The 4-acetylantroquinonol B isolated from mycelium of Antrodia cinnamomea inhibits proliferation of hepatoma cells.

BACKGROUND: Antrodia cinnamomea is known for its antihepatoma activity, yet the identity of its active compound was unclear. In this study, a 5-ton fermenter was used to prepare sufficient mycelium of A. cinnamomea for active compound isolation and identification. RESULTS: Using antiproliferative activity toward HepG2 cells as guidance in the isolation process, 4-acetylantroquinonol B was purified and identified to be the major bioactive compound of A. cinnamomea cultivated by submerged fermentation. The median effective doses (EC(50)) of 4-acetylantroquinonol B for HepG2 cells were 0.10 +/- 0.00 and 0.08 +/- 0.00 microg mL(-1) for 72 and 96 h treatments, respectively. The selective indices of 4-acetylantroquinonol B were 100 and 125 for 72 and 96 h treatments, respectively, indicating that this compound had high selective activity for hepatoma cells. CONCLUSION: 4-Acetylantroquinonol B is the major antihepatoma constituent of Antrodia cinnamomea mycelium produced by submerged fermentation.

Diallyl disulfide and diallyl trisulfide suppress oxidized LDL-induced vascular cell adhesion molecule and E-selectin expression through protein kinase A- and B-dependent signaling pathways.

Uptake of oxidized LDL (ox-LDL) by vascular endothelial cells is a critical step in the initiation and development of atherosclerosis. Adhesion molecules are upregulated by ox-LDL and numerous inflammatory cytokines and play a pivotal role in atherogenesis. In this study, we examined whether diallyl sulfide (DAS), diallyl disulfide (DADS), and diallyl trisulfide (DATS), 3 major organosulfur compounds of garlic oil, reduce adhesion molecule expression induced by ox-LDL and, if so, through what mechanism. Human umbilical vein endothelial cells were preincubated with 1 mmol/L DAS, 200 mumol/L DADS, or 100 mumol/L DATS for 16 h and then with 40 mg/L ox-LDL for an additional 24 h. ox-LDL induction of cellular and cell surface expression of E-selectin and vascular cell adhesion molecule (VCAM)-1 was suppressed by garlic allyl sulfides in the order DATS > DADS > DAS. The adhesion of HL-60 cells to endothelial cells was inhibited 27 and 33% and the production of cellular peroxides was inhibited 43 and 50% by DADS and DATS, respectively (P < 0.05). ox-LDL alone dephosphorylated protein kinase B (PKB) and cAMP responsive element binding protein (CREB); such deactivation was reversed by DADS and DATS. Electrophoretic mobility shift assay showed that the activation of CREB binding to DNA was consistent with changes in CREB phosphorylation. The protein kinase A (PKA) inhibitor H89 reversed the suppression of VCAM-1 by DADS and DATS, but the phosphoinositide 3-kinase (PI3K) inhibitor wortmannin had no effect. In contrast, wortmannin abolished DADS- and DATS-induced suppression of ox-LDL-induced E-selectin expression. These results suggest that the suppression of ox-LDL-induced E-selectin and VCAM-1 expression by DADS and DATS and, thus, monocyte adhesion to endothelial cells is likely dependent on the PI3K/PKB or PKA/CREB signaling pathway in an adhesion molecule-specific manner. To our knowledge, this is the first report that garlic modulates ox-LDL-mediated leukocyte adhesion to human endothelial cells through the PKB and PKA pathways.

DATS reduces LPS-induced iNOS expression, NO production, oxidative stress, and NF-kappaB activation in RAW 264.7 macrophages.

Diallyl trisulfide (DATS), diallyl sulfide (DAS), and diallyl disulfide (DADS) are the three major organosulfur compounds (OSCs) in garlic oil. In contrast to DADS and DATS, evidence of an anti-inflammatory effect of DATS is limited. In this study compares the efficacy of DATS with those of DAS and DADS on lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production in RAW 264.7 macrophages. The NO production in LPS-activated RAW 264.7 macrophages was suppressed by both DADS and DATS in a dose-dependent manner. At 100 muM, the nitrite levels of DADS- and DATS-treated cells were 57 and 34%, respectively, of cells treated with LPS alone. DAS, however, had no influence on NO production even at a concentration of 1 mM. Western blot and Northern blot assays showed that DADS and DATS but not DAS dose-dependently suppressed LPS-induced iNOS protein and mRNA expression in a pattern similar to that noted for NO production. LPS-induced cellular peroxide production was significantly inhibited by DADS and DATS (P < 0.05) but not by DAS. Electrophoresis mobility shift assays further indicated that DADS and DATS effectively inhibited the activation of NF-kappaB induced by LPS. Taken together, these results indicate that the differential efficacy of three major OSCs of garlic oil on suppression of iNOS expression and NO production is related to the number of sulfur atoms and is in the order DATS > DADS > DAS. The inhibitory effect of DATS on LPS-induced iNOS expression is likely attributed to its antioxidant potential to inhibit NF-kappaB activation.