Mycotoxins, a Major Challenge in Global Food Security
 
Abbas Ali Jafari; PhD
 
Department of Medical Parasitology and Mycology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
 

ARTICLE INFO
EDITORIAL ARTICLE		Corresponding author: jaabno@gmail.com Department of Medical Parasitology and Mycology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.  Postal code: 8915173149 Tel: +9838203411 Key words: Mycotoxin; Food; Food Safety.
Article history: Received: 11 Jun  2017 Revised: 5 Aug  2017 Accepted: 17 Sep 2017

 

T

he world's population has recently reached to more than 7.5 billion and it is estimated to surpass 9 billion by the year 2050 (Unep,
2013). Since the condition of food-producing ecosystems necessarily affects the human health populations, food supply limitations may directly impact both the quantity and quality of available
food. Mycotoxins, as low-molecular-weight natural products of common filamentous toxic fungi, can contaminate a wide variety of
human and animals' food (Bennett, 1987). Mycotoxins are a structurally diverse group of small molecular weight compounds produced
by several fungal genera such as Aspergillus, Penicillium, Fusarium, Alternaria, Chaetomium, Cladosporium, Claviceps, Diplodia, Myrothecium, Monascus, Phoma, Phomopsis, Pithomyces, Trichoderma, and Stachybotry (Magan et al., 2011, Nielsen et al., 2006, Streit et al., 2012).
Although these metabolites have no biochemical significance in fungal growth and development, they cause serious risks for human and animal health upon ingestion, inhalation, or skin contact (Stoev, 2013).
The term mycotoxin was coined in 1962 following an unusual veterinary crisis in London, England, where approximately 100,000 turkeys died. The cause of such casualties was known as a mysterious turkey X-disease until scientists found a link to turkeys' meal, which was contaminated with secondary metabolites from Aspergillus flavus (aflatoxins). This guided scientists to investigate the possibility of the threats caused by  fungal metabolites (Allcroft and Carnaghan, 1962).
These toxins have caused a worldwide problem in various agricultural commodities. Fungal contamination occurs to products within pre-harvest period in the farm and continues to post-harvest processes, such as drying storing, and consuming (Streit et al., 2012). Usually mycotoxins are the crucial problem in developing countries, as they are not entirely protected, while usually developed countries' infrastructures have well-designed monitoring for their food quality (Stoev, 2013). The disease resulting from exposure to mycotoxins may be manifested as acute, can progress to a chronic disease, and then result in rapid death in acute
forms to tumor formation, immunosuppression, estrogenic, and generic disorders in chronic forms (Marin et al., 2013). However, about 18,000 fungal metabolites have been determined since 1960s, but only a few of them attracted the scientific interest (Cole and Cox, 1981, Science, 2003). Aflatoxins (AF), ochratoxins (OT), trichothecenes, zearalenone (ZEN), fumonisins (F), and ergot alkaloids are defined as the most important examples for mycotoxins that have the greatest public health and agro-economic significance.
Aflatoxins are defined as the most prevalent and dangerous fungal toxins, as produced by common worldwide toxic fungal species of Aspergillus and Penicillium. However, several species of Aspergillus and Penicillium can produce aflatoxin, but A. flavus, A. parsiticus, and P. puberulum are known as the most prevalent producers of aflatoxins including aflatoxin B1 (AFB₁), B₂ (AFB₂), G₁ (AFG₁), and Aflatoxin G₂ (AFG₂). These toxins, particularly AFB₁, are determined as the most potent hepatocarcinogenic substances, which have been recently proven to also be genotoxic as well. In dairy cattle, another problem arises from the transformation of AFB₁ and AFB₂ into hydroxylated metabolites, known as aflatoxins M₁ and M₂ (AFM₁ and AFM₂), which are found in milk and milk products obtained from livestock that have ingested contaminated feed (Boudra et al., 2007). In addition to aflatoxins, ochratoxin, trichothecenes, fumonisins, and zearalenone were also evaluated as the carcinogenic potential mycotoxins by the WHO-International Agency for Research on Cancer (WHO-IARC, 1993). Ochratoxins especially Ochratoxin A, as the toxic metabolite of Aspergillus ochraceus has also been shown to be hepatotoxic, teratogenic, immunotoxic, and carcinogenic in experimental models. Trichothecenes mainly produced by Fusarium sp. can cause neurotoxicity, immunosuppression, and renal toxicity (Richard, 2007).
Zearalenone is an esterogenic mycotoxin produced by several species of Fusarium in cereals, mainly in maize. This mycotoxin exhibited two different reactions in females and males; it caused precocious puberty in females and degrees of infertility in males with anabolic effects (Goertz et al., 2010). Fumonisins are usually seen in contaminated maize and other cereal grains produced by Fusarium verticilliodies and F. proliferatum at high temperatures in humid climates that often co-occur with aflatoxins especially in corns (Sun et al., 2011). This mycotoxin is nephrotoxic, hepatotoxic, and possibly human carcinogen (Alizadeh et al., 2012, Humans
et al., 2002).
Ergot alkaloids that include several mycotoxins are produced by the fungus Claviceps purpure and cause ergotism. They are also named as St Anthony’s fire, which is known as one of the oldest food-borne diseases in human beings. Ergotism caused hallucinatory symptoms and death of many people in France and other European countries during the middle ages (Betina, 1989).
Despite the widely neglected problem of mycotoxins, the Food and Agriculture Organization of the United Nations (FAO) estimated that approximately 25% of worldwide crops and cereals are contaminated by molds and affected with mycotoxins (Rice and Ross, 1994). So, in the present global environment, mycotoxicosis and contamination of human and animal foods with mycotoxins are still unavoidable especially in developing countries such as Iran. Therefore, this is a crucial responsibility for health authorities to train the public and design strategies that allow us to cope with this burden of mycotoxins in order to improve peoples’ food security.

 
References

United Nations Environmental Program (UNEP) GRID Adrenal, 2013. Food Demand and Need. http://www.grida.no/ publications/ rr/ food-crisis/ page/ 3559.aspx
World Health Organization International Agency for Research on Cancer (WHO-IARC), 1993b. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans.
Alizadeh AM, et al. 2012. Fumonisin B1 contamination of cereals and risk of esophageal cancer in a high risk area in northeastern Iran. Asian Pacific journal of cancer prevention. 13 (6): 2625-2628.
Allcroft R & Carnaghan R 1962. Groundnut toxicity. Aspergillus flavus toxin (aflatoxin) in animal products: preliminary communication. Veterinary record. 74: 863-864.
Bennett J 1987. Mycotoxins, mycotoxicoses, mycotoxicology andMycopathologia. Mycopathologia. 100 (1): 3-5.
Betina V 1989. Mycotoxins. Chemical, biological and environmental aspects. Elsevier.
Boudra H, Barnouin J, Dragacci S & Morgavi D 2007. Aflatoxin M 1 and ochratoxin A in raw bulk milk from French dairy herds. Journal of dairy science. 90 (7): 3197-3201.
Cole R & Cox R 1981. Handbook of Toxic Fungal Metabolites, 1981. Academic Press INC.
Goertz A, et al. 2010. Fusarium species and mycotoxin profiles on commercial maize hybrids in Germany. European journal of plant pathology. 128 (1): 101-111.
Humans IWGotEoCRt, Organization WH & Cancer IAfRo 2002. Some traditional herbal medicines, some mycotoxins, naphthalene and styrene. World Health Organization.
Magan N, Medina A & Aldred D 2011. Possible climate‐change effects on mycotoxin contamination of food crops pre and
postharvest. Plant pathology. 60 (1): 150-163.
Marin S, Ramos A, Cano-Sancho G & Sanchis V 2013. Mycotoxins: occurrence, toxicology, and exposure assessment. Food and chemical toxicology. 60: 218-237.
Nielsen KF, Sumarah MW, Frisvad JC & Miller JD 2006. Production of metabolites from the Penicillium roqueforti complex. Journal of agricultural and food chemistry. 54 (10): 3756-3763.
Rice LG & Ross PF 1994. Methods for detection and quantitation of fumonisins in corn, cereal products and animal excreta. Journal of food protection. 57 (6): 536-540.
Richard JL 2007. Some major mycotoxins
and their mycotoxicoses—An overview. International journal of food microbiology. 119 (1): 3-10.
Science CfA 2003. Mycotoxins: risks in plant, animal, and human systems. Council for Agricultural.
Stoev SD 2013. Food safety and increasing hazard of mycotoxin occurrence in foods and feeds. Critical reviews in food science and nutrition. 53 (9): 887-901.
Streit E, et al. 2012. Current situation of mycotoxin contamination and co-occurrence in animal feed—Focus on Europe. Toxins. 4 (10): 788-809.
Sun G, et al. 2011. Co-contamination of aflatoxin B1 and fumonisin B1 in food and human dietary exposure in three areas of China. Food additives and contaminants. 28 (4): 461-470.