Effect of three fatty acids from the leaf extract of Tiliacora triandra on P-glycoprotein function in multidrug-resistant A549RT-eto cell line.

Background: Cancer cells have the ability to develop resistance to chemotherapy drugs, which then leads to a reduced effectiveness and success of the treatment. Multidrug resistance (MDR) involves the resistance in the same cell/tissue to a diverse range of drugs of different structures. One of the characteristics of MDR is an overexpression of P-glycoprotein (P-gp), which causes the efflux of the accumulated drug out of the cell.

Studies of the in vitro cytotoxic, antioxidant, lipase inhibitory and antimicrobial activities of selected Thai medicinal plants.

Background: Traditional folk medicinal plants have recently become popular and are widely used for primary health care. Since Thailand has a great diversity of indigenous (medicinal) plant species, this research investigated 52 traditionally used species of Thai medicinal plants for their in vitro cytotoxic, antioxidant, lipase inhibitory and antimicrobial activities.

Methods: The 55 dried samples, derived from the medicinally used parts of the 52 plant species were sequentially extracted by hexane, dichloromethane, ethanol and water.

The potential of cellulosic ethanol production from grasses in Thailand.

The grasses in Thailand were analyzed for the potentiality as the alternative energy crops for cellulosic ethanol production by biological process. The average percentage composition of cellulose, hemicellulose, and lignin in the samples of 18 types of grasses from various provinces was determined as 31.85-38.

The impact of non-tumor-derived circulating nucleic acids implicates the prognosis of non-small cell lung cancer.

Background: A high level of circulating DNA (cirDNA) in cancer patients has been correlated with poor outcomes. Studies have demonstrated the critical contributions of the tumor-derived cirDNA. In this report, we investigated the roles of the non-tumor-derived cirDNA (nt-cirDNA) in determining the prognosis of non-small cell lung cancer (NSCLC).

Overcoming multidrug resistance in human lung cancer with novel benzo[a]quinolizin-4-ones.

Aim: To investigate the ability of synthetic benzo[a]quinolizin-4-one derivatives to reverse multidrug resistance (MDR) in lung cancer cells.

Materials And Methods: A cell line with MDR, A549RT-eto, was established by exposure to 1.5 μM etoposide.

Isolation and characterization of a novel thermophilic-organic solvent stable lipase from Acinetobacter baylyi.

The benzene tolerant Acinetobacter baylyi isolated from marine sludge in Angsila, Thailand could constitutively secrete lipolytic enzymes. The enzyme was successfully purified 21.89-fold to homogeneity by ammonium sulfate precipitation and gel-permeable column chromatography with a relative molecular mass as 30 kDa.

Glutamate-64, a newly identified residue of the functionally conserved electron-sharing network contributes to catalysis and structural integrity of glutathione transferases.

In Anopheles dirus glutathione transferase D3-3, position 64 is occupied by a functionally conserved glutamate residue, which interacts directly with the gamma-glutamate moiety of GSH (glutathione) as part of an electron-sharing network present in all soluble GSTs (glutathione transferases). Primary sequence alignment of all GST classes suggests that Glu64 is one of a few residues that is functionally conserved in the GST superfamily. Available crystal structures as well as consideration of the property of the equivalent residue at position 64, acidic or polar, suggest that the GST electron-sharing motif can be divided into two types.

An electron-sharing network involved in the catalytic mechanism is functionally conserved in different glutathione transferase classes.

In Anopheles dirus glutathione transferase D3-3, there are electrostatic interactions between the negatively charged glutamyl alpha-carboxylate group of glutathione, the positively charged Arg-66, and the negatively charged Asp-100. This ionic interaction is stabilized by a network of hydrogen bonds from Ser-65, Thr-158, Thr-162, and a conserved water-mediated contact. This alternating ionic bridge interaction between negatively and positively charged residues stabilized by a network of hydrogen bonding we have named an electron-sharing network.

Catalytic and structural contributions for glutathione-binding residues in a Delta class glutathione S-transferase.

Glutathione S-transferases (GSTs) are dimeric proteins that play a major role in cellular detoxification. The GSTs in mosquito Anopheles dirus species B, an important malaria vector in South East Asia, are of interest because they can play an important role in insecticide resistance. In the present study, we characterized the Anopheles dirus (Ad)GST D3-3 which is an alternatively spliced product of the adgst1AS1 gene.