Food & Nutrition

Arab Journal of Food & Nutrition
66. High performance liquid chromatography “Study of Some Adverse
Nutritional and Health Effects of Using Different Levels of Thyme (Origanum
syriacum) in Rat Meals” (2003)
Hiba Fathi Al-Sayyed\ University of Jordan
Supervisor: Dr. Hamed R. Takruri
230
The bioavailability of iron from different levels of locally-purchased sun-dried
thyme leaves (Origanum syriacum L.) (1.25 %, 2.5 %, 5 %, 10 %, 20 % and 40 % of
the diet weight) was studied by the total collection method using fourty two adult
Sprague-Dawley rats. Liver and serum iron concentrations were taken as parameters
for the bioavailability. Hemoglobin concentration, red blood cell count, white blood
cell count and serum iron concentration were measured.
Iron and tannins were determined in thyme and the results indicate that it is rich
in both components (95.15 mg and 1.79 g / 100 g dry matter respectively). It is
suggested that thyme tannins may have contributed to rat mortality among the
experimental groups; mortality ranged from 17 % in the 2.5 % thyme-based diet group
to 83 % in the 20 % thyme diet group. Rats fed thyme-free diet (control group) gained
weight (71.9 ± 7.5g). Thyme- based diets (regardless of thyme percentage) caused
weight loss of the rats. Weight loss ranged from 26.7 ± 7.5 g in the 1.25 % thyme diet
group to 53.0 ± 9.2 g in the 10 % thyme diet group.
The highest food intake was for the control group (426.8 ± 17.5 g). All rats fed
thyme-based diets (regardless of thyme content) had lower (p < 0.05) food intake
(compared to the control group). Furthermore, food consumption was the lowest
(170.1± 21.4 g) in the 10 % thyme diet group and the highest (223.8 ± 17.5 g) in the
1.25 % thyme diet group. Consequently feed efficiency ratio [(weight change ÷ food
intake) ×100 %] ranged from – 35.1 ± 5.6 in the 10 % thyme diet group to 16.9 ± 4.6
in the control group.
The highest iron intake was for the control group (30.4 ± 1.5 mg) and the lowest
was for 1.25 % thyme diet group (7.3 ± 1.5 mg). There was significant increase (p <
0.05) in iron intake as the percentage of thyme in the diet increased. Apparent iron
absorption percentage was the highest (42.9 ± 7.3 %) from the 10 % thyme diet group
and the lowest from the control group (14.1 ± 6.0 %). This was reflected by increase in
liver iron concentration (μg / g dry liver) from 137.6 ± 29.7 μg / g dry liver in the
control group to 987.1 ± 36.4 μg / g dry liver in the 10 % thyme diet group. Retained
iron ranged from 0.44 ± 1.39 mg in the 1.25 % thyme diet group to 1.80 ± 1.71 mg in
the 10 5 thyme diet group.
Rats exhibited normal values for the measured hematological parameters i.e.
hemoglobin concentration, red blood cell count, and white blood cell count. Serum
iron concentration values showed insignificant (p > 0.05) differences among all rat
groups.
Weight loss, reduced food intake, and feed efficiency ratio may be attributed to
Volume 229 11, No. 25, 2011