Inhibitory effect of oxycoumarins isolated from the Thai medicinal plant Clausena guillauminii on the inflammation mediators, iNOS, TNF-α, and COX-2 expression in mouse macrophage RAW 264.7

Primary human monocyte differentiation regulated by Nigella sativa pressed oil

Background

Oxidized low density lipoprotein plays an important role in development of foam cells in atherosclerosis. The study was focused on regulation of primary human monocyte growth and CD11b expression in presence of Nigella sativa oil.

Methods

Primary human monocytes were isolated from whole blood and grown at 37°C and 5% CO2 saturation for five days prior to treatment with Nigella sativa oil. The cells were plated and washed before treatment with ox-LDL (10 μg/ml) as positive control and combined treatment of ox-LDL (10 μg/ml) and (140 ng/ml) Nigella sativa oil. The growth progression was monitored every 24 hours for 3 days.

Results

Macrophages showed reduced growth in comparison to monocytes 24 hours after treatment with Nigella sativa oil. The mean cell diameter was significantly different between untreated and treated condition in monocytes and macrophages (p < 0.001). Similarly, intracellular lipid accumulation was hindered in combined treatment with Nigella sativa oil. This was further supported by cell surface expression analysis, where CD11b was markedly reduced in cells treated with combination oxLDL and Nigella sativa oil compared to oxLDL alone. More cells differentiated into macrophage-like cells when monocytes were supplemented with oxidized LDL alone.

Conclusions

The finding provides preliminary evidence on regulation of cell growth and differentiation in monocyte and monocyte-derived macrophages by Nigella sativa oil. Further investigations need to be conducted to explain its mechanism in human monocyte.

Neuroprotective effects of osthole pretreatment against traumatic brain injury in rats

Osthole, a coumarin compound isolated from the plant-derived herb Cnidium monnieri, has been the subject of considerable interest because of its broad spectrum of pharmacological properties. The aim of this study was to investigate the potential protective effects of osthole in adult rats in the setting of traumatic brain injury (TBI). We employed Feeney's weight-drop model to ascertain whether intraperitoneal administration of osthole (10mg/kg, 20mg/kg and 40 mg/kg) 30 min before TBI could reduce the severity of neurological deficits, cerebral edema, and hippocampal neuron loss. The levels of malondialdehyde (MDA) and glutathione (GSH), the activity of superoxide dismutase (SOD), the expressions of Bcl-2, Bax, and active caspase-3, and the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive apoptotic cells were also measured to characterize the antioxidative and antiapoptotic properties. A significant reduction of neurological deficits, cerebral edema and hippocampal neuron loss was observed in the osthole pretreatment groups (20mg/kg and 40 mg/kg, but not 10mg/kg) by 24h after TBI compared with the TBI group. Furthermore, pretreatment with osthole (40 mg/kg) significantly increased the activity of SOD, the level of GSH, and the ratio of Bcl-2/Bax, and also reduced the level of MDA, the expression of active caspase-3, and the number of apoptotic cells at 24h after TBI. In summary, these results suggested that osthole had a neuroprotective effect against TBI, and the protection may be associated with its antioxidative and antiapoptotic functions.

Claurailas A-D, cytotoxic carbazole alkaloids from the roots of Clausena harmandiana

Four new carbazole alkaloids, claurailas A-D (1-4), as well as 12 known carbazoles and three known coumarins were isolated from the roots of Clausena harmandiana. Heptaphylline (6) and 7-methoxyheptaphylline (7) showed strong cytotoxicity against NCI-H187 and KB cell lines with IC(50) values ranging from 1.3 to 2.7 μM. Compound 7 showed no cytotoxicity against Vero cells.

Carbazoles and coumarins from Clausena harmandiana stimulate glucose uptake in L6 myotubes

Two carbazoles (compounds 1 and 2) and one coumarin (compound 8) from Clausena harmandiana exhibited significant glucose uptake activity in L6 myotubes in a time and dose dependent manner. In addition, compounds 2 and 8 were inhibited by p38 mitogen-activated protein kinases and phosphatidylinositol 3-kinases, respectively.

Osthole regulates inflammatory mediator expression through modulating NF-κB, mitogen-activated protein kinases, protein kinase C, and reactive oxygen species

Osthole, a coumarin compound, has been reported to exhibit various biological activities; however the cellular mechanism of its immune modulating activity has not yet been fully addressed. In this study we isolated osthole from the seeds of Cnidium monnieri and demonstrated that osthole inhibited TNF-α, NO and COX-2 expression in LPS-stimulated macrophages, without reducing the expression of IL-6. Furthermore, the phosphorylation of p38, JNK1/2, PKC-α and PKC-ε induced by LPS was inhibited by osthole; however, the phosphorylation of ERK1/2 and PKC-δ was not reduced by osthole. Osthole also inhibited NF-κB activation and ROS release in LPS-stimulated macrophages. Our current results indicated that osthole is the major anti-inflammatory ingredient of Cnidium monnieri seed ethanol extract.

Biological activity of chemical constituents from Clausena harmandiana

The activity guided fractionation of the Clausena harmandiana root extracts led to the isolation of a coumarin, a ferulate, and eight carbazoles. This is the first report of the isolation of compounds 2-4 and 6-10 from this species, and this is the first time 10 was isolated from this genus. Compound 4 showed strong cytotoxicity against NCI-H187 cells with an IC(50) value of 1.63 microg/mL. Compound 5 demonstrated strong cytotoxicity against MCF-7 and KB cell lines with IC50 values of 2.21 and 1.74 microg/mL, respectively. Compounds 3 and 4 exhibited moderate cytotoxicity against the MCF-7 cell line, and 8 showed moderate cytotoxicity against NCIH187 and KB cell lines. Compounds 3 and 5 showed antiplasmodial activity with IC(50) values of 3.27 and 2.94 microg/mL, respectively.

Attenuation of experimental autoimmune encephalomyelitis in C57 BL/6 mice by osthole, a natural coumarin

Osthole, a natural coumarin, is known to have a variety of pharmacological and biochemical uses and is considered to have potential therapeutic applications. Here we examined the effects of osthole on the central nervous system demyelination in experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis and its mechanism(s). C57 BL/6 mice immunized with myelin oligodendrocyte glycoprotein 35-55 amino acid peptide were treated with osthole at day 7 post immunization (7 p.i., subclinical periods, early osthole treatment) and day 13 p.i. (clinical periods, late osthole treatment) respectively and both therapies continued throughout the study. The content of nerve growth factor (NGF) and interferon gamma (IFN-gamma) in the sera and brain of mice in vivo as well as the splenocytes culture supernatants in vitro were detected. The results showed that osthole retarded the disease process when the therapy was initiated at subclinical periods, attenuated the clinical severity of EAE mice when the therapy was initiated at both subclinical and clinical periods, ameliorated inflammation and demyelination and improved the outcomes of magnetic resonance imaging. In addition, osthole blocked the reduction of NGF and suppressed IFN-gamma increase in EAE mice. These results suggested that osthole might be a new pharmacological approach to treat multiple sclerosis.