Abstract
The aim of this study was to investigate the in vitro antiobesity activities and in vivo anti-lipolytic effect of Terpenoids and Lipid derivatives fraction (TLDF) of Alstonia boonei stem bark.
The TLDF was prepared from methanol extract (ME) through solvent partitioning of the stem bark of the plant using separating funnel, and thereafter the TLDF was analysed using LCMS-MS. The ME and TLDF were assessed for anti-lipase and anti-amylase activity. The anti-adipogenic effect of the ME and TLDF at different concentrations was assessed on differentiated 3T3-L1 adipocytes. The anti-lipolytic effect of 125 and 250 mg/kg of TLDF was determined by serum triacylglycerol level determination after oral administration of lipid emulsion in normal male Sprague-dawley rats. Experimental procedures involving rats followed the European Community guidelines (EEC Directive of 1986; 86/609/EEC) for animal use.
The TLDF constituted the following major compounds: Gardenoside, cis-2-Carboxycyclohexyl acetic acid, 3-Methyl-2 Z-heptenoic acid, 18-acetoxy-1alpha-hydroxyvitamin D3, 3-O-cis-Coumaroylmaslinic acid, 3 alpha-O-trans-Feruloyl-2 alpha-hydroxy-12-ursen-28-oic acid, 1,2,10-Trihydroxydihydro-trans-linalyl oxide 7-O-beta-D-glucopyranoside and Lucidumol A. The ME and TLDF of A. boonei had inhibitory activity against pancreatic lipase enzyme (PLE) with IC50 values of 27.89 and 3.43 microgram per millilitres respectively. But both ME and TLDF had no inhibitory activity against alpha-amylase enzyme at 1 mg/ml. The ME and TLDF of A. boonei reduced the lipid droplet formation in 3T3-L1 adipocytes after staining with Oil Red O dye, and significantly reduced (p<0.05) intracellular fat accumulation in differentiated 3T3-L1 adipocytes. Also, ME and TLDF increased the glycerol released from the cells. Although, ME and TLDF of A. boonei reduced the cell viability, the reduction was not significant at p>0.05. The triacylglycerol levels were significantly decreased (p < 0.05) by 125 and 250 mg/kg of ME and TLDF in rats three hours after oral administration of lipid emulsion.
The Terpenoids and Lipid derivatives fraction from A. boonei possess anti-lipase, anti-adipogenic and anti-lipolytic activities which are indicative of antiobesity potential.
