Six weeks oral gavage of a Phyllanthus acidus leaf water extract decreased visceral fat, the serum lipid profile and liver lipid accumulation in middle-aged male rats

摘要

Ethnopharmacological relevance Advancing age is associated with an increased accumulation of visceral fat and liver lipid which is then responsible for an age-related risk for cardiovascular disease. Looking after ourselves well with suitable micronutrients could prevent disease or prolong our healthy cardiovascular functions. In Thai traditional medicine, leaves of Phyllanthus acidus (PA) have been used for many purposes including as an antihypertensive agent and to provide relief from a headache caused by hypertension. We aimed to investigate the effects of a chronic oral administration of PA extracts to middle-aged (12-14 months) rats on their body weight, food intake, body fats, liver and kidney functions, fasting blood glucose and lipid profiles, liver lipid accumulation and on blood pressure. Materials and methods Three different kinds of PA extracts were used: (1) a PA water extract, (2) a heated PA water extract, and (3) an n-butanol fraction of the PA water extract, prepared from fresh leaves of Phyllanthus acidus. The rats were orally gavaged with the three PA extracts at 1.0 g/kg body weight or, as a control, with distilled water once a day for 6 weeks. Fasting blood sugar, lipid profile and ALP, SGOT, SGPT, BUN and creatinine levels were measured by enzymatic methods. Liver lipid accumulation was measured using oil red O staining on fresh thin cryostat liver tissue sections. The animal basal blood pressure and heart rate were measured in anesthetized rats via a common carotid artery using a polygraph. Results Results showed that after 6 weeks of treatment using gavaged heated PA extract and PA n-butanol extract there were no changes in any of the parameters studied. However, the initial PA water extract caused a slight decrease in the animal body weight with no change in food intake. No changes were observed in the liver and kidney functions (serum ALP, SGOT, SGPT, BUN and creatinine did not change), nor did the fasting blood sugar or triglyceride levels differ significantly. Serum cholesterol, HDL and LDL levels, as well as visceral and subcutaneous adipose tissue and liver lipid accumulation were significantly decreased compared to that of the control group. There were no differences found in the basal systolic and diastolic blood pressure and the basal heart rate between the PA water extract treatment and the control group. Conclusions These results indicated that the PA water extract had an effect on lipid metabolisms that resulted in a decrease of the serum lipid profile, visceral and subcutaneous fat, as well as on liver lipid accumulation in middle-aged rats. The active component that is responsible for these effects is likely to be a water soluble substance(s) and is heat labile. As a consequence of these beneficial effects of the PA water extract, it would be a good choice for further development for use as a nutraceutical or health product to prevent and/or to slow down the development of obesity and/or cardiovascular disease.