Standardized flavonoid-rich fraction of Artemisia princeps Pampanini cv. Sajabal induces apoptosis via mitochondrial pathway in human cervical cancer HeLa cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Artemisia princeps Pampanini is widely used in Eastern traditional medicine for the treatment of circulatory disorders, such as, dysmenorrhea, hematuria, hemorrhoids, and inflammation, and is also used to treat chronic conditions, such as, cancers, ulcers, and digestive disorders. AIM OF THE STUDY: The purpose of this study is to investigate the effect of a standardized flavonoid-rich fraction of Artemisia princeps Pampanini cv. Sajabal (FRAP) on the induction of apoptosis and the molecular mechanism involved in human cervical cancer HeLa cells. MATERIALS AND METHODS: Human cervical cancer HeLa cells were treated with FRAP and apoptosis was detected by cell morphologic observation, annexin-V-PI staning and western blot analysis on the expression of protein associated with cell death. RESULTS: FRAP led to the cleavages of caspase-3, -8, and -9 and the cleavage of poly (ADP-ribose) polymerase (PARP) in HeLa cells. Caspase-3 inhibitor (z-DEVD-fmk), caspase-8 inhibitor (z-IETD-fmk), caspase-9 inhibitor (z-LEHD), and broad caspase inhibitor (z-VAD-fmk) significantly suppressed the FRAP-induced accumulation of annexin V positive cells. Furthermore, it was found that FRAP caused a loss of mitochondrial membrane potential (MMP) and the release of cytochrome c to the cytosol. Furthermore, the overexpression of Bcl-xL significantly prevented FRAP-induced apoptosis, MMP changes, and the activations of caspase-3, -8, and -9. Interestingly, pretreatment with caspase-8 inhibitor significantly reduced the FRAP-induced activation of caspase-3 but not that of caspase-9, whereas the caspase-3 inhibitor, z-DEVD-fmk, markedly attenuated the FRAP-induced activation of caspase-8. In BALB/c(nu/nu) mice bearing a HeLa xenograft, FRAP dosed at 25 or 50mg/kg significantly inhibited tumor growth. CONCLUSION: Our results indicate caspase-mediated activation of the mitochondrial death pathway plays a critical role in the FRAP-induced apoptosis of HeLa cells and that FRAP inhibits the in vivo tumor growth of HeLa xenograft mice.

Virtual screening and synthesis of quinazolines as novel JAK2 inhibitors.

JAK2 is an important target in multiple processes associated with tumor growth. In this study, virtual screening was employed for hit compound identification with chemical libraries using SurflexDock. Subsequently, hit optimization for potent and selective candidate JAK2 inhibitors was performed through synthesis of diverse C-1 substituted quinazoline derivatives. A novel compound 5p, (6,7-dimethoxyquinazolin-4-yl)naphthalen-1-ylamine, was thus obtained. JAK2 inhibitory activity of 5p was 43% at 20µM and this was comparable to AG490, a representative JAK2 inhibitor. Moreover, 5p showed a positive correlation between JAK2 inhibition and cytotoxicity; 5p treatment in HT-29 cells strongly inhibited JAK2 activation and subsequent STAT3 phosphorylation, reduced anti-apoptotic protein levels, and finally induced apoptosis. This suggests that compound 5p is a candidate inhibitor of JAK2 and its downstream STAT3 signaling pathway for antitumor therapy. In the docking model, the quinazoline template of 5k, the lead compound, occupied a hydrophobic region such as Leu856, Leu855, Ala880, Leu932 and Gly935, and the highly conserved hydrogen bond was created by 6-OMe of the ring template, which binds to the NH of Arg980. Moreover, hydrophobic interactions were identified between morpholine moiety and the hydrophobic region formed by Leu855, Ala880, Tyr931, Val911 and Met929. Also, compound 5k more strongly inhibited JAK2 phosphorylation in mouse embryonic stem cells than AG490. Our study shows the successful application of virtual screening for lead discovery and we propose that the novel compound 5p can be an effective JAK2 inhibitor candidate for further antitumor agent research.

Use of NaCl prevents aggregation of recombinant COMP-angiopoietin-1 in Chinese hamster ovary cells.

To investigate the effect of hyperosmotic medium on production and aggregation of the variant of Angiopoietin-1 (Ang1), cartilage oligomeric matrix protein (COMP)-Ang1, in recombinant Chinese hamster ovary (CHO) cells, CHO cells were cultivated in shaking flasks. NaCl and/or sorbitol were used to raise medium osmolality in the range of 300-450mOsm/kg. The specific productivity of COMP-Ang1, q(COMP-Ang1), increased as medium osmolality increased. At NaCl-450mOsm/kg, the q(COMP-Ang1) was 7.7-fold higher than that at NaCl-300mOsm/kg, while, at sorbitol-450mOsm/kg, it was 2.9-fold higher than that at sorbitol-300mOsm/kg. This can be attributed to the increased relative mRNA level of COMP-Ang1 at NaCl-450mOsm/kg which was approximately 2.4-fold higher than that at sorbitol-450mOsm/kg. Western blot analysis showed that COMP-Ang1 aggregates started to occur in the late-exponential phase of cell growth. When sorbitol was used to raise the medium osmolality, a severe aggregation of COMP-Ang1 was observed. On the other hand, when NaCl was used, the aggregation of COMP-Ang1 was drastically reduced at NaCl-400mOsm/kg. At NaCl-450mOsm/kg, the aggregation of COMP-Ang1 was hardly observed. This suggests that environmental conditions are critical for the aggregation of COMP-Ang1. Taken together, the use of NaCl-induced hyperosmotic medium to cell culture process turns out to be an efficient strategy for enhancing COMP-Ang1 production and reducing COMP-Ang1 aggregation.

Fibroblast activation protein alpha identifies mesenchymal stromal cells from human bone marrow.

Mesenchymal stromal cells (MSCs) have gained widespread popularity in cell therapy, but their development into clinical products has been impeded by the scarcity of cell-specific markers. We previously explored transcriptome and membrane proteome of MSCs, from which fibroblast activation protein alpha (FAP) was recognized as a prime surface marker candidate. The present study showed that FAP was constitutively expressed on MSCs, but not on other cells. FAP immunoselection yielded homogeneous MSCs from cryopreserved bone marrow (BM). These results suggest that FAP serves as a surface protein marker that can singly define MSCs from BM and possibly from other sources.

Dual inhibition of cyclooxygenases-2 and 5-lipoxygenase by deoxypodophyllotoxin in mouse bone marrow-derived mast cells.

Deoxypodophyllotoxin (Anthricin) is a medicinal herbal product isolated from Anthriscus sylvestris HOFFM. that inhibits cyclooxygenase-2 (COX-2) and COX-1-dependent phases of prostaglandin D(2) (PGD(2)) generation in bone marrow-derived mast cells (BMMC) in a concentration-dependent manner with IC(50) values of 1.89 microM and 65.3 microM, respectively. This study also found that this compound inhibited COX-1 and 2-dependent conversion of the exogenous arachidonic acid to PGD(2) in a dose-dependent manner with an IC(50) values of 0.01 microM and 12.1 microM, respectively using a COX enzyme assay kit. However, this compound did not inhibit COX-2 protein expression up to a concentration of 30 microM in the BMMC, indicating that deoxypodophyllotoxin directly inhibits COX-2 activity. Furthermore, this compound consistently inhibited the production of leukotriene C(4) (LTC(4)) in a dose dependent manner, with an IC(50) value of 0.37 microM. These results demonstrate that deoxypodophyllotoxin has a dual cyclooxygenase-2 selective/5-lipoxygenase inhibitory activity, and therefore this compound might provide a basis for novel anti-inflammatory drugs.

Inhibition of nitric oxide and tumor necrosis factor-alpha (TNF-alpha) production by propenone compound through blockade of nuclear factor (NF)-kappa B activation in cultured murine macrophages.

Lipopolysaccharide (LPS)-stimulated macrophages produce large amounts of nitric oxide (NO) by inducible nitric oxide synthase (iNOS). This is an important mechanism in macrophage-induced septic shock and inflammation. In the present study, we tested a synthetic propenone compound, 1-furan-2-yl-3-pyridin-2-yl-propenone (FPP-3) for its ability to inhibit the production of tumor necrosis factor-alpha (TNF-alpha) and an inducible enzyme, iNOS, in the LPS-stimulated murine macrophage-like cell line, RAW264.7. FPP-3 consistently inhibited nitric oxide (NO) and TNF-alpha production in a dose dependent manner, with IC(50) values of 10.0 and 13.1 microM, respectively. Western blotting probed with specific anti-iNOS antibodies showed that the decrease in quantity of the NO product was accompanied by a decrease in the iNOS protein level. In cells transiently transfected with nuclear factor (NF)-kappaB promoter-luciferase reporter construct, this compound clearly inhibited the LPS-stimulated NF-kappaB activation. Moreover, this compound inhibited IkappaB-alpha degradation in a concentration and time-dependent manner. These results indicate that FPP-3 inhibits NO production via inhibition of degradation of IkappaB-alpha through NF-kappaB activation.

Deoxypodophyllotoxin, a naturally occurring lignan, inhibits the passive cutaneous anaphylaxis reaction.

This study examined the effect of a podophyllotoxin derivative, deoxypodophyllotoxin (anthricin), which is a medicinal herb product isolated from Anthriscus sylvestris Hoffm. Deoxypodophyllotoxin was tested in a rat PCA (passive cutaneous anaphylaxis) assay by administering deoxypodophyllotoxin intraperitoneally (1.0 to 10 mg/kg, i.p.) and intravenously (0.25 to 1.0 mg/kg, i.v.). Deoxypodophyllotoxin dose-dependently inhibited the PCA reaction activated by anti-dinitrophenyl (DNP) IgE. The PCA inhibitory activity of deoxypodophyllotoxin was stronger than those of prednisolone and indomethacin, which were used as positive controls. These results suggest that deoxypodophyllotoxin may be beneficial in regulating the immediate-type allergic reaction.

Simple aromatic compounds containing propenone moiety show considerable dual COX/5-LOX inhibitory activities.

For the development of safer anti-inflammatory agents, simple aromatic compounds containing propenone moiety were prepared and evaluated for their dual COX/5-LOX inhibitory activities. Among the 17 prepared compounds, most of the compounds exhibited considerable COX/5-LOX inhibitory activities. Especially compound C(15) showed the most significant dual COX/5-LOX inhibitory activity.

Inhibitory effects of a new iridoid, patridoid II and its isomers, on nitric oxide and TNF-alpha production in cultured murine macrophages.

Patridoids I, II and IIA, are new iridoids isolated from the whole plants of Patrinia saniculaefolia. These compounds were examined by assessing their effects on the production of tumor necrosis factor-alpha (TNF-alpha) as well as by investigating the expression of two enzymes, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in the lipopolysaccharide (LPS)-stimulated murine macrophage-like cell line, Raw 264.7. Among them, patridoid II consistently inhibited nitric oxide (NO) and TNF-alpha production in a dose-dependent manner, with IC (50) values of 14.1 and 17.6 microM, respectively. Western Blotting probed with specific anti-iNOS antibodies showed that the decrease in the quantity of the NO product was accompanied by a decrease in the iNOS protein level. However, all three patridoids did not affect the COX-2 protein expression level in the LPS-stimulated macrophages. In addition, the C-5 isomer of patridoid II, patridoid I, only slightly affected the production of NO. Moreover, the C-3 isomer of patridoid II, patridoid IIA, did not inhibit proinflammatory cytokines and NO production. These results suggest that the orientations of the C-3 and C-5 methoxy groups in the patridoids have a significant role in the expression of their biological activity.

Inhibitory effects of nardostachin on nitric oxide, prostaglandin E2, and tumor necrosis factor-alpha production in lipopolysaccharide activated macrophages.

Nardostachin, which is an iridoid isolated from Patrinia saniculaefolia, was examined by assessing its effect on the production of tumor necrosis factor-alpha (TNF-alpha) and expression of 2 enzymes, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in lipopolysaccharide (LPS)-stimulated Raw264.7 macrophages. This compound consistently inhibited the production of nitric oxide (NO) and TNF-alpha production in a dose-dependent manner, with respective IC(50) values of 12.3 and 16.2 microM. The decrease in quantity of NO products was accompanied by a decrease in the iNOS protein level, as assessed by Western blotting probed with specific anti-iNOS antibodies. In addition, this compound also reduced the COX-2 protein expression level and the attendant PGE(2) production in LPS-stimulated macrophages. These results suggest that nardostachin may be useful for inhibiting the production of inflammatory mediators such as TNF-alpha, NO and PGE(2) in inflammatory diseases.

Melanin biosynthesis inhibitors from the bark of Machilus thunbergii.

The bioassay-guided fractionation of the methylene chloride soluble portion of a methanol extract of Machilus thunbergii bark led to the isolation of four known lignans, machilin A (1), meso-monomethyl dihydroguaiaretic acid (2), nectandrin A (3) and nectandrin B (4), which exhibited potent inhibitory activity on melanin biosynthesis in cultured B-16 mouse melanoma cells (IC(50): 39.9, 15.1, 19.4 and 37.8 microM, respectively).