Re-evaluation of anti-inflammatory potential of eugenol in IL-1β-stimulated gingival fibroblast and pulp cells

BACKGROUND

We recently reported that eugenol exerted comparable cytotoxicity towards human normal and tumor cells. In the present study, we investigated the effect of eugenol on interleukin-8 (IL-8) production by IL-1β-stimulated oral cells.

MATERIALS AND METHODS

The viable cell number was determined by direct cell counting with a hemocytometer after trypsinization. IL-8 released into the culture medium was determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

IL-1β (5 ng/ml) induced two orders of magnitude higher production of IL-8 by human cultured cells than unstimulated cells. Upon IL-1β stimulation, both gingival fibroblasts (HGF) and periodontal ligament fibroblasts (HPLF) produced the greatest amounts of IL-8 (approximately 200-300 ng/ml), followed by pulp cells (HPCs) (approximately 40-50 ng/ml), whereas skin keratinocyte (HaCat) and oral squamous cell carcinoma cells (HSC-2, HSC-4) produced much less IL-8 (less than 15 ng/ml). The production of IL-8 depended on growth factor(s), since the omission of fetal bovine serum from the culture medium resulted in an approximately 90% decline of IL-8 production. Eugenol (5-500 μM) significantly stimulated IL-8 production in HGF cells, but had bi-modal effects on HPCs, causing slight stimulation at lower concentration (5 μM) and a significant inhibition at higher concentration (500 μM), regardless of the presence or absence of serum. Eugenol exerted similar effects on lipopolysaccharide-stimulated HGFs and HPCs.

CONCLUSION

These results demonstrate that an anti-inflammatory effect of eugenol is observed in HPCs, but not in HGFs. The narrow therapeutic range of eugenol suggests the importance of careful usage of this compound for dental treatment.

Changes of metabolic profiles in an oral squamous cell carcinoma cell line induced by eugenol

BACKGROUND

We have recently reported that eugenol exerted indiscriminate cytotoxicity towards normal oral cells and oral squamous cell carcinoma (OSCC) cell lines without induction of apoptosis markers. In order to investigate the underlying mechanisms of cytotoxicity induction, we investigated the effect of short-term treatment with eugenol on the metabolic profiles of a human OSCC cell line (HSC-2).

MATERIALS AND METHODS

The viable cell number was determined by direct cell counting with a hemocytometer after trypsinization. After washing with 5% D-mannitol solution (found to retain the highest amounts of intracellular metabolites among several washing conditions), cellular metabolites were extracted with methanol with internal markers and then subjected to metabolomic analysis.

RESULTS

Cytotoxic concentrations of eugenol induced the reduction of ATP utilization (assessed by a significant reduction of the AMP/ATP and ADP/ATP ratio), of oxidative stress (assessed by the increase in oxidized form of glutathione, cysteine-glutathione disulfide and methionine sulfoxide), and an increase in the polyamines and glycolytic metabolites.

CONCLUSION

The metabolic changes observed in this study suggest the induction of non-apoptotic cell death by eugenol.

Cytotoxicity of dental compounds towards human oral squamous cell carcinoma and normal oral cells

AIM

The cytotoxicity of four dental compounds, hydroquinone, benzoquinone, eugenol and phtharal towards human oral squamous cell carcinoma (OSCC) cell lines, normal human oral cells (gingival fibroblast, pulp cell, periodontal ligament fibroblast) and skin keratinocytes was investigated.

MATERIALS AND METHODS

Viable cell number was determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) method. The concentration that reduced the viable cells by 50% (CC(50)) and the concentration that increased the viability of UV-irradiated cells to 50% (EC(50)) were determined from the dose-response curves. The tumor-specificity index (TS) was determined by the ratio of the mean CC(50) for normal cells to the one for tumor cells. Apoptosis induction was monitored by assay of internucleosomal DNA fragmentation and caspase-3/-7 activation.

RESULTS

When both oral OSCC and normal oral cells were incubated for 4 h with any of hydroquinone, benzoquinone, eugenol and phtharal, irreversible cell growth inhibition, accompanied by cell death occurred without induction of apoptotic markers, although caspase-3/-7 activation was observed at 6 h or later. These compounds exhibited very low tumor-specificity (TS=0.4-1.3), as compared with anticancer drugs (5-fluorouracil, melphalan, peplomycin) (TS=4.1-9.7). Human skin keratinocytes were the most resistant to these drugs, and a long incubation time was required to induce irreversible growth inhibition. However, all dental compounds exhibited very low tumor-specificity (TS=0.4-2.4), compared to human skin keratinocytes and OSCC cell lines. None of the dental compounds exhibited any hormetic growth stimulation, nor protected the cells from UV-induced damage.

CONCLUSION

These results suggest that apoptosis is not involved in the early stage of growth inhibition induced by dental compounds.

Anti-UV activity of lignin-carbohydrate complex and related compounds

BACKGROUND

We recently reported that an alkaline extract of the leaves of Sasa senanensis Rehder (SE) and Lentinus edodes mycelia extract (LEM), exhibiting lignin-carbohydrate complex (LCC)-like activity, protected cells from UV-induced injury (referred to as anti-UV activity). We investigated whether LCC is the major active components responsible for anti-UV activity.

MATERIALS AND METHODS

Human oral squamous cell carcinoma HSC-2 cells were exposed to short UV irradiation in phosphate-buffered saline, containing different concentrations of LCC. After culturing for 48 h in fresh culture medium, the viable cell number was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. From the dose-response curve, the 50% cytotoxic concentration (CC(50)) and the concentration that increased the viability of the UV-irradiated cells to 50% of the control value (EC(50)) were determined. The selectivity index (SI) was determined by the following equation: SI=CC(50)/EC(50).

RESULTS

LCCs (Fr. VI) of pine cones and seed shell, and sulfated LCC exhibited relatively high anti-UV activity (SI=7.1-38), compared with that of SE and LEM. LCCs with lower lignin content (Fr. VII) exhibited anti-UV activity, approximately one half that of Fr. VI. However, polysaccharides (laminarin, pullulan, dextran) introduced with dimethylaminoethyl- or sulfate groups with different substitution ratios were totally inactive (SI<1). The introduction of a sulfate group to LCC did not enhance the anti-UV activity of LCC. Sodium ascorbate and vanillin were the most active (SI=65), whereas gallic acid (SI=5), epigallocatechin gallate (SI=2.6), ar-trumeron (SI<1), and turmeric extract (SI<1) were much less active.

CONCLUSION

The prominent anti-UV activity of SE and LEM seems to be generated by LCCs present in the extract.

Pilot study of changes in salivary metabolic profiles induced by template therapy

BACKGROUND

Occlusal raising method (so-called 'Template therapy') has been reported to alleviate various diseases and symptoms, but the underlying mechanism is not clear. We searched the low-molecular weight metabolite(s) in the saliva, the concentration of which is significantly changed by the template therapy.

MATERIALS AND METHODS

One female patient with headache underwent the template therapy for 12 days, and her total saliva was subjected to non-targeted analysis using capillary electrophoresis time-of-flight mass spectrometry (CE-TOF-MS).

RESULTS

One hundred and thirteen substances were identified in the saliva. Glycine was the most abundant amino acid in the saliva, followed by alanine, serine and proline. After the start of the template therapy, her headache was alleviated, accompanied by a significant (p=0.042) increase of salivary concentration of glycine, as compared with total amino acids whereas that of other amino acids was not significantly changed. In the metabolomics profile, salivary concentration of large number of metabolites as compared with total metabolite concentration decreased, including N-acetylneuraminate (p=0.025) and p-hydroxyphenylacetate (p=0.039).

CONCLUSION

This pilot study demonstrated, to our knowledge for the first time, that only glycine exhibited unique changes among total metabolites, suggesting its significant role in template therapy.

Comparative inhibitory effects of magnolol, honokiol, eugenol and bis-eugenol on cyclooxygenase-2 expression and nuclear factor-kappa B activation in RAW264.7 macrophage-like cells stimulated with fimbriae of Porphyromonas gingivalis

BACKGROUND

The anti-inflammatory activity of magnolol and related compounds is currently a focus of interest. In the present study, the inhibitory effects of these compounds on cyclooxygenase (COX-2) expression and nuclear factor-kappa B (NF-κB) activation were investigated in RAW264.7 macrophage-like cells stimulated with the fimbriae of Porphyromonas gingivalis, an oral anaerobe.

MATERIALS AND METHODS

The cytotoxicity of magnolol, honokiol, eugenol and bis-eugenol against RAW264.7 cells was determined using a cell counting kit (CCK-8). The regulatory effect of these compounds on the expression of COX-2 mRNA, stimulated by exposure to the fimbriae was investigated by real-time polymerase chain reaction (PCR). NF-κB activation was evaluated by enzyme-linked immunosorbent assay (ELISA)-like microwell colorimetric transcription factor activity assay (Trans-AM) and western blot analysis. The radical-scavenging activity was determined using the induction period method in the methyl methacrylate-azobisisobutyronitrile (AIBN) polymerization system under nearly anaerobic conditions. The phenolic bond dissociation enthalpy (BDE) and orbital energy were calculated at the density functional theory (DFT) B3LYP/6-31G* level.

RESULTS

The cytotoxicity against RAW264.7 cells declined in the order bis-eugenol>eugenol> honokiol>magnolol, whereas the radical-scavenging activity declined in the order honokiol, bis-eugenol>magnolol> eugenol. Magnolol and honokiol significantly inhibited the fimbria-induced expression of COX-2 at non-cytotoxic concentrations. Both the fimbria-stimulated binding of NF-κB to its consensus sequence and phosphorylation-dependent proteolysis of inhibitor κB-α were markedly inhibited by magnilol and honokiol, whereas eugenol and bis-eugenol did not inhibit COX-2 expression and NF-κB activation. Magnolol and honokiol possessed a high electronegativity (χ) value.

CONCLUSION

Magnolol and honokiol exhibit antioxidative activity, low cytotoxicity, and anti-inflammatory activity. These compounds may be capable of preventing chronic inflammatory diseases induced by oral bacteria.

Pilot clinical study of Sasa senanensis Rehder leaf extract treatment on lichenoid dysplasia

BACKGROUND

Previous studies have shown antiviral, antibacterial, and anti-inflammatory activity of alkaline extract of the leaves of Sasa senanensis Rehder (SE). Here, we investigated whether SE is effective on oral lichenoid dysplasia and osteoclastogenesis.

MATERIALS AND METHODS

A male patient with white lacy streaks in the oral mucosa was orally administered SE three times a day for 11 months. The area of white streaks was monitored by intraoral photography. Interleukin-6 and -8 in the saliva were determined by enzyme-linked immunosorbent assay. Osteoclastogenesis of mouse macrophage-like RAW264.7 cells, induced by receptor activator of nuclear factor-κB ligand (RANKL) was monitored by tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cell formation.

RESULTS

Long-term treatment with SE progressively reduced both the area of white steaks and the levels of salivary interleukin-6 and -8. SE significantly inhibited the macrophage differentiation towards osteoclasts.

CONCLUSION

The present study suggests the therapeutic potential of SE towards oral diseases.

Effects of curcumin and capsaicin irradiated with visible light on murine oral mucosa

The purpose of this study was to evaluate the histopathological effects of curcumin and capsaicin, with or without visible light (VL) irradiation for 5 min, on the oral mucous membrane in mice. Capsaicin-treated, but not curcumin-treated, buccal epithelium exhibited slight tissue damage; VL irradiation caused excessive tissue damage, particularly when combined with the former treatment. The TdT-mediated dUTP-biotin nick end-labeling (TUNEL) method demonstrated that both capsaicin and curcumin induced apoptosis, with the apoptotic effect of capsaicin appearing at an early stage of application. VL irradiation increased the number of apoptotic cells, particularly those upon in the capsaicin-treated area. Capsaicin and curcumin acted as photosensitizers exposure to VL, in the presence of oxygen. Curcumin and capsaicin with VL irradiation could thus be used for photodynamic therapy in the clinical setting, especially in precancerous oral diseases.

Effect of three fluoride compounds on the growth of oral normal and tumor cells

AIM

Comparative study of the growth inhibition by different types of fluoride compounds used in dentistry has been limited. We investigated the effects of sodium fluoride (NaF), diammine silver fluoride [Ag(NH3)2F] and 5-fluorouracil (5-FU) on the growth of eleven human normal and tumor cells in total.

MATERIALS AND METHODS

Viable cell number was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis induction was evaluated by caspase-3 activation and DNA fragmentation. Fluoride was determined using a fluoride-specific electrode.

RESULTS

All compounds had little or no growth stimulating effect (hormesis) on all cells. Ag(NH3)2F exhibited the highest cytotoxicity towards both normal and tumor cells. 5-FU had the selective cytostatic activity towards oral squamous cell carcinoma cell lines, whereas NaF was selectively cytotoxic towards glioblastoma cell lines. None of the compounds induced internucleosomal DNA fragmentation and only 5-FU induced slight activation of caspase-3 in an oral squamous cell carcinoma cell line (HSC-2). Cytotoxicity of fluoride compounds was not reduced by superoxide dismutase and catalase, reducing the possibility of the involvement of reactive oxygen species in the mechanism of action. Approximately 0.01-0.09% initially added NaF was recovered from the cells, whereas the cellular uptake of Ag(NH3)2F and 5-FU was below the detection limit.

CONCLUSION

Cytotoxicity of fluoride compounds may not be directly linked to their tumor specificity nor to their apoptosis-inducing activity.

Porphyromonas gingivalis Fimbria-Induced Expression of Inflammatory Cytokines and Cyclooxygenase-2 in Mouse Macrophages and Its Inhibition by the Bioactive Compounds Fibronectin and Melatonin

Porphyromonas gingivalis (Pg) fimbriae, in addition to lipopolysaccharide, are involved in the pathogenesis of periodontal disease. At the same time, bioactive compounds such as fibronectin (FN) and melatonin in saliva and gingival crevicular fluid have been reported to exert a preventive effect against periodontitis. Here, we review current knowledge regarding the potent inhibitory effects of FN and melatonin against Pg fimbria-induced induction of proinflammatory cytokines, cyclooxygenase-2 (COX-2) expression, and NF-kappa B activation in mouse macrophages and discuss their possible clinical application for prevention of periodontal diseases induced by oral bacteria.

Effect of melatonin on cyclooxygenase-2 expression and nuclear factor-kappa B activation in RAW264.7 macrophage-like cells stimulated with fimbriae of Porphyromonas gingivalis

BACKGROUND

The possible link between melatonin and anti-inflammatory activity is currently a focus of interest. In the present study, COX-2 expression and NF-κB activation in RAW264.7 macrophage-like cells stimulated with the fimbriae of Porphyromonas gingivalis, an oral anaerobe, in the absence and presence of melatonin were investigated.

MATERIALS AND METHODS

The cytotoxicity of melatonin and indole against RAW264.7 cells was determined using a cell counting kit. The regulatory effect of melatonin, and of indole on the expression of COX-2 mRNA stimulated by exposure to the fimbriae was investigated by Northern blot analysis. NF-κB activation was evaluated by both electrophoretic mobility-shift assay and Western blot analysis.

RESULTS

The half maximal (50%) effective concentration (EC(50)) values for melatonin and indole were 3300 μM and 130 μM, respectively. Melatonin at non-cytotoxic concentrations significantly inhibited the fimbria-induced expression of COX-2. The fimbria-stimulated binding of NF-κB to its consensus sequence and phosphorylation-dependent proteolysis of inhibitor κB-α were markedly inhibited by melatonin. However, indole did not inhibit COX-2 expression and NF-κB activation.

CONCLUSION

Melatonin may be able to prevent diseases induced by oral bacteria.

Changes in salivary amino acid composition during aging

BACKGROUND

it has been suggested that the features of saliva reflect the physiological and psychological state of primates as well as subprimates, however, studies revealing the relationship between aging and the concentrations of salivary amino acids are limited. In order to better understand their physiological role, age-related changes of salivary amino acids were investigated.

MATERIALS AND METHODS

forty-five participants including 5 children [6.60 ± 1.67 (5-9) years old], 20 adults [46.55 ± 14.68 (23-64) years old), and 20 senior citizens [71.60 ± 4.27 (66-82) years old] took part in this study. Whole saliva (one sample per each person) was collected in the daytime (10:00-11:00 or 14:00-15:00). Salivary amino acids were recovered after deproteinization with 5% trichloroacetic acid and determined by an amino acid analyzer.

RESULTS

glycine was the most abundant amino acid in the saliva. Glycine and lysine levels increased significantly (p<0.05) with aging, regardless of gender difference. When the glycine and lysine levels were plotted, much higher correlation (p<0.001) was observed. On the other hand, there was no significant correlation between the salivary concentration of glutamic acid or histidine and age.

CONCLUSION

salivary amino acid levels may be regarded as markers of aging.

Multiple biological complex of alkaline extract of the leaves of Sasa senanensis Rehder

Previous studies have shown anti-inflammatory potential of alkaline extract of the leaves of Sasa senanensis Rehder (SE). The aim of the present study was to clarity the molecular entity of SE, using various fractionation methods. SE inhibited the production of nitric oxide (NO), but not tumour necrosis factor-α by lipopolysaccharide (LPS)-stimulated mouse macrophage-like cells. Lignin carbohydrate complex prepared from SE inhibited the NO production to a comparable extent with SE, whereas chlorophyllin was more active. On successive extraction with organic solvents, nearly 90% of SE components, including chlorophyllin, were recovered from the aqueous layer. Anti-HIV activity of SE was comparable with that of lignin-carbohydrate complex, and much higher than that of chlorophyllin and n-butanol extract fractions. The CYP3A inhibitory activity of SE was significantly lower than that of grapefruit juice and chlorophyllin. Oral administration of SE slightly reduced the number of oral bacteria. When SE was applied to HPLC, nearly 70% of SE components were eluted as a single peak. These data suggest that multiple components of SE may be associated with each other in the native state or after extraction with alkaline solution.

Radical-scavenging activity and cytotoxicity of p-methoxyphenol and p-cresol dimers

Compounds with two phenolic OH groups like curcumin possess efficient antioxidant and anti-inflammatory activity. We synthesized p-cresol dimer (2,2'-dihydroxy-5,5'-dimethylbiphenol, 2a) and p-methoxyphenol dimer (2,2'-dihydroxy-5,5'-dimethoxybiphenol, 2b) by ortho-ortho coupling reactions of the parent monomers, p-cresol (1a) and p-methoxyphenol (1b), respectively. Their antioxidant activity was determined using the induction period method, and their cytotoxicity towards RAW 264.7 cells was also investigated using a cell counting kit. The stoichiometric factors n (number of free radicals trapped by one mole of antioxidant moiety) for 2a and 2b were 3 and 2.8, respectively, being greater than those for 1a and 1b. The ratio of the rate constant of inhibition to that of propagation (k_inh/k_p) for 2a and 2b was similar to that for 2-t-butyl-4-methoxyphenol (BHA), a conventional food antioxidant. The 50% inhibitory dose (ID₅₀) declined in the order 1b > 1a >> 2b > 2a > BHA. The cytotoxicity for 2a and 2b was significantly greater than that for the parent monomers (p < 0.001), but smaller than that for BHA (p < 0.01). Compounds 2a and 2b may be useful as food antioxidants.

Antioxidant and cyclooxygenase-2-inhibiting activity of 4,4'-biphenol, 2,2'-biphenol and phenol

The anthropogenic substance 4,4'-biphenol and its analogues are estrogenic and cytotoxic. It has been previously found that synthesized ortho-dimers of phenolic compounds possess potent antioxidative and anti-inflammatory activity. To clarify the relationships between radical-scavenging and anti-inflammatory activities, the radical-scavenging activities of 4,4'-biphenol, 2,2'-biphenol and phenol were investigated by using differential scanning calorimetry to measure the induction period for polymerization of methyl methacrylate initiated by thermal decomposition of 2,2'-azobisisobutyronitrile. We also investigated tThe inhibitory effects of these compounds on lipopolysaccharide (LPS)-stimulated cyclooxygenase-2 (COX-2) mRNA and protein expression and on binding of activator-protein-1 (AP-1) and nuclear factor kappa-B (NF-kappaB) to their respective consensus sequences were also investigated in RAW 264.7 cells. Furthermore, theoretical parameters such as phenolic-OH bond dissociation enthalpy (BDE) and ionization potential (IP(koopman)) were calculated at the density functional theory (DFT)/B3LYP levels. Cytotoxicity declined in the order 4,4'-biphenol > 2,2'-biphenol >> phenol. 2,2'-Biphenol, but not 4,4'-biphenol, showed inhibitory effects on LPS-stimulated COX-2 expression and on AP-1 and NF-kappaB binding to their consensus sequences at 1-10 muM. Expression of COX-2 in RAW cells was enhanced by 4,4'-biphenol plus LPS, possibly because of radical-mediated transformation of 4,4'-biphenol to the cytotoxic diphenylquinone, as judged by the stoichiometric factor (n value) of 3.429 and low IP(koopman) value of this biphenol. In contrast, the anti-inflammatory activity of 2,2'-biphenol may be the result of the formation of a dimer derived from oxidation of this compound, as suggested by its n value close to 1. Phenol showed anti-inflammatory activity but did not completely inhibit COX-2 expression, even at higher concentrations.

Effects of visible light-irradiated camphorquinone and 9-fluorenone on murine oral mucosa

The purpose of this study was to evaluate the histopathological effects of camphorquinone (CQ) and 9-fluorenone (9F) with or without visible light (VL) irradiation on the oral mucous membranes of mice. VL irradiation resulted in a higher degree of tissue damage after CQ or 9F application, particularly the latter. Necrosis and apoptosis were responsible for the tissue damage after application of either agent in the presence of VL irradiation.

Comparative anti-inflammatory activities of curcumin and tetrahydrocurcumin based on the phenolic O-H bond dissociation enthalpy, ionization potential and quantum chemical descriptor

Curcumin and its reduced derivative tetrahydrocurcumin have been shown to exhibit chemopreventive activity. Cyclooxygenase-2 (COX-2) inhibition in lipopolysaccharide (LPS)- or Porphyromonas gingivalis fimbria-stimulated RAW 264.7 cells was investigated using Northern blot analysis. The fimbria-stimulated expression of the COX-2 gene was inhibited by curcumin but not by tetrahydrocurcumin. LPS-stimulated COX-2 gene expression was completely inhibited by curcumin, but an increase in the concentration of tetrahydrocurcumin did not cause complete inhibition of COX-2 expression. The inhibitory effect of curcumin on nuclear factor kappa B (NF-kappaB) activation in the cells was clearly observed, but that of tetrahydrocurcumin was incomplete even at a concentration of 20 microM. To explain the difference in effect between the two compounds, analysis of the frontier orbital was performed using ab initio 6-31G* wave function. The calculated chemical hardness (eta) for curcumin was clearly smaller, whereas its electronegativity (chi) and electrophilicity (omega) were clearly greater than the corresponding values for the curcumin-related compounds tetrahydrocurcumin, isoeugenol and eugenol. This suggested that the anti-inflammatory activities of curcumin may be related to eta-, chi- and/or omega-controlled enzymes. In addition, the bond dissociation enthalpy (BDE) of the phenolic OH was calculated using the density function theory (DFT)/B3LY. The total BDE values of curcumin and tetrahydrocurcumin were almost identical, but the BDE of one-electron oxidation and ionization potential (IP) for curcumin were lower than those for tetrahydrocurcumin, suggesting the highly pro-oxidative activity of curcumin. Curcumin has both oxidant and antioxidant properties. A causal link between the anti-inflammatory activities and molecular properties of phenolic antioxidants is suggested.

Re-evaluation of cyclooxygenase-2-inhibiting activity of vanillin and guaiacol in macrophages stimulated with lipopolysaccharide

Phytophenols such as para-substituted 2-methoxyphenols exhibit antioxidant and anti-inflammatory activities, however, their biological activities are concentration-dependent, possibly due to their dual property of being both antioxidant and prooxidant. Eugenol (2-allyl-2-methoxyphenol) and isoeugenol (4-propenyl-2-methoxyphenol) did not reveal cyclooxygenase-2 (COX-2)-inhibiting activity in macrophages stimulated with lipopolysaccharide (LPS). In contrast, vanillin (2-hydroxy-3-methoxybenzaldehyde) and guaiacol (2-methoxyphenol), especially the former, inhibited LPS-stimulated nuclear factor kappa B (NF-kappaB) activation and cyclooxygenase (COX)-2 gene expression in cells of the RAW 264.7 murine macrophage cell line. Among the 2-methoxyphenols, vanillin demonstrated a potent anti-inflammatory activity. The phenolic O-H bond dissociation enthalpy (BDE) and molecular orbital energies (chemical hardness [eta], electronegativity [chi], and electrophilicity [omega]) were examined to clarify the mechanism responsible for inhibition of COX-2 expression. The BDE, chi, and omega values for vanillin were significantly higher than the corresponding values for the other 2-methoxyphenols. The anti-inflammatory activity of 2-methoxyphenols depended on the BDE and the phenol function was crucial for eliciting this activity. In addition, the anti-inflammatory activity depended on the chi and omega. These findings make vanillin attractive as a candidate therapeutic agent.

Re-evaluation of antitumor activity of Cepharanthin

The antitumor potential of Cepharanthin was re-evaluated. Cepharanthin, a biscoclaurin alkaloid extracted from Stephania cepharantha Hayata, dose-dependently reduced the viable cell number of both normal and tumor cells, showing no tumor-specific cytotoxic action. Cepharanthin synergistically enhanced the cytotoxic activity of vitamin K3 and epigallocatechin gallate. Cepharanthin induced internucleosomal DNA fragmentation only in the human promyelocytic leukemic cell line HL-60. ESR spectroscopy showed that Cepharanthin effectively scavenged the superoxide anion (produced by hypoxanthine-xanthine oxidase reaction), the hydroxyl radical (produced by Fenton reaction) and nitric oxide (NO) (produced by NOC-7 in the presence of C-PTIO). The radical scavenging activity of Cepharanthin suggests its possible anticarcinogenic action. Cepharanthin dose-dependently inhibited the production of nitric oxide, but not that of tumor necrosis factor by lipopoysaccharide-stimulated mouse macrophage-like cells Raw 264.7. These data present a cautionary note that the cytotoxic activity of Cepharanthin is more prominent than its immunopotentiating activity.

Induction of apoptosis by dopamine in human oral tumor cell lines

Dopamine dose-dependently reduced the viable cell number of both human salivary gland tumor HSG and oral squamous cell carcinoma HSC-2, HSC-4, and NA cells. CoCl2 significantly reduced both the cytotoxic activity and radical intensity of dopamine (determined by ESR spectroscopy). Dopamine produced DNA fragments (demonstrated by TUNEL method) and induced degradation of cytokeratin by activated caspase in HSG cells (detected by an immunocytochemical method, using a specific M30 monoclonal antibody). FACS analysis demonstrated that dopamine induced DNA fragmentation, a biochemical hallmark of apoptosis, in human promyelocytic leukemia HL-60 cells. The addition of catalase did not prevent the apoptosis-inducing activity of dopamine, reducing the possibility of the involvement of H2O2 for dopamine-induced apoptosis. Dopamine transiently induced p38 mitogen-activated protein kinase (MAP kinase) phosphorylation. However, an inhibitor of p38 MAP kinase phosphorylation, SB203680, failed to inhibit the dopamine-induced apoptosis. These data suggest that p38 phosphorylation at an early stage may not be a causative event for apoptosis.

[Experimental study on injury of the rat nasal mucosa by distilled water irrigation, and its regeneration]

Injuries caused by distilled water and the regeneration process in the nasal mucosa in the respiratory region of the rat were examined electron microscopically and immunohistochemically by light microscopy. The mucosal injury was observed as exfoliation and desquamation of ciliated cells and goblet cells almost everywhere. The basal cells and basal membrane were intact. The regeneration process was completed by the migration, proliferation and differentiation of basal cells. The numbers of nuclear mitotic figures started to increase in a group of rats observed 6 hours after treatment (6-hour group), peaked at 48 hours, and returned to the baseline state after day 4. The BrdU labeling index, on the other hand, started to increase after 6 hours, peaked at 36 hours, and returned to the baseline state after day 4. The goblet cells were predominant even in the 21-day group, compared to the control group. Nuclear mitotic figures and secretory granules were observed together in one cell in the 36-hour group.

[Meatoplasty using island pedicle flap]

Meatoplasty is designed to create a lasting external auditory canal and provide improvement in hearing acuity. In three patients with congenital atresia of the external auditory canal not requiring otoplasty, we carried out meatoplasty using an island pedicle flap obtained from the postauricular region. The island pedicle flap was made into a tubed pedicle when sutured with the epidermis facing inward, which was then made into a blind tube pedicle flap when sutured to a free skin graft. The external auditory canal was completed when the blind tubed pedicle flap was inserted into a newly created external auditory canal. Since the operation, two of the three patients have benefited from remarkable improvement in hearing acuity, and all three patients have been free of atresia in the newly created auditory canal. This procedure has the following major advantages: the island pedicle flap is nourished by the posterior auricular artery; the procedure provides an island flap wide enough to cover the newly created auditory canal; and the operation can be performed in a one-stage procedure.

Ciliated mucous cells found in the nasal mucosa of a patient with Kartagener's syndrome

Transmission electron microscopy revealed the presence of ciliated cells containing many mucous secretory granules in the nasal surface epithelium of a 13-year-old patient suffering from Kartagener's syndrome. In these cells, mucous secretory granules were accumulated in the apical cytoplasm, and the Golgi apparatus was well developed in the supranuclear region. Mucous secretory granules were discharged infrequently through the apical cell membranes by single or compound exocytosis. The cells were considered to be ciliated mucous cells, which have already been reported to be present in the lower respiratory tract but not in the upper respiratory tract.

Cupulogenesis and glycoconjugates in the labyrinthine ampulla as revealed by WGA-gold labeling

We studied the distribution of wheat germ agglutinin (WGA)-bindable glycoconjugates in the vestibular ampulla of mongolian gerbils. WGA was conjugated with gold particles and applied to Lowicryl K4M sections of the ampulla. WGA-binding sites were found on the cupula and some of the secretory granules and Golgi apparatuses in the supporting cells of the sensory epithelia. The granules were seen to secrete into the endolymphatic space through reticular membrane. It is likely, therefore, that glycoconjugates are glycosylated at the Golgi apparatus in the supporting cells, stored in the granules, and secreted through the reticular membrane into the endolymphatic space to be used as a component of the cupula. The cell membranes of various cells, connective tissue filaments in the perilymphatic space and the cytoplasm of melanocytes were also labeled with WGA-gold.

Polymyxin B binding sites in Escherichia coli as revealed by polymyxin B-gold labeling

A complex of polymyxin B, bovine serum albumin, and colloidal gold was prepared and used for the ultrastructural localization of polymyxin B binding sites on thin sections of Epon-embedded Escherichia coli cells. Gold particles were found on the outer membrane of E. coli, which is consistent with reported biochemical findings. We concluded that gold labeling with polymyxin B is useful in localizing the binding sites of polymyxin.

Cytochemical localization of specific carbohydrates in the cochlea using wheat germ agglutinin-gold

Localization of specific carbohydrates in the cochlea was examined by postembedding labelling by wheat germ agglutinin (WGA)-gold at the electron microscopic level. Gold labelling was observed in the tectorial membrane, basilar membrane, basal membrane of the capillary and other connective tissues. In these areas, the labelling was observed over either fibrous structures or the ground substance. WGA is known to bind specifically with N-acetylneuraminic acid, N-acetyl-D-galactosamine, N-acetyl-D-glucosamine and its beta-(1-4)-linked oligosaccharides. The labelled sites, therefore, are considered to indicate the presence of glycoconjugates that contain these carbohydrates as their constituent.

Wheat germ agglutinin binding sites in the organ of Corti as revealed by lectin-gold labeling

The distribution of wheat germ agglutinin(WGA)-binding sites in the organ of Corti of the guinea pig and mongolian gerbil was studied. WGA was conjugated with gold particles and applied on thin sections of the cochlea embedded in Spurr's resin and in Lowicryl K4M. WGA-binding sites were found on the plasma membrane, lysosomes and cytoskeletons of hair and supporting cells as well as on the tectorial and basilar membranes. No distinct difference was discovered between hair cells and supporting cells in terms of WGA-binding activities.

Amylase secretion by nasal glands. An immunocytochemical study

Amylase, an enzyme that hydrolyzes starch, has been localized in the nasal mucosa for the first time by the protein A-gold technique. The amylase appeared to be produced by serous cells of the nasal glands. This enzyme has the potential for use as a tumor marker for cancer of the nasal cavity. The function of amylase in the physiology of nasal secretions is discussed.

Lysozyme producers in nasal mucosa. An immunocytochemical study

The question of whether or not goblet cells in the nasal mucosa are lysozyme producers has yet to be examined. In the present study, lysozyme was localized by the protein A-gold technique in human nasal mucosa with special attention to goblet cells. Both light and electron microscopic immunostaining revealed lysozyme in the secretory granules of the goblet cells, although far less than the amount present in the serous cells of the nasal glands. We concluded that the nasal glands were the main producer and goblet cells the subsidiary producer of lysozyme in nasal mucosa.

Aminoglycoside binding sites in the cochlea as revealed by neomycin-gold labelling

Neomycin/bovine serum albumin/gold was used as a probe to detect the binding sites of aminoglycosides on the thin sections of the cochlea embedded in Spurr. The binding sites were mainly located on the stereocilia, the cuticular plate of hair cells, the head plates of Deiters' cells, fibrous structures in pillar cells, in the spiral limbus and tectorial membrane and basilar membrane, plasma membranes, mitochondria and the chromatin of various kinds of cells. Triphosphoinositide, acidic glycosaminoglycans, and RNA were considered to be responsible for the binding activity.

Polymyxin-B-binding sites in the cochlea as demonstrated by polymyxin-B/gold labeling

A polymyxin-B/bovine-serum-albumin/gold complex was used as a probe to detect the binding sites of polymyxin B on thin sections of cochlea embedded in Spurr's resin. The binding sites were found to be mainly located on the stereocilia, the cuticular plate of hair cells, the head plate of Deiters' cells, the tonofilaments in pillar cells and Deiters' cells, fibrous structures in the spiral limbus, the tectorial membrane and the basilar membrane and neural elements such as nerve endings, fibers, and the myelin sheath. The mitochondria, plasma membrane, and chromatin of the nuclei of the cells observed also exhibited binding. Our results suggest that phospholipids, glycoconjugates, cytoskeletal proteins and nucleic acids are responsible for this binding activity.

Bacteriolytic activity of lysozyme in the nasal mucosa

During an experiment to study the localization of the lysozyme in the nasal mucosa of humans by the protein A-gold technique, we observed the accumulation of lysozymes around bacteria possibly causing bacteriolysis. The lysozyme, therefore, seems to play a preventive role against some kind of bacterial infection in the nasal mucosa in situ.

Binding sites of an aminoglycoside in the cochlea examined by immunocytochemistry

To localize the binding sites of aminoglycosides in the cochlea, immunocytochemistry was used with the antibody to gentamicin and the protein-A/gold complex. We found that the main binding sites were the stereocilia, the cuticular plates of hair cells, the head plates of Deiters' cells, cell filaments and the cones of pillar cells, tectorial membranes, basilar membranes, the matrix of the spiral limbus, plasma membranes, mitochondria, and the chromatin of various kinds of cells. Triphosphoinositide and acidic glycosaminoglycans are the two most likely candidates for the cause of binding activity.

Experimental immune complex otitis media: localization of IgG by protein A-gold technique

Immune complex (IC) was made of bovine serum albumin (BSA) and anti-BSA guinea pig serum, and instilled into the tubotympanic cavity of untreated guinea pigs. The location of IgG was determined by using the protein A-gold technique to trace IC in the tubotympanic mucosa of the otitis media with effusion (OME) caused by the instillation. IgG was found on the effusion, degenerated ciliated cells and on granules of goblet cells. There was no evidence of intense accumulation of IgG on the basement membrane of the mucosal epithelium or the capillaries. It is likely that IC activates complements in the tubotympanic cavity to cause OME.

Localization of lysozyme in the frozen section of nasal mucosa by protein A-gold technique

The location of lysozyme was studied in frozen sections of the nasal gland by protein A-gold technique, modified for the frozen section. Serous glands were enriched with lysozyme. Within the glands, the apical portion of the serous cells was most heavily stained. The epithelial layer was virtually unstained for lysozyme. The result was essentially the same as that obtained by the peroxidase-antiperoxidase method. Electronmicroscopic examination of the stained sections supports the possible application of this method for pre-embedding immunostaining, although further improvement of the technique is necessary.

Studies of the substructures of the lysozyme-rich secretory granule of the serous cell in the human nasal gland

Using a protein A-gold immunohistochemical technique, the lysozyme rich core and the lysozyme free peripheral rim were differentiated in the secretory granule of the serous cell in the human nasal mucosa, under the electronmicroscope. The shperical lysozyme rich core, which had been excreted into the gland lumen, was also wrapped with the peripheral rim. This finding suggests that the peripheral rim defends the integrity of the core and inhibits the release of lysozyme from the core.

The site of involvement of hypertension within the cochlea. A comparative study of normotensive and spontaneously hypertensive rats

The function and morphology of the cochlea of the spontaneously hypertensive rat (SHR) were examined and compared with the age-paired normotensive Wistar Kyoto rat (WKY). Electro- cochleographic study revealed that the function of the cochlea in the SHR declined with increasing age to a greater extent than that of WKY. Electronmicroscopic study revealed that the primary site of the cochlear deterioration of the SHR was the vascular stria, followed by the organ of Corti. Some hypotheses to explain this phenomenon are proposed for further study.

Freeze-replica observations of guinea pig middle ear muscles

The histological characteristics of the middle ear muscles, Musculus tensor tympani and M. Stapedius, of the guinea pig were studied using freeze-fracturing technique. No gap junction was observed but the tight junction was found in the tensor tympani muscle, possibly between muscle cells. No distinct difference was found between the size distributions of the apertures and caveolae on the fracture face of the sarcolemma of the two kinds of muscles.

Localization of triphosphoinositide in the cochlea. An electronmicroscopic immunocytochemical study

Triphosphoinositide (TPI) has been demonstrated to be a receptor for aminoglycosides in the cochlea and may regulate ionic permeability by its binding with Ca++. This phospholipid was localized by a protein A-gold technique in the cochlea at the electronmicroscopic level. TPI was prepared by a neomycin column and antibodies to it were raised in rabbits. The antibody used in this study reacted virtually only to TPI among the tested lipids. TPI was localized mainly at stereocilia, cuticular plates, head plates of Deiters' cells, plasma membrane, and mitochondria of various cells in the organ of Corti. In the vascular stria, TPI was found mainly at the plasma membrane of basal infoldings of the marginal cells. Possible physiological and pathophysiological roles of TPI in the cochlea are briefly discussed.

Establishment and characterization of a carcinoembryonic antigen producing cell line derived from human pancreatic exocrine cancer

A human pancreatic carcinoma cell line derived from well differentiated tubular adenocarcinoma of the pancreas head has been established and maintained for nearly 4 years. This established cell line produces and releases carcinoembryonic antigen into the culture medium. The cell line grows as a monolayer in RPMI-1640 medium containing 10 percent fetal calf serum. Xenotransplantation in athymic nude mice after subcutaneous injection of EDTA-trypsin treated cells did not succeed.

Fine morphology of the secretory mode of the tetragastrin-stimulated chief cells of human and dog gastric mucosa

The chief cells of the gastrin-stimulated gastric mucosa of human and dog were observed under a light and electron microscope. Four microgram/kg AOC-tetragastrin were given parenterally by a single shot to a man and three dogs respectively. Pepsinogen in the gastric mucosa increased at the wash-out stage and at the following dynamic equibrium stage of the chief cell secretion cycle after the administration of AOC-tetragastrin. During those stages, the chief cells released zymogen granules intensively. As the main ultrastructural process for releasing the zymogen granules, the emiocytosis in man and the apical cytoplasm dissociation in dog were discussed.

On the periodically aggregated particles on the fracture face of the cochlear hair cell

By means of the freeze-fracture technique, the membrane specialization of the cochlear hair cell of guinea pigs was studied. Periodically aggregated particles were revealed on the PF face of the plasma membrane of the outer hair cell. The particles were around 12 nm in diameter and 10 to 17 nm in center-to-center spacing. Their arragement was hexagonal, orthogonal or parallel. Possible involvement of this structure in the electrical excitability of the membrane was discussed.

Membrane unbound crystals in pancreatic acinar cells of the mouse

The exocrine pancreas of normal mice was investigated electron microscopically. The crystals were encountered in the basal cytoplasm of the acinar cells. They exhibited usually rectangular or rhomboidal profiles, measuring less than 5 mum in length and more than 0.1 mum in width. The matrices of these crystals displayed substructures of parallel dense linear pattern. The center-to-center distances between the dense lines were 100 similar to 150 A. The crystals were not limited at their surface by any membrane, but rather were densely circumscribed or sporadically surrounded by ribosomes. Filaments were interposed between ribosomes and crystal matrices and also between matrices of abutting crystals. The significance of the close relation of ribosomes to crystals was discussed.