Humans and animals are constantly exposed to
crude petroleum contaminated diets in petroleum producing areas of the world.
As a result, researches are on-going to find simple ameliorative agent against
crude petroleum contaminated diet toxicity. The aim of this study was to
evaluate the protective effect Monodora
myristica on some biochemical parameters of rats fed with crude petroleum
oil contaminated catfish (Clarias
gariepinus) meal. Thirty male albino rats were separated into six groups of five rats and were maintained as follows: group 1: control, group 2: rats were fed crude petroleum
oil contaminated catfish diet (CPO-CCD) only, group 3: CPO-CCD plus 1 ml/kg of
1 % tween 80, group 4: CPO-CCD plus M.
myristica water extract (MWE), group
5: CPO-CCD plus M. myristica ethanol extract
(MEE) and group 6: CPO-CCD plus M.
myristica diethyl ether extract (MDEE). The feeding of the rats with CPO-CCD
and administration of extracts using cannula lasted for 28 days. The results
showed significant (p0.05) difference were observed in the level of
globulin in the serum and liver after treatment with MDEE when compared with
of M. myristica extracts on the liver histology of rats fed CPO-CCD.
In fig. 5, the control
group showed normal histological structure of hepatic lobule, hepatic cell
(HC), and central vein (CV). Rat liver section of CPO-CCD control group
indicated congestion of central vein (CCV), perivascular mononuclear cells
infiltration (MCI), and ballooned hepatocyte (BH). Treatment of CPO-CCD with
MWE the rat liver sections showed CCV, and HC moderate regeneration. Treatment
of CPO-CCD with MEE group showed slight CCV, and regeneration of HC. No
necrosis and ballooning formation were also observed. However, treatment of
rats fed CPO-CCD with MDEE showed normal histological structure of hepatic
lobule with moderate CV, and HC.
Crude petroleum oil polluted catfish had high
content of total petroleum hydrocarbon (PHC) that higher than the Department of
petroleum resource (DPR) exposure limits 22. This observation suggests that consumption
of crude oil contaminated diet exposes man and animals to hydrocarbon toxicity. This finding is in line with the study
conducted by Ubong et al. 23, who hinted that presence of petroleum hydrocarbon in the aquaculture environment is
of global importance because fishes bioaccumulation and transfer toxic and carcinogenic chemicals to humans.
That the consumption of
petroleum contaminated diet is injurious to animal health is indicated by the
increase in serum liver function enzymes (Table 1 and 2).This is consistent
with earlier studies (Achuba and Ogwumu, 2014; Achuba and Nwokogba 2015). The
increase in serum liver enzymes has been attributed to damage to the liver cell
membrane and cellular leakage of these enzymes into general circulation. This
explains why a positive correlation was observed between AST and ALT (r
=0.946). Exposure to crude petroleum contaminated diet induced organ/tissue
damages is further expressed by the increase in alkaline phosphatase activities
(Table 3). This finding is also in accordance with the studies of Adeyemi et
al. 25; Momoh and Oshin 26 which indicated that crude petroleum oil induced
renal toxicity, damage to the plasma membranes and vascular endothelium of the
brain. However, the activities of AST
and ALT in various tissues (liver, brain and kidney) in rats fed CPO-CCD
treated with MDEE, MEE and MWE were restored close to control values. These
observations therefore portray the protective effect of M. myristica extracts against damage to the plasma membranes of the
tissues. The protective influence of plant materials against chemical toxicity
is previously reported (Achuba et al 2016; Kadiri, 2017)
In addition, other markers
of organ/tissue damage were affected by consumption crude oil contaminated diet.
This is indicated by decreases in albumin, globulin and total protein levels in
the serum of rats fed with CPO-CCD only and CPO-CCD when compared to control (figure
3 and 4). Generally, that the liver is damaged by the contaminated diet is
further highlighted by histological study. The hepatic histoarchitechure of
rats fed CPO-CCD resulted in severe hepatic necrosis (HN), congestion of central
vein (CCV), perivascular mononuclear cells infiltration (MCI), and ballooned
hepatocyte (BH) (Figure 5; group 2 and
3) when compared with the control ( group 1). The distortion of architectural integrity
of damaged organs and tissues by petroleum was reported previously (Achuba and
The damage produced result in failure of the
endoplasmic reticulum, which leads to decrease in protein synthesis 27. The
results is also in line with previous study conducted by
Sunmonu and Oloyede 15, who
stated that crude petroleum oil contaminated diet may lead to reduced dietary
intake and hence a reduction in serum albumin levels. Similar to liver function
enzymes treatment with MDEE, MEE and MWE were restored close to control values.
The extracts may have stabilized the endoplasmic reticulum leading to protein
synthesis which is in line with the report of Sureshkumar and Mishra 27.
The protective potency
of polysorbates (tween 80), a known food additive, against crude petroleum oil
contaminated diet induced liver toxicity was also evaluated. No change was showed in AST and ALT activities when
rats fed CPO-CCD only were compared
with rats fed CPO-CCD + tween 80, thus confirming the nontoxic effect of tween 80 with respect to liver function.
This is in agreement with the statements of Rowe et al. 24, who reported that
polysorbates (tween 80) are widely used in food products, and topical
pharmaceutical formulations, and are regarded as nontoxic materials. Similar to M. myristica extracts, tween 80 protected the exposed rats
from liver damage. The use of commercially available chemical against crude oil
toxicity is previously documented (Achuba and Ahwin 2009; Uboh et al 2009; Ita
et al 20016)
It is pertinent to suggest
that the CPO-CCD triggered hepatotoxicity and disturbance in the levels of
hepatic enzymes activities and other tissues (kidney and brain) as shown in
this study. However, administration of M. myristica extracts (MDEE, MEE and
MWE) significantly rescued the CPO-CCD induced tissue damage and structural
alterations. Moreover, MDEE showed a strong effect as compared with MEE and MWE
(MDEE > MEE > MWE).Thus this study was able to establish that M. myristica extracts compares
favourably with synthetic protective agents.