Scopoletin in Cassava Products as an Inhibitor of Aflatoxin Production

Abstract

The scopoletin level in a cassava variety from Benin, BEN 86052, and the compounds effect on the growth of an Aspergillus flavus isolate from cassava chips were investigated. The influence on the biosynthesis of aflatoxins was also investigated. Scopoletin was quantified using high performance liquid chromatography. An in vitro test was used to evaluate the inhibitory effects of cassava flour extracts and pure scopoletin on growth and biosynthesis. The A. flavus isolate was genetically characterized to be an aflatoxin producer using polymerase chain reaction. Scopoletin was found in roots and chips with a level ranging from 4.9 to 242.5 mg/kg dry weight. Scopoletin induction was noticed after a peeling and drying process (6 days). Aflatoxin production by a strain of A. flavus holding the cluster Nor1, Omt1 and OmtB responsible for aflatoxin biosynthesis was inhibited by scopoletin and cassava flour at lower concentrations (0.024 mM). Scopoletin could be used on other commodities susceptible to mycotoxin contamination. PRACTICAL APPLICATIONS Scopoletin accumulated in cassava variety used for chips production. Scopoletin inhibited the production of aflatoxin by toxigenic Aspergillus flavus. The use of this compound on other crops susceptible to fungi infection and aflatoxin contamination could be investigated to reduce food spoilage and mycotoxin contamination.

An Evaluation of Cassava Pulp Feedstuff Fermented with <i>A. oryzae</i>, on Growth Performance, Nutrient Digestibility and Carcass Quality of Broilers

“…This confirmed the previous studies which reported that cassava products are unlikely to be a source of aflatoxin like maize and groundnuts (Muzanila et al, 2000;Gnonlonfin et al, 2012). Gnonlonfin et al (2011) reported that scopoletin, accumulated in cassava chips, has the potential to inhibit aflatoxin production. In addition, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were also analyzed to determine the toxicology of liver.…”

Mycotoxins: Producing Fungi and Mechanisms of Phytotoxicity

“…Among 18 different types of aflatoxins produced by A. flavus strains, aflatoxin B1 (AFB1, Figure 1) is the most extremely toxic, mutagenic and carcinogenic type [31,32]. Thus, numerous studies have been conducted to determine the effects of various food additives, preservatives, chemicals and environmental conditions to inhibit growth and aflatoxin production effectively [33][34][35][36][37][38]. …”

Search for aflatoxin and trichothecene production inhibitors and analysis of their modes of action

“…In the review by Holmes et al 10) , aflatoxin production inhibitors from plant constituents were classified into a variety of groups such as alkaloids (caffeine, piperine, piperlongumine, pipernonaline, and piperoctadecalidine); phenylpropanoids [coumarins and furanocumarins (bergapten, p-coumaric acid, 5,7-dihydroxychromone, khellin, psoralene, visnagin, and xanthotoxin), flavonoids (amentoflavone, 6,6′ ′-bigenkwanin, 7,7′′-dimethoxyagathisflavone, tetradimethoxy-6,6′′-bigenkwanin, cyanidin, cyanidin 3-galactoside, cyanidin 3-glucoside, delphinidin, eriodictyol, glyceollin, kaempferol, luteolin, malvidin, pelargonidin, pelargonidin 3-glucoside, and peonidin), and phenolics (eugenol, ferulic acid, vanillic acid, vanillylacetone, diferuloylputrescine, and p-coumaroylferuloylputrescine)]; hydroxamic acids (4-acetyl-2-benzoxazolinone and 6methoxy-2-benzoxazolinone); terpenoides (camphene, canthaxanthin, α-carotene, β-carotene, β-cryptoxanthin, αionone, β-ionone, limonene, lutein, lycopene, and zeaxanthin); a tannin component (gallic acid); an inositol derivative (phytic acid), peroxidation products of unsaturated fatty acids, alkyl aldehydes (nonyl aldehyde); and signal molecules (ethylene and methyl jasmonate). Holmes et al summarized aflatoxin production inhibitory activities of these inhibitors in detail and pointed out that many Notes: (9), ethylene (10), (2-chloroethyl)phosphonic acid (11), dillapiol (12), apiol (13), spiroether (14), methyl syringate (15), gallic acid (16), methyl gallate (17), methyl 3,4,5-trimethoxybenzoate 18 plant-derived inhibitors have antioxidant activity, but their modes of action for inhibiting aflatoxin production are not clear.…”

“…Scopoletin (7) 11) and (E)-2-hexenal (8) 12) were recently reported as the key compounds for obtaining resistance of cassava and soybean seed to aflatoxin contamination, respectively. As scopoletin, a phytoalexin of cassava, showed strong aflatoxin production inhibitory activity against A. flavus at the concentration of 2 mM, and content level of scopoletin in cassava was suggested to correlate with resistant level of cassava to aflatoxin contamination.…”

“…However, when linolenic acid was exposed to air, its peroxidation products were produced by autoxidation and the products inhibited aflatoxin production. 14) Ethylene (10) and (2-chloroethyl) phosphonic acid (11), an ethylene-generating compound, inhibited aflatoxin production. 15) It was shown that (2-chloroethyl) phosphoric acid inhibits aflatoxin production due to oxidative stress alleviation.…”