Dihydroartemisinin

Kinase experiment:

To determine NF-κB Dihydroartemisinin-binding activity, an electrophoretic mobility shift assay (EMSA) is performed. Nuclear extracts are prepared and incubated with 32P-end-labeled 45-mer double-stranded oligonucleotide (15 μg protein with 16 fmol DNA) from the HIV long terminal repeat, 5′-TTGTTACAAGGGACTTTCCGCTG GGGACTTTCCAGGGAGGCGTGG-3′ (boldface indicates NF-κB binding sites), for 30 min at 37 °C. The Dihydroartemisinin-protein complex formed is separated from free oligonucleotide on 6.6% native polyacrylamide gels. A double-stranded mutated oligonucleotide, 5′-TTGTTACAA CTCACTTTCCGCTGCTCACTTTCCAGGGAGGCGTGG-3′, is used to examine binding specificity of NF-κB to the DNA. The binding specificity is also examined by competition with the unlabeled oligonucleotide. Preimmune serum (PIS) is included as a negative control. The dried gels are visualized with a Storm 820, and radioactive bands are quantified using Imagequant software[1].

Cell experiment:

Eca109 (4×103 cells/well) and Ec9706 (5×103 cells/well) cells are grown in 96-well plates and cultured overnight to allow for cell attachment. Eca109 and Ec9706 cells are treated with Dihydroartemisinin (80 μM), PDT (25 and 20 J/cm2, respectively) or their combination. After incubation for 24h, MTT (20 μL) is added to each well and incubated for 4 h at 37°C. Formazan crystals are dissolved in 150 μL of DMSO for 10 min with shaking. The absorbance is measured at 490 nm on a plate reader, and the experiment is repeated three times[2].

Animal experiment:

Mice[3]Mice of the Kunming strain, each weighing 20-24 g, are used. In the first experiment, design to investigate the effect of multiple doses of Dihydroartemisinin on the schistosomula and adult worms of S. japonicum, mice are given three daily doses, of 200, 300, 400 or 600 mg Dihydroartemisinin/kg (in dose volumes of 25 mL/kg), on days 6-8 or 34-36 post-infection, respectively. An additional group of mice, infected but not given the drug, serve as a control.

References:

[1]. Hu W, et al. Dihydroartemisinin induces autophagy by suppressing NF-κB activation. Cancer Lett. 2014 Feb 28;343(2):239-48.
[2]. Li HJ, et al. Dihydroartemisinin-praziquantel combinations and multiple doses of dihydroartemisinin in the treatment of Schistosoma japonicum in experimentally infected mice. Ann Trop Med Parasitol. 2011 Jun;105(4):329-33.
[3]. Li YJ, et al. Dihydroartemisinin accentuates the anti-tumor effects of photodynamic therapy via inactivation of NF-κB in Eca109 and Ec9706 esophageal cancer cells. Cell Physiol Biochem. 2014;33(5):1527-36.