Triterpenic Acids Present in Hawthorn Lower Plasma Cholesterol by Inhibiting Intestinal ACAT Activity in Hamsters

Table 2

ACAT inhibitory effect of hawthorn extracts and pure OA and UA in Caco-2 cells.

Test materials	Final OA + UA content in medium (μM)	ACAT activity (percentage of control)
Control	0	100 ± 0.0
Solvent extract (50 𝜇g/well)
Heptane	2.8	77.2 ± 11.8
Ethanol	8.4	86.4 ± 10.8
Acetone	28.1	46.7 ± 8.6
Ethylacetate	42.6	36.5 ± 8.0
Dichloromethane	44.3	37.9 ± 11.1
Pure compounds
OA	50.0	30.9 ± 3.9
UA	50.0	50.5 ± 8.5

Hawthorn powder was extracted with indicated solvents to generate various hawthorn extracts. Caco-2 cells were incubated with medium (1 mL) containing 50 𝜇g of each hawthorn extract dissolved in 10  𝜇L DMSO or indicated amount of OA or OA for 24 h. OA and UA content in each extract is presented in Table 1. 4 h before the end of the incubation, [9,10-³H]oleic acid (62.5 𝜇M, 1 μCi/well) was added to each well to monitor cholesterol ester synthesis. Cellular lipids were extracted by solvents and cholesterol esters were isolated using a silica column as described in Methods. The radioactivity of generated [³H]cholesterol esters was measured by scintillation counting. Data are presented as mean ± SE from six independent incubations. ACAT activity in each treatment was significantly different from control value (P <   .05).