Maize is a food and feed crop that is commonly contaminated with mycotoxins, which are chemical products of molds, such as aflatoxins, fumonisins and zearalenone. The toxin producing molds infest and cause many diseases in the maize plant (Ritchie, 2002; Arora and Khachatourians, 2004; Osweiler, 1996). With its tropical monsoon climate, Vietnam has favourable conditions (high humidity and temperature) for the development of these fungi and for the production of mycotoxins (CAST, 2003). Maize in Vietnam plays an important role, as in many countries in the world (Thanh Ha et al., 2004; http://www.fao.org/inpho/content/compend/text/ch23_01.htm). Although, maize is the source of several products for humans and animals, and maize production has risen sharply since 1990 in Vietnam, there are still many constraints in production; for example5, drought, insect damage and flooding provide suitable conditions for mycotoxin formation (Thanh Ha et al., 2004; CAST, 2003).
In addition, mycotoxins are harmful to animal and human health and cause economic losses worldwide (http://www.fao.org/ag/agn/agns/chemicals_mycotoxins_en.asp). Aflatoxins (AF), are well known for their toxicity and occurrence in food and feed, and are produced by Aspergillus flavus, A. parasiticus, A. nominus and A. niger molds (Ritchie, 2002). These mycotoxins have negative impacts on growth performance, liver function, and the immune system of poultry and pigs (Ledoux et al., 1998; Quezada et al., 2000; Hale et al., 1979; Schell et al., 1993; Silvotti et al., 1997). Moreover, they are liver cancer risk factor in humans (Wogan, 1992). Fumonisins are also a cause of outbreaks of equine leukoencephalomalacia disease in horse and porcine pulmonary edema in pigs (CAST, 2003). Besides, they induce hepatotoxicosis, changes of some serum enzymes for liver function, changes of sphinganine to sphingosine ratio, are carcinogenic factor and have cardiovascular effects in animals (Osweiler et al., 1992; Casteel et al., 1993; Zomborszky et al., 2002; Tran et al., 2003; Smith et al., 1996a; Voss et al., 2001). There was found to be a relationship between fumonisins consumption and human esophageal cancer in China and Southern Africa (CAST, 2003). Zearalenone (ZEA), the second most frequently found mycotoxin in maize after deoxynivalenol (DON), is produced mainly by Fusarium roseum (F. graminearum), F. culmorum and F. Sacchari species. ZEA has an influence on the reproductive system of animals, especially swine, owing to its estrogenic toxicity (Nollet, 2000). It causes hyperestrogenism in females, lengthens the weanling to estrus interval and causes feminization in young male pigs (CAST, 2003; Young et al., 1989). Furthermore elevated blood parameters and serum enzymes in rabbits and rats revealed the effect on liver function (Maaroufi et al., 1996; Conkova ´ et al., 2001). However, there are few studies and surveys about the contamination of mycotoxins in maize in Vietnam (Trung et al., 2007; Wang, 1995; Thieu, 2008) and this does not reflect the mycotoxin situation in the country. In addition, to reduce the detrimental effects of mycotoxins in Vietnamese animal production, farmers and feed factories use some decontamination methods, particularly mixing in feed additives to adsorp or to degrade mycotoxins. Almost all these feed additives come from foreign companies and are expensive. Thieu et al. (2008) tested the efficiency of a cheap local adsorbent, bentonite, as feed additive in preventing aflatoxicosis in piglets, but it did not show any positive effects. On the other hand, the Vietnamese usually use herbs as traditional medicine in treating intoxication of the human liver. Phyllanthus amarus is a popular traditional plant in Vietnam for detoxifying liver disease (National Institute of Medical Materials, 2004). Today, we are focusing on using traditional plants to treat animal diseases. Therefore, Phyllanthus amarus can be a suitable detoxicant for mycotoxicosis in animals.
For those reasons, the objectives of the study were:
To determine the mycotoxin contamination in maize in Southeastern and Central Highlands provinces of Vietnam
To
evaluate the efficacy of Phyllanthus amarus extract in reducing fumonisin
effects in piglets.
.