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-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.

Biological activity of SE-10, granulated powder of Sasa senanensis Rehder leaf extract.

BACKGROUND: We have previously reported that alkaline extract of Sasa senanensis leaves (SE) showed potent anti-HIV, anti-UV and radical scavenging activity. In the present study, we investigated the biological activities of SE-10, a granulated powder of SE supplemented with lactose, lactitol, trehalose and tea extract. MATERIALS AND METHODS: Cell viability of mock-infected, HIV-infected, and UV-irradiated cells was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Scavenging activity of superoxide anion and hydroxyl radicals was determined by electron-spin resonance spectroscopy. Cytochrome P-450 (CYP)3A4 activity was measured by ß-hydroxylation of testosterone in human recombinant CYP3A4. RESULTS: SE-10 had slightly higher anti-HIV and anti-UV activities, but slightly lower radical-scavenging and CYP3A4-inhibitory activities, as compared with SE. CONCLUSION: The present study demonstrates that the biological activities of SE were well preserved during the manufacturing process of SE-10.

Comparative study of biological activity of three commercial products of Sasa senanensis Rehder leaf extract.

BACKGROUND: We have previously reported that alkaline extract of Sasa senanensis leaves (SE) has several biological activities characteristic of lignin-carbohydrate complex (LCC). In the present study, we compared the biological activity of three commercially available products of SE (products A, B and C). MATERIALS AND METHODS: Cell viability of mock-infected, HIV-infected, UV-irradiated cells was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Radical intensity was determined by electron spin resonance spectroscopy. Cytochrome P-450 (CYP)3A4 activity was measured by ß-hydroxylation of testosterone in human recombinant CYP3A4. RESULTS: Product A is a pure SE that contains Fe(II)-chlorophyllin, whereas products B and C contain Cu(II)-chlorophyllin and less LCC. Product C is supplemented with ginseng and pine (Pinus densiflora) leaf extracts. Product A exhibited 5-fold higher anti-HIV, 4-fold higher anti-UV, 5-fold higher hydroxyl radical-scavenging, and 3-fold lower CYP3A4 inhibitory activities as compared to those of product B, and 5-fold higher, 1.5-fold higher, comparable, and 7-fold lower activities, respectively, as compared to those of product C. CONCLUSION: The present study demonstrates for the first time the superiority of product A over products B and C, suggesting the beneficial role of LCC and Fe(II)-chlorophyllin.

Re-evaluation of anti-inflammatory activity of mastic using activated macrophages.

Mastic is a resinous exudate obtained from the stem and the main leaves of Pistacia lentiscus. Mastic has shown several beneficial pharmaceutical properties such as antibacterial and apoptosis-modulating activities. The aim of this study was to investigate whether mastic affects the function of activated macrophages. Both solid and liquid types of mastic inhibited the production of pro-inflammatory substances such as nitric oxide (NO) and prostaglandin (PG)E(2) by lipopolysaccharide (LPS)-activated mouse macrophage-like RAW264.7 cells. This was accompanied by the decline of viable cell number. Western blot and RT-PCR analyses showed that mastic inhibited the expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 at both protein and mRNA levels. ESR spectroscopy revealed that mastic scavenged NO and superoxide radicals very poorly, in contrast to its potent hydroxyl radical scavenging activity. These data demonstrate that mastic inhibits the production of both NO and PGE(2) by activated macrophages mostly via its cytotoxic action. The narrow range of effective concentration of mastic due to its cytotoxicity may limit its potential application as an anti-inflammatory agent.

Non-apoptotic cell death induced by nutritional starvation in J774.1 mouse macrophage-like cell line.

The growth and amino acid utilization of a mouse macrophage-like cell line J774.1 was investigated in two different culture media supplemented with 10% fetal bovine serum (FBS). The J774.1 cells grew faster, and consumed glutamine and serine at higher rates in DMEM than in RPMI1640 medium. The consumption of other amino acids was much less, while considerable quantities of alanine, glutamic acid and glycine were produced by the J774.1 cells. When the cells became confluent, serine, but not glutamine, was nearly depleted from the culture medium, followed by cell death characterized by smear DNA fragmentation, slight caspase-3 activation and structural damage of the mitochondria. Serine is required for the growth of mouse macrophage-like cell lines, and DMEM is superior to RPMI1640 for long-term cell culture.