2,3-Diaryl-3-imidazo4,5-pyridine derivatives as potential anticancer and anti-inflammatory agents

In this study we examined the suitability of the-imidazo[4,5-]pyridine ring system in developing novel anticancer and anti-inflammatory agents incorporating a diaryl pharmacophore. Eight 2,3-diaryl-3-imidazo[4,5-]pyridine derivatives retrieved from our in-house database were evaluated for their cytotoxic activity against nine cancer cell lines. The results indicated that the compounds showed moderate cytotoxic activity against MCF-7, MDA-MB-468, K562 and SaOS2 cells, with K562 being the most sensitive among the four cancer cell lines. The eight 2,3-diaryl-3-imidazo[4,5-]pyridine derivatives were also evaluated for their COX-1 and COX-2 inhibitory activity. The results showed that compoundexhibited 2-fold selectivity with ICvalues of 9.2 and 21.8 µmol/L against COX-2 and COX-1, respectively. Molecular docking studies on the most active compoundrevealed a binding mode similar to that of celecoxib in the active site of the COX-2 enzyme.

Antineoplastic activity of Holoptelea integrifolia [Roxb.] Planch bark extracts [in vitro]

Cancer remains the major public health concern with a number of cancer patients relying on chemotherapy as a treatment option. Although, advances in biomedical research have led to increased anticancer agents in recent years, the treatment is not always effective due to resistance, toxicity or other factors. Phytochemicals and their active components isolated from plants have provided diversified effective drugs many of them are currently used against cancer and other diseases. Holoptelea integrifolia [Roxb] Planch [Ulmaceae] is a widely distributed plant in many parts of the world, also grown in gardens of Pakistan. It is an ornamental plant with certain medicinal characteristics due to many valuable and active phyto constituents in various parts of the plant. We looked at in vitro antineoplastic effects of four different extracts, in butanol [BMBU], hexane [BMHx], ethyl acetate [BMET] and chloroform [BMCHF], from bark of Holoptelea integrifolia on small cell lung cancer, breast, prostate, coloretal and hepatocellular cancer cell lines. Plant extracts BMHx and BMET showed significant cytotoxic effects on breast and prostate cancer cells. These preliminary studies are encouraging to proceed further this research in future, regarding the isolation of active phytoconstituents in these extracts as well as its mechanism in chemoprevention and combination anticancer therapy

Overexpression of P-glycoprotein induces acquired resistance to imatinib in chronic myelogenous leukemia cells / 癌症

Imatinib, a breakpoint cluster region (BCR)-Abelson murine leukemia(ABL) tyrosine kinase inhibitor (TKI), has revolutionized the treatment of chronic myelogenous leukemia (CML). However, development of multidrug resistance(MDR) limits the use of imatinib. In the present study, we aimed to investigate the mechanisms of cellular resistance to imatinib in CML. Therefore, we established an imatinib-resistant human CML cell line(K562-imatinib) through a stepwise selection process. While characterizing the phenotype of these cells, we found that K562-imatinib cells were 124.6-fold more resistant to imatinib than parental K562 cells. In addition, these cells were cross-resistant to second- and third-generation BCR-ABL TKIs. Western blot analysis and reverse transcription-polymerase chain reaction(RT-PCR) demonstrated that P-glycoprotein(P-gp) and MDR1 mRNA levels were increased in K562-imatinib cells. In addition, accumulation of [14C]6-mercaptopurine (6-MP) was decreased, whereas the ATP-dependent efflux of [14C]6-MP and [3H]methotrexate transport were increased in K562-imatinib cells. These data suggest that the overexpression of P-gp may play a crucial role in acquired resistance to imatinib in CML K562-imatinib cells.