2 
 
The leaf of G. ulmifolia contain a number of 
phytochemical constituents i.e. colistin, colatannins, 
caffeine, tartaric acid, theobromine, xanthan gum, 
catechins, kaempferol, some of procyanidin 
(procyanidin B-2, B-5, and C-1), and tiliroside 
(Sharma and Prasad, 2014; Departement of Health 
Republic of Indonesia, 2008). Among these 
compounds, namely catechins, kaempferol, 
prosianidin and tiliroside including flavonoid 
derivatives compounds. The presence of this 
compounds gives the estimate of G. ulmifolia leaf as 
anti-obesity by inhibiting adipogenesis. 
In this study, the ethanolic extract of G. ulmifolia 
leaf was fractionated by means of the liquid-liquid 
partition using chloroform, ethyl acetate. The 
obtained fractions (chloroform, ethyl acetate, and 
last remaining ethanol) were tested for inhibiting the 
proliferation and differentiation of rat preadipocytes. 
2 MATERIALS AND METHODS  
2.1 Materials 
Organic solvents of n-hexane, chloroform, ethyl 
acetate and ethanol were in proanalytical grade 
(Merck), TLC plate (Merck), collagenase type I 
(Sigma), culture media DMEM,  HEPES, NaHCO
3
, 
biotin, D-pantothenate, FBS, Penicillin and 
Streptomycin (Sigma), differentiation induction 
materials insulin, dexamethasone, IBMX (Sigma)  
2.2 Collection and Drying of  G. 
ulmifolia Leaf 
Leaf of G. ulmifolia was collected from Meru Betiri 
National Park with an altitude of 900 - 1,223 m asl 
and an average rainfall of 2,300 mm/year in October 
2016. Prior to collection, the plants were determined 
in LIPI Botanical Gardens, Purwodadi, East Java. 
The leaf was sorted, i.e. removed the damaged leaf 
and other impurities then washed with running 
water. The clean leaf was dried and then pulverized 
(grounded) to powder. 
2.3 Extraction and Fractionation 
G. ulmifolia leaf powder weighing 800 g was 
defatted with n-hexane four times (each 1000 mL). 
The residue was collected, air dried, and macerated 
in 70% ethanol (2000 mL) for 24 hours. This 
procedure was repeated three times using the same 
powdered leaf. The filtrate then concentrated by 
using a rotary evaporator at 45°C under reduced 
pressure to obtain a less 70% ethanol extract. 
Successively, the extract was fractionated using 
chloroform and ethyl acetate (3 x 350 mL of each 
solvent) to obtain chloroform, ethyl acetate, and 
residual 70% ethanol fraction. The fractions solvent 
was completely removed under the vacuum to obtain 
dry fractions and preserved in vials and kept at 4 °C 
before use.  
2.4  Determination of Total Flavonoid 
Content 
Total flavonoid content was measured by the 
aluminum chloride colorimetric assay. An aliquot 
(150  μL) of fractions or standard solution of 
quercetin (5, 10, 20, 40, 60, 80 and 100 mg/L) was 
added to 1.5 ml cuvet containing 0.4 ml of aqua 
distilled water. To the cuvet was added 0.03 mL 5 % 
NaNO
2
 and 0.03 mL 10 % AlCl
3
. After 6 min, 0.2 
mL 1 N NaOH and 0,24 of mL distilled water were 
added. The solution was stirred until homogeneous, 
then the absorbance was measured at 415 nm. Total 
flavonoid content of fraction was expressed as mg 
quercetin equivalents (QE)/g fraction. Samples were 
analyzed in triplicates (Ratnadewi et al., 2018). 
2.5  Preparation of Cell Culture  
Preadipocytes were isolated from mice adipose 
tissue aged 4-8 weeks. The visceral fat tissue was 
sliced in a sterile condition and cleaned as much as 
possible from surrounding tissues. The tissue was 
washed with PBS and chopped into small pieces. 
Chopped tissue was digested by type I of 
collagenase at 37 °C for an hour. After that, the 
suspension was filtered through 250 µm nylon mesh. 
The suspension containing isolated cells were 
centrifuged at 1000 rpm for 7 minutes, and the two 
types of cells were separated. Mature adipocytes 
were found at the top layer of the suspension and the 
pellet at the bottom of a tube containing 
preadipocytes cells.  Furthermore, the pellet was 
resuspended in culture medium containing FBS 
10%, homogenized, and plated on plate culture, then 
incubated at 37˚C, 5% CO
2 
(Duarte,  et al., 2012). 
After two days, differentiation was induced by the 
addition of induction medium ((DMEM/F12 added 
by 66 mM insulin, 100 nM dexamethasone, 0.5 mM 
3-isobutyl-1-methylxanthine) and incubated at 37°C 
in a 5% CO
2
 incubator for 24 hours. 
The cell culture was incubated with chloroform, 
ethyl acetate, and ethanol fractions of G. ulmifolia 
leaf fraction for up to 24 hours (Lin, Della-Fera, and