Anti-atherosclerotic activity of n-Hexane extract of Eleutherine americana Merr. on human macrophage primary cell culture

Atherosclerosis, a chronic disorder and the main pathogenesis of various cardiovascular diseases, is initiated by theformation of the macrophage foam cell at the subendothelial layer of the blood vessel wall. This study aimed toinvestigate the anti-atherosclerosis activity of n-hexane extract of Eleutherine americana Merr. (E. americana) onhuman macrophage through in vitro induction with oxidized-Low Density Lipoprotein (ox-LDL). The macrophagewas obtained from peripheral blood mononuclear cells (PBMCs) that were isolated from the serum of a healthy male.After the monocytes were maturely differentiated, the n-hexane extract of E. americana with a dose of 0.25, 1, and2 mg/ml was added before stimulation with ox-LDL. The foam cell was determined through Oil Red O staining, theexpressions of Toll-Like Receptor 4 (TLR4) and Adenosine Triphosphate-binding cassette transporter A1/G1 (ABCA1/ABCG1) were measured by immunofluorescence, and the activity of peroxisome-proliferator-activator receptor γ(PPARγ) was measured through Enzyme-linked immunosorbent assay. The results demonstrated that the foam celland the expression of TLR4 on the group with E. americana extract treatment were lower than the ox-LDL group (p <0.05). The expression of ABCA1 and ABCG1 on the group that was given the extract was higher than ox-LDL group(p < 0.05). This study concluded that the n-hexane extract of E. americana demonstrated anti-atherosclerosis activityon human macrophage induced with ox-LDL.

A new quinone compound from Eleutherine americana / 中草药

Objective To study the chemical constituents from the ethnic medicines of Eleutherine americana. Methods Compounds were separated by silica gel and semi-preparative HPLC, detected by TLC, and identified by their NMR and MS data. Results Five compounds were isolated from E. americana. They were ameriquinone A (1), elecanacin (2), 3-[2-(acetyloxy) propyl]-2-hydroxy- 8-methoxy-1,4-naphthoquinone (3), 2-acetyl-1,8-di-methoxy-3-methylnaphthalene (4), and dihydroeleutherinol (5). Conclusion Compound 1 is a new compound. Compounds 1-5 have different degrees of inhibitory effect on the growth of Staphylococcus aureus and Escherichia coli. The MIC values of compound 5 against two strains were 0.30 μg/mL and 0.06 μg/mL, respectively.

Chemical constituents and bioactive activities of Eleutherine americana / 中草药

Objective: To study the chemical constituents of Eleutherine americana. Methods: The compounds were isolated by various chromatographic techniques, including silica gel, TLC, sephadex LH-20, and semi-preparative HPLC, and their structures were identified by their physicochemical properties and 1H-NMR and 13C-NMR data. Results: Fifteen compounds were isolated from E. americana, which were germacrenin B (1), phaffiaol (2), 4,8-dihydroxy-3-methoxy-l-methylonthra-9,10-quinone-2-carboxylic acid methyl ester (3), 3-heptadecyl-5-methoxyphenol (4), ethyl linoleate (5), 3,5-dimethoxybiphenyl-4’-ol (6), karwinaphthol A (7), 5-hydroxylkarwinaphthol A (8), 3,4-dimethoxy-8-hydroxy-1-methyl-anthra-9,10-quinone-2-carboxylic acid methyl ester (9), isoeleutherin (10), eleutherin (11), isoeleutherol (12), naphtho-γ-lactone (+)-9-hydroxyeleutherol (13), senkyunone (14), and palmitoleic acid (15). Conclusion: Compounds 2, 4-7, and 13-15 were isolated from the genus for the first time. The compounds 3, 8, and 13 had strong vasodilator effects with diastolic rate of 85.3%, 81.8%, and 89.5%, respectively, which were basically equivalent to the positive drug of tanshinone IIA (86.3%).