Effects of a crude Aloe vera leaf aqueous extract and fenofibrate on diet induced metabolic dysfunction in growing rats.

Globally, the consumption of unhealthy diets and leading sedentary lifestyles contribute significantly to the high prevalence of metabolic syndrome (MetS). Although the complications of MetS can be managed with conventional medicines, there is a growing use of medicinal plants. Previous studies exploring the metabolic effects of Aloe vera have been in adult animals in which metabolic dysfunction was induced pharmacologically. We evaluated the effects of a crude Aloe vera leaf extract and fenofibrate on growth, visceral fat, circulating and stored metabolic substrates, and glucose tolerance of growing rats fed a high carbohydrate diet. Fifty nine male Sprague-Dawley rats (21 days old) were randomly allocated to six groups. Group I was fed normal rat chow (NRC). Group II received a high carbohydrate diet (HCD); Group III received NRC and fenofibrate at 100mg.kg^-1; Group IV received a HCD and fenofibrate at 100mg.kg^-1; Group V received normal rat chow and Aloe vera at 300mg.kg^-1; Group VI received a HCD and Aloe vera at 300mg.kg^-1. The Aloe vera crude aqueous leaf preparation and fenofibrate were administered in gelatine cubes. After 20 weeks the rats were fasted over night, an oral glucose tolerance test was performed, the rats were then killed with sodium pentobarbital (200mg.kg^-1 i.p.) and tissue collected for further analysis. The rats fed the HCD had a significantly higher body mass than the other groups (p < 0.05, ANOVA), however the administration of fenofibrate prevented the HCD-induced increase in body mass whilst Aloe vera was not effective. Linear growth as measured by the tibial length was not significantly different between the groups (p >0.05, ANOVA). Fasting concentrations of glucose, triglycerides and free fatty acids were not significantly different between the groups and no significant differences (p>0.05, ANOVA) were observed in the circulating concentrations of insulin and the index of insulin resistance (HOMA-IR). The rats in all groups were able to tolerate an oral glucose load. Feeding the rats a HCD resulted in a significantly increased (p< 0.05, ANOVA) visceral fat mass. Fenofibrate administration prevented the HCD-induced visceral fat mass gain whilst Aloe vera administration had no effect. Although there was no significant difference in the lipid and glycogen content in the liver, fenofibrate administration resulted in a significantly increased liver mass compared to the other groups. Thus, weaning rats onto a high carbohydrate diet and feeding them the diet for 20 weeks resulted in the development of visceral obesity without altering their glucose tolerance and concentrations of metabolic substrates. Treatment with fenofibrate prevented the high carbohydrate diet-induced visceral adiposity however the Aloe vera leaf preparation was ineffective. [ABSTRACT FROM AUTHOR]