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Liver as an organ of metabolism is disposed to toxins deposition and Livestock liver contributes to food security as major source of protein. Aflatoxin M1 (AFM1) is a carcinogenous metabolite aflatoxin B1 resulting from hydroxylation. To elucidate aflatoxin M1 incidence and levels in livestock livers from Minna-Nigeria, 24 hours fresh liver samples (n=122; 72 cow livers and 50 goat livers) were collected from five abattoirs and subjected to standard aflatoxin extractions via column chromatography and quantification by high performance liquid chromatography. Data showed the presence of AFM1 in some livestock livers. However, detected toxin levels in mean percentages and correlation of variation amongst the individual livestock livers was evident, with a 83.3% (60/72) incidence and a mean detection level of 1.464 µg/kg in cattle livers, as compared to 58.0% (29/50) incidence and a mean of 0.425 µg/kg in goats livers. Contamination in some samples; 52% (26/50) of goat liver and 62.5% (45/72) cow liver exceeded the EU, US and FDA limit of 0.05 µg/kg, indicating human exposure to animal liver with high level aflatoxin contamination. Therefore, there is a need to limit the exposure to aflatoxin by enforcing regulatory limits on animal feed.

Cytotoxicity testing of aflatoxin (AF) on the viability of cells grown in cultures can be widely used to predict the potential toxic effects of AF in animals. To this end, an in vitroexperimental study was conducted to ascertain the toxic effects of AF extracts obtained from compound feeds in South Africa on human lymphocytes in comparison to that of an AFB1 standard. The approach adopted was on the basis of viable cells reducing methyl tetrazolium bromide (MTT) from blue to a purple formazan dye, which was then spectrophotometrically quantified to provide the rate of cytotoxicity. Data obtained indicated no cytotoxic response in control cells, as the viability of cells without treatment with AF standard or methanolic extracts of AF extracts [negative control] using methanol as the reconstituting solvent, was 99.9% after 24 hrs of incubation. However, cell viability significantly (p<0.001) decreased upon exposure to AF extracts especially for poultry feed. This was influenced by both the dose and duration of exposure, which was much more pronounced when the cells were exposed to AFB1 standard than for all the AF extracts tested. This implies that these feeds on exposure to AF can greatly influence animal health with respect to both the contamination dose and exposure time.

Study Method Materials and ReagentsAflatoxins levels in food samples from Gauteng province were estimated by High Performance Liquid Chromatography (HPLC) and thin layer chromatography following an immune-affinity clean up. Aflatoxins extraction, detection and quantification were reached using the following materials and reagents that were of MERCK specifications except otherwise. They include: Separating funnels fitted with stoppers, large test tubes (15x25cm)/boiling tubes, wash bottles, elastic bands, methanol (HPLC grade), sodium chloride, nitric acid, potassium bromide, anhydrous sodium bicarbonate solution (saturated), acetonitrile, toluene, formic acid, Propan-2-ol, Ethyl acetate, dichloromethane, variable hot air drier (FENICI, 41512), TLC tank (Camag Ltd), Amber vials, HPLC vials, UV box, rotary blade blender (Torrington, CT. USA), phosphate buffered saline tablets (Prod codes: RP202), microfiber filter paper (Whatmann N o 113 (Prod codes: P66 and P67), aflaprep immunoaffinity columns (Prod code: AP01; R-Biopharm AG; Darmstadt, Germany), mobile phases, standards of aflatoxins (AFs) i.e. aflatoxin G 1 (AFG 1 ), aflatoxin G 2 (AFG 2 ), aflatoxin B 1 (AFB 1 ) and aflatoxin B 2 (AFB 2 ) (ARC, South Africa), 20 x 20 cm pre-coated aluminium backed silica gel G TLC plates Merck Art 5553, Aldrich), HPLC Spectra Physics SCM400 SYSTEM (Shimadzu Corporation, Kyoto,