Systematic screening of plant extracts from the Brazilian Pantanal with antimicrobial activity against bacteria with cariogenic relevance.

This study proposes a bioprospection methodology regarding the antimicrobial potential of plant extracts against bacteria with cariogenic relevance. Sixty extracts were obtained from ten plants--(1) Jatropha weddelliana, (2) Attalea phalerata, (3) Buchenavia tomentosa, (4) Croton doctoris, (5) Mouriri elliptica, (6) Mascagnia benthamiana, (7) Senna aculeata, (8) Unonopsis guatterioides, (9) Allagoptera leucocalyx and (10) Bactris glaucescens--using different extraction methods - (A) 70° ethanol 72 h/25°C, (B) water 5 min/100°C, (C) water 1 h/55°C, (D) water 72 h/25°C, (E) hexane 72 h/25°C and (F) 90° ethanol 72 h/25°C. The plants were screened for antibacterial activity at 50 mg/ml using the agar well diffusion test against Actinomyces naeslundii ATCC 19039, Lactobacillus acidophilus ATCC 4356, Streptococcus gordonii ATCC 10558, Streptococcus mutans ATCC 35688, Streptococcus sanguinis ATCC 10556, Streptococcus sobrinus ATCC 33478 and Streptococcus mitis ATCC 9811. The active extracts were tested to determine their minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), cytotoxicity and chemical characterization. Forty-seven extracts (78%) were active against at least one microorganism. Extract 4A demonstrated the lowest MIC and MBC for all microorganisms except S. gordonii and the extract at MIC concentration was non-cytotoxic. The concentrated extracts were slightly cytotoxic. Electrospray ionization with tandem mass spectrometry analyses demonstrated that the extract constituents coincided with the mass of the terpenoids and phenolics. Overall, the best results were obtained for extraction methods A, B and C. The present work proved the antimicrobial activity of several plants. Particularly, extracts from C. doctoris were the most active against bacteria involved in dental caries disease.

Hydroxyurea therapy in sickle cell anemia patients aids to maintain oral fungal colonization balance.

BACKGROUND: The aim of this study was to evaluate the frequency of Candida species and presence of lesions in the oral cavity of patients with sickle cell anemia (SS). METHODS: The study included 30 patients diagnosed with sickle cell anemia and taking hydroxyurea for at least 90 days (SS/HU+); and 39 patients with sickle cell anemia and without hydroxyurea therapy (SS/HU-). Two control groups were constituted by healthy individuals matched to the test groups in age, gender, and oral conditions (C/HU+ for SS/HU+ and C/HU- for SS/HU-). Oral clinical examination and anamnesis were performed. Yeasts were collected by oral rinses and identified by API system. Antifungal susceptibility evaluation was performed according to the CLSI methodology. Data obtained for microorganisms counts were compared by Student's t test (SS/HU+ vs. C/HU+ and SS/HU- vs. C/HU-) using MINITAB for Windows 1.4. Significance level was set at 5%. RESULTS: No oral candidosis lesions were detected. Significant differences in yeasts counts were observed between SS/HU- group and the respective control, but there were no differences between SS/HU+ and C/HU+. Candida albicans was the most prevalent species in all groups. Candida famata was observed both in SS and control groups. Candida dubliniensis, Candida glabrata, Candida krusei, Candida tropicalis, Candida pelliculosa, and Candida parapsilosis were observed only in SS groups. Most strains were susceptible to all antifungal agents. CONCLUSION: Hydroxyurea therapy seems to decrease candidal counts and resistance rate in sickle cell anemia patients. However, further studies should be conducted in the future to confirm this finding. Hydroxyurea therapy in sickle cell anemia patients maintains fungal species balance in oral cavity.

Induction of apoptosis by carbazole alkaloids isolated from Murraya koenigii.

In the current study, we isolated 10 carbazole alkaloids from the plant species Murraya koenigii (Rutaceae), and examined their effects on the growth of the human leukemia cell line HL-60. Three carbazole alkaloids, mahanine (6), pyrayafoline-D (7) and murrafoline-I (9), showed significant cytotoxicity against HL-60 cells. Fluorescence microscopy with Hoechst 33342 staining revealed that the percentage of apoptotic cells with fragmented nuclei and condensed chromatin was increased in a time-dependent manner after treatment with each alkaloid. Interestingly, each carbazole alkaloid induced the loss of mitochondrial membrane potential. In addition, both caspase-9 and caspase-3 were also time-dependently activated upon treatment with the alkaloids. Caspase-9 and caspase-3 inhibitors suppressed apoptosis induced by these alkaloids. The results suggest that these three alkaloids induced apoptosis in HL-60 cells through activation of the caspase-9/caspase-3 pathway, through mitochondrial dysfunction.

Cancer chemopreventive activity of naphthoquinones and their analogs from Avicennia plants.

As a part of screening studies for cancer chemopreventive agents (anti-tumor promoters), six natural and four synthetic naphthoquinones and five of their analogs were tested for their inhibitory activities against Epstein-Barr virus early antigen activation induced by 12-O-tetradecanoylphorbol-13-acetate in Raji cells. Some of the 1,4-naphthoquinones and their analogs were found to show remarkably potent activities, without showing any cytotoxicity. 1,4-Furanonaphthoquinone (5) and its analog (9) isolated from Avicennia plants (Avicenniaceae), having an alcoholic OH group on the dihydrofuran-ring, displayed the most potent activity. Furthermore, avicenol-A (9) exhibited a marked inhibitory effect on mouse skin tumor promotion in an in vivo two-stage carcinogenesis test. The result of the present investigation indicated that some of these 1,4-naphthoquinones and their analogs might be valuable as potent cancer chemopreventive agents.

Chemopreventive activity of isoquinoline alkaloids from Corydalis plants.

Eighteen isoquinoline alkaloids including protoberberines (1-12), benzophenanthridines (13-16) and an aporphine (17) isolated from plants of Corydalis species (Fumariaceae) were tested for inhibitory effects on Epstein-Barr virus early antigen activation induced by 12-O-tetradecanoylphorbol 13-acetate in Raji cells. In a primary screening test, all of the isoquinoline alkaloids showed inhibitory activity with the IC50 values being in the range of 140-410 mol ratio/32 pmol TPA. The data demonstrate that these isoquinoline alkaloids might be valuable as anti-tumor promoters.

Cancer chemopreventive agents, 4-phenylcoumarins from Calophyllum inophyllum.

In a search for anti-tumor-promoting agents, we carried out a primary screening of ten 4-phenylcoumarins isolated from Calophyllum inophyllum L. (Guttiferae), by examining their possible inhibitory effects on Epstein--Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate in Raji cells. All of the compounds tested in this study showed inhibitory activity against EBV, without showing any cytotoxicity. Calocoumarin-A (5) showed more potent activity than any of the other compounds tested. Furthermore, calocoumarin-A (5) exhibited a marked inhibitory effect on mouse skin tumor promotion in an in vivo two-stage carcinogenesis test. The results of the present investigation indicate that some of these 4-phenylcoumarins might be valuable as potential cancer chemopreventive agents (anti-tumor-promoters).

Cancer chemopreventive agents. New depsidones from Garcinia plants.

In a search for cancer chemopreventive agents from natural sources, chemical constituents of two kinds of Garcinia plants, Garcinia neglecta and Garcinia puat, collected in New Caledonia, were examined. Five new depsidones, garcinisidone-B (2), -C (3), -D (4), -E (5), and -F (6), were isolated, and their structures were determined by spectrometric analyses. Inhibitory effects of these depsidones on EBV-EA activation induced by TPA in Raji cells were also demonstrated.

Lignans as anti-tumor-promoter from the seeds of Hernandia ovigera.

Seven lignans (2-8) isolated from the seeds of Hernandia ovigera L. (Hernandiaceae) were tested for their inhibitory effects on Epstein-Barr virus early antigen activation induced by 12-O-tetradecanoylphorbol 13-acetate in Raji cells. Using a primary screening test, all the lignans showed inhibitory activity with IC50 470-590 mol ratio/32 pmol TPA. The data demonstrated that these lignans might be valuable anti-tumor-promoters.

Synthesis and evaluation of novel 2-oxo-1,2-dihydro-3-quinolinecarboxamide derivatives as potent and selective serotonin 5-HT4 receptor agonists.

A series of 8'-substituted N-(endo-8-azabicyclo[3.2.1]oct-3-yl)-1-isopropyl-2-oxo-1,2-dihydro-3-quinolinecarboxamides were synthesized. The 5-HT4 receptor agonistic activity was evaluated using the isolated guinea pig ileum preparation. Of the compounds synthesized, N-(endo-8-(3-hydroxypropyl)-8-azabicyclo[3.2.1]oct-3-yl)-1-isopropyl-2-oxo-1,2-dihydro-3-quinolinecarboxamide (15a, TS-951) exhibited the most potent serotonin 5-HT4 receptor agonistic activity. This compound had a high affinity for the serotonin 5-HT4 receptor although it had no affinities for other broad spectrum receptors. Furthermore, it remarkably enhanced gastrointestinal motility in conscious fed dogs without unfavorable effects that non-selective serotonin 5-HT4 receptor agonist has. TS-951 may be useful in improving gastrointestinal dysfunction.

Cancer chemopreventive activity of 3,5,6,7,8,3',4'-heptamethoxyflavone from the peel of citrus plants.

Nobiletin and 3,5,6,7,8,3',4'-heptamethoxyflavone (HPT), isolated from the peel of Citrus plants, were examined for the anti-tumor-initiating activity on two-stage carcinogenesis of mouse skin tumors induced by a nitric oxide donor, (+/-)-(E)-methyl-2-[(E)-hydroxyimino]-5-nitro-6-methoxy-3-hexenamide, as an initiator and 12-O-tetradecanoylphorbol-13-acetate as a promoter. HPT exhibited the remarkable anti-tumor-initiating effect on mouse skin and it suggested the possibility of HPT being a chemopreventive agent against nitric oxide (NO) carcinogenesis.

[Comparison between real-time pollen monitor KH-3000 and Burkard sampler].

Special apparatus capable of instantly measuring airborne Cryptomeria japonica pollen grains were recently appeared on the market. We examined one of them called real-time pollen monitor KH-3000 (Yamato Manufacturing Co. Ltd.). To confirm the accuracy of the monitor, comparison was made with conventional Burkard Seven-Day Recording Volumetric Spore Trap operating simultaneously at the same place. Most peaks from KH-3000 were coincided with Cry j 1 from Burkard sampler, and the greater part of the counts from KH-3000 had a strong resemblance to the counts from Cry j 1. Therefore, it is confirmed that KH-3000 counts the numbers of airborne C. japonica pollen grains. KH-3000 sometimes counts particles which do not belong to pollen grains, however. It is also confirmed that some pollens other than C. japonica, such as walnut (Juglans spp.) pollen, a part of grass pollen were counted.

Constituents and cytotoxicity of Zanthoxylum rhesta stem bark.

3,5-Dimethoxy-4-geranyloxycinnamyl alcohol (1), 8-methoxy-N-methylflindersine (2), xanthyletin and sesamin have been isolated from petroleum ether extract of the stem bark of Zanthoxylum rhesta. The petroleum ether extract and 8-methoxy-N-methylflindersine showed cytotoxicity on brine shrimp nauplii.

Constituents of Boronia pinnata.

A novel quinolone, pinolinone (1); seven new phenylpropanoids, boropinols A (2), B (3), C (4), boropinals A (5), B (6), C (7), and boropinic acid (8); and a new lignan, boropinan (9), were isolated from the roots of Boronia pinnata, and their structures were elucidated by NMR and MS analyses. In a search for novel cancer chemopreventive agents (antitumor-promoters), we screened 10 compounds isolated from the plant for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate in Raji cells. Boropinic acid (8) and 4'-hydroxy-3'-prenylcinnamaldehyde were observed to significantly inhibit the EBV-EA activation.

Xanthone and dihydroisocoumarin from Montrouziera sphaeroidea.

A xanthone, montrouxanthone and a dihydroisocoumarin, montroumarin were isolated from the stem bark of Montrouziera sphaeroidea Pancher Ex Planchon et Triana [Guttiferae], along with two known compounds. Their structures were elucidated on the basis of spectroscopic analyses. This is the first report of the analysis of chemical constituents of Montrouziera species.

Inhibitory effect of flavonoids from citrus plants on Epstein-Barr virus activation and two-stage carcinogenesis of skin tumors.

To search for possible anti-tumor promoters, thirteen flavones (1-13) obtained from the peel of Citrus plants were examined for their inhibitory effects on the Epstein-Barr virus early antigen (EBV-EA) activation by a short-term in vitro assay. Of these flavones, 3,5,6,7,8,3',4'-heptamethoxyflavone (HPT) (13) exhibited significant inhibitory effects on the EBV-EA activation induced by the tumor promoter, 12-O-tetradecanoylphorbol 13-acetate (TPA). Further, compound 13 exhibited remarkable inhibitory effects on mouse skin tumor promotion in an in vivo two-stage carcinogenesis test.

Anti-tumor-promoting effects of isoflavonoids on Epstein-Barr virus activation and two-stage mouse skin carcinogenesis.

As a part of screening studies for anti-tumor promoters, fifteen isoflavonoids isolated from plants of the genus Millettia (Leguminosae) were evaluated by examining their possible inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate in Raji cells. All of the compounds tested in this study showed inhibitory activity against EBV, without showing any cytotoxicity. Auriculasin (11) and millepurone (13), which is an oxidized isoflavone analogue, both having one or more prenyl side-chains and a 3',4'-dihydroxyphenyl group in the molecule, showed more potent activity than any of the other compounds tested. Furthermore, millepurone (13) exhibited a marked inhibitory effect on mouse skin tumor promotion in an in vivo two-stage carcinogenesis test. The results of the present investigation indicate that some of these isoflavonoids might be valuable anti-tumor promoters.

Four new furanone-coumarins from Clausena excavata.

Four new furanone-coumarins, clauslactones-N (4), -O (5), -P (6) and -Q (7) were isolated from the leaves and twigs of Clausena excavata BURM. f. (Rutaceae) collected in Indonesia and their structures were elucidated by spectroscopic analysis.

Chemical constituents of Glycosmis citrifolia (Willd.) Lindl. Structures of four new acridones and three new quinolone alkaloids.

The structures of two new dimeric acridone alkaloids, glycobismine-D (1) and -E (2), having a novel linkage as binary acridones, three monomeric acridones, glycocitrine-IV (3), -V (4), and -VI (5), and three quinolone alkaloids, glycocitlone-A (6), -B (7), and -C (8) from Glycosmis citrifolia (Willd.) Lindl. (Rutaceae) have been elucidated by spectrometric studies.

Chemical constituents of Micromelum minutum. Isolation and structural elucidation of new coumarins.

The chemical constituents of an acetone extract of the stems of Micromelum minutum Wight et Arn (Rutaceae), collected at Nakorn-Rachasima province in Thailand, were studied. Six new coumarins, named micromarin-A (1), -B (2), -C (3), -F (4), -G (5), and -H (6), were isolated along with six known coumarins, and their structures were elucidated by chemical and spectroscopic methods.

Chemical constituents of Avicennia alba. Isolation and structural elucidation of new naphthoquinones and their analogues.

Three new naphthoquinones and their analogues, named avicequinone-A (1), -B (2), -C (3), and avicenol-A (4), -B (5), -C (6), respectively, were isolated from the stem bark of Avicennia alba (Avicenniaceae) collected in Singapore, and their structures were elucidated by means of spectral methods. Gillan and co-workers have proposed that the structures of the new phytoalexins isolated from Avicennia marina are 1,2-naphthoquinones 8 and 9. Our synthetic and spectrometric studies showed that these structures should be revised respectively to 1,4-naphthoquinones 2 and 3, named avicequinone-B and -C by us.