxidants, (BHA, BHT, TBHQ, GallatEster).synthetic antioxidants, have undesirable effects such cancer, motation in human body, therefore it was removed from consumption”s list gradually, and it seems necessary production of natural Antioxidants. In this research the first, plant extract included phenolic compounds, Tocopherol was extracted by methanolic solvent from kiwi peel and added at 2 concentration (400 and 80ppm) to sunflower oil without antioxidant and storage at 250c during 60 day Then oxidative stability determined by parameters such, proxid value, OSI, Acid value, Carbonyl value, Total polar compound at storage Temperature at time(0,15,45,60)days during storage and were compared with sunflower oil containing 100ppm (TBHQ). Results showed that concentration (800ppm) of kiwi peel extract was more effective than on stability of sunflower oil Related to 100ppmTBHQ, 400ppm kiwi peel extract. It seems Concentration of 800ppm peel kiwi extract to having higher levels of Phenols and tocopherols content is more effective

Determination and Evaluation of Antioxidative Activity in Red Dragon Fruit (&lt;i&gt;Hylocereus undatus&lt;/i&gt;) and Green Kiwi Fruit (&lt;i&gt;Actinidia deliciosa&lt;/i&gt;)

Problem statement: Dragon fruit or pitahaya (Hylocereus undatus), is believed to be a healthy source of vitamins, fiber and antioxidants, especially the red-fleshed varieties which contain lycopene. Approach:Compared to green kiwi fruit (Actinidia deliciosa), which already known contain high antioxidant activity. Results:The antioxidant capacity of Hylocereus undatus (H. undatus) and Actinidia deliciosa (A. deliciosa) in three different solvent extraction; ethanol, methanol and aqueous, was estimated by DPPH free radical scavenging assay. The inhibition of free radical by A. deliciosa is almost 90% compared with H. undatus which only 60-10% in different solvents. Additionally, their total phenolic contents were analyzed by folin-ciocalteau method. The result showed that A. deliciosa (533.70 mg L-1 in ethanol, 460.87 mg L-1 in methanol and 420.652 mg L-1 in distilled water) seemed to be better sources of antioxidant compounds then H. undatus (179.35 mg L-1 in ethanol, 160.87 mg L-1 in methanol and 157.61 in distilled water). Conclusion: When compared between the three different solvent, extract in ethanol shown the most highly antioxidant content followed by methanol and water. The experiment showed the potential of dragon fruit and kiwi extracts high rich in antioxidant which can scavenge free radical in human body. Further study on isolation of individual antioxidant in both extracts can be providing for commercialize the extracts in jus form.

Allergy to kiwi in patients with baker's asthma: identification of potential cross-reactive allergens

Baker's asthma is a frequent IgE-mediated occupational disorder mainly provoked by inhalation of cereal flour. Allergy to kiwifruit has being increasingly reported in the past few years. No association between both allergic disorders has been described so far. Twenty patients with occupational asthma caused by wheat flour inhalation were studied. Kiwi allergens Act d 1 and Act d 2 were purified by cation-exchange chromatography. Wheat, rye, and kiwi extracts, purified kiwi allergens, and model plant glycoproteins were analyzed by IgE immunodetection, enzyme-linked immunosorbent assay (ELISA), and inhibition ELISAs. Kiwifruit ingestion elicited oral allergy syndrome in 7 of the 20 patients (35%) with baker's asthma. Positive specific IgE and skin prick test responses to this fruit were found in all these kiwi allergic patients, and IgE to Act d 1 and Act d 2 was detected in 57% and 43%, respectively, of the corresponding sera. Actinidin Act d 1 and bromelain (harboring cross-reactive carbohydrate determinants) reached above 50% inhibition of the IgE binding to wheat and/or kiwi extracts. A potential association between respiratory allergy to cereal flour and allergy to kiwifruit has been disclosed. Cross-reactive carbohydrate determinants and thiol-proteaseshomologous to Act d 1 are responsible for wheat-kiwi crossreactivity in some patients.

Allergy to kiwi: A double-blind, placebo-controlled food challenge study in patients from a birch-free area

Background Allergy to kiwi fruit is being increasingly reported, but it has never been evaluated by means of a double-blind, placebo-controlled food challenge (DBPCFC) study. Objective We sought to assess kiwi allergy on the basis of a DBPCFC and identify the patterns of allergen recognition in sensitized patients from a birch-free area. Methods Forty-three patients with allergy symptoms who were sensitized to kiwi were evaluated by means of clinical history, skin tests, IgE determinations, and DBPCFCs. The pattern of allergen recognition was assessed by means of IgE immunoblotting. Sequence analysis of IgE-binding bands was performed by using Edman degradation. Results DBPCFCs were performed in 33 patients; 4 patients had experienced severe anaphylaxis, and 6 patients declined informed consent. DBPCFC results were positive in 23 patients and negative in 10 patients. The most frequent clinical manifestation was oral allergy syndrome. Twenty-one percent of the patients were not allergic to pollen. Forty-six percent of patients experienced systemic symptoms, and this happened with higher frequency in patients not allergic to pollen (100%). Twenty-eight percent of the patients were sensitized to latex. The IgE-binding bands in kiwi extract more frequently recognized by patient sera were those of 30, 24, 66, and 12 kd, and they could not be associated with any pattern of kiwi-induced allergic reactions. Conclusion The results provide evidence that kiwi allergy is not a homogeneous disorder because several clinical subgroups can be established. No definite allergen-recognition pattern was associated with the type of allergic reactions to kiwi. One of 5 patients with kiwi allergy was not allergic to pollen, and these patients had the highest risk of systemic reactions to kiwi.

Immunochemical study of a pineapple ( Ananas comosus) extract

Rationale Pineapple is an exotic fruit very common in the population diet. No IgE-mediated reactions to pineapple have been described, and no major allergens have yet been identified. The aim of this study was to start characterizing the allergens of pineapple. Methods Informed consent was obtained from subjects involved in the investigation. Eleven sera from patients with allergic symptoms after eating pineapple were tested for specific IgE antibodies by ELISA and the positive sera were used for immunoblotting assays. Pineapple extract was separated by means of SDS-PAGE and transferred onto 0.2 μg nitrocellulose (NC) membrane. IgE antibody detection was performed with alkaline phosphatase-conjugated mouse polyclonal anti-human IgE. ELISA inhibition experiments were done with kiwi and pineapple extracts using two positive sera. Results Five of the eleven patients (45%) with symptoms of pineapple allergy had a positive ELISA. Immunoblotting with these sera showed IgE binding to proteins of 24KD (5/5), 39KD (3/5) and 70KD (3/5). Conclusions Specific IgE in pineapple allergic patients binds several allergens in a pineapple extract. Inhibition experiments with kiwi extract suggest cross-reactivity between these two fruits.

Isolation and biochemical characterization of a thaumatin-like kiwi allergen

Background: Kiwi fruit allergy, as well as its association with hypersensitivity to other foods and to pollen, has been extensively reported in the last few years. Several IgE-binding components have been detected in kiwi extract, but only one 30-kd allergen has been isolated; it was identified as actinidin (Act c 1). Recently, we have reported a 24-kd kiwi protein to be a potential major allergen in a group of patients with oral allergy syndrome (OAS). Objective: The aim of this study was to purify and characterize the 24-kd kiwi allergen biochemically. Methods: Seven polysensitized patients with OAS to kiwi were used in this study. The kiwi allergen was isolated by using a combination of gel permeation, ion exchange, and immobilized metal ion affinity chromatography. Its biochemical characterization included determination of its isoelectric point, molecular weight, N-terminal sequencing, concanavalin A –binding ability, digestibility in simulated gastric fluid, and antifungal activity. Western blotting, 2-dimensional PAGE immunoblotting, and skin prick tests were performed to characterize the isolated protein immunochemically. Results: All 7 patients recognized the isolated 24-kd kiwi protein as an allergen. The isolated protein consisted of 2 isoforms with isoelectric points of 9.4 and 9.5 migrated as one protein band of 20 kd after SDS-PAGE under nonreducing conditions or at 24 kd under reducing conditions. The partial N-terminal sequence revealed that it is a thaumatin-like protein (TLP) with concanavalin A –binding ability. The protein showed antifungal activity toward Saccharomyces carlsbergensis , and Candida albicans . The protein was degraded by the simulated gastric fluid within 1 minute. Both isoforms bound IgE from a pool of sera in a 2-dimensional PAGE immunoblot. The TLP elicited positive skin prick test responses in 4 (80 %) of 5 patients with OAS. Conclusion: This study reported isolation and full characterization of a new kiwi allergen, TLP (isoelectric points of 9.4 and 9.5 and molecular weight of 24 kd), which belongs to the family of pathogenesis-related proteins. The isolated protein expressed antifungal activity toward S carlsbergensis and C albicans . (J Allergy Clin Immunol 2002;110:805-10.)

Kiwifruit Protects Against Oxidative DNA Damage in Human Cells and In Vitro

Antioxidant micronutrients may account for the beneficial effects of fruits on human health. A direct demonstration that consumption of fruit decreases oxidative DNA damage in human cells would support this hypothesis. Kiwifruit was taken as an example of a food with putative antioxidant properties, and its effectiveness at decreasing oxidative DNA damage was assessed in ex vivo as well as in vitro tests. The comet assay (single-cell gel electrophoresis) was used to measure DNA damage in lymphocytes collected during a human supplementation trial with a single 0.5-liter drink of kiwifruit juice (with water as a control). The comet assay was also modified to assess the antioxidant effect of kiwifruit in vitro by measuring the ability of an extract to interfere with oxidative damage to DNA induced by H2 O2. Ex vivo, consumption of kiwifruit led to an increased resistance of DNA to oxidative damage induced by H2 O2 in isolated lymphocytes, in comparison with lymphocytes collected after a control drink of water. No effect was seen on endogenous DNA damage. In vitro, a simple extract of kiwifruit, buffered to pH 7, was more effective than a solution of vitamin C (of equivalent concentration) at protecting DNA from damage, whereas at the highest concentrations tested, neither kiwi extract nor vitamin C had a protective effect. We have demonstrated significant antioxidant activity of kiwifruit ex vivo and in vitro, not attributable entirely to the vitamin C content of the fruit. Our dual approach is appropriate for testing other fruit and vegetable products for potential antioxidant effects.

Antimutagenic Effect of Fruit and Vegetable Aqueous Extracts against N-Nitrosamines Evaluated by the Ames Test

The inhibitory effect of nine fruit and vegetable aqueous extracts against the mutagenicity of N-nitrosodimethylamine (NDMA), N-nitrosopyrrolidine (NPYR), N-nitrosodibutylamine (NDBA), and N-nitrosopiperidine (NPIP) was evaluated by means of the Ames test. Onion extract (500 μg/plate) showed the greatest inhibitory effect (60%) against NDMA, and the mutagenicity of NPYR was inhibited markedly (54%) by apple extract (50 μg/plate). The antimutagenic effect of carrot extract (250 μg/plate) was remarkable (49%) against NDBA, and the mutagenicity of NPIP was also strongly inhibited (65 and 50%) by garlic and kiwi extracts (2000 μg/plate), respectively. Vegetable and fruit extracts that exhibited an antimutagenic effect in decreasing order against NDMA and NPYR were as follows: onion > licorice > kiwi = apple > carrot > garlic > pineapple > broccoli; and apple > broccoli > kiwi > onion = pineapple, respectively. Decreasing orders against NDBA and NPIP were, respectively, carrot > garlic > broccoli > onion > kiwi and garlic > kiwi > broccoli > green pepper > pineapple > carrot > onion = apple. Keywords: Vegetables; fruits; N-nitrosamines; mutagenicity; Ames test

Allergenic properties of kiwi-fruit extract: cross-reactivity between kiwi-fruit and birch-pollen allergens.

Our investigation aimed to produce and characterize a kiwi extract and to use this extract to investigate a possible cross-reactivity with birch pollen. Kiwi was extracted in two buffers: phosphate-buffered saline (PBS) and borate-buffered saline (BBS). Extraction in BBS produced a double amount of protein, and a more stabile extract. Tandem crossed-immunoelectrophoresis showed that the BBS and PBS extracts had several common, but also a few individual, proteins. The mixture of both extracts was assumed to represent the most complete allergen extract. The allergenic properties of the kiwi extract were investigated by immunoblotting (IB), RAST, and histamine-release (HR) test in 15 birch-pollen-allergic patients (eight of them with clinical kiwi allergy) and one with clinical monoallergy to kiwi. All eight birch-pollen-allergic patients with kiwi allergy and the kiwi-monoallergic patient were positive in kiwi IB binding most frequently to proteins of 10-12 and 20-25 kDa. With our extract, RAST was positive in four kiwi-allergic and one non-kiwi-allergic patient, whereas the HR test was positive in five kiwi-allergic patients and negative in all non-kiwi-allergic patients. RAST and IB inhibition demonstrated cross-reactivity between birch-pollen and kiwi allergens due to a 10-12 kDa protein. In conclusion, a kiwi extract with allergenic properties was produced, and, by the methods used, cross-reactivity was demonstrated between birch-pollen and kiwi allergens.

Identification of the allergenic components of kiwi fruit and evaluation of their cross-reactivity with timothy and birch pollens

BACKGROUND: Only a few food allergens have as yet been identified, mainly because of the difficulty of obtaining a sufficient number of patients who are clinically sensitized to a given food. This is more feasible in the case of the oral allergy syndrome (OAS), a common form of food allergy, which is especially prevalent in patients with pollinosis. OBJECTIVE: We designed a study to identify the allergens of kiwi fruit (Actinidia chinensis) by analyzing the sera of patients with OAS for kiwi and to examine the cross-reactivity of these allergens with timothy and birch pollen allergens. METHODS: Twenty-seven patients with OAS for kiwi, a positive skin prick test response and serum IgE antibody to kiwi, and a positive open kiwi challenge test result and three patients who had OAS with severe systemic symptoms, which excluded a challenge test, were included in this study. The different polypeptide components of an extract of fresh kiwi were separated by sodium dodecylsulfate–polyacrylamide gel electrophoresis and analyzed by IgE immunoblotting with sera from these patients. Cross-reactivity with the two pollen extracts was assessed by inhibition of the immunoblots with pooled and individual patients’ sera. RESULTS: Twelve IgE-binding components with molecular weights ranging from 12 to 64 kd were identified in the kiwi extract, but only a 30 kd component acted as major allergen, being recognized by sera of 100% of these patients. Inhibition of kiwi immunoblots with timothy and birch pollen extracts demonstrated strong cross-reactivity with some of the kiwi allergens, suggesting complete identity between certain food and pollen allergens; whereas others, particularly the 30 kd allergen, were only partially inhibited, suggesting much weaker cross-reactivity. CONCLUSIONS: Kiwi fruit contains a large number of allergens widely cross-reacting with allergens in grass and birch pollen extracts. Nevertheless, the major allergen at 30 kd appears to be specific for kiwi. (J A LLERGY C LIN I MMUNOL 1996;98:601-10.)