Kriti Gupta

Maillard reaction in food allergy: Pros and cons

ABSTRACT Food allergens have a notable potential to induce various health concerns in susceptible individuals. The majority of allergenic foods are usually subjected to thermal processing prior to their consumption. However, during thermal processing and long storage of foods, Maillard reaction (MR) often takes place. The MR is a non-enzymatic glycation reaction between the carbonyl group of reducing sugars and compounds having free amino groups. MR may sometimes be beneficial by damaging epitope of allergens and reducing allergenic potential, while exacerbation in allergic reactions may also occur due to changes in the motifs of epitopes or neoallergen generation. Apart from these modulations, non-enzymatic glycation can also modify the food protein(s) with various type of advance glycation end products (AGEs) such as Nϵ-(carboxymethyl-)lysine (CML), pentosidine, pyrraline, and methylglyoxal-H1 derived from MR. These Maillard products may act as immunogen by inducing the activation and proliferation of various immune cells. Literature is available to understand pathogenesis of glycation in the context of various diseases but there is hardly any review that can provide a thorough insight on the impact of glycation in food allergy. Therefore, present review explores the pathogenesis with special reference to food allergy caused by non-enzymatic glycation as well as AGEs.

Health Risks and Benefits of Chickpea (Cicer arietinum) Consumption

Chickpeas (CPs) are one of the most commonly consumed legumes, especially in the Mediterranean area as well as in the Western world. Being one of the most nutritional elements of the human diet, CP toxicity and allergy have raised health concerns. CPs may contain various antinutritional compounds, including protease inhibitors, phytic acid, lectins, oligosaccharides, and some phenolic compounds that may impair the utilization of the nutrients by people. Also, high consumption rates of CPs have enhanced the allergic problems in sensitive individuals as they contain many allergens. On the other hand, beneficial health aspects of CP consumption have received attention from researchers recently. Phytic acid, lectins, sterols, saponins, dietary fibers, resistant starch, oligosaccharides, unsaturated fatty acids, amylase inhibitors, and certain bioactive compounds such as carotenoids and isoflavones have shown the capability of lowering the clinical complications associated with various human diseases. The aim of this paper is to unravel the health risks as well as health-promoting aspects of CP consumption and to try to fill the gaps that currently exist. The present review also focuses on various prevention strategies to avoid health risks of CP consumption using simple but promising ways.

Peptide based immunotherapy: A pivotal tool for allergy treatment

Immunotherapies with T-cell epitope peptides have shown a promising impact over allergic diseases as a potential therapeutic tool in in vitro and in vivo conditions. It is recognized as an effective treatment with long lasting clinical effects and subsequent reduction of the allergic inflammatory reactions. In this review, we have summarized the role of peptide based immunotherapy and emphasis has been given to the recent advancement in pollen, cat, hymenoptera venom, and food allergy.

Pathophysiology of IL-33 and IL-17 in allergic disorders

Allergic diseases are among common clinical conditions, affecting millions of children and adults throughout the world. Food allergies, skin allergies (atopic dermatitis), and respiratory allergies (allergic rhinitis and asthma) are the common types of allergies. Recently discovered cytokines IL-17 and IL-33 have been found to play an important role in the pathogenicity of various hypersensitive disorders. After exposure to allergens or infection with parasites or viruses, IL-17 and IL-33 producing cells, such as Th17 and specialized epithelial cells respectively, become activated and trigger the pathogenic immune responses in different susceptible conditions. Potent inhibitors of these cytokines have been identified recently that may represent potential therapeutic agents to overcome the clinical complications of allergies. In the present review, we have discussed the cellular sources, modes of action and regulation of IL-17 and IL-33 in the context of hypersensitive diseases. We have also assessed the therapeutic potential of inhibitory molecules that may alter production of both these cytokines, and thus modulate susceptible conditions.

Elucidation of immediate type I reactions in native and GM mustard (Brassica spp.)

Mustard, a widely consumed spice can provoke allergic manifestations in mustard sensitive individuals. The aim of this study is to explore the allergenicity potential of GM mustard varieties (GM-V2 and GM-V4) having increased carotenoid content and compare it with the native (Varuna) and commercially available variety (Urvashi). Mustard protein sensitized (GM and non-GM) BALB/c mice sera were used to identify the allergenic proteins by IgE immunoblotting. Immunoglobulin levels, mouse mast cell protease-1, monocyte chemotactic protein and histamine were measured in serum. The levels of Th1/Th2 transcription factors GATA-3, T-bet, SOCS3, STAT 6 and c-maf in intestinal proteins of all groups were detected by immunoblotting and PCR. Major IgE-binding proteins of 21, 29 and 33kDa were found in all mustard varieties. The enhanced levels of Th2 cytokines IL-4, IL-5 and IL-13 and transcription factors GATA-3 and SOCS-3 were observed. The increased levels of MCP-1, MCPT-1 and histamine were also evident in commercial, native, GM-V2 and GM-V4 varieties of mustard treated groups. Conclusively, all these finding indicate that introduction of GM mustard varieties with increased carotenoid content did not cause any increase in allergenicity as compared to its native counterpart and therefore can be safe from allergenicity point of view.

Glycation of clinically relevant chickpea allergen attenuates its allergic immune response in Balb/c mice

Glycation of food allergens may alter their immunological behaviour. We sought to investigate the impact of glycation on the allergenicity of a food protein. Herein, a chickpea protein (≈26kDa) was purified and characterized as lectin. Further, glycation of this purified protein was carried out. Thereafter, allergic behaviour of this glycated protein was compared with its native form, using various allergic parameters in Balb/c mice. The reduced allergenicity of glycated protein was observed as lesser allergic phenotypes, reduced serum immunoglobulins and allergic mediators, lower mast cells and eosinophil counts, lower protein expressions of Th2 cytokines and associated transcription factors. In addition, more Th1 and less Th2 cytokine production in exposed splenocyte, were evident in the glycated protein treated mice as compared to its native protein treatment. Thus, glycation of the chickpea allergen attenuated the sensitizing potential and allergic responses in Balb/c mice significantly and could also be clinically beneficial.

Cutaneous exposure to clinically-relevant pigeon pea (Cajanus cajan) proteins promote TH2-dependent sensitization and IgE-mediated anaphylaxis in Balb/c mice

Abstract Epicutaneous (EC) sensitization to food allergens may occur when the skin has been lightly damaged. The study here tested whether cutaneous exposure to pigeon pea protein(s) may cause allergic sensitization. BALB/c mice were either orally gavaged or epicutaneously sensitized by repeated application of pigeon pea crude protein extract (CPE) on undamaged areas of skin without any adjuvant; afterwards, both groups were orally challenged with the pigeon pea CPE. Anaphylactic symptoms along with measures of body temperature, MCPT-1, TSLP, pigeon pea-specific IgE and IgG1, myeloperoxidase (MPO) activity, TH2 cytokines, TH2 transcription factors (TFs) and filaggrin expression were determined. Mast cell staining, eosinophil levels and histopathological analysis of the skin and intestines were also performed. In the epicutaneously-sensitized mice, elevated levels of specific IgE and IgG1, as well as of MCPT-1, TSLP, TH2 cytokines and TFs, higher anaphylactic scores and histological changes in the skin and intestine were indicative of sensitization ability via both routes in the pigeon pea CPE-treated hosts. Elevated levels of mast cells were observed in both the skin and intestine; increased levels of eosinophils and MPO activity were noted only in the skin. Decreased levels of filaggrin in skin may have played a key role in the skin barrier dysfunction, increasing the chances of sensitization. Therefore, the experimental data support the hypothesis that in addition to oral exposure, skin exposure to food allergens can promote TH2-dependent sensitization, IgE-mediated anaphylaxis and intestinal changes after oral challenge. Based on this, an avoidance of cutaneous exposures to allergens might prevent development of food anaphylaxis.

Recent Advancements in the Therapeutics of Food Allergy

Food allergy is a health complication induced by certain food in the susceptible individuals. Due to lack of permanent cure and the global prevalence, the preventive approach is highly required for food allergy. Recently published patents have shown significant improvements in the food allergy research. In this review, an attempt has been done to highlight the recently developed patents related to the detection of allergens in food mixture. Also, patents regarding treatment options like use of herbal therapy, antihistamines, pre-, pro and synbiotics, nanocarriers, hypoallergens and several immune molecules towards amelioration of food allergy have been reviewed in this article.