Rings or arcs of fungus-stimulated plant growth occur worldwide; these are commonly referred to as "fairy rings". In 2010, we discovered 2-azahypoxanthine (AHX), a compound responsible for the fairy-ring phenomenon caused by fungus; AHX stimulated the growth of all the plants tested. Herein, we reveal the isolation and structure determination of a common metabolite of AHX in plants, 2-aza-8-oxohypoxanthine (AOH). AHX is chemically synthesized from 5-aminoimidazole-4-carboxamide (AICA), and AHX can be converted into AOH by xanthine oxidase. AICA is one of the members of the purine metabolic pathway in animals, plants, and microorganisms. However, further metabolism of AICA remains elusive. Based on these results and facts, we hypothesized that plants themselves produce AHX and AOH through a pathway similar to the chemical synthesis. Herein, we demonstrate the existence of endogenous AHX and AOH and a novel purine pathway to produce them in plants.

Senile dementia of the Alzheimer type and multi-infarct dementia are considered to be major problems of contemporary societies. In traditional Chinese medicine, Polygalae Radix (Japanese name: Onji), the root of Polygala tenuifolia WILLDENOW (Polygalaceae), is prescribed for amnesia, neurasthenia, palpitation, noctural emission and insomnia. 1) According to the Chinese Materia Medica, the root is guessed to have a special effect upon the will and mental powers, improving understanding and strengthening the memory.There have been numerous studies regarding the reputed memory-enhancing potential of the roots of P. tenuifolia. DX-9368, which is composed of four herbs (Panax ginseng, P. tenuifolia, Acorus gramineus and Poria cocos), ameliorated the ethanol-and scopolamine-induced memory impairment in mice.2) It is reported by Yabe et al. that the water extract of this plant up-regulates choline acetyltransferase (ChAT) activity and increases NGF secretion in vitro.3) Recently, Egashira et al. reported that the water extract improved the scopolamine-induced impairment of passive avoidance response and enhanced oxotremorine-induced tremors in mice.4) There are few reports, however, on the active constituents involved in the reputed memory-enhancing potential of the roots of P. tenuifolia, and we therefore studied these cognitive improving constituents. In this paper, we report that tenuifoliside B (1) 5) showed a cerebral protective effect on potassium cyanide (KCN)-induced anoxia and an ameliorative effect on the scopolamine-induced impairment of passive avoidance response in rats.It is well known that a decrease in oxygen supply to the brain (hypoxia) depresses cerebral function in experimental animals and humans 6,7) and that memory and learning are impaired by hypoxia in animals and humans. 8,9) The KCN anoxia model is widely used in preclinical evaluations of drugs for the treatment of cerebrovascular disorders. 6,10,11) Therefore, we used this model in addition to the scopolamine-induced impairment of passive avoidance performance as screening method. MATERIALS AND METHODSExtraction and Fractionation of P. tenuifolia As shown in Fig 1, the dried roots (9.4 kg) of P. tenuifolia from Shanxi Province in China (purchased from Yamamoto Yakuhin Kogyo Co., Ltd., Tokyo) were pulverized and extracted twice with boiling MeOH (50 l) for 2 h. The concentrated MeOH extract (PM) (2.21 kg) was dissolved in H 2 O and successively extracted with ether and n-BuOH. These layers were concentrated to give an ethereal soluble fraction (PE, xanthone-containing fraction) (398 g), an n-BuOH soluble fraction (902 g), and a water soluble fraction (PW) (609 g), respectively. The n-BuOH soluble fraction was chromatographed on silica gel [Kieselgel 60, 230-400 mesh (Merck)] (5 kg) with EtOAc-MeOH (4 : 1) and then with MeOH. Concentration of elutions with EtOAc-MeOH (4 : 1) and MeOH afforded the acylated oligosaccharide-containing fraction (PA) (468 g) and saponin-containing fraction (PS) Research Division, Tsumura & Co.; 3586 Yoshiwara Ami-...

The inflammasomes induce maturation of pro-interleukin-1β (IL-1β) and pro-IL-18. We investigated roles of the NLRP3 inflammasome in the pathogenesis of ulcerative colitis (UC). After induction of oxazolone-induced colitis, a mouse UC model, colonic tissues were assayed for inflammatory mediators. Histological studies were performed on inflamed colonic tissue from mice and UC patients. Histological severity of murine colitis peaked on day 1, accompanied by an increase in the expression of Th2 cytokines including IL-4 and IL-13. Oxazolone treatment stimulated maturation of pro-caspase-1 and pro-IL-1β, while it reduced IL-18 expression. Either exogenous IL-1β or IL-18 ameliorated the colitis with or without reduction in Th2 cytokine expression, respectively. Induction of colitis decreased MUC2 expression, which was reversed by administration of IL-18, but not IL-1β. Compared to wild-type mice, NLRP3−/− mice exhibited higher sensitivity to oxazolone treatment with enhancement of Th2 cytokine expression and reduction of mature IL-1β and IL-18 production; this phenotype was rescued by exogenous IL-1β or IL-18. Immunofluorescent studies revealed positive correlation of NLRP3 expression with disease severity in UC patients, and localization of the inflammasome-associated molecules in macrophages. The NLRP3 inflammasome-derived IL-1β and IL-18 may play a protective role against UC through different mechanisms.

Nanoparticle technology is being incorporated into many areas of molecular science and biomedicine. Because nanoparticles are small enough to enter almost all areas of the body, including the circulatory system and cells, they have been and continue to be exploited for basic biomedical research as well as clinical diagnostic and therapeutic applications. For example, nanoparticles hold great promise for enabling gene therapy to reach its full potential by facilitating targeted delivery of DNA into tissues and cells. Substantial progress has been made in binding DNA to nanoparticles and controlling the behavior of these complexes. In this article, we review research on binding DNAs to nanoparticles as well as our latest study on non-viral gene delivery using polyethylenimine-coated magnetic nanoparticles.

Nonsteroidal anti-inflammatory drugs (NSAIDs) induce cytokines, including tumor necrosis factor-α and interleukins (ILs), in the small intestine via a Toll-like receptor 4 (TLR4)-dependent pathway, leading to intestinal ulceration. Activation of the inflammasome promotes pro-caspase-1 cleavage, leading to pro-IL-1β maturation. We examined the role of NLRP3 inflammasome in NSAID-induced enteropathy. Small intestinal damage developed 3 h after indomethacin administration, accompanied by increases in IL-1β and NLRP3 mRNA expression and mature caspase-1 and IL-1β levels. In vivo blocking of IL-1β using neutralizing antibodies attenuated indomethacin-induced damage, whereas exogenous IL-1β aggravated it. NLRP3(-/-) and caspase-1(-/-) mice exhibited resistance to the damage with reduction of mature IL-1β production. This resistance was abolished by exogenous IL-1β. TLR4 deficiency prevented intestinal damage and inhibited upregulation of NLRP3 and IL-1β mRNAs and maturation of pro-caspase-1 and pro-IL-1β, whereas TLR4 activation by its agonists exerted opposite effects. Apyrase, an adenosine triphosphate (ATP) scavenger, or Brilliant Blue G, a purinergic P2X7 receptor antagonist, inhibited the damage as well as caspase-1 activation and IL-1β processing, despite there being sufficient amounts of pro-IL-1β and NLRP3. These results suggest that NLRP3 inflammasome-derived IL-1β plays a crucial role in NSAID-induced enteropathy and that both TLR4- and P2X7-dependent pathways are required for NLRP3 inflammasome activation.