Background: Carnitine is essential for fatty acids translocation, muscles function and exercise performance. Choline is a lipotropic agent that prevents deposition of fat in the liver. The studies concerning the effects of carnitine and choline supplementation with exercise on carnitine status and serum leptin are rare. The aim of the present study was to study the effect of carnitine and its combination with choline, with or without exercise on body and total fat pad (TFP) weights, serum carnitine, leptin, β-hydroxy butyric acid (β-HBA), triacylglycerols (TAG) and Free Fatty acids (FFA). Also, total lipids (TL) and TAG content of TFP and urinary carnitine were investigated.
Material and Methods: 48 male rats were equally divided to the following groups: control (C), carnitine (5 g/Kg diet) supplemented, carnitine plus choline (5 and 11.5 g /Kg diet respectively) supplemented. Half of each group was subjected to short term aerobic exercise on manual treadmill, in which the speed and duration were gradually increased via the course of the experiment, to be 10 m/min for 20 min/day, 5 days/week in the last 2 weeks. Body weights were recorded weekly. After 6 weeks, The 24 hours urine was collected then the fasted rats were sacrificed and blood and the total fat pad (TFP) were collected for analysis.
Results: Carnitine supplementation, tended to decrease body weight, TFP, TAG content and serum FFA, and significantly decreased the TL content, serum leptin, TAG (P<0.0005). Carnitine feeding resulted in a significant elevation of serum carnitine, β-HBA and urinary carnitine (P<0.0005), compared to sedentary control rats. These values became more pronounced on choline addition to the diet except for serum and urinary carnitine that reversed (i.e. decreased) by choline addition. Exercise intervention resulted in a significant decrease in body weight, TFP, TL content and serum leptin, TAG and FFA. These values were more pronounced in both supplements with exercise, specially serum carnitine. However, exercise caused reduction of urinary carnitine in non-supplemented and carnitine supplemented groups and this was reversed by choline and exercise.
Conclusion: Our study demonstrated that the beneficial effects of carnitine supplements is promoted by choline with or without mild exercise to reduce body weight, body fat, serum leptin and promote fat loss by increasing lipolysis as indicated by increased serum β-HBA. These results may or may not be applicable to humans, so further research is recommended to determine whether similar effects would result in humans or not.