
B. Iranloye et al. / Journal of Diabetes Mellitus 3 (2013) 221-226 225
Table 2. Effect of virgin coconut oil (VCO) on serum insulin
level.
Insulin level (μiu/ml)
Control (C) 3.05 ± 0.25
Diabetes untreated (DUT) 1.19 ± 0.04*
Diabetes + 7.5 ml/kg VCO (DT7.5) 1.90 ± 0.40*
Diabetes + 10 ml/kg VCO (DT10) 2.50 ± 0.03#
Values are expressed as mean ± S.E.M. *p < 0.05 is significant compared
with Control. #p < 0.05 is significant compared with Diabetes untreated
group.
even after 3 hours indicating impairment in glucose tol-
erance which is an indication of diabetes. In DT7.5 and
DT10 rats there was a significant improvement in glucose
tolerance compared with the DUT rats, supporting the
view that ingestion of VCO improves glucose tolerance
in diabetic rats [21]. In addition, the 10 ml/kg dosage of
VCO proved to have a greater effect as the blood glucose
level in DT10 rats after 3 hours of glucose challenge was
closer to the control value than in DT7.5 rats.
It has been reported that the lauric oil in VCO pos-
sesses insulino-tropic properties [18]. Serum insulin was
increased in DT10 rats with a non significant increase in
DT7.5 rats compared with DUT rats. Since the dosage of
7.5 ml/kg body weight of VCO could not elevate serum
insulin, it implies that the 10 ml/kg body weight dose is
more effective in the control of glucose homeostasis than
the 7.5 ml/kg body weight. This is evidenced by the re-
duction in blood glucose level and the improvement in
glucose tolerance compared to DUT rats as discussed
earlier.
Antioxidant enzymes are critical part of cellular pro-
tection against reactive oxygen species and ultimately
oxidative stress. Oxidative stress is determined by the
balance between the generation of ROS such as super-
oxide anion (2
O) and the antioxidant defense systems
such as superoxide dismutase (SOD). Antioxidants en-
zymes involved in the elimination of ROS include SOD,
CAT and GSH, respectively. The present study showed a
decrease in the activity of all measured antioxidants en-
zymes in DUT rats. This indicates a decrease in the anti-
oxidant defense system. However treatment with VCO in
DT7.5 and DT10 rats increased the activities of the anti-
oxidant enzymes. Since oxidative stress contributes sig-
nificantly to the pathophysiology of diabetes [22], sub-
stances that suppress oxidative stress might be therapeu-
tically beneficial. Studies have shown that exogenously
administered antioxidants have protective effects on dia-
betes, thus providing insight into the relationship be-
tween free radicals and diabetes [20,22-24]. The reduc-
tion in fasting blood glucose of rats treated with VCO
after 4 weeks and a decrease in the OGTT of the rats
compared with the diabetic untreated rats can be associ-
ated to the antioxidant effect of VCO.
5. CONCLUSION
VCO alleviates hyperglycemia and improves glucose
tolerance probably by its antioxidant effect which con-
sequently leads to improvement of insulin secretion as
examined in this study. The study also shows that a dos-
age of 10 ml/kg body weight of VCO is quite beneficial
and more effective than that of 7.5 ml/kg body weight.
This was evident because the 7.5 ml/kg body weight did
not increase insulin secretion and possibly because of the
higher OGTT values.
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