Miho Aga

The natural plant product tryptanthrin ameliorates dextran sodium sulfate-induced colitis in mice.

The therapeutic effects of tryptanthrin (TRYP), a natural product from the medicinal plant Polygonum tinctorium, were examined in a murine model of inflammatory bowel disease (IBD). Colitis was induced by 5% dextran sodium sulfate (DSS) in drinking water for 7 days from day 0. TRYP (100 mg/kg) was administered orally suspended in 5% arabia gum everyday from day 3 for 5 days. Histopathological analysis showed reduced colon damage in TRYP-treated mice on day 6; however, colon injury resumed after treatment was stopped. The production of prostaglandin E2 (PGE2), tumor necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) by untreated and treated mouse colon tissues cultured in vitro were mostly unchanged by TRYP treatment. However, mitogen-stimulated spleen cells from TRYP-treated colitic mice produced less interleukin 2 (IL-2) and less interferon-gamma (IFN-gamma) than untreated colitic mouse spleen cells, early after induction of colitis. When colitis was induced with 5% DSS for 7 days and TRYP was given to the mice for 8 days from day 3, TRYP enhanced the survival of the mice but results were not significant. A significant reduction of weight loss was observed in TRYP-treated mice with colitis induced by 5% DSS for 4 days as compared to control mice. Remarkably, whereas 90% of the vehicle-treated mice died from wasting disease, all the TRYP-treated mice survived, suggesting that TRYP may have a therapeutic effect on colitis.

Preventive effect of Coriandrum sativum (Chinese parsley) on localized lead deposition in ICR mice

The preventive effect of Coriandrum sativum, Fam. UMBELLIFERAE (Chinese parsley) on lead deposition was investigated in male ICR mice given lead (1000 ppm) as lead acetate trihydrate in drinking water for 32 days. Administration of Chinese parsley to mice by gastric intubation was performed for 25 days from day 7 after the start of lead exposure up to the end of the experiment. The mice were then sacrificed for comparison of lead distribution. The lead reached its highest concentration in the femur but localized lead deposition in the femur was significantly decreased by meso-2,3-dimercaptosuccinic acid (DMSA), a chelating agent used as a positive control to validate this experimental model. Administration of Chinese parsley also significantly decreased lead deposition in the femur and severe lead-induced injury in the kidneys. In addition, urinary excretion of delta-aminolevulinic acid (ALA) which is known to increase with lead intake was significantly decreased after administration of Chinese parsley. The MeOH extract of Chinese parsley also reduced lead-induced inhibition of delta-aminolevulinic acid dehydratase (ALAD) activity in vitro. These results suggest that Chinese parsley has suppressive activity on lead deposition, probably resulting from the chelation of lead by some substances contained in Chinese parsley.

Cholesteryl Pullulan Encapsulated TNF-α Nanoparticles Are an Effective Mucosal Vaccine Adjuvant against Influenza Virus

We encapsulated tumor necrosis factor-α (TNF-α), a major proinflammatory cytokine, into cholesteryl pullulan (CHP) to prepare TNF/CHP nanoparticles. In this report, we describe the immune-enhancing capability of the nanoparticles to act as a vaccine adjuvant. TNF/CHP nanoparticles showed excellent storage stability and enhanced host immune responses to external immunogens. The nanoparticles were effective via the nasal route of administration for inducing systemic IgG1 as well as mucosal IgA. We applied the nanoparticles in a model experimental influenza virus infection to investigate their adjuvant ability. TNF/CHP nanoparticles combined with a conventional split vaccine protected mice via nasal administration against a lethal challenge of A/PR/8/34 (H1N1) influenza virus. Mechanistic studies showed that the nanoparticles enhanced antigen uptake by dendritic cells (DCs) and moderately induced the expression of inflammation-related genes in nasopharynx lymphoid tissue (NALT), leading to the activation of both B and T cells. Preliminary safety study revealed no severe toxicity to TNF/CHP nanoparticles. Slight-to-moderate influences in nasal mucosa were observed only in the repeated administration and they seemed to be reversible. Our data show that TNF/CHP nanoparticles effectively enhance both humoral and cellular immunity and could be a potential adjuvant for vaccines against infectious diseases, especially in the mucosa.

Ley glycolipid acts as a co-factor for tumor procoagulant activity

We have generated a monoclonal antibody (MAb), FS01, which inhibits the procoagulant activity (CCA‐1) produced by a human squamous cell carcinoma cell line, LK52. Expression of the antigen recognized by FS01 MAb in various cancer cell lines correlated well with the procoagulant activities of the expressing cell lines. Our objective was to characterize the molecule reacting with FS01 MAb and to analyze its involvement in the CCA‐1 procoagulant activity. The molecule was identified as a glycolipid and found to be involved in the procoagulant activity because both procoagulant activity and reactivity to FS01 MAb were lost after endoglycoceramidase treatment of CCA‐1. Furthermore, FS01 MAb recognized the Lewis Y (Ley) antigen. To confirm the involvement of a glycolipid incorporating the Ley antigen in the procoagulant activity, we attempted to purify CCA‐1 from LK52 culture supernatant. In one of the purification steps, a fraction containing low procoagulant activity (CCA‐1p) separated from the Ley‐positive fraction (CCA‐1c). Although CCA‐1c alone did not show procoagulant activity, the procoagulant activity of CCA‐1p was augmented by CCA‐1c and this augmentation was inhibited by FS01 MAb. Furthermore, CCA‐1c enhanced the procoagulant activity of 33 cell lines tested as well as CCA‐1p. In addition, purified Ley glycolipid from canine intestine augmented the procoagulant activity of CCA‐1p, and this augmentation also could be inhibited by FS01 MAb. We conclude that Ley glycolipid is a co‐factor for the procoagulant activity derived from cancer cells. Int. J. Cancer 73:903–909, 1997.

Establishment of Antihuman IFN-α8-Specific Monoclonal Antibodies and Their Application in the Enzyme-Linked Immunosorbent Assay (ELISA)

In the present study, we describe the generation of a series of anti-interferon-alpha8 (IFN-alpha8)-specific monoclonal antibodies (mAbs), their characterization, and the establishment of a sandwich enzyme-linked immunosorbent assay (ELISA) system for human IFN-alpha8. The sandwich ELISA system is highly sensitive to human natural IFN-alpha8 (nIFN-alpha8), with a minimum detection limit of 50 pg/mL, which did not cross-react with the other IFN preparations and several cytokines tested. Using this ELISA system, pharmacokinetic properties of an IFN-alpha preparation administered in mice were examined. We found that IFN-alpha8 has higher vascular permeability and stability than IFN-alpha2 in the circulation. These results suggest that this ELISA would be very useful for determination of IFN-alpha8 protein concentrations in various experimental samples and also of pharmacokinetic properties of IFN-alpha preparations in human.