ingredients and chemical compounds of HFD including vegetable
oil and butter, as a major source of lipids, are presented in Table 1.
After melting at 100 C, the butter was mixed with all ingredients
and chemical compounds in a stainless blender. The homogeneous
diet was transformed into a piece of cake, then dried at 45 C and
stored at þ4 C for short periods. The HFD provides 3400 kcal/kg
with fat accounting for 24%, carbohydrate for 52% and protein for
24% of calories. Energy from fat was about 4-fold higher in HFD
than that of a normal diet for rats. Detailed of fatty acid composition
of HFD is presented in legend of Table 1.
2.3. Experimental protocol
Male Wistar rats aged 6 weeks ago and weighing between 120
and 140 g were purchased from Siphat company-Tunisia and
housed in stainless steel cages and maintained under standard
laboratory conditions (temperature 25 ± 2 C and light 12-h light/
dark cycle, lights on 07.00 to 19.00) with tap water and regular
standard food for rat [13] provided ad libitum. The animals were
treated in accordance with the European Community guidelines
based on declaration of Helsinki concerning the care and use of
laboratory animals. After 1-week acclimation, the rats were
weighed and randomly assigned into three groups (n ¼ 10e12 rats
each) with comparable body weight, and given ad libitum HFD and
free access towater (CTRL), GTD (GTGr) or BTD (BTGr) for 10 weeks.
The HFD, water, GTD and BTD were distributed to rats every
morning at 08.00 h. However, to standardize the fluid intake between
tea groups and the CTRL group, each rat of GTGr and BTGr
was given about 5 ml of distilled water before tea distribution
(Table 3). In addition, the body weight gains were determined once/
week and feces were individually collected twice a week, dried and
stored for total polyphenolic compounds (TPC), triglycerides and
caffeine analysis. At the end of the experimental period, the rats
were weighed, and then killed by decapitation. Fasting blood was