DCA increases the antitumor effects of capecitabine in a mouse B16 melanoma allograft and a human non-small cell lung cancer A549 xenograft.

PURPOSE: Capecitabine is one of the few chemotherapy drugs with high oral availability. Recently, sodium dichloroacetate (DCA) has shown great potential as an anticancer agent. In the present study, we assessed the anticancer effect of DCA in combination with capecitabine for cancers that modestly expressed TP. METHODS: A mouse B16 melanoma allograft and a human non-small cell lung cancer A549 xenograft were used to assess the effect of DCA and capecitabine combined treatment. Histology and immunohistochemistry were used to detect the apoptosis and proliferation of cancer cells. Real-time PCR and Western blot were carried out to detect the expression of TP and caspases, respectively. RESULTS: For the first time, we report that DCA increased the antitumor effects of capecitabine in a mouse B16 allograft and a human A549 xenograft by promoting apoptosis of tumor cells. DCA has little effect on the expression of TP. CONCLUSIONS: Our finding suggests that DCA in combination with capecitabine might be potential as a new therapeutic regimen against some cancers.

Structure-activity relationship and enzyme kinetic studies on 4-aryl-1H-1,2,3-triazoles as indoleamine 2,3-dioxygenase (IDO) inhibitors.

Previously, we have reported the design and synthesis of 4-aryl-1H-1,2,3-triazoles as inhibitors of indoleamine 2,3-dioxygenase (IDO), a promising therapeutic target of cancer. Here, we present the structure-activity relationship and enzyme kinetic studies on a series of 4-aryl-1H-1,2,3-triazoles. Three compounds (1, 6, 8) were found to possess more IDO inhibitory potency than the most commonly used 1-methyltryptophan. The results from the structure-activity relationship and molecular docking studies indicated that an electron-withdrawing group with low steric hindrance near the NH group of triazoles was necessary for the IDO inhibition.

Oren-gedoku-to and its constituents with therapeutic potential in Alzheimer's disease inhibit indoleamine 2, 3-dioxygenase activity in vitro.

A well-known traditional Chinese medicinal prescription, Oren-gedoku-to (OGT), has been used in clinical therapies for many types of dementia in China and Japan. Additionally, it ameliorates the age-related deterioration of learning and memory in an Alzheimer's disease (AD) rat model. Indoleamine 2, 3-dioxygenase (IDO-1) is the first and rate-limiting enzyme in the kynurenine pathway of tryptophan catabolism, which ultimately leads to the production of the excitotoxin quinolinic acid (QUIN). IDO-1 has recently been established as one of the key players involved in the pathogenesis of AD. OGT is indicated to prevent cholinergic dysfunction and reduce oxidative stress; however, the exact mechanism underlying its ability to improve cognitive ability remains elusive. Here we present a novel mechanism of OGT's therapeutic potential in AD. We demonstrated that OGT significantly inhibited recombinant human IDO-1 (rhIDO-1) activity in vitro, and its four main constituents (i.e., berberine, palmatine, jatrorrhizine, and baicalein) were potent IDO-1 inhibitors. IC50 values, obtained from a cell-based assay, of HEK 293 cells and an enzymatic assay were much lower than the most commonly used IDO-1 inhibitor, 1-methyl tryptophan (1-MT). Berberine was the best inhibitor and had IC50 values of 7 µM (cell-based assay) and 9.3 µM (enzymatic assay). Jatrorrhizine and palmatine exhibited irreversible inhibition of rhIDO-1, whereas berberine and baicalein behaved as uncompetitive, reversible inhibitors with Ki values of 8 µM and 215 µM, respectively. In conclusion, constituents of OGT show strong IDO-1 inhibitory activity and may have significant therapeutic potential for AD.

Involvement of mitochondrial permeability transition in hepatitis B virus replication.

The HBx protein of human hepatitis B virus (HBV) activates a calcium-dependent kinase pathway which is essential for the viral replication. In this study, we found that HBx expression in the absence of other HBV proteins and in the context of HBV replication decreased the mitochondrial calcein-AM/CoCl(2) signals by 10% and 14% in HepG2 cells and by 15% and 10% in Huh7 cells, respectively. This indicates that HBx can induce mitochondrial permeability transition (MPT) and cause calcium effusion into the plasma. In addition, RNA interference of Cylophilin D decreased HBx-induced MPT and suppressed HBV DNA replication by 41% in HepG2 cells. Our results suggest that HBx expression can induce MPT and facilitate HBV DNA replication.