International Journal of Aquaculture, 2017, Vol.7, No.5, 31
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biochemical alterations in exposed fishes as well as in other aquatic species (Boonyanratpalin et al., 2001).
Heterobranchus longifilis
a Clariid fish cultured in the West African sub region, is generally fed with feed
produced from maize (Ayinla, 2007; Tiamiyu and Solomon, 2011) thereby, inadvertently imposing the risk of
dietary FB
1
exposures. There is a paucity of information on the effects of dietary FB
1
in
H. longifilis
, this study
was therefore designed to profile the effects of dietary FB
1
on the serum biochemistry and serum lipids of
H.
longifilis
catfish juveniles following dietary exposure.
2 Materials and Methods
A total of 450
H. longifilis
catfish juveniles (with an average initial weight of 120 ± 9.16 g) were randomly
distributed into fifteen 1 000 L plastic tanks at a stock density of 30 fish per tank. Prior to the commencement of
the study, the fish were acclimatized to the experimental conditions for 15 days. Water was replaced daily and
water quality parameters were monitored throughout the duration of the study.
2.1 Production of the Basal and Fumonisin B1 amended diets
The basal diet and the Fumonisisn B1amended diets were produced according to Ayinla, (2007) with slight
adjustments as described by Adeyemo et al. (2016). Briefly, 1 gram crystalline fumonisin B1 procured from
Sigma Aldrich was dissolved in 1 000 µL acetonitrile-water (Vol:Vol), resulting in a 1 mg: 1 µL stock solution of
fumonisin B1. From this FB
1
stock solution, micro-volumes of solutions needed to produce the experimental diets
for the various FB
1
inclusions (namely: diet F0 = 0.0 mg FB
1
/Kg; diet F1 = 10.0 mg FB
1
/Kg; diet F2 = 20.0 mg
FB
1
/Kg; diet F3 = 40.0 mg FB
1
/Kg and diet F4 = 80.0 mg FB
1
/Kg) were pipetted into 1 000 mL beakers into
which had been placed 200 mL distilled water. After careful stirring, weighted portions of the starch binders were
added, followed by the addition of the weighed portions of the basal diets. The dough produced were then
pelletized using a bench extruder fitted with a 3 mm dais, oven dried at 65
o
C for 30 minutes, allowed to cool to
ambient temperature, and thereafter, subjected to proximate and fumonisin B1 content analyses before being
packed in cellophane bags and then stored at 4
o
C until used.
2.2 Extraction of Serum and Determination of Lipids and Biochemical parameters
At time points 7, 28 and Day 56, post dietary exposure to the fumonisin B1 amended diets, blood was collected
from the caudal vein using a 5 ml syringe fitted with a 23 gauge needle. The aspirated blood was carefully
dispensed into clean narrow bored glass test tube and allowed to clot for 5 minutes. The separated serum were
then eluted from the clotted blood by the use of clean tuberculin syringes after which, they were dispensed into
Ependorph tubes and stored at 0.0
o
C until used.
2.2.1 Determination of Biochemical parameters
The serum assays were done using commercial test kits (Spectrum Laboratory, Egypt) and adhering strictly to
manufacturer’s instructions. Serum total protein was determined by the biuret test (Campbell, 2012), Albumin was
determined by the Bromocresol-green method and globulin calculated mathematically by subtracting the value
obtained for albumin from the values obtained for total protein (Coz-Rakovac et al., 2005; Campbell, 2012).
Serum urea nitrogen and serum creatinine were determined by the modified Berthrlot-Searcy and Modified Jaffe
method respectively (Campbell, 2012). Serum activity of aspartate aminotransferase and alanine aminotransferase
were determined following the Rietman-Frankel colorimetric method (Schumann et al., 2002). Serum alkaline
phosphatase activity was determined using the phenolphthalein monophosphate method (Campbell, 2012).
2.2.2 Determination of Lipid profile
Total serum cholesterol was estimated using automatic serum chemistry auto analyser and kit (AUTOPAK
supplied by Beyer Diagnostics India) by the enzymatic (Cholesterol Esterase, Cholesterol Oxidase and Peroxidase
method of Allain et al. (1974). Results obtained were expressed as mg dL
-1
of serum. Serum Triglycerides
estimation was carried out with the use of the automatic serum analyser and kit (AUTOPAK, Bayer Diagnostics
India) by the enzymatic Lipoprotein lipase, Glycerol kinase, Glycerol-3-Phosphate Oxidase method of McGowan
et al. (1983) and the results expressed as mg dL
-1
of serum. The serum high density lipid was estimated using the
