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PubMed2004

Development of a real-time PCR and a sandwich ELISA for detection of potentially allergenic trace amounts of peanut (Arachis hypogaea) in processed foods.

Hidden allergens in food products are, especially for peanut-allergic consumers, a serious problem because even low amounts (approximately 200 microg) of peanut can elicit allergic reactions. Undeclared peanut traces can be found in processed food products, because contaminations with peanut during production processes are frequent. To minimize the risk of such cross-contaminations, it is necessary to develop sensitive analytical methods for the detection of hidden allergens in foods. For this approach we developed two peanut-specific assays based on the detection of peanut protein by specific antibodies (sandwich ELISA) and by the detection of peanut-specific DNA (part of the coding region of Ara h 2) by a real-time PCR. Both tests did not show any cross-reactivity with 22 common food ingredients (cereals, nuts, legumes), and the limit of detection is <10 ppm peanut in processed foods. Thirty-three random samples of food products were tested for the presence of peanut to compare both assay types with each other and to evaluate the percentage of foods on the German market that are contaminated with peanut traces. We found that four products (13.3%) without peanut in the list of ingredients contained peanut protein in a range from 1 to 74 ppm peanut protein and that the results of both tests correlated well. The real-time PCR was able to detect one more positive sample than the sandwich ELISA. In conclusion, both assays are sensitive and specific tools for the detection of hidden allergens in processed foods.

Allergens↗
PubMed2003

Monitoring peanut allergen in food products by measuring Ara h 1.

BACKGROUND: Peanut allergy is an important health problem in the United States, affecting approximately 0.6% of children. Inadvertent exposure to peanut is a risk factor for life-threatening food-induced anaphylaxis. OBJECTIVE: The purpose of this investigation was to develop an immunoassay for a major peanut allergen, Ara h 1, to detect peanut allergen in foods so that the risk of inadvertent exposure can be reduced. METHODS: A specific 2-site monoclonal antibody-based ELISA was developed to measure Ara h 1 in foods. The sensitivity of the assay was 30 ng/mL. Ara h 1 was measured in foods (n = 83) with or without peanut and in experiments to optimize allergen yield and to determine peanut contamination in spiked foods. RESULTS: Ara h 1 levels in food products ranged from less than 0.1 microg/g to 500 microg/g. Ara h 1 measured in ng/mL was transformed to microg/g for food products. Peanut butter contained the highest amounts of Ara h 1. Peanut extracts contained from 0.5 to 15 mg Ara h 1/g of peanut depending on the extraction conditions. Optimal extraction of Ara h 1 was obtained by using phosphate buffer with 1 mol/L NaCl and Tween at 60 degrees C. Ara h 1 was not always detected in presence of chocolate under the extraction conditions tested. Spiking experiments showed that the assay could detect approximately 0.1% Ara h 1 contamination of food with ground peanut. There was an excellent correlation between Ara h 1 levels and peanut content measured by using a commercial polyclonal antibody-based ELISA (r = 93, n = 31, P <.001). CONCLUSION: A new sensitive and specific monoclonal antibody-based ELISA was used to monitor Ara h 1 content in food products. This assay should be useful for monitoring peanut contamination in the food manufacturing and processing industry and in developing thresholds for sensitization or allergic reaction in persons with peanut allergy.

Allergens↗
PubMed2000

Peanuts as a source of beta-sitosterol, a sterol with anticancer properties.

Work from our laboratory, as well as others, suggests a protective role of phytosterols (PS), especially beta-sitosterol, from colon, prostate, and breast cancer. Asians and vegetarians consume higher amounts of PS than Western societies. The latter societies have a higher incidence of these cancers than Asians and vegetarians. The aim of this study was to evaluate peanuts and its products as sources of PS in the American diet. Roasted peanuts contain 61-114 mg PS/100 g depending on the peanut variety, 78-83% of which is in the form of beta-sitosterol. Unrefined peanut oil contains 207 mg PS/100 g, which is similar to that of the US Department of Agriculture Nutrient Database. This value is higher than that of unrefined olive oil. Refining these oils results in reduction in PS concentration in the oil. This loss is greater in the case of olive oil than peanut oil. Further refining, such as deodorization, results in significant loss in PS, but hydrogenation after refining has a minimal effect on PS loss. Peanut butter, which represents 50% of the peanuts consumed in the United States, contains 144-157 mg PS/100 g. Peanut flour, which results from partial removal of oil from peanuts, contains 55-60 mg PS/100 g. The data suggest that peanuts and its products, such as peanut oil, peanut butter, and peanut flour, are good sources of PS.

Antineoplastic Agents↗
PubMedDate not supplied

Peanut sensitivity.

Peanuts are one of the most allergenic foods. The allergic reactions may vary in severity from mild urticaria to severe anaphylactic episodes and death. The prevalence of peanut sensitivity is unknown, but it may affect as many as 10% of allergic individuals. The chemistry of peanut proteins has been extensively studied. Two major protein fractions have been prepared from saline extracts of peanut flour, arachin and conarachin. A major peanut allergen termed "Peanut-1" has been isolated. However, a number of protein constituents, including the arachin and conarachin fractions, have been shown to be allergenic. The ability to diagnose peanut sensitivity accurately has been hampered by the lack of standardized peanut extracts. However, efforts are under way to prepare such standardized reagents. Treatment consists of avoiding peanut protein products and using self-administered epinephrine. A number of peanut protein-containing products are allergenic, although peanut oil is not. The peanut-allergic consumer should be instructed to carefully read labels of foods. This can at times, however, be misleading, because certain foods may be inadvertently contaminated by peanut proteins.

Allergens↗
PubMed2004

Survival, growth, and thermal resistance of Listeria monocytogenes in products containing peanut and chocolate.

Outbreaks of listeriosis associated with the consumption of ready-to-eat foods have raised interest in determining growth, survival, and inactivation characteristics of Listeria monocytogenes in a wide range of products. A study was undertaken to determine the thermal tolerance of L. monocytogenes in a peanut-based beverage (3.1% fat), whole-fat (3.5%) milk, wholefat (4.0%) and reduced-fat (1.0%) chocolate milk, a chocolate-peanut spread (39% fat), and peanut butter (53% fat). The D60 degrees C value (decimal reduction time at 60 degrees C) in peanut beverage (3.2 min) was not significantly different (P > 0.05) than the D60 degrees C value in whole-fat milk (3.3 min) or whole-fat chocolate milk (4.5 min) but significantly lower (P < or = 0.05) than the D60 degrees C value in reduced-fat chocolate milk (5.9 min). The pathogen was significantly more resistant to heat when enmeshed in chocolate-peanut spread (water activity [aw] of 0.46; D60 degrees C = 37.5 min) and peanut butter (aw of 0.32; D60 degrees C = 26.0 min) than in liquid products. At 10 degrees C, the pathogen grew most rapidly in whole-fat chocolate milk and slowest in peanut beverage. At 22 degrees C, populations increased significantly within 12 and 16 h in whole-fat milk and reduced-fat chocolate milk, respectively, and within 8 h in whole-fat chocolate milk and peanut beverage. Initial populations (3.37 to 4.42 log CFU/g) of L. monocytogenes in chocolate-peanut spread and peanut butter adjusted to an aw of 0.33 and 0.65 declined, but the pathogen was not eliminated during a 24-week period at 20 degrees C. Survival was enhanced at reduced aw. Results indicate that a pasteurization process similar to that used for full-fat milk would be adequate to ensure the destruction of L. monocytogenes in peanut beverage. The pathogen survives for at least 24 weeks in chocolate-peanut spread and peanut butter at an aw range that encompasses that found in these products.

Arachis↗
PubMed2004

Distribution of peanut allergen in the environment.

BACKGROUND: Patients with peanut allergy can have serious reactions to very small quantities of peanut allergen and often go to extreme measures to avoid potential contact with this allergen. OBJECTIVE: The purpose of this study was to detect peanut allergen under various environmental conditions and examine the effectiveness of cleaning agents for allergen removal. METHODS: A monoclonal-based ELISA for Arachis hypogaea allergen 1 (Ara h 1; range of detection, 30-2000 ng/mL) was used to assess peanut contamination on cafeteria tables and other surfaces in schools, the presence of residual peanut protein after using various cleaning products on hands and tabletops, and airborne peanut allergen during the consumption of several forms of peanut. RESULTS: After hand washing with liquid soap, bar soap, or commercial wipes, Ara h 1 was undetectable. Plain water and antibacterial hand sanitizer left detectable Ara h 1 on 3 of 12 and 6 of 12 hands, respectively. Common household cleaning agents removed peanut allergen from tabletops, except dishwashing liquid, which left Ara h 1 on 4 of 12 tables. Of the 6 area preschools and schools evaluated, Ara h 1 was found on 1 of 13 water fountains, 0 of 22 desks, and 0 of 36 cafeteria tables. Airborne Ara h 1 was undetectable in simulated real-life situations when participants consumed peanut butter, shelled peanuts, and unshelled peanuts. CONCLUSION: The major peanut allergen, Ara h 1, is relatively easily cleaned from hands and tabletops with common cleaning agents and does not appear to be widely distributed in preschools and schools. We were not able to detect airborne allergen in many simulated environments.

Adult↗
PubMed2006

Late diagnosis of tree nut and sesame allergy in patients previously sensitized but tolerant to peanut.

BACKGROUND: Recent studies have indicated that tolerance to peanut can occur in patients with a history of peanut allergy. Tree nut and sesame allergies have been reported to occur at increased incidence in patients with peanut allergy. Although the coexistence may be simply due to a predisposition to food allergy in these individuals, cross-reactivity has been demonstrated between peanut and tree nuts and between peanut and sesame seed. OBJECTIVE: To describe 3 patients previously sensitized but tolerant to peanut who were subsequently diagnosed as having either tree nut or sesame allergy. METHODS: All the patients had a clinical history of peanut sensitivity and underwent follow-up peanut skin testing to commercial extracts using a bifurcated needle followed by a graded peanut challenge. One patient had a previous positive radioallergosorbent test reaction to sesame and underwent a graded sesame challenge. RESULTS: All the patients had negative peanut challenge results. Two patients subsequently had exposure to tree nuts at home and had systemic reactions and positive skin test reactions to the incriminated tree nut. One patient had a positive challenge reaction to sesame. CONCLUSION: Demonstration of tolerance to peanut may falsely reassure patients and physicians that patients no longer need to avoid tree nuts or sesame. Tree nut and sesame allergies can exist or develop in patients despite the development of tolerance to peanut.

Adolescent↗
PubMed2000

Systemic effect of peanut agglutinin following intravenous infusion into rats.

BACKGROUND: Ingested peanut agglutinin stimulates colonic proliferation in humans. In rats, ingested peanut agglutinin stimulates hormone release and proliferation in the small and large intestines. Peanut agglutinin is absorbed into the circulation but little is known about the systemic effect of this lectin. Therefore, we studied the effect of intravenous peanut agglutinin on hormone release and intestinal growth. METHOD: Six rats per group received peanut agglutinin infusion at 0, 2, 20 or 200 microg/rat/day for 6 days via the right jugular vein. Organ weights were measured, pancreatic enzymes, DNA, RNA and protein levels were analysed. Plasma hormones were measured by radioimmunoassay. All tissues were examined histologically. Small intestinal and colonic proliferation rates were estimated by metaphase arrest. RESULTS: High-dose peanut agglutinin significantly reduced the wet weight of the stomach by 7% (P < 0.05) and large intestine by 10% (P < 0.05). Peanut agglutinin dose-dependently released enteroglucagon; low-, medium- and high-dose by 64%, 126% (P < 0.01) and 180% (P < 0.01), respectively, and glucagon-like peptide-1 by 127% (P < 0.01), 169% (P < 0.01) and 315% (P < 0.001), respectively. Peanut agglutinin had no effect on cholesystokinin, gastrin or insulin levels. Peanut agglutinin, low-, medium- and high-dose stimulated proliferation in the mid colon by 42% (P < 0.01), 30% and 38%, respectively. Only high-dose peanut agglutinin stimulated proliferation in the distal colon by 54% (P < 0.01). No histological changes were evident in any tissue. CONCLUSION: Intravenous peanut agglutinin released hormones and stimulated colonic proliferation. Proliferation of the small intestine seen after ingestion of peanut agglutinin in previous studies appears to require luminal contact between enterocytes and the lectin. Possible clinical applications include reversal of atrophy during total parenteral nutrition, anastomotic healing after surgery and restoration of mucosa integrity in colitis.

Animals↗
PubMed2003

Thresholds of clinical reactivity to milk, egg, peanut and sesame in immunoglobulin E-dependent allergies: evaluation by double-blind or single-blind placebo-controlled oral challenges.

BACKGROUND: The prevalence of food anaphylaxis due to masked allergens has increased within the last 10 years. Contamination of manufactured products by food allergens is a key concern for food industries. OBJECTIVE: To determine quantities eliciting reactions in patients who have an IgE-dependent food allergy, thanks to standardized oral provocation tests. To evaluate the subsequent levels of sensitivity required for the detection tests of allergens for egg, peanut, milk and sesame. METHODS: Prick-in-prick tests, Cap system RAST, and single or double-blind placebo-controlled food challenges (SBPCFC or DBPCFC) were performed. The doses of natural food were gradually increased from 5 to 5000 mg for solid food and from 1 to 30 mL for peanut oil, sunflower oil, soy oil and sesame oil. RESULTS: Data from 125 positive oral challenges to egg, 103 to peanut, 59 to milk and 12 to sesame seeds were analysed. Haemodynamic modifications were observed in 2%, 3%, 1.7%, and 8% of the oral challenges (OCs) to egg, peanut, milk and sesame, respectively. Respiratory symptoms were observed in 12%, 20%, 10% and 42% of egg, peanut milk and sesame allergies, respectively. A cumulative reactive dose inferior or equal to 65 mg of solid food or 0.8 mL of milk characterized 16%, 18%, 5% and 8% of egg, peanut, milk and sesame allergies, respectively. 0.8% of egg allergies, 3.9% of peanut allergies, and 1.7% of milk allergies reacted to 10 mg or less of solid food or to 0.1 mL for milk. The lowest reactive threshold has been observed at less than 2 mg of egg; 5 mg of peanut, 0.1 mL of milk and 30 mg of sesame seed. Ten out of 29 OC with peanut oil, two out of two OC with soy oil and three out of six OC with sunflower oil were positive. Five out six OC with sesame oil were positive: 1 and 5 mL induced an anaphylactic shock. CONCLUSION: The risk of asthma and anaphylactic shock to sesame and peanut is confirmed. Minimal reactive quantities show that, in order to guarantee a 95% safety for patients who are allergic to egg, peanut and milk, and on the basis of consumption of 100 g of food, the detection tests should ensure a sensitivity of 10 p.p.m. for egg, 24 p.p.m. for peanut and 30 p.p.m. for milk proteins. Oil allergies being considered, the limit of sensitivity should fall to 5 p.p.m.

Administration, Oral↗
PubMed2002

A neonatal swine model for peanut allergy.

BACKGROUND: Peanut allergy represents a significant health threat in the United States. The factors contributing to the severity of the allergic response and the immunopathogenic mechanisms underlying peanut allergy remain to be completely characterized. As yet, no animal model has been developed that will completely mimic the physical, immunologic, and histologic features of food allergy. OBJECTIVE: The purpose of this investigation was to develop a neonatal pig model of peanut allergy that would mimic the allergic symptoms and the immunologic and histologic profile of human peanut allergy. METHODS: Newborn piglets sensitized intraperitoneally with peanut extract and cholera toxin were orally challenged repeatedly with peanut meal. Physical symptoms, including emesis, lethargy, diarrhea, and respiratory distress, were monitored to determine the allergic response. Immunologic assessment was conducted through use of skin testing and the antigenic response to peanut proteins. Histologically, tissues derived from the esophagus, stomach, small intestine, and colon were assessed for morphologic changes after the oral challenge. RESULTS: Peanut-sensitized pigs responded with physical symptoms that mimicked those seen in double-blinded, placebo-controlled oral food challenges to peanuts in children and adults. Skin testing suggested an IgE-mediated response; this was confirmed by a negative passive cutaneous anaphylaxis response of heat-treated sera obtained from peanut-sensitized animals. Damage to villi of the small intestine was similar to that seen in endoscopically obtained tissue specimens from certain food-allergic individuals. CONCLUSION: The neonatal pig model of peanut allergy mimics the physical and immunologic characteristics of peanut allergy in human beings. The model will be useful for determining IgE-mediated mechanisms and conducting endoscopic histologic assessment of tissues and immunotherapeutic intervention strategies with repeated allergen challenges.

Anaphylaxis↗
PubMed2002

Rising prevalence of allergy to peanut in children: Data from 2 sequential cohorts.

BACKGROUND: Allergy to peanut is common. However, it is not known whether the prevalence of sensitization and clinical allergy to peanut is increasing. OBJECTIVE: We sought to determine any change in the prevalence of peanut sensitization and reactivity in early childhood in 2 sequential cohorts in the same geographic area 6 years apart. METHODS: Of 2878 children born between September 1, 1994, and August 31, 1996, living on the Isle of Wight, 1273 completed questionnaires, and 1246 had skin prick tests at the age of 3 to 4 years. Those with positive skin prick test responses to peanut were subjected to oral peanut challenges, unless there was a history of immediate systemic reaction. These data were compared with information on sensitization and clinical allergy to peanut available from a previous cohort born in 1989 in the same geographic area. RESULTS: There was a 2-fold increase in reported peanut allergy (0.5 % [6/1218] to 1.0 % [13/1273]), but the difference was nonsignificant (P =.2). Peanut sensitization increased 3-fold, with 41 (3.3 %) of 1246 children sensitized in 1994 to 1996 compared with 11 (1.1 %) of 981 sensitized 6 years ago (P =.001). Of 41 sensitized children in the current study, 10 reported a convincing clinical reaction to peanut, and 8 had positive oral challenge results, giving an overall estimate of peanut allergy of 1.5% (18/1246). CONCLUSIONS: Sensitization to peanut had increased between 1989 and 1994 to 1996. There was a strong but statistically nonsignificant trend for increase in reported peanut allergy.

Child, Preschool↗
PubMed2003

Patients with anaphylaxis to pea can have peanut allergy caused by cross-reactive IgE to vicilin (Ara h 1).

BACKGROUND: Serologic cross-reactivity among legumes has been described; however, it is rarely clinically significant. In this study 3 patients with a history of anaphylaxis to pea are described who subsequently had symptoms after ingestion of peanut. OBJECTIVE: We investigated whether the peanut-related symptoms were due to cross-reactivity between pea and peanut proteins. METHODS: Peanut-related symptoms were documented according to case history or double-blind, placebo-controlled food challenge results. Skin prick tests were performed, and specific IgE levels were determined for pea and peanut with the CAP system FEIA. IgE-binding proteins in pea and peanut were identified by using immunoblot analysis. Cross-reactivity was studied by means of immunoblot and ELISA inhibition studies with whole extracts and purified allergens. RESULTS: Peanut-related symptoms consisted of oral symptoms in all patients, with additional urticaria and dyspnea or angioedema in 2 patients. All patients had a positive skin prick test response and an increased IgE level to pea and peanut. Immunoblotting revealed strong IgE binding to mainly vicilin in pea extract and exclusively to Ara h 1 in crude peanut extract. Immunoblot and ELISA inhibition studies with crude extracts, as well as purified proteins, showed that IgE binding to peanut could be inhibited by pea but not or only partially the other way around. CONCLUSION: Clinically relevant cross-reactivity between pea and peanut does occur. Vicilin homologues in pea and peanut (Ara h 1) are the molecular basis for this cross-reactivity.

Allergens↗
PubMed2003

Presence of undeclared peanut protein in chocolate bars imported from Europe.

Peanut allergens are both stable and potent and are capable of inducing anaphylactic reactions at low concentrations. Consequently, the consumption of peanuts remains the most common cause of food-induced anaphylactic death. Since accidental exposure to peanuts is a common cause of potentially fatal anaphylaxis in peanut-allergic individuals, we tested for the presence of peanut protein in chocolate bars produced in Europe and North America that did not list peanuts as an ingredient. Ninety-two chocolate bars, of which 32 were manufactured in North America and 60 were imported from Europe, were tested by the Veratox assay. None of the 32 North American chocolate products, including 19 with precautionary labeling, contained detectable peanut protein. In contrast, 30.8% of products from western Europe without precautionary labeling contained detectable levels of peanut protein. Sixty-two percent of products from eastern Europe without precautionary labeling contained detectable peanut protein at levels of up to 245 ppm. The absence of precautionary labeling and the absence of the declaration of "peanut" as an ingredient in chocolate bars made in eastern and central Europe were not found to guarantee that these products were actually free of contaminating peanut protein. In contrast, North American manufacturers have attained a consistent level of safety and reliability for peanut-allergic consumers.

Arachis↗
PubMed1990

Immunoassay of peanut allergens in food-processing materials and finished foods.

To quantitate trace amounts of peanut allergens in food-processing materials and finished foods, we established a solid-phase radioimmunoassay inhibition using pooled sera from five peanut-sensitive subjects and a roasted peanut-meal extract covalently linked to polyacrylamide beads. Test samples were extracted, dialyzed, lyophilized, and reconstituted at 10 to 225 mg of dry weight per milliliter concentrations. The peanut-allergen content of test samples was expressed relative to a reference extract of roasted peanut meal that was assigned an arbitrary potency of 100,000 U/ml. In confectionery products spiked with varying quantities of peanut (0.7% to 0.0175%), the recovery of peanut allergen ranged from 31% to 94%. The sensitivity of the assay was 2.5 U/mg of dry weight from these samples (0.00875% peanut). Peanut allergens were undetectable in virgin vegetable oil used to roast peanuts, but 600 to 7600 U/mg of dry weight were present in oil after varying periods of use. The allergen content of used oil was reduced to 8 U/mg of dry weight by filtration and steam cleaning. The availability of such assays provides a means of monitoring finished food products for potential allergens. This monitoring in turn will provide the means to correlate symptoms experienced by sensitive patients with the exact quantity of allergen ingested. At the present time, there is little information on the quantities of ingested peanut allergen that pose risks to peanut-sensitive subjects.

Allergens↗
PubMed1998

Serological characteristics of peanut allergy.

BACKGROUND: Peanut is the most common cause of severe or fatal food-associated anaphylaxis. Studies indicate that peanut extracts contain many allergenic proteins. The identification of major and minor allergenic components is necessary for standardization of experimental and diagnostic extracts. OBJECTIVE: To identify further major and minor allergenic components of peanut extract using a large population of peanut allergics, and to relate serological findings to clinical parameters. METHODS: The crude peanut extract was fractionated by fast protein liquid chromatography and the IgE binding proteins identified by sodium dodecyl sulphate polyacrylamide gel electrophoresis followed by western blotting. Serum from 89 peanut allergics with a positive history of peanut allergy and elevated specific IgE and control serum from four atopic and four non-atopic, non-peanut allergics were used. RESULTS: Nineteen peanut proteins were found to bind IgE from peanut allergic sera. Over 70% of subjects reacted to protein bands of 63 and 17 kDa (consistent with Ara h 1 and Ara h 2, respectively), confirming the importance of these two proteins as major allergens. A high proportion of patient sera also bound proteins at 15, 10, 30, 18 and 51 kDa in decreasing order. The percentage of cases with sensitivity to a 15 kDa protein was found to be higher in patient groups with severe reactions to peanut. CONCLUSION: This study highlights the diversity of peanut allergens. Diagnostic extracts containing a high proportion of the 15 kDa component may aid in diagnosis.

Adolescent↗
PubMed2001

Food Allergy Herbal Formula-1 (FAHF-1) blocks peanut-induced anaphylaxis in a murine model.

BACKGROUND: Peanut allergy is a major cause of fatal and near-fatal anaphylactic reactions to foods. There is no curative therapy for this condition. Traditional Chinese medicines have been reported to have antiallergic properties, which might be useful for treating peanut allergy. OBJECTIVE: The purpose of this study was to investigate the effects of a Chinese herbal formula, FAHF-1, on peanut anaphylactic reactions in a mouse model of peanut allergy. METHODS: Mice were sensitized with freshly ground whole peanut in the presence of cholera toxin and boosted 1 and 3 weeks later. FAHF-1 treatment was initiated 1 week later and continued for 7 weeks. After treatment, mice were challenged with peanut, and anaphylactic symptoms, body temperatures, and plasma histamine and IgE levels were measured. T-cell proliferative responses and cytokine production were also determined. RESULTS: FAHF-1 completely blocked peanut-induced anaphylactic symptoms and markedly reduced mast cell degranulation and histamine release. Peanut-specific serum IgE levels were significantly reduced by 2 weeks of treatment at the time of challenge, and they remained lower 4 weeks after discontinuation of treatment. FAHF-1 significantly reduced peanut-induced lymphocyte proliferation as well as IL-4, IL-5, and IL-13 synthesis but not IFN-gamma synthesis. No toxic effects on liver or kidney functions were observed, nor was there any overall immune suppression. CONCLUSION: FAHF-1 protected peanut-sensitized mice from anaphylactic reactions and significantly reversed established IgE-mediated peanut allergy. This suggests that FAHF-1 might prove valuable for the treatment of peanut allergy.

Administration, Oral↗
PubMed2003

The major peanut allergen, Ara h 2, functions as a trypsin inhibitor, and roasting enhances this function.

BACKGROUND: The widespread use of peanut products, the severity of the symptoms, and its persistence in afflicted individuals has made peanut allergy a major health concern in western countries such as the United States, United Kingdom, and Canada. In a previous study, the authors showed that the allergenic properties of peanut proteins are enhanced as a result of thermal processing. OBJECTIVE: The purpose of this investigation was to determine whether any specific functions are associated with the major peanut allergen, Ara h 2, and whether the functionality of this protein is influenced by processing. An assay was developed and used to assess structure/function changes in Ara h 2 induced by roasting and the effect of these alterations on the allergenic properties of this major peanut allergen. METHODS: A protein domain homology search was used to determine possible functions for Ara h 2. One of the putative functions (protease inhibition) was tested by means of appropriate enzyme assays and protein gel electrophoresis. Circular dichroism was used to compare the structural properties of Ara h 2 purified from raw and roasted peanuts. RESULTS: Ara h 2 purified from peanuts is homologous to and functions as a trypsin inhibitor. Roasting caused a 3.6-fold increase in trypsin inhibitory activity. Functional and structural comparison of the Ara h 2 purified from roasted peanuts to native and reduced Ara h 2 from raw peanuts revealed that the roasted Ara h 2 mimics the behavior of native Ara h 2 in a partially reduced form. CONCLUSIONS: The data indicate that thermal processing might play an important role in enhancing the allergenic properties of peanuts. Not only has it previously been shown to affect the structural and allergic properties of peanut proteins but also, for the first time, the functional characteristics of an allergen. These structural and functional alterations are likely to influence the allergenicity of peanuts.

2S Albumins, Plant↗
PubMed1998

Lectin may contribute to the atherogenicity of peanut oil.

Peanut oil is unexpectedly atherogenic for rats, rabbits, and primates. The lesions it produces are more fibrous than fatty. The mechanism underlying the atherogenicity of peanut oil has been elusive. Randomization of peanut oil reduces significantly its atherogenic properties, but native and randomized peanut oils have similar rates of lipolysis, and rats fed the two oils absorb and transport lipids in a similar fashion. Peanut oil differs from other oils in having a relatively high lectin content, and the randomization process markedly reduces the lectin content as well. The biologically active lectin of peanut oil has an affinity for glycoproteins found specifically on arterial smooth muscle cells. Peanut lectin has been shown to stimulate growth of smooth muscle and pulmonary arterial cells. Vigorous washing of peanut oil reduces its lectin content by 46%. Compared to rabbits fed cholesterol and peanut oil, rabbits fed cholesterol and washed peanut oil exhibited less severe atherosclerosis in the aortic arch (by 9%) and in the thoracic aorta (by 31%). The data suggest that peanut oils' endogenous lectin may contribute significantly to its atherogenic properties.

Animals↗