Peanut

Peanut Full Name

peanut

Peanut Introduction

Peanuts are a rare high-protein source in the plant kingdom, with protein content typically accounting for 25% to 32% of their dry weight. These proteins contain a variety of amino acids essential for the human body. The fat in peanuts consists mainly of unsaturated fatty acids that are beneficial to health, with oleic acid—a monounsaturated fatty acid—being particularly prominent. Oleic acid has been widely shown to help reduce LDL-C levels in the blood while maintaining or increasing HDL-C levels, which is crucial for cardiovascular health. Additionally, peanuts are rich in phytosterols such as β-sitosterol. These compounds are structurally similar to cholesterol and can competitively inhibit cholesterol absorption in the intestines, further enhancing their lipid-lowering effects.

On the other hand, peanuts are one of the most common and dangerous food allergens worldwide, posing a serious health threat to certain individuals. Peanut allergy is a classic type I hypersensitivity reaction. When a genetically susceptible individual is first exposed to peanut proteins, their immune system misidentifies them. Antigen-presenting cells (such as dendritic cells) capture and process peanut proteins, then present them to T helper cells. Driven by specific cytokine environments (e.g., IL-4, IL-13), these T cells differentiate into Th2 cells. Th2 cells subsequently "instruct" B cells to transform into plasma cells and produce large amounts of specific IgE antibodies (sIgE) targeting peanut proteins. These sIgE antibodies then bind via their Fc regions to high-affinity receptors (FcεRI) on the surfaces of mast cells and basophils, sensitizing the body. At this stage, the individual does not experience any allergic symptoms.

When a sensitized individual consumes peanuts again, the peanut proteins (allergens) act as antigens, directly cross-linking with the sIgE antibodies bound to mast cells and basophils. This cross-linking triggers a series of intracellular signaling cascades, leading to rapid degranulation of these cells and the release of large amounts of pre-stored or newly synthesized inflammatory mediators, such as histamine, leukotrienes, prostaglandins, and various cytokines. These mediators act on target organs and tissues throughout the body, triggering a range of immediate pathophysiological reactions, including increased vascular permeability (causing edema and wheals), smooth muscle contraction (leading to bronchospasm and abdominal pain), and increased mucus secretion (causing nasal congestion and runny nose). Ara h 1, Ara h 2, Ara h 3, and Ara h 6—these four storage proteins are considered the most important allergens in peanuts. In particular, Ara h 2 and Ara h 6 are recognized as the strongest predictors of severe, systemic allergic reactions. High levels of sIgE against Ara h 2 typically indicate that a patient has a true, persistent peanut allergy.

Figure 1. Ribbon representations of the known structures of peanut allergens. (Source: Palladino C, et al. 2018)

Alternate Names for Peanut

pnut; peanut; anon-EST:Liang-2.18; CG8705; clone 2.18; Dmel\CG8705; E(sina)44C; E(sina)8; l(2)02502; Pnut; PNUT; CG8705 gene product from transcript CG8705-RB; CG8705-PA; CG8705-PB; enhancer of seven in absentia 8; pnut-PA; pnut-PB; septin; septin 3; sept

• 1. Palladino C, et al. Peanut allergens. Mol Immunol. 2018 Aug;100:58-70.
  2. Geng Q, et al. Allergenicity of peanut allergens and its dependence on the structure. Compr Rev Food Sci Food Saf. 2023 Mar;22(2):1058-1081.