L-Carnitine (β-hydroxy-γ-trimethyl aminobutyric acid) plays a critical role in inflammatory diseases by modulating inflammatory cell functions. Inducible nitric oxide synthase (iNOS), a proinflammatory enzyme responsible for the generation of nitric oxide (NO), has been implicated in the pathogenesis of inflammatory diseases. Mechanism of action of L-carnitine on inflammation via iNOS and nuclear factor κB (NF-κB) is unclear. In this study, we aimed to investigate the effect of L-carnitine on nitric oxide synthesis in lipopolysaccharide (LPS)-stimulated RAW 264·7 macrophage cells. For this purpose, cells were pretreated with various concentrations of L-carnitine and subsequently incubated with LPS (1 µg·ml(-1) ). NO levels, iNOS protein expression, and NF-κB activity were determined using colorimetric detection, Western blotting and transfection assays. Our results showed that treatment with L-carnitine suppressed nitric oxide production, iNOS protein expression and NF-κB activity. We demonstrated that inhibitory effect of L-carnitine on iNOS protein expression is at transcriptional level. This study may contribute to understanding the anti-inflammatory effect of L-carnitine.
Methylsulfonylmethane (MSM) is an organic sulfur-containing compound which has been used as a dietary supplement for osteoarthritis. MSM has been shown to reduce oxidative stress and inflammation, as well as exhibit apoptotic or anti-apoptotic effects depending on the cell type or activating stimuli. However, there are still a lot of unknowns about the mechanisms of actions of MSM. In this study, MSM was tested on colon cancer cells. 3-(4,5-Dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay and flow cytometric analysis revealed that MSM inhibited cell viability and increased apoptotic markers in both HCT-116 p53 +/+ and HCT-116 p53 −/− colon cancer cells. Increased poly (ADP-ribose) polymerase (PARP) fragmentation and caspase-3 activity by MSM also supported these findings. MSM also modulated the expression of various apoptosis-related genes and proteins. Moreover, MSM was found to increase c-Jun N-terminal kinases (JNK) phosphorylation in both cell lines, dose-dependently. In conclusion, our results show for the first time that MSM induces apoptosis in HCT-116 colon cancer cells regardless of their p53 status. Since p53 is defective in >50% of tumors, the ability of MSM to induce apoptosis independently of p53 may offer an advantage in anti-tumor therapy. Moreover, the remarkable effect of MSM on Bim, an apoptotic protein, also suggests its potential use as a novel chemotherapeutic agent for Bim-targeted anti-cancer therapies.
We show for the first time that Akirin-2 can be a novel biomarker in imatinib resistance. Targeting Akirin-2, NFκB and β-catenin genes may provide an opportunity to overcome imatinib resistance in CML.
Background:
Poly (ADP-ribosyl) polymerase-1 (PARP-1) inhibitors are compounds that are used to treat cancers, which are
defective in DNA-repair and DNA Damage-Response (DDR) pathways.
Objective:
In this study, a series of potential PARP-1 inhibitor substituted (piperazine-1-carbonyl)phenyl)-1H- benzo[d]imidazole4-carboxamide compounds were synthesised and tested for their PARP-1 inhibitory and anti-cancer activities.
Methods: Compounds were tested by cell free colorimetric PARP-1 activity and MTT assay in MDA-MB-231, MDA-MB-436,
MDA-MB-468 breast cancer and L929 fibroblast cell lines.
Results:
Our results showed that compound 6a inhibited viability in MDA-MB-231 and MDA-MB-468 cells whereas 8a inhibited
viability in MDA-MB-468 cells. Compound 6b significantly inhibited cell viability in tested cancer cells. However, 6b exhibited
toxicity in L929 cells whereas 6a and 8a were found to be non-toxic for L929 cells. Compounds 6a, 6b and 8a exhibited significant
inhibition of PARP-1 activity.
Conclusion:
These three compounds exhibited PARP-1 inhibitory activities and anticancer effects on breast cancer cells and
further research will enlighten the underlying mechanisms of their effects.
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