Objective: This study examined the anti-adipogenic effects of extracts of Ficus deltoidea var. deltoidia and var. angustifolia, a natural slimming aid, on 3T3-L1 adipocytes.
Methods: Methanol and water extracts of leaves of the F. deltoidea varieties were analyzed to determine their total flavonoid content (TFC) and total phenolic content (TPC), respectively. The study was initiated by determining the maximum non-toxic dose (MNTD) of the methanol and water extracts for 3T3-L1 preadipocytes. Possible anti-adipogenic effects were then examined by treating 2-d post confluent 3T3-L1 preadipocytes with either methanol extract or water extract at MNTD and half MNTD (½MNTD), after which the preadipocytces were induced to form mature adipocytes. Visualisation and quantification of lipid content in mature adipocytes were carried out through oil red O staining and measurement of optical density (OD) at 520 nm, respectively.
Results: The TFCs of the methanol extracts were 1.36 and 1.97 g quercetin equivalents (QE)/100 g dry weight (DW), while the TPCs of the water extracts were 5.61 and 2.73 g gallic acid equivalents (GAE)/100 g DW for var. deltoidea and var. angustilofia, respectively. The MNTDs determined for methanol and water extracts were (300.0 ± 28.3) and (225.0 ± 21.2) µg/ml, respectively, for var. deltoidea, while much lower MNTDs [(60.0 ± 2.0) µg/ml for methanol extracts and (8.0 ± 1.0) µg/ml for water extracts] were recorded for var. angustifolia. Studies revealed that the methanol extracts of both varieties and the water extracts of var. angustifolia at either MNTD or ½MNTD significantly inhibited the maturation of preadipocytes.
Conclusions: The inhibition of the formation of mature adipocytes indicated that leaf extracts of F. deltoidea could have potential anti-obesity effects.