The delivery of nanoparticles improves the pharmacokinetic properties of celecoxib to open a therapeutic window for oral administration of insoluble drugs.

A sensitive and reliable LC-MS/MS method is established and validated to determine the concentration of celecoxib, in the serum of cynomolgus monkey, using celecoxib-D7 as an internal standard. The pharmacokinetic process was investigated after giving Celebrex, celecoxib nanoparticles (CXB-NPs) and hyaluronic acid celecoxib nanoparticles (HA-CXB-NPs) by intragastric (i.g.) administration. Chromatographic separation was performed with a C18 column (2.1 × 100 mm, 2.6 µm) at 40°C with a mobile phase of 2‰ HCOOH in water and acetonitrile. The mass spectral acquisition was then performed in the multiple reaction monitoring mode, with negative ESI ion at m/z 380.0 → 316.0 and m/z 387.1 → 323.1 for celecoxib and celecoxib-D7, respectively. Good linearity was observed over the concentration range from 3 to 2,000 ng/ml (R2 = 0.9954). The intra- and inter-day precision and accuracy, matrix effect and extraction recovery, as well as stability, all met the determination requirements of biological samples. The pharmacokinetic parameters of Celebrex, CXB-NPs and HA-CXB-NPs were determined as: area under the curve, 1,855.98 ± 346.59, 1,908.00 ± 1,130.24 and 2,164.48 ± 657.47 h·ng/ml; peak concentration, 261.08 ± 113.26, 261.12 ± 94.67 and 263.34 ± 151.78 µg/L; time to peak concentration, 2.00 ± 1.22, 4.00 ± 0.00 and 3.60 ± 0.89 h; half-life, 4.39 ± 1.26, 2.33 ± 0.94 and 4.92 ± 3.13 h; relative bioavailability, 102.80 ± 49.62 and 116.63 ± 25.55%. The validated method was successfully applied to the pharmacokinetic study of celecoxib in cynomolgus monkey, after i.g. administration. The preparation of the nanoparticles of celecoxib and the modification of hyaluronic acid on the surface of nanoparticles could improve the bioavailability and prolong the circulation of celecoxib in vivo, which could lay the foundation for further development of celecoxib nanoparticles.

Molecular Characterization, Gene Evolution, and Expression Analysis of the Fructose-1, 6-bisphosphate Aldolase (FBA) Gene Family in Wheat (Triticum aestivum L.).

Fructose-1, 6-bisphosphate aldolase (FBA) is a key plant enzyme that is involved in glycolysis, gluconeogenesis, and the Calvin cycle. It plays significant roles in biotic and abiotic stress responses, as well as in regulating growth and development processes. In the present paper, 21 genes encoding TaFBA isoenzymes were identified, characterized, and categorized into three groups: class I chloroplast/plastid FBA (CpFBA), class I cytosol FBA (cFBA), and class II chloroplast/plastid FBA. By using a prediction online database and genomic PCR analysis of Chinese Spring nulli-tetrasomic lines, we have confirmed the chromosomal location of these genes in 12 chromosomes of four homologous groups. Sequence and genomic structure analysis revealed the high identity of the allelic TaFBA genes and the origin of different TaFBA genes. Numerous putative environment stimulus-responsive cis-elements have been identified in 1,500-bp regions of TaFBA gene promoters, of which the most abundant are the light-regulated elements (LREs). Phylogenetic reconstruction using the deduced protein sequence of 245 FBA genes indicated an independent evolutionary pathway for the class I and class II groups. Although, earlier studies have indicated that class II FBA only occurs in prokaryote and fungi, our results have demonstrated that a few class II CpFBAs exist in wheat and other closely related species. Class I TaFBA was predicted to be tetramers and class II to be dimers. Gene expression analysis based on microarray and transcriptome databases suggested the distinct role of TaFBAs in different tissues and developmental stages. The TaFBA 4-9 genes were highly expressed in leaves and might play important roles in wheat development. The differential expression patterns of the TaFBA genes in light/dark and a few abiotic stress conditions were also analyzed. The results suggested that LRE cis-elements of TaFBA gene promoters were not directly related to light responses. Most TaFBA genes had higher expression levels in the roots than in the shoots when under various stresses. Class I cytosol TaFBA genes, particularly TaFBA10/12/18 and TaFBA13/16, and three class II TaFBA genes are involved in responses to various abiotic stresses. Class I CpFBA genes in wheat are apparently sensitive to different stress conditions.