Potent nitric oxide inhibitory sesquiterpenoids from the rhizome of Curcuma aromatica Salisb.

One new sesquiterpenoid, curcaromatin (1), together with twenty-one known compounds 2-22, were isolated from the rhizomes of Curcuma aromatica Salisb. (Zingiberaceae). Their structures were established by extensive spectroscopic (1D and 2D NMR and HR-MS) analysis. Most of the isolated compounds were investigated for nitric oxide (NO) production in lipopolysaccharide (LPS)-activated RAW264.7 cells. (-)-Xanthorrhizol (3) displayed the strongest NO inhibitory activity with an IC50 value of 4.3 µM, which was 3.7-fold more active than the reference compound, aminoguanidine (IC50 15.9 µM). The selectivity index (SI > 28.1) of compound 3 was almost 3-fold higher than that of aminoguanidine.

Induction of apoptotic cell death of cholangiocarcinoma cells by tiliacorinine from Tiliacora triandra: A mechanistic insight.

BACKGROUND: Cholangiocarcinoma (CCA) exhibits poor response to the present chemotherapeutic agents and frequently develops drug resistance. Finding novel anticancer drugs might enhance patient outcomes. Tiliacorinine, a bisbenzylisoquinoline alkaloid from the Thai medicinal plant Tiliacora triandra, effectively induced apoptosis of human CCA cell lines and inhibited tumor growth in mice. Here, we elucidate further the molecular mechanisms underlining the cytotoxicity of tiliacorinine and its implication in overcoming gemcitabine-resistance of CCA cells. METHODS: Cytotoxicity of tiliacorinine against CCA cell lines was assessed using MTT assay. The molecular signaling was determined using Western blot analysis. Molecular docking simulations were applied to predict the binding affinity and orientation of tiliacorinine to the possible binding site(s) of the target proteins. RESULTS: Tiliacorinine induced apoptotic cell death of CCA cells in a dose- and time-dependent manner. Tiliacorinine significantly suppressed the expression of anti-apoptotic proteins, Bcl-xL and XIAP; activated apoptotic machinery proteins, caspase-3, caspase-9, and PARP; and decreased the levels of pAkt and pSTAT3. EGF/EGFR activation model and molecular docking simulations revealed EGFR, Akt, and STAT3 as potent targets of tiliacorinine. Molecular docking simulations indicated a strong binding affinity of tiliacorinine to the ATP-binding pockets of EGFR, PI3K, Akt, JAK2, and SH2 domain of STAT3. Tiliacorinine could synergize with gemcitabine and restore the cytotoxicity of gemcitabine against gemcitabine-resistant CCA cells. CONCLUSION: Tiliacorinine effectively induced apoptosis via binding and blocking the actions of EGFR, Akt, and STAT3. GENERAL SIGNIFICANCE: Tiliacorinine is a novel multi-kinase inhibitor and possibly a potent anti-cancer agent, in cancers with high activation of EGFR.

Marginaols G-M, anti-inflammatory isopimarane diterpenoids, from the rhizomes of Kaempferia marginata.

Marginaols G-M, a series of undescribed isopimarane diterpenoids, together with four known analogs were isolated from the rhizomes of Kaempferia marginata. The structures of these isolated compounds were characterized using high-resolution mass spectrometry and extensive 1D- and 2D-nuclear magnetic resonance (NMR) analyses. In addition, the absolute configurations of marginaol G and H were determined by X-ray crystallographic analysis and comparison with the literature values. When compared to the standard drug dexamethasone (IC50 4.7 µM), marginaol G, H, and 6ß-acetoxysandaracopimaradien-1α,9α-diol had an intriguing anti-inflammatory effect on NO inhibition in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages, with IC50 values ranging from 4.5 to 7.3 µM and being less cytotoxic to the cells. The anti-inflammatory action of these isopimarane diterpenoids from K. marginata supports the use of Thai traditional medicine for inflammation treatment.