Structures and antiosteoclastogenic activity of compounds isolated from edible lotus (Nelumbo nucifera Gaertn.) leaves and stems

One new 1,4-bis-phenyl-1,4-butanedione glycoside (14), one new eudesmane-type sesquiterpenoid (16), and 16 known compounds were isolated from the leaves and stems of Nelumbo nucifera Gaertn. The structures of the isolated compounds were elucidated by interpretation of their 1D and 2D NMR spectroscopic and HRESIMS data. Time-dependent density functional theory calculations and Electronic Circular Dichroism (ECD) spectroscopy was used to determine absolute configurations of the new eudesmane-type sesquiterpenoid (16). All the isolated compounds were examined for their antiosteoclastogenic activity. Preliminarily results of the TRAP staining on RAW 264.7 cells indicated that compounds 1 and 11 possess potential inhibitory effects on RANKL-induced osteoclast formation. Further bioassay investigation was carried out to reveal that compounds 1 and 11 suppressed RANKL-induced osteoclast formation in a concentration-dependent manner with the inhibition up to 55% and 78% at the concentration of 10 μM, respectively. In addition, the structure-activity relationship analysis showed that the 1,3-dioxole substitute and the double bond at C-6a/C-7 in the aporphine skeleton may be responsible for the antiosteoclastogenic activity. The findings provided valuable insights for the discovery and structural modification of aporphine alkaloids as the antiosteoclastogenic lead compounds.

Glycosylated constituents isolated from the trunk of Abies holophylla and their anti-inflammatory and neurotrophic activity

Eleven previously undescribed glycosylated compounds with phenolic (abeoside A-F), monoterpenyl (abeoside G and H), or 2-heptanyl (abeoside I-K) aglycone, and twenty one reported compounds were isolated from the trunk of Abies holophylla. The structures of the previously undescribed compounds were elucidated on the basis of the conventional NMR and HRMS data analysis, and the absolute configuration of sugar units were assigned by chiral derivatization and LC-MS analysis. All the isolated compounds were evaluated for their anti-neuroinflammatory and neurotrophic activities. Among the evaluated compounds, twelve compounds including abeoside A, B, E, G, H, J, and K exhibited strong anti-neuroinflammatory activities with IC₅₀ values of 4.6-18.2 μM by inhibiting production of LPS-induced NO levels, and abeoside C and 1-O-[(S)-oleuropeyl]-β-D-glucoside showed powerful effects on the stimulation of NGF secretion levels with 157.09 ± 8.53% and 154.74 ± 1.24%, respectively.

Oral immunization with Helicobacter pylori-loaded poly(D, L-lactide-co-glycolide) nanoparticles

BACKGROUND

Helicobacter pylori is a major cause of chronic antral gastritis and peptic ulcer diseases. Many researchers have examined the possibility of immunologically-mediated prevention of H. pylori infection using an oral vaccine. The purpose of this study is to investigate whether mucosal and systemic immune responses are induced by oral immunization with H. pylori lysate-loaded poly(D, L-lactide-coglycolide)[PLG] nanoparticles, and if so, how the distribution of serum IgG subclasses are produced.

METHODS

PLG nanoparticles (H. pylori-PLG) with encapsulated H. pylori lysates were prepared by the solvent evaporation method, and the physical properties of the nanoparticles were investigated. Following the oral immunization of the H. pylori-PLG nanoparticles into mice, antibody induction was assayed in serum and gut washings, and the pattern of serum IgG subclasses was determined by ELISA.

RESULTS

The prepared H. pylori-PLG nanoparticles were spherical, nonporous particles with a mean diameter of less than 1 microm. The multiple oral immunization with H. pylori-PLG nanoparticles induced significantly H. pylori-specific mucosal IgA response as well as serum IgG responses. The serum antibody subclasses elicited were predominantly IgG1 and IgG2b.

CONCLUSION

Our results suggested that oral immunization of H. pylori-PLG nanoparticles induced the H. pylori-specific mucosal and systemic responses in mice and enhanced Th2-type responses.

Induction of mucosal and systemic immune response by oral immunization with H. pylori lysates encapsulated in poly(D,L-lactide-co-glycolide) microparticles

Helicobacter pylori is a major cause of chronic antral gastritis and peptic ulcer diseases. Several kinds of poly(D,L-lactide-coglycolide) microparticles containing H. pylori whole-cell lysate (PLG-HP) were prepared by the solvent evaporation method using double emulsion. Physical properties, such as particle size, protein content, and morphology were investigated. All prepared microparticles showed a smooth surface morphology from 0.5-0.86 microm in diameter and high degree of encapsulation efficiency from 62-75%. SDS-PAGE and immunoblotting of extracted antigen confirmed that the molecular weight and antigenicity of the antigen remained unaltered by the encapsulation procedure. Following the oral immunization of the microparticles to mice, antibody production was assayed in serum and gut washings by ELISA and antibody secreting cells were determined in intestinal lamina propria lymphocytes (LPL) by ELISPOT. Multiple oral immunizations induced significant H. pylori-specific intestinal IgA response as well as serum IgG response than those detected with soluble antigen (P < 0.001). The presence of antibody-secreting cell in intestinal lamina propria lymphocytes (LPL) was correlated with IgA level in gut washing fluids. After boosting at week-8, the antibody induction levels were highly increased irrespective of microparticles prepared with different PLG molecular weights. These data suggested that PLG-HP could stimulate the H. pylori-specific mucosal and systemic response in vivo and might be useful adjuvant in future H. pylori vaccine development.

Synthesis and evaluation of 2 beta-oxyimino and alkenylpenicillanic acid sulfone derivatives as beta-lactamase inhibitors

The synthesis and in vitro synergies of 2 beta-alkenyl and oxyiminopenam sulfone derivatives are described. Most of the compounds synthesized exhibited good inhibitory activities and synergistic antibacterial activities with piperacillin and ceftriaxone, respectively, against several beta-lactamase producing strains. Particularly the 2 beta-alkenylpenam sulfone derivatives. 1e and 1g, showed good synergistic activity with ceftriaxone against Citrobacter freundi NIH 10018-68 and Proteus vulgaris 20. Also the compounds 2a, 2c, and 2f, 2 beta-oxyiminopenam sulfone derivatives, exhibited improved synergistic activity with piperacillin against Citrobacter freundi NIH 10018-68.

Serodiagnosis of Helicobacter pylori infection in Korean patients using enzyme-linked immunosorbent assay

Helicobacter pylori (H. pylori) is a gram-negative spiral bacteria that are associated with gastritis, peptic ulcer and gastric cancer. We have developed enzyme-linked immunosorbent assay (ELISA) that detects serum anti-H. pylori immunoglobulin G antibodies using H. pylori strains isolated from Korean patients. To assess the sensitivity and specificity of our assay system with different commercial kits, serum samples from 249 Korean patients with a variety of gastrointestinal diseases were tested. Among 249 Korean patients, 178 (71.5%) were positive in culture and/or urease test. The sensitivity and specificity between our assay system and four other commercial kits (Bio-Rad, DAKO, ROCHE, and IPR) were as follows: 97.8% and 92%, 94.3% and 53%, 56.5% and 92%, 83.3% and 96%, 58.2% and 92%, respectively. All sera showing discordant immunoassay results between different ELISA kits were confirmed by immunoblot analysis. These results indicate that our assay system showed a highly accurate and reliable results in diagnosis of H. pylori infection in Korean patients.

Identification of immunodominant epitopes in the core and non-structural region of hepatitis C virus by enzyme immunoassay using synthetic peptides

Thirty-two synthetic peptides, components of the core and non-structural protein of Hepatitis C virus (HCV), were tested for their reactivities against antibodies in sera of healthy, HCV antibody positive of chronic liver disease patients. Among them, 8 of the core peptides, 4 of the NS4 peptides and 3 of the NS5 peptides reacted with the HCV infected sera. In particular, C22 (core peptide) and NS4-1924 (NS4 peptide) were most reactive with the serum samples giving a positive signal with commercially available enzyme-linked immunosorbent assay (ELISA) kit. Our results indicate that the immunodominant regions of the HCV-derived proteins are located at three regions in the core protein, three regions in the NS4 protein, and one region in the NS5 protein. These results indicate that the selected peptides are useful antigens in detecting antibodies in the sera from individuals infected with HCV.