Antinociceptive effects of St. John's wort, Harpagophytum procumbens extract and Grape seed proanthocyanidins extract in mice

Hypericum perforatum extract (St. John's wort, SJW), Harpagophytum procumbens extract (HPE) and Grape seed proanthocyanidin extract (GSPE) have a broad spectrum of biological activities including antidepressant, anti-inflammatory or anti-oxidant effects. The aim of this study was to clarify antinociceptive properties of SJW, HPE and GSPE in mice with mechanisms that might potentially underlie these activities. Also, the effects of these herbal extracts on the antinociception and plasma and brain concentrations of morphine were examined. Oral pretreatment with SJW (100-1000 mg/kg) and HPE (30-300 mg/kg) attenuated significantly times of licking/biting both first and second phases of formalin injection in mice in the dose-dependent manner, and GSPE (10-300 mg/kg) suppressed second phase. Naloxone (5 mg/kg, s.c.) significantly attenuated antinociceptive effect of HPE but not SJW and GSPE. Formalin injection resulted in significant increase in the content of nitrites/nitrates (NO(x)) in mouse spinal cord. The rise of spinal NO(x) content by formalin was significantly attenuated by HPE and SJW. The pretreatment with SJW significantly potentiated an antinociceptive effect of morphine (0.3 mg/kg, s.c.), although concentrations of morphine in plasma and brain were not significantly changed by these herbal extracts. In conclusion, the present study has shown that SJW, HPE and GSPE exert significant antinociceptive effects in the formalin test of mice. In addition, opioidergic system seems to be involved in the antinociceptive effect of HPE but not SJW and GSPE. Furthermore, SJW potentiates morphine-induced antinociception possibly by pharmacodynamic interaction.     

Anti-inflammatory and immunomodulatory properties of 2-amino-3H-phenoxazin-3-one

Accumulating evidence suggests that nitric oxide (NO) and prostaglandin E(2) (PGE(2)) are involved in the pathogenesis of various chronic inflammatory diseases and cancer. During the course of a screening program to identify natural anti-inflammatory substances, we isolated the compound 2-amino-3H-phenoxazin-3-one (APO) from an extract of the edible brown mushroom Agaricus bisporus IMBACH. APO inhibited NO production by mouse peritoneal macrophages in response to the pro-inflammatory stimuli lipopolysaccharide (LPS) and interferon (IFN)-gamma (LPS/IFN-gamma) at low concentrations (IC(50)=1.5 microM) through reduced inducible NO synthase protein expression. PGE(2) production by LPS/IFN-gamma-stimulated macrophages was inhibited by APO at much lower concentrations (IC(50)=0.27 microM) than those required for the inhibition of NO production. Mechanistic analysis showed that APO inhibited both cyclooxygenase (COX)-1 and COX-2 enzyme activities with almost equal selectivity. Secretion of NO and the pro-inflammatory cytokine IL-6 by IFN-gamma-activated RAW264.7 cells, a murine macrophage-like cell line, was also dose-dependently reduced by APO. Furthermore, APO increased the secretion of the anti-inflammatory cytokine IL-4 by antigen-stimulated T cells and promoted the polarization of CD4(+) Th cells toward the anti-inflammatory Th2 phenotype at equimolar concentrations that inhibited NO production. Our results suggested that APO induced polarization toward the Th2 subset, at least in part through the down-regulation of IL-12 production. Thus, APO appears to have potent anti-inflammatory and immunoregulatory properties that may provide a promising therapeutic strategy for the treatment of T cell-mediated inflammatory autoimmune diseases as well as for bacteria-induced chronic-inflammatory diseases.     

Phase 1 study of TAS-102 administered once daily on a 5-day-per-week schedule in patients with solid tumors

This study was designed to determine the safety and optimal dosing of TAS-102, a novel oral combination of alphaalphaalpha-trifluorothymidine (FTD) and an inhibitor of thymidine phoshorylase, in patients with solid tumors. Patients who met the eligibility criteria were treated with one of two different TAS-102 regimens: once per day on either days 1-5 and 8-12 every 4 weeks (schedule A) or days 1-5 every 3 weeks (schedule B). The primary objectives were the determination of the maximum tolerated dose, dose-limiting toxicities (DLTs), and recommended phase II dose. Pharmacokinetic analysis was conducted during courses 1 and 2. Sixty-three patients received a total of 172 courses of therapy with the median number of courses delivered on both schedules being 2. DLTs were observed in three patients on schedule A, 70 mg/m(2)/day (1) and 110 mg/m(2)/day (2); and in five patients on schedule B, 120 mg/m(2)/day (1), 170 mg/m(2)/day (2), 180 mg/m(2)/day (2). Granulocytopenia was the DLT in seven of the eight cases. The most frequent toxicities were nausea, fatigue, granulocytopenia, anemia, diarrhea, and abdominal pain. Twelve patients, 6 on schedule A and 6 on schedule B, were treated at the recommended phase II dose, with good tolerance. No objective responses were seen in this heavily pretreated, 5-FU-refractory population. The pharmacokinetic parameters of FTD are a T (max) of 0.53 to 3.15 h, t (1/2) of 1.46 to 4.20 h, volume of distribution of 0.0526 to 0.483 l/kg, and clearance of 0.0194 to 0.197 1/h/kg. The recommended phase II doses for TAS-102 are 100 mg/m(2)/day on schedule A and 160 mg/m(2)/day on schedule B. Future development of TAS-102 should focus upon multiple daily dosing schedules.     

The effects of age on insulin sensitivity and insulin secretion in Japanese subjects with normal glucose tolerance

The prevalence of impaired glucose tolerance and type 2 diabetes increases with age. However, controversial results have been reported in regard to which has a greater influence on the deterioration of glucose tolerance with age, namely impaired insulin sensitivity or impaired insulin secretion. The conflicting results may arise mainly from differences in the evaluation of insulin secretion and insulin sensitivity, and from differences in the physical composition and the ethnicity of the study subjects. We therefore selected Japanese subjects, between 20 and 80 years of age, with normal glucose tolerance (NGT) and with a body mass index (BMI) below 25.0 kg/m2, and then examined the subject's insulin sensitivity based on the indices of a homeostasis model assessment-insulin resistance index (HOMA-IR) and ISI composite (ISI), and beta-cell function by these of HOMA-beta, AUC I/G(0-120), an insulinogenic index (deltaI30/deltaG30), and then (deltaI30/deltaG30)/HOMA-IR derived from a 75 g-oral glucose tolerance test (OGTT). The subjects were divided into the six subgroups according to sex and age, below age 30, between ages 30 and 49, and equal to and over age 50. Both HOMA-IR and the ISI showed no differences across the range of age and sex. HOMA-beta decreased with age, and AUC I/G(0-120) decreased in the elderly. No change was observed in deltaI30/deltaG30 across the age range in men, however deltaI30/deltaG30/HOMA-IR, the index of the early phase insulin secretion adjusted for insulin sensitivity, decreased with age in both men and women. These data indicated that aging itself had no effect on insulin sensitivity, while insulin secretion in both the early and late phase during the OGTT deteriorated with age even within the NGT subjects.     

Novel tumor marker discovery of gastrointestinal cancers using various proteomic approaches

Cancer has been the disease with the highest cause of death for a decade. This is partly due to the lack of ideal tumor markers for early diagnosis, which causes cancer found at the advanced stage where no curative treatment is available. Therefore, development of tumor markers with higher sensitivity and specificity is waiting to emerge. The ideal source for the tumor markers are serum, plasma or urine samples that are routinely used as clinical laboratory test. They contain a number of proteins that could be useful for cancer diagnosis. Recent advances in proteomic technology made it possible to identify the low abundant proteins in the clinical samples and thus extensive efforts are now attempted to search for the tumor markers across the country. There are two prominent types of proteomic approaches, 2D gel-based (2DE) and MS/MS based approach. 2DE is favorable to analyze relatively high moleculer weight proteins (MW > 20kD) and MS is superior to detect low molecular proteins or peptides. In this article, we introduce our recent studies on tumor marker discovery using various proteomic approaches and will discuss future application for cancer     

Pathophysiological significance of N‐myc downstream‐regulated gene 2 in cancer development through protein phosphatase 2A phosphorylation regulation

N‐myc downstream‐regulated gene 2 (NDRG2) is a candidate tumor suppressor in various cancers, including adult T‐cell leukemia/lymphoma (ATLL). NDRG2, as a stress‐responsive protein, is induced by several stress‐related signaling pathways and NDRG2 negatively regulates various signal transduction pathways. Although it has not been found to function alone, NDRG2 binds serine/threonine protein phosphatase 2A (PP2A), generating a complex that is involved in the regulation of various target proteins. The main function of NDRG2 is to maintain cell homeostasis by suppressing stress‐induced signal transduction; however, in cancer, genomic deletions and/or promoter methylation may inhibit the expression of NDRG2, resulting in enhanced tumor development through overactivated signal transduction pathways. A wide variety of tumors develop in Ndrg2‐deficient mice, including T‐cell lymphoma, liver, lung and other tumors, the characteristics of which are similar to those in Pten‐deficient mice. In particular, PTEN is a target molecule of the NDRG2/PP2A complex, which enhances PTEN phosphatase activity by dephosphorylating residues in the PTEN C‐terminal region. In ATLL cells, loss of NDRG2 expression leads to the failed recruitment of PP2A to PTEN, resulting in the inactivation of PTEN phosphatase with phosphorylation, ultimately leading to the activation of PI3K/AKT. Thus, NDRG2, as a PP2A adaptor, regulates the global phosphorylation of important signaling molecules. Moreover, the downregulation of NDRG2 expression by long‐term stress‐induced methylation is directly correlated with the development of ATLL and other cancers. Thus, NDRG2 might be important for the development of stress‐induced leukemia and other cancers and has become an important target for novel molecular therapies.     

Significance of fistulography findings to the healing time of postoperative pancreatic fistula after pancreaticoduodenectomy

Pancreatic fistula (PF) is a common and serious complications after pancreaticoduodenectomy (PD). However, few studies have discussed the time required for PF healing in patients with this complication. This study investigates the PF healing time (PF-HT) and its association with findings of postoperative fistulography performed via the drainage tubes. The subjects of this study were 35 patients with PF among a total of 144 patients who underwent PD for periampullary diseases in our hospital. PF-HT, which was defined as the duration from the first postoperative fistulography to removal of the drainage tubes, was assessed in the enrolled patients. Fistulography findings were classified into four types based on fluid collection and communication with the jejunal loop. We investigated the factors affecting the PF-HT, including the fistulography findings. The average PF-HT was 22 ± 20 days. Multivariate analysis revealed that the fistulography type was the only independent factor that affected PF-HT significantly. The PF-HT was significantly shorter in patients without fluid collection than in those with fluid collection. Moreover, those patients with fluid collection and a communication had a significantly shorter PF-HT than those without a communication. We found that fistulography findings were significantly associated with the PF-HT. This suggests that fistulography findings could help to predict the time needed for PF healing.