Inhibition of platelet thromboxane formation and phosphoinositides breakdown by diisoeugenol

Stereocontrolled syntheses of (-)- and (+)-γ-diisoeugenol along with optically active eight stereoisomers of 7,8'-epoxy-8,7'-neolignan

It was shown that reduction of the tertiary benzylic hydroxy group of (2R,3S,4R,5S)-3,5-bis(4-benzyloxy-3-methoxyphenyl)-2,4-dimethyltetrahydro-3-furanol 17 followed by the intramolecular Friedel-Crafts reaction gave exclusively indane with (7S,7'S,8R,8'R)-2,7'-cyclo-7,8'-neolignan structure 18 along with (7S,7'R,8S,8'R)-7,8'-epoxy-8,7'-neolignan structure 19. Indane 18 was converted to (-)-γ-diisoeugenol ((-)-4). On the other hand, (2S,3R,4R,5S)-3,5-bis(4-benzyloxy-3-methoxyphenyl)-2,4-dimethyltetrahydro-3-furanol 22 did not afford indane, but the tetrahydrofuran structure with (7S,7'S,8S,8'S)-7,8'-epoxy-8,7'-neolignan structure 23 and 7'-epi-23.

Eugenolol and Glyceryl-Isoeugenol Suppress LPS-Induced INOS Expression by Down-Regulating NF-κB and AP-1 through Inhibition of Mapks and AKT/IκBα Signaling Pathways in Macrophages

Eugenol and isoeugenol, two components of clover oil, have been reported to possess several biomedical properties, such as anti-inflammatory, antimicrobial and antioxidant effects. This study aims to examine the anti-inflammatory effects of eugenol, isoeugenol and four of their derivatives on expression of inducible nitric oxide synthase (iNOS) activated by lipopolysaccharide (LPS) in mouse macrophages (RAW 264.7), and to investigate molecular mechanisms underlying these effects. We found that two derivatives, eugenolol and glyceryl-isoeugenol, had potent inhibitory effects on LPS-induced upregulation of nitrite levels, iNOS protein and iNOS mRNA. In addition, they both suppressed the release of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) induced by LPS. Moreover, they both attenuated the DNA binding of NF-κB and AP-1, phosphorylation of inhibitory κBα (IκBα), and nuclear translocation of p65 protein induced by LPS. Finally, we demonstrated that glyceryl-isoeugenol suppressed the phosphorylation of ERK1/2, JNK and p38 MAPK, whereas eugenolol suppressed the phosphorylation of ERK1/2 and p38 MAPK. Taken together, these results suggest that that eugenolol and glyceryl-isoeugenol suppress LPS-induced iNOS expression by down-regulating NF-κB and AP-1 through inhibition of MAPKs and Akt/IκBα signaling pathways. Thus, this study implies that eugenolol and glyceryl-isoeugenol may provide therapeutic benefits for inflammatory diseases.

Comparison of in vitro surface properties of clove oil-phospholipid suspensions with those of ALEC, Exosurf and Survanta

Dipalmitoyl phosphatidylcholine, the main component of lung surfactant is ineffective as a replacement surfactant due to its poor adsorption. We studied clove oil as a possible additive for improving the surface activity of protein-free phospholipid suspensions. We added low doses of clove oil, to phospholipid suspensions and studied the surface properties by in vitro analysis using a pulsating bubble surfactometer and a Wilhelmy balance. Survanta, ALEC and Exosurf were used as controls for comparison. The test surfactants, which were phospholipid-oil suspensions at 1% concentration, in buffer containing either 2 or 5 mM calcium, were pulsated at 40 cpm in a pulsating bubble surfactometer. The phospholipids studied were dipalmitoyl phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), binary mixtures of PC:PE (2:3) and PC:PG (2:3). The addition of clove oil (CO) to each of the above phospholipids was in the ratio of nine parts of phospholipid to one part of oil. The presence of CO caused a significant improvement in the adsorption and minimum surface tension of all the phospholipid suspensions studied. The mixtures PC with CO, both in the presence of 2 and 5 mM calcium, and PCPE with CO at 2 mM calcium concentration had surface properties significantly better than those of ALEC and Exosurf and equivalent to those of Survanta. The addition of clove oil helps improve the surface properties of phospholipids.