Toxicity Potential of Cyanogenic Glycosides in Edible Plants

Abstract

Cyanogenic glycosides are natural phytotoxins produced by over 2000 plant species, many of which are consumed by humans. The important food crops that contain cyanogenic glycosides include cassava (Manihot esculenta), sorghum (Sorghum bicolor), cocoyam (Colocasia esculenta L. and Xanthosoma sagittifolium L.), bamboo (Bambusa vulgaris), apple (Malus domestica), and apricot (Prunus armeniaca). Cyanogenic glycosides and their derivatives have amino acid-derived aglycones, which spontaneously degrade to release highly toxic hydrogen cyanide (HCN). Dietary cyanide exposure has been associated with several health challenges such as acute cyanide poisoning, growth retardation, and neurological disorders. This chapter will introduce general cyanogenesis principles, highlight major food plants with lethal cyanide levels, and provide epidemiological-based health conditions linked to cyanide intake. Furthermore, strategies for elimination of cyanogens from food crops, such as processing technologies, will be discussed. Finally, the chapter will analyze the role of cyanogenic plants in ensuring food security among resource-poor communities.

Inflammation, It’s Regulation and Antiphlogistic Effect of the Cyanogenic Glycoside Amygdalin

“…Thus, amygdalin poses a high risk, especially when administered orally [ 28 ], because cyanide is released in much larger amounts after oral ingestion than by intravenous administration, not only due to the rapid action of the intestinal microflora [ 29 ] but also due to chewing or grinding [ 30 ]. Plants containing amygdalin also include separated β-glycosidases, which mix when chewed [ 31 ].…”

Factors Affecting the Utilisation of Cassava Products for Poultry Feeding [Review]

“…The major ANF in cassava are Cyanogenic Glucosides (CG), which naturally occurs in plants for self-defence against predation and damages [43]. Cyanogenic glucosides are originated from amino acids namely isoleucine, leusine, valine, tyrosine and phenylalanine [44]. Cassava contains CG in the form of Linamarin 93-95% and Lotaustralin 5-7% [7,45] in the leaves, stem, tuber and peels.…”

“…Bitter cassava variety has higher cyanide content compared to sweet varieties thus needs proper processing before consumption and better utilisation of cassava products [6]. Poorly processed bitter cassava have been found to cause several health problems such as cyanide toxicity both acute and chronic, neurological disorders, stunted growth, goitre and cretinism in humans [10,44]. The FAO/WHO [54] recommend safe limit of 10 mg HCN/ kg dry weight as safe for consumption.…”

Cyanogenic glycosides and plant-herbivore interactions

“…The host plant is Sedum lanceolatum. Bitter almond, Prunus dulcis Kernels Amygdalin, Prunasin 4700 Source: Jane Philpott's Food, Nutrition and Cookery Blog [12,20] Fig 1 : Structure of major CNGs in edible plants [20]…”

“…They are phytoanticipins which is known to be present in more than 2500 plant species and also have been found in few arthropod clades. The CNGs containing major food crops are cassava (Manihot esculenta), sorghum (Sorghum bicolor), giant taro Alocasia macrorrhizos, bamboo (Bambusa vulgaris), apple (Malus domestica) and apricot (Prunus armeniaca) [20] . They offer plant defense against insects due to its bitter taste and release of toxic HCN upon tissue disruption [27] .…”