Modulatory Effect of Green Tea on Lipid Metabolism and Brain Neurotransmitters of Obese Mice Model
Abstract
Objective. The main goal of the present work was to study the relationship between the weight-reducing effect of green tea and its effect on GABA and 5-HT neurotransmitters in obese mice. Furthermore, the antilipidemic activity of green tea was also evaluated.
Methods. Adult male albino mice weighing 20 to 35 gm (both obese and non-obese) were used. The newborn mice were injected SC with MSG for the first 5 postnatal days. A control group was injected SC with physiological saline solution. The animals were weaned at the age of 4 weeks and kept on a commercial chow and tap water. At the age of 8 weeks, female mice were excluded from the study. At age of 12 weeks, each group was further subdivided into two different groups: group (a) that was not allowed to take green tea and group (b) that was allowed to take green tea (1% in diet for 2 weeks). Now, mice groups are four: control group without tea intake (Ia), control group with tea intake (Ib), obesity group without tea intake (IIa) and obesity group with tea intake (IIb). Serum cholesterol, triglyceride, HDL cholesterol and LDL cholesterol were measured by enzymatic calorimetric method using kits. Brain tissue GABA and 5-HT were determined by spectrophoto-fluorometric method.
Results. The obtained data revealed that; green tea caused a significant decrease in body weight, Lee index and food intake of obese mice group (IIb). There was also a significant decreased level of serum cholesterol, TAG and LDL and increased level of HDL in group (Ib). The study showed a significant increased level of serum cholesterol, TAG and LDL and decreased level of HDL in group (IIa). There was no significant difference between GABA concentration in group (Ia) and group (IIa). Treatment with green tea caused non-significant changes in brain GABA and significant elevation of the brain levels 5-HT. The present work clearly demonstrated that; obese mice have been shown reduced 5-HT brain levels compared to non-obese animals.
Conclusion. It is concluded that the green tea has antiobesity effect might be mediated by modulation of serum lipid profiles and brain 5-HT neurotransmitter.