Colostrum fails to prevent bovine/camelid neonatal neutrophil damage from AFB1

Sajad Najafi,Gholamreza Mohammadi,Mehrdad Mohri,Saman Hosseinkhani,Jalil Mehrzad

doi:10.1080/1547691x.2020.1725693

Sajad Najafi, Gholamreza Mohammadi + Show 3 more

Open Access

https://doi.org/10.1080/1547691x.2020.1725693

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Abstract

Exposure to environmental toxicants that affect the immune system and overall health of many mammals is mostly unavoidable. One of the more common substances is the mycotoxins, especially carcinogenic aflatoxin (AF)B1 which also causes immune suppression/dysregulation in exposed hosts. The present study analyzed the effects of naturally occurring levels of AFB1 on apoptosis of healthy bovine and camelid neonatal neutrophils (PMN) that were isolated both before and after host consumption of colostrum. Cells from bovine and camel neonates (n = 12 sets of PMN/mammal/timepoint) were exposed for 24 h to a low level of AFB1 (i.e. 10 ng AFB1/ml) and then intracellular ATP content and caspase-3, -7, and -9 activities (determined by bioluminescence) were assessed. The results indicated a significant lessening of intracellular ATP content and equivalents of luminescence intensity in AFB1-treated PMN in all studied samples, i.e. isolated pre-and post-colostrum consumption. In contrast, caspase-3, -7, and -9 activities in both pre- and post-colostrum consumption bovine and camelid PMN were noticeably increased (∼>2-fold). The damaging effects of AFB1 were more pronounced in bovine neonate PMN than in camelid ones. These results showed that camelid or bovine neonatal PMN collected pre- and post-colostrum are sensitive (moreso after consumption) to naturally occurring levels of AFB1. While merits of colostrum are well known, its failure to mitigate toxic effects of AFB1 in what would translate into a critical period in the development of immune competence (i.e. during the first few days of life in bovine and camelid calves) is surprising. The observed in vitro toxicities can help clarify underlying mechanisms of immune disorders caused by AFs in animals/humans.

Highlights

There are many environmental substances that can affect the functions of immune cells in mammals,directly leading to increases in infectious and noninfectious diseases (Mehrzad et al 2011, 2017; Viegas et al 2013, 2015; Mehrzad, Devriendt, et al 2015; Mehrzad, Shajari, et al 2015; Taheri et al 2016)
In cells isolated before the first colostrum consumption, ATP contents in both the bovine and camelid neonate PMN were increased 1.8-fold and 2.0-fold, respectively (Figure 2(a,c)) vs. levels in species-specific control PMN by the AFB1 treatment
In cells harvested after colostrum consumption, 24-h AFB1-induced decreases in ATP levels were only by 33% and 25% in the bovine and camelid PMN, respectively (Figure 2(b,d)) vs. in species-control PMN levels

Summary

Introduction

There are many environmental substances that can affect the functions of immune cells in mammals, (in)directly leading to increases in infectious and noninfectious diseases (Mehrzad et al 2011, 2017; Viegas et al 2013, 2015; Mehrzad, Devriendt, et al 2015; Mehrzad, Shajari, et al 2015; Taheri et al 2016). In developing nations (and even European/Nordic nations), animals/humans are routinely exposed to very low levels of AFB1 (Martins et al 2007; Gallo et al 2008; Hernandez Hierro et al 2008; Viegas et al 2013, 2015) This has been shown to result in damage to innate immune cells and their associated molecules (Mehrzad et al 2013; Mehrzad, Devriendt, et al 2014; Mehrzad, Maleki, et al 2014) and increases in the incidence of a variety of chronic infectious/noninfectious diseases that impact on animal and human health.

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