The experiment was conducted in the Department of Physiology, Bangladesh Agricultural University, Mymensingh during a period of 3 months from 25 September through 25 December 2013.
Animals: One month old 30 Swiss Albino mice with an average body weight of 15-18 gm were purchased from ICDDR, Bangladesh, Mohakhali, Dhaka . Before being used in the experiment, mice were adapted for 7 days in order to acclimatize in the environment. All groups were housed in a compartmentalized rectangular metallic cages (9×11×7 cubic inches) wrapped with wire mesh. The cages were kep t in well ventilated room at 28 ±20C and a relative humidity of 70 - 80% with natural day and light.
Experimental design: The mice were randomly divided into 3 equal groups (M, M1 and M2). Each group consisted of 10 mice (n=10). Group M was kept as control and animals were fed with normal broiler pellet (HI-PRO-VITE feed; 5gm/mice/day). Mice of group M1 and M1 were fed with 10% and 20% butter with feed, respectively. Butter was collected from local KR market of Bangladesh Agricultural University (BAU), Mymensingh. All groups were supplied with standard broiler pellet (HI-PRO-VITE feed; 5gm/mice/day) and fresh drinking water was given adlibitum throughout the experimental period of 90 days.
Collection of samples: On the 1st day (after acclimation) from the tail and at the end of the experiment, blood sample was collected by sacrificing the mice. S era samples were separated and stored at -200C temperature until being used. On the 90th day of the experiment, heart from the experimental mice were collected by sacrificing in 10% buffered formalin and used for histopathological study.
Biochemical studies: The biochemical parameters of serum like Total Cholesterol, Triglyceride, HDL, LDL, Blood glucose, Billurubin, Blood urea nitrogen, serum creatinine, ALT, AST, were estimated.
Determination o f total serum cholesterol and triglycerides: The cholesterol was determined using the procedure described by Trinder (1969). The result was expressed in mg/dl. The triglyceride of blood serum was determined by Biochemistry Humalyzer-3000 (Human type, Germany) according to the technique described by Trinder (1969). The result was expressed in mg/dl. Determination of HDL and LDL cholesterol The concentration of serum HDL cholesterol was estimated with the incubation of supernatant of serum sample and rea gent mixture in Reflectron®Humalyzer 3000 (Human type, Germany) and then placing the mixture in the Reflection®against the blank reagent. The result was expressed in mg/dl. The LDL was determined by subtracting the HDL cholesterol value from the subtracted value of triglyceride from total serum cholesterol that was divided by five.
LDL LDL-C= (Total serum cholesterol/5)-HDL-C
Determination of blood glucose: The Blood glucose was determined after enzymatic hydrolysis with amylases. The blood glucose was determined by Biochemistry Humalyzer-3000 (Human type, Germany) according to GOD TAT method. The result was expressed in mg/dl.
Determination of AST & ALT: AST and ALT values were recorded through placing the mixture of serum sample and test reagent (enzyme/coenzyme/α–oxoglutarate AL 1205) in the Humalyzer 2000. The AST value was calculated as: AST/ALT Concen. = 1746 × absorbance U/L.
Determination of Bilirubin and Blood Urea Nitrogen: Bilirubin estimation was performed according to the method described by Peterson et al. (1952). The result was expressed in mg/dl. Blood urea nitrogen was determined applying the Modified Berthelot Methodology and expressed as gm/dl.
Histopathological study: Histopathological examination was performed in the Department of Anatomy and Histology, BAU, Mymensingh. Fixed tissue sections were processed; paraffin-embedded and sectioned were routinely stained with Hematoxylin and Eosin (H&E) stain as per standard procedure.
Statistical analyses: All data were expressed as mean ± SD, and differences among the groups of animals were compared using one - way ANOVA with post-hoc Duncans test. Paired t-tests were used to compare pre - treatment and post - treatment value of different groups. Statistical significance was set at P < 0 .05. Statistical analysis was performed using SPSS software version 17 (SPSS Inc., Chicago, IL, USA ) .