Effect of Spermidine Analogues on Cell Growth of Escherichia coli Polyamine Requiring Mutant MA261

The effects of spermidine analogues [norspermidine (NSPD, 33), spermidine (SPD, 34), homospermidine (HSPD, 44) and aminopropylcadaverine (APCAD, 35)] on cell growth were studied using Escherichia coli polyamine-requiring mutant MA261. Cell growth was compared at 32°C, 37°C, and 42°C. All four analogues were taken up mainly by the PotABCD spermidine-preferential uptake system. The degree of stimulation of cell growth at 32°C and 37°C was NSPD ≥ SPD ≥ HSPD > APCAD, and SPD ≥ HSPD ≥ NSPD > APCAD, respectively. However, at 42°C, it was HSPD » SPD > NSPD > APCAD. One reason for this is HSPD was taken up effectively compared with other triamines. In addition, since natural polyamines (triamines and teteraamines) interact mainly with RNA, and the structure of RNA is more flexible at higher temperatures, HSPD probably stabilized RNA more tightly at 42°C. We have thus far found that 20 kinds of protein syntheses are stimulated by polyamines at the translational level. Among them, synthesis of OppA, RpoE and StpA was more strongly stimulated by HSPD at 42°C than at 37°C. Stabilization of the initiation region of oppA and rpoE mRNA was tighter by HSPD at 42°C than 37°C determined by circular dichroism (CD). The degree of polyamine stimulation of OppA, RpoE and StpA synthesis by NSPD, SPD and APCAD was smaller than that by HSPD at 42°C. Thus, the degree of stimulation of cell growth by spermidine analogues at the different temperatures is dependent on the stimulation of protein synthesis by some components of the polyamine modulon.

Enhanced Anti-tumour Effect of Cisplatin with Low-voltage Electrochemotherapy in Hamster Oral Fibrosarcoma

The aim of this study was to determine the effects of low-voltage electrochemotherapy with intraperitoneal cisplatin on hamster oral fibrosarcoma. Oral fibrosarcoma was transplanted sub-mucosally into the cheek pouch mucosa of 100 hamsters. After transplantation, the hamsters were randomly divided into four equal groups. These groups received no treatment (D-E-); 2 mg/kg body weight cisplatin treatment without electroporation (D+E-); electroporation without cisplatin treatment (D-E+);or 2 mg/kg body weight cisplatin treatment followed by electroporation (D+E+). Electrical pulse treatment together with cisplatin injection markedly reduced the size of the tumour, whereas cisplatin injection or electrical pulse treatment alone did not. These results clearly indicate that the anti-tumour effect of cisplatin on hamster oral fibrosarcoma was considerably potentiated or enhanced by the administration of local electrical pulses at low voltages.

Synthesis and biological evaluation of piperic acid amides as free radical scavengers and α-glucosidase inhibitors

A series of piperic acid amides (4-24, 29, 30) were synthesized and their 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and α-glucosidase inhibitory activities were evaluated. Among the synthesized compounds, the amides 11, 13 and 15, which contain o-methoxyphenol, catechol or 5-hydroxyindole moieties, showed potent DPPH free radical scavenging activity (11: EC50 140 µM; 13: EC50 28 µM; 15: EC50 20 µM). The amides 10, 18 and 23 showed higher inhibitory activity of α-glucosidase (10: IC50 21 µM; 18: IC50 21 µM; 23: IC50 12 µM). These data suggest that the hydrophobicity of the conjugated amines is an important determinant of α-glucosidase inhibitory activity. In addition, the amides 13 and 15 showed both potent DPPH free radical scavenging activity and α-glucosidase inhibitory activity (13: IC50 46 µM; 15: IC50 46 µM). This is the first report identifying the DPPH free radical scavenging and α-glucosidase inhibitory activities of piperic acid amides and suggests that these amides may serve as lead compounds for the development of novel α-glucosidase inhibitors with antioxidant activity.

Synthesis and evaluation of fatty acid amides on the N-oleoylethanolamide-like activation of peroxisome proliferator activated receptor α

A series of fatty acid amides were synthesized and their peroxisome proliferator-activated receptor α (PPAR-α) agonistic activities were evaluated in a normal rat liver cell line, clone 9. The mRNAs of the PPAR-α downstream genes, carnitine-palmitoyltransferase-1 and mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase, were determined by real-time reverse transcription-polymerase chain reaction (RT-PCR) as PPAR-α agonistic activities. We prepared nine oleic acid amides. Their PPAR-α agonistic activities were, in decreasing order, N-oleoylhistamine (OLHA), N-oleoylglycine, Oleamide, N-oleoyltyramine, N-oleoylsertonin, and Olvanil. The highest activity was found with OLHA. We prepared and evaluated nine N-acylhistamines (N-acyl-HAs). Of these, OLHA, C16:0-HA, and C18:1Δ(9)-trans-HA showed similar activity. Activity due to the different chain length of the saturated fatty acid peaked at C16:0-HA. The PPAR-α antagonist, GW6471, inhibited the induction of the PPAR-α downstream genes by OLHA and N-oleoylethanolamide (OEA). These data suggest that N-acyl-HAs could be considered new PPAR-α agonists.

Effects of 3-styrylchromones on metabolic profiles and cell death in oral squamous cell carcinoma cells

4H-1-benzopyran-4-ones (chromones) are important naturally-distributing compounds. As compared with flavones, isoflavones and 2-styrylchromones, there are only few papers of 3-styrylchromones that have been published. We have previously reported that among fifteen 3-styrylchromone derivatives, three new synthetic compounds that have OCH₃ group at the C-6 position of chromone ring, (E)-3-(4-hydroxystyryl)-6-methoxy-4H-chromen-4-one (compound 11), (E)-6-methoxy-3-(4-methoxystyryl)-4H-chromen-4-one (compound 4), (E)-6-methoxy-3-(3,4,5-trimethoxystyryl)-4H-chromen-4-one (compound 6) showed much higher cytotoxicities against four epithelial human oral squamous cell carcinoma (OSCC) lines than human normal oral mesenchymal cells. In order to further confirm the tumor specificities of these compounds, we compared their cytotoxicities against both human epithelial malignant and non-malignant cells, and then investigated their effects on fine cell structures and metabolic profiles and cell death in human OSCC cell line HSC-2. Cytotoxicities of compounds 4, 6, 11 were assayed with MTT method. Fine cell structures were observed under transmission electron microscope. Cellular metabolites were extracted with methanol and subjected to CE-TOFMS analysis. Compounds 4, 6, 11 showed much weaker cytotoxicity against human oral keratinocyte and primary human gingival epithelial cells, as compared with HSC-2, confirming their tumor-specificity, whereas doxorubicin and 5-FU were highly cytotoxic to these normal epithelial cells, giving unexpectedly lower tumor-specificity. The most cytotoxic compound 11, induced the mitochondrial vacuolization, autophagy suppression followed by apoptosis induction, and changes in the metabolites involved in amino acid and glycerophospholipid metabolisms. Chemical modification of lead compound 11 may be a potential choice for designing new type of anticancer drugs.

Quantitative Structure-Cytotoxicity Relationship of 3-Styryl-2H-chromenes

BACKGROUND

Sixteen 3-styryl-2H-chromenes were subjected to quantitative structure-activity relationship analysis based on their cytotoxicity, tumor selectivity and anti-HIV activity, in order to find their new biological activities.

MATERIALS AND METHODS

Cytotoxicity against four human oral squamous cell carcinoma (OSCC) cell lines, three mesenchymal and two epithelial normal oral cells was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Tumor-selectivity (TS) was evaluated by the ratio of the mean CC50 (50% cytotoxic concentration) against normal human oral cells to that against OSCC cell lines. Anti-HIV activity was evaluated by the ratio of CC50 to EC50 (50% cytoprotective concentration from HIV infection). Potency-selectivity expression (PSE) was determined by the ratio of TS/CC50 against OSCC. Physicochemical, structural and quantum-chemical parameters were calculated based on the conformations optimized by the LowModeMD method.

RESULTS

All 3-styryl-2H-chromene derivatives showed relatively high tumor selectivity. Especially, the compound that has a methoxy group at 7-position of the chromene ring and chlorine at 4'-position of phenyl group in styryl moiety [ 12: ] showed the highest TS and PSE values, exceeding those of resveratrol, doxorubicin and 5-FU. All compounds showed no anti-HIV activity. Among 330 chemical descriptors, 8, 74 and 16 descriptors significantly correlated to the cytotoxicity of normal and tumor cells, and tumor-specificity, respectively.

CONCLUSION

Multivariate statistics with chemical descriptors for molecular shape and flatness may be useful for the evaluation of tumor-specificity of 3-styryl-2H-chromenes.

Quantitative Structure-Cytotoxicity Relationship of Oleoylamides

Eighteen oleoylamides were subjected to quantitative structure-activity relationship analysis based on their cytotoxicity, tumor selectivity and anti-HIV activity, in order to assess their biological activities. Cytotoxicity against four human oral squamous cell carcinoma (OSCC) cell lines and five human oral normal cells (gingival fibroblast, periodontal ligament fibroblast, pulp cell, oral keratinocyte, primary gingival epithelial cells) was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Tumor-selectivity (TS) was evaluated by the ratio of the mean 50% cytotoxic concentration (CC50) against normal human oral cells to that against OSCC cell lines. Potency-selectivity expression (PSE) was determined by the ratio of TS to CC50 against OSCC. Anti-HIV activity was evaluated by the ratio of CC50 to the concentration leading to 50% cytoprotection from HIV infection (EC50). Physicochemical, structural and quantum-chemical parameters were calculated based on the conformations optimized by the LowModeMD method. Among 18 derivatives, compounds 8: with a catechol group) and 18: with a (2-pyridyl)amino group) had the highest TS. On the other hand, doxorubicin and 5-fluorouracil (5-FU) were more highly cytotoxic to normal epithelial cells, displaying unexpectedly lower TS and PSE values. None of the compounds had anti-HIV activity. Among 330 chemical descriptors, 75, 73 and 19 descriptors significantly correlated to the cytotoxicity to normal and tumor cells, and TS, respectively. Multivariate statistics with chemical descriptors for molecular polarization and hydrophobicity may be useful for the evaluation of cytotoxicity and TS of oleoylamides.

Synthesis and biological evaluation of 3-styrylchromone derivatives as free radical scavengers and α-glucosidase inhibitors

A series of 3-styrylchromone derivatives (4-20) were synthesized and the structure-activity relationships for α-glucosidase inhibition and antioxidant activities were analyzed. Among the synthesized compounds, compounds 15 and 20, which contain a catechol moiety, showed both potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity (15: EC₅₀=17 µM; 20: EC₅₀=23 µM) and α-glucosidase inhibitory activity (15: IC₅₀=16 µM; 20: IC₅₀=10 µM). Our data suggest that 3-styrylchromone derivatives are novel α-glucosidase inhibitors that have the potential to counteract diet-induced hyperglycemia in diabetes.

Quantitative structure-cytotoxicity relationship of 3-styrylchromones

BACKGROUND

Fifteen 3-styrylchromones were subjected to quantitative structure-activity relationship (QSAR) analysis based on their cytotoxicity, tumor selectivity and anti-HIV activity, in order to explore their biological activities.

MATERIALS AND METHODS

Cytotoxicity against four human oral squamous cell carcinoma (OSCC) cell lines and three human oral normal cells was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Tumor-selectivity was evaluated by the ratio of the mean CC50 (50% cytotoxic concentration) against normal human oral cells to that against OSCC cell lines. Anti-HIV activity was evaluated by the ratio of CC50 to EC50 (50% cytoprotective concentration from HIV infection). Physicochemical, structural and quantum-chemical parameters were calculated based on the conformations optimized by the LowModeMD method followed by the density functional theory (DFT) method.

RESULTS

All 3-styrylchromone derivatives showed moderate-to-high tumor selectivity. Especially, compounds that have a methoxy group at 6-position of the chromone ring and hydroxyl group at 4'-position of phenyl group in styryl moiety [ 11: ] showed the highest tumor-selectivity. On the other hand, their cytotoxicity against normal cells showed good correlation to the descriptors that reflect hydrophobic interaction and molecular shapes.

CONCLUSION

Multivariate statistics with chemical descriptors for the location of substituted group, molecular shape and electrostatic interaction may be useful for designing the most favorable compound with higher tumor selectivity.

Quantitative structure-cytotoxicity relationship of piperic acid amides

BACKGROUND

A total of 12 piperic acid amides, including piperine, were subjected to quantitative structure-activity relationship (QSAR) analysis, based on their cytotoxicity, tumor selectivity and anti-HIV activity, in order to find new biological activities.

MATERIALS AND METHODS

Cytotoxicity against four human oral squamous cell carcinoma (OSCC) cell lines and three human oral normal cells was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Tumor selectivity was evaluated by the ratio of the mean 50% cytotoxic concentration (CC50) against normal oral cells to that against OSCC cell lines. Anti-HIV activity was evaluated by the ratio of the CC50 to 50% HIV infection-cytoprotective concentration (EC50). Physicochemical, structural, and quantum-chemical parameters were calculated based on the conformations optimized by LowModeMD method followed by density functional theory method.

RESULTS

All compounds showed low-to-moderate tumor selectivity, but no anti-HIV activity. N-Piperoyldopamine ( 8: ) which has a catechol moiety, showed the highest tumor selectivity, possibly due to its unique molecular shape and electrostatic interaction, especially its largest partial equalization of orbital electronegativities and vsurf descriptors.

CONCLUSION

The present study suggests that molecular shape and ability for electrostatic interaction are useful parameters for estimating the tumor selectivity of piperic acid amides.

Quantitative structure-cytotoxicity relationship of phenylpropanoid amides

BACKGROUND

A total of 12 phenylpropanoid amides were subjected to quantitative structure-activity relationship (QSAR) analysis, based on their cytotoxicity, tumor selectivity and anti-HIV activity, in order to investigate on their biological activities.

MATERIALS AND METHODS

Cytotoxicity against four human oral squamous cell carcinoma (OSCC) cell lines and three human oral normal cells was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Tumor selectivity was evaluated by the ratio of the mean CC50 (50% cytotoxic concentration) against normal oral cells to that against OSCC cell lines. Anti-HIV activity was evaluated by the ratio of CC50 to EC50 (50% cytoprotective concentration from HIV infection). Physicochemical, structural, and quantum-chemical parameters were calculated based on the conformations optimized by the LowModeMD method followed by density functional theory (DFT) method.

RESULTS

Twelve phenylpropanoid amides showed moderate cytotoxicity against both normal and OSCC cell lines. N-Caffeoyl derivatives coupled with vanillylamine and tyramine exhibited relatively higher tumor selectivity. Cytotoxicity against normal cells was correlated with descriptors related to electrostatic interaction such as polar surface area and chemical hardness, whereas cytotoxicity against tumor cells correlated with free energy, surface area and ellipticity. The tumor-selective cytotoxicity correlated with molecular size (surface area) and electrostatic interaction (the maximum electrostatic potential).

CONCLUSION

The molecular size, shape and ability for electrostatic interaction are useful parameters for estimating the tumor selectivity of phenylpropanoid amides.

Development of irreversible inactivators of spermine oxidase and N1-acetylpolyamine oxidase

Three functional groups (2-propenyl, 2-propynyl, and 2,3-butadienyl) were introduced onto one of the terminal amino groups of spermidine. Of the six compounds synthesized, N-(3-aminopropyl)-N'-2,3-butadienyl-1,4-butanediamine (N(8)-butadienyl Spd) and N-[3-(2,3-butadienylamino)propyl]-1,4-butanediamine (N(1)-butadienyl Spd) irreversibly inactivated human spermine oxidase (SMO) and N(1)-acetylpolyamine oxidase (APAO). Interestingly, N(8)-butadienyl Spd inactivated SMO far more potently than N,N'-di-2,3-butadienyl-1,4-butanediamine (MDL 72527).

Follicular dendritic cell-secreted protein is decreased in experimental periodontitis concurrently with the increase of interleukin-17 expression and the Rankl/Opg mRNA ratio

BACKGROUND AND OBJECTIVE

T-helper type 17 (Th17) cells produce interleukin-17 (IL-17) and help to protect against inflammation and infection in periodontal disease. Furthermore, while follicular dendritic cell-secreted protein (FDC-SP) may be involved in the inflammation of periodontal tissue, the biological role of FDP-SP in periodontal disease is still unknown. The purpose of the present study was to clarify the expression of IL-17 and FDC-SP in experimental periodontitis in rats.

MATERIAL AND METHODS

Seven-week-old male Wistar rats were divided into baseline control, sham and test groups. Experimental periodontitis was induced by placing a ligature in the mesiopalatal area, and untreated rats served as a baseline control group. Morphological changes in alveolar bone were investigated 7, 14 and 28 d after treatment. Expression of the Rankl, osteoprotegerin (Opg) and Il17 genes was analyzed 5 and 7 d after the induction of experimental periodontitis.

RESULTS

Alveolar bone resorption progressed in the test group for 7 d, but not thereafter. At 5 d after the induction of periodontitis, the Rankl/Opg mRNA ratio and the expression of IL-17 in the test group were significantly increased compared with the respective values in the baseline control group; however, there were no significant differences between the test and control groups at 7 d. The expression of FDC-SP was significantly decreased in the test group compared with the baseline control group at 5 and 7 d after the induction of periodontitis, and this value had returned to normal levels at 14 and 28 d.

CONCLUSION

These results suggest that both IL-17 and FDC-SP could be involved in the inflammatory response, and FDC-SP in the junctional epithelium might play an important role in the Th17 cell-related immune response.

Pentamines as substrate for human spermine oxidase

Substrate activities of various linear polyamines to human spermine oxidase (hSMO) were investigated. The activities were evaluated by monitoring the amount of H2O2 released from sample polyamines by hSMO. H2O2 was measured by a HPLC method that analyzed fluorescent dimers derived from the oxidation of homovanillic acid in the presence of horseradish peroxidase. Six triamines were tested and were found not to be hSMO substrates. Of sixteen tetramines tested, spermine (Spm) was the most active substrate, followed by homospermine and N-butylated Spm. Pentamines showed a characteristic pattern of substrate activity. Of thirteen pentamines tested, 3343 showed higher substrate activity than Spm, and 4343 showed similar activity to Spm. The activities of the other pentamines were as follows: 3443, 4443, 4344, 3344, 4334, 4444, and 3334 (in decreasing order). Product amines released from these pentamines by hSMO were then analyzed by HPLC. Triamine was the only observed product, and the amount of triamine was nearly equivalent to that of released H2O2. A marked difference in the pH dependency curves between tetramines and pentamines suggested that hSMO favored reactions with a non-protonated secondary nitrogen at the cleavage site. The Km and Vmax values for Spm and 3343 at pH 7.0 and 9.0 were consistent with the higher substrate activity of 3343 compared to Spm, as well as with the concept of a non-protonated secondary nitrogen at the cleavage site being preferred, and 3343 was well degraded at a physiological pH by hSMO.

Gene expression analysis of rheumatoid arthritis synovial lining regions by cDNA microarray combined with laser microdissection: up-regulation of inflammation-associated STAT1, IRF1, CXCL9, CXCL10, and CCL5

Objectives

The main histological change in rheumatoid arthritis (RA) is the villous proliferation of synovial lining cells, an important source of cytokines and chemokines, which are associated with inflammation. The aim of this study was to evaluate gene expression in the microdissected synovial lining cells of RA patients, using those of osteoarthritis (OA) patients as the control.

Methods

Samples were obtained during total joint replacement from 11 RA and five OA patients. Total RNA from the synovial lining cells was derived from selected specimens by laser microdissection (LMD) for subsequent cDNA microarray analysis. In addition, the expression of significant genes was confirmed immunohistochemically.

Results

The 14 519 genes detected by cDNA microarray were used to compare gene expression levels in synovial lining cells from RA with those from OA patients. Cluster analysis indicated that RA cells, including low- and high-expression subgroups, and OA cells were stored in two main clusters. The molecular activity of RA was statistically consistent with its clinical and histological activity. Expression levels of signal transducer and activator of transcription 1 (STAT1), interferon regulatory factor 1 (IRF1), and the chemokines CXCL9, CXCL10, and CCL5 were statistically significantly higher in the synovium of RA than in that of OA. Immunohistochemically, the lining synovium of RA, but not that of OA, clearly expressed STAT1, IRF1, and chemokines, as was seen in microarray analysis combined with LMD.

Conclusions

Our findings indicate an important role for lining synovial cells in the inflammatory and proliferative processes of RA. Further understanding of the local signalling in structural components is important in rheumatology.