7-Geranyloxycinnamic Acid Isolated from Melicope lunu-ankenda Leaves Perturbs Colon Cancer and Breast Cancer Cell Lines' Growth via Induction of Apoptotic Pathway.

Globally, breast cancer is the most prevalent form of cancer in women and there is a need for alternative therapies such as plant-derived compounds with low systemic toxicity and selective toxicity to cancer cells. The aim of this study is to assess the cytotoxicity effects of 7-geranyloxycinnamic acid isolated from leaves of Melicope lunu-ankenda, a traditional medicinal plant, on the human breast cancer cell lines. Dried leaf powder was used for the preparation of different crude extracts using different solvents of increasing order of polarity. The structure of the isolated compound from the petroleum ether extract was elucidated by 1H and 13C NMR, LC-MS, and DIP-MS spectroscopy. The cytotoxic activity of the crude extract and 7-geranyloxycinnamic acid analyzed using MTT assay. Apoptotic analysis was evaluated using Annexin V-PI staining, AO/PI staining, intracellular ROS measurement, and measurement of activities of caspases 3/7, 8, and 9. Crude extracts and the isolated pure compound showed significant cytotoxicity against tested cancer cell lines. 7-geranyloxycinnamic acid was found to exert significant cytotoxic effects against breast cancer cell lines such as the MCF-7 and MDA-MB-231 cell lines. The cytotoxic effects are attributed to its ability to induce apoptosis via accumulation of ROS and activation of caspases in both breast cancer cell lines. The pure compound, 7-geranyloxycinnamic acid isolated from the leaves of M. lunu-ankenda, can exert significant cytotoxic effects against breast cancer cell lines without affecting the normal cells.

Apoptotic Potential of Glucomoringin Isothiocyanate (GMG-ITC) Isolated from Moringa oleifera Lam Seeds on Human Prostate Cancer Cells (PC-3).

Inhibition of several protein pathways involved in cancer cell regulation is a necessary key in the discovery of cancer chemotherapy. Moringa oleifera Lam is often used in traditional medicine for the treatment of various illnesses. The plant contains glucomoringin isothiocyanate (GMG-ITC) with therapeutic potential against various cancer cells. Therefore, GMG-ITC was evaluated for its cytotoxicity against the PC-3 prostate cancer cell line and its potential to induce apoptosis. GMG-ITC inhibited cell proliferation in the PC-3 cell line with IC50 value 3.5 µg/mL. Morphological changes as a result of GMG-ITC-induced apoptosis showed chromatin condensation, nuclear fragmentation, and membrane blebbing. Additionally, Annexin V assay showed proportion of cells in early and late apoptosis upon exposure to GMG-ITC in a time-dependent manner. Moreover, GMG-ITC induced a time-dependent G2/M phase arrest, with reduction of 39.1% in the PC-3 cell line. GMG-ITC also activates apoptotic genes including caspase, tumor suppressor gene (p53), Akt/MAPK, and Bax of the proapoptotic Bcl family. Early apoptosis proteins (JNK, Bad, Bcl2, and p53) were significantly upregulated upon GMG-ITC treatment. It is concluded that apoptosis induction was observed in PC-3 cells treated with GMG-ITC. These phenomena suggest that GMG-ITC from M. oleifera seeds could be useful as a future cytotoxic agent against prostate cancer.

Antioxidant Activity, α-Glucosidase Inhibition and UHPLC-ESI-MS/MS Profile of Shmar (Arbutus pavarii Pamp).

The genus Arbutus (Ericaceae) has been traditionally used in folk medicine due to its phytomedicinal properties, especially Arbutus pavarii Pamp. However, this plant has not been evaluated for its efficacy, quality, and consistency to support the traditional uses, potentially in treating diabetes. Despite previous studies that revealed the biological activities of A. pavarii as antioxidant and α-glucosidase inhibitory agents, scientific reports on the bioactive compounds that contribute to its health benefits are still scarce. Therefore, this research focused on the evaluation of antioxidant and α-glucosidase inhibitory activities of the methanol crude extracts and various fractions of the leaf and stem bark, as well as on metabolite profiling of the methanol crude extracts. The extracts and fractions were evaluated for total phenolic (TPC) and total flavonoid (TFC) contents, as well as the DPPH free radical scavenging, ferric reducing antioxidant power (FRAP), and α-glucosidase inhibitory activities. Methanol crude extracts of the leaf and stem bark were then subjected to UHPLC-ESI-MS/MS. To the best of our knowledge, the comparative evaluation of the antioxidant and α-glucosidase inhibitory activities of the leaf and stem bark of A. pavarii, as well as of the respective solvent fractions, is reported herein for the first time. Out of these extracts, the methanolic crude extracts and polar fractions (ethyl acetate and butanol fractions) showed significant bioactivities. The DPPH free radical and α-glucosidase inhibitions was highest in the leaf ethyl acetate fraction, with IC50 of 6.39 and 4.93 µg/mL, respectively, while the leaf methanol crude extract and butanol fraction exhibited the highest FRAP with 82.95 and 82.17 mmol Fe (II)/g extract. The UHPLC-ESI-MS/MS analysis resulted in the putative identification of a total of 76 compounds from the leaf and stem bark, comprising a large proportion of plant phenolics (flavonoids and phenolic acids), terpenoids, and fatty acid derivatives. Results from the present study showed that the different parts of A. pavarii had potent antioxidant and α-glucosidase inhibitory activities, which could potentially prevent oxidative damage or diabetes-related problems. These findings may strengthen the traditional claim on the medicinal value of A. pavarii.

Oxygen radical antioxidant capacity (ORAC) and antibacterial properties of Melicope glabra bark extracts and isolated compounds.

Melicope glabra (Blume) T. G. Hartley from the Rutaceae family is one of the richest sources of plant secondary metabolites, including coumarins and flavanoids. This study investigates the free radical scavenging and antibacterial activities of M. glabra and its isolated compounds. M. glabra ethyl acetate and methanol extracts were prepared using the cold maceration technique. The isolation of compounds was performed with column chromatography. The free radical scavenging activity of the extracts and isolated compounds were evaluated based on their oxygen radical absorbance capacity (ORAC) activities. The extracts and compounds were also subjected to antibacterial evaluation using bio-autographic and minimal inhibitory concentration (MIC) techniques against two oral pathogens, Enterococcus faecalis and Streptococcus mutans. Isolation of phytoconstituents from ethyl acetate extract successfully yielded quercetin 3, 5, 3'-trimethyl ether (1) and kumatakenin (2), while the isolation of the methanol extract resulted in scoparone (3), 6, 7, 8-trimethoxycoumarin (4), marmesin (5), glabranin (6), umbelliferone (7), scopoletin (8), and sesamin (9). The study is the first to isolate compound (1) from Rutaceae plants, and also the first to report the isolation of compounds (2-5) from M. glabra. The ORAC evaluation showed that the methanol extract is stronger than the ethyl acetate extract, while umbelliferone (7) exhibited the highest ORAC value of 24 965 µmolTE/g followed by glabranin (6), sesamin (9) and scopoletin (8). Ethyl acetate extract showed stronger antibacterial activity towards E. faecalis and S. mutans than the methanol extract with MIC values of 4166.7 ± 1443.4 µg/ml and 8303.3 ± 360.8 µg/ml respectively. Ethyl acetate extract inhibited E. faecalis growth, as shown by the lowest optical density value of 0.046 at a concentration of 5.0 mg/mL with a percentage inhibition of 95%. Among the isolated compounds tested, umbelliferone (7) and sesamin (9) exhibited promising antibacterial activity against S. mutans with both exhibiting MIC values of 208.3 ± 90.6 µg/ml. Findings from this study suggests M. glabra as a natural source of potent antioxidant and antibacterial agents.

Antibacterial Activity of Arbutus pavarii Pamp against Methicillin-Resistant Staphylococcus aureus (MRSA) and UHPLC-MS/MS Profile of the Bioactive Fraction.

Arbutus pavarii Pamp is a medicinal plant commonly used by local tribes in East Libya for the treatment of many diseases, such as gastritis, renal infections, cancer and kidney diseases. In this study, the antibacterial activity of the leaf and stem bark extracts of the plant against methicillin-resistant Staphylococcus aureus (MRSA), as well as the metabolite profiles of the bioactive fractions, was investigated. The antibacterial activity was determined by disc diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), while the microbial reduction by the bioactive fraction was evaluated using time-kill test. The bioactive fraction was further subjected to ultrahigh-performance liquid chromatography-mass spectrometry (UHPLC-ESI-MS/MS) analysis to putatively identify the chemical constituents contained therein. All the extracts and fractions showed different levels of antibacterial activity on the tested MRSA strains. The highest total antibacterial activity, i.e., 4007.6 mL/g, was exhibited by the crude leaf methanolic extract. However, the ethyl acetate fraction of the leaf showed moderate to significant antibacterial activity against MRSA at low MIC (0.08-1.25 mg/mL). Metabolite profiling of this fraction using UHPLC-ESI-MS/MS resulted in the putative identification of 28 compounds, which included phenolic acids, flavan-3-ols and flavonols. The results of this study showed that the ethyl acetate fraction of Arbutus pavarii leaf possessed potential antibacterial activity against MRSA and hence can be further explored for pharmaceutical applications as a natural antibacterial agent.

Antibacterial and Antispore Activities of Isolated Compounds from Piper cubeba L.

Piper cubeba L. is the berry of a shrub that is indigenous to Java, Southern Borneo, Sumatra, and other islands in the Indian Ocean. The plant is usually used in folk traditional medicine and is an important ingredient in cooking. The purpose of this study was to isolate and purify the bioactive compounds from P. cubeba L. fractions. In addition, the isolated compounds were tested for their antibacterial and antispore activities against vegetative cells and spores of Bacillus cereus ATCC33019, B. subtilis ATCC6633, B. pumilus ATCC14884, and B. megaterium ATCC14581. The phytochemical investigation of the DCM fraction yielded two known compounds: ß-asarone (1), and asaronaldehyde (2) were successfully isolated and identified from the methanol extract and its fractions of P. cubeba L. Results showed that exposing the vegetative cells of Bacillus sp. to isolated compounds resulted in an inhibition zone with a large diameter ranging between 7.21 to 9.61 mm. The range of the minimum inhibitory concentration (MIC) was between 63.0 to 125.0 µg/mL and had minimum bactericidal concentration (MBC) at 250.0 to 500.0 µg/mL against Bacillus sp. Isolated compounds at a concentration of 0.05% inactivated more than 3-Log10 (90.99%) of the spores of Bacillus sp. after an incubation period of four hours, and all the spores were killed at a concentration of 0.1%. The structures were recognizably elucidated based on 1D and 2D-NMR analyses (1H, 13C, COSY, HSQC, and HMBC) and mass spectrometry data. Compounds 1, and 2 were isolated for the first time from this plant. In conclusion, the two compounds show a promising potential of antibacterial and sporicidal activities against Bacillus sp. and thus can be developed as an anti-Bacillus agent.

Phytochemical Constituents and Biological Activities of Melicope lunu-ankenda.

Natural products, either pure compounds or standardized plant extracts, have provided opportunities for the discovery of new drugs. Nowadays, most of the world's population still relies on traditional medicines for healthcare purposes. Plants, in particular, are always used as traditional medicine, as they contain a diverse number of phytochemicals that can be used for the treatment of diseases. The multicomponent feature in the plants is considered a positive phytotherapeutic hallmark. Hence, ethnopharmacognosy has been the focus for finding alternative treatments for diseases. Melicope lunu-ankenda, also known as Euodia lunu-ankenda, is widely distributed in tropical regions of Asia. Different parts of M. lunu-ankenda have been used for treatment of hypertension, menstrual disorder, diabetes, and fever, and as an emmenagogue and tonic. It has also been consumed as salad and as a condiment for food flavorings. The justification of use of M. lunu-ankenda in folk medicines is supported by its reported biological activities, including its cytotoxic, antibacterial, antioxidant, analgesic, antidiabetic, and anti-inflammatory activities. This review summarizes the phytochemical compounds isolated from various parts of M. lunu-ankenda, such as root and leaves, and also its biological activities, which could make the species a new therapeutic agent for some diseases, including diabetes, in the future.

Solvent Extraction and Identification of Active Anticariogenic Metabolites in Piper cubeba L. through ¹H-NMR-Based Metabolomics Approach.

The aim of this study was to determine the effects of different solvents for extraction, liquid⁻liquid partition, and concentrations of extracts and fractions of Piper cubeba L. on anticariogenic; antibacterial and anti-inflammatory activity against oral bacteria. Furthermore, ¹H-Nuclear Magnetic Resonance (NMR) coupled with multivariate data analysis (MVDA) was applied to discriminate between the extracts and fractions and examine the metabolites that correlate to the bioactivities. All tested bacteria were susceptible to Piper cubeba L. extracts and fractions. Different solvents extraction, liquid⁻liquid partition and concentrations of extracts and fractions have partially influenced the antibacterial activity. MTT assay showed that P. cubeba L. extracts and fractions were not toxic to RAW 264.7 cells at selected concentrations. Anti-inflammatory activity evaluated by nitric oxide (NO) production in lipopolysaccharide (LPS) stimulated cells showed a reduction in NO production in cells treated with P. cubeba L. extracts and fractions, compared to those without treatment. Twelve putative metabolites have been identified, which are (1) cubebin, (2) yatein, (3) hinokinin, (4) dihydrocubebin, (5) dihydroclusin, (6) cubebinin, (7) magnosalin, (8) p-cymene, (9) piperidine, (10) cubebol, (11) d-germacrene and (12) ledol. Different extraction and liquid⁻liquid partition solvents caused separation in principal component analysis (PCA) models. The partial least squares (PLS) models showed that higher anticariogenic activity was related more to the polar solvents, despite some of the active metabolites also present in the non-polar solvents. Hence, P. cubeba L. extracts and fractions exhibited antibacterial and anti-inflammatory activity and have potential to be developed as the anticariogenic agent.

Inhibition of UVB-induced pro-inflammatory cytokines and MMP expression by Zanthoxylum rhetsa bark extract and its active constituent hesperidin.

The antiphoto aging property of Zanthoxylum rhetsa obtained from Pangkor Island, Malaysia, was evaluated. Solvent fractions of different polarity obtained from the methanolic extract of the bark material were initially tested for anticollagenase and antielastase activities. The ethyl acetate fraction showed bioactivity against the protease enzymes. Hence, it was subjected to further purification via column chromatography, to yield a major constituent, hesperidin. Subsequently, the ethyl acetate fraction and hesperidin were tested for their effects against UVB-induced cytotoxicity and expressions of inflammatory cytokines (IL-6, IL-1ß, and TNF-α), NF-κB, and MMPs (MMP1, 3, and 9) in human dermal fibroblasts (HDF). Both fraction and pure compound prevented UVB-induced cytotoxicity in HDF cells, in a dose dependent manner. Moreover, the ethyl acetate fraction inhibited the increase of pro-inflammatory cytokines induced by UVB to a level similar to the control (without UV treatment). Additionally, the fraction significantly inhibited the expressions of NF-κB, MMP 1, MMP 3, and MMP 9 in HDF cells treated with UVB. Similar effects were observed with hesperidin. The results obtained suggested that the ethyl acetate fraction of Z. rhetsa and its bioactive constituent, hesperidin, have the potential to be used as active ingredients in sunscreen and antiphoto aging formulations.

Antibacterial Activity of Ethanolic Extract of Syzygium polyanthum L. (Salam) Leaves against Foodborne Pathogens and Application as Food Sanitizer.

The aim of this study was to determine antibacterial activity of S. polyanthum L. (salam) leaves extract foodborne pathogens. All the foodborne pathogens were inhibited after treating with extract in disk diffusion test with range 6.67 ± 0.58-9.67 ± 0.58 mm of inhibition zone. The range of MIC values was between 0.63 and 1.25 mg/mL whereas MBC values were in the range 0.63 mg/mL to 2.50 mg/mL. In time-kill curve, L. monocytogenes and P. aeruginosa were found completely killed after exposing to extract in 1 h incubation at 4x MIC. Four hours had been taken to completely kill E. coli, S. aureus, V. cholerae, and V. parahaemolyticus at 4x MIC. However, the population of K. pneumoniae, P. mirabilis, and S. typhimurium only reduced to 3 log CFU/mL. The treated cell showed cell rupture and leakage of the cell cytoplasm in SEM observation. The significant reduction of natural microflora in grapes fruit was started at 0.50% of extract at 5 min and this concentration also was parallel to sensory attributes acceptability where application of extract was accepted by the panellists until 5%. In conclusion, S. polyanthum extract exhibits antimicrobial activities and thus might be developed as natural sanitizer for washing raw food materials.

Moringa oleifera Lam: Targeting Chemoprevention.

Moringa oleifera Lam, family Moringaceae, is a perennial plant which is called various names, but is locally known in Malaysia as "murungai" or "kelor". Glucomoringin, a glucosinolate with from M. oleifera is a major secondary metabolite compound. The seeds and leaves of the plant are reported to have the highest amount of glucosinolates. M. oleifera is well known for its many uses health and benefits. It is claimed to have nutritional, medicinal and chemopreventive potentials. Chemopreventive effects of M. oleifera are expected due to the existence of glucosinolate which it is reported to have the ability to induce apoptosis in anticancer studies. Furthermore, chemopreventive value of M. oleifera has been demonstrated in studies utilizing its leaf extract to inhibit the growth of human cancer cell lines. This review highlights the advantages of M. oleifera targeting chemoprevention where glucosinolates could help to slow the process of carcinogenesis through several molecular targets. It is also includes inhibition of carcinogen activation and induction of carcinogen detoxification, anti-inflammatory, anti-tumor cell proliferation, induction of apoptosis and inhibition of tumor angiogenesis. Finally, for synergistic effects of M. oleifera with other drugs and safety, essential for chemoprevention, it is important that it safe to be consumed by human body and works well. Although there is promising evidence about M. oleifera in chemoprevention, extensive research needs to be done due to the expected rise of cancer in coming years and to gain more information about the mechanisms involved in M. oleifera influence, which could be a good source to inhibit several major mechanisms involved in cancer development.

Bioactive Constituents of Zanthoxylum rhetsa Bark and Its Cytotoxic Potential against B16-F10 Melanoma Cancer and Normal Human Dermal Fibroblast (HDF) Cell Lines.

Zanthoxylum rhetsa is an aromatic tree, known vernacularly as "Indian Prickly Ash". It has been predominantly used by Indian tribes for the treatment of many infirmities like diabetes, inflammation, rheumatism, toothache and diarrhea. In this study, we identified major volatile constituents present in different solvent fractions of Z. rhetsa bark using GC-MS analysis and isolated two tetrahydrofuran lignans (yangambin and kobusin), a berberine alkaloid (columbamine) and a triterpenoid (lupeol) from the bioactive chloroform fraction. The solvent fractions and purified compounds were tested for their cytotoxic potential against human dermal fibroblasts (HDF) and mouse melanoma (B16-F10) cells, using the MTT assay. All the solvent fractions and purified compounds were found to be non-cytotoxic to HDF cells. However, the chloroform fraction and kobusin exhibited cytotoxic effect against B16-F10 melanoma cells. The presence of bioactive lignans and alkaloids were suggested to be responsible for the cytotoxic property of Z. rhetsa bark against B16-F10 cells.

Development of nanoantibiotic delivery system using cockle shell-derived aragonite nanoparticles for treatment of osteomyelitis.

A local antibiotic delivery system (LADS) with biodegradable drug vehicles is recognized as the most effective therapeutic approach for the treatment of osteomyelitis. However, the design of a biodegradable LADS with high therapeutic efficacy is too costly and demanding. In this research, a low-cost, facile method was used to design vancomycin-loaded aragonite nanoparticles (VANPs) with the aim of understanding its potency in developing a nanoantibiotic bone implant for the treatment of osteomyelitis. The aragonite nanoparticles (ANPs) were synthesized from cockle shells by a hydrothermal approach using a zwitterionic surfactant. VANPs were prepared using antibiotic ratios of several nanoparticles, and the formulation (1:4) with the highest drug-loading efficiency (54.05%) was used for physicochemical, in vitro drug release, and biological evaluation. Physiochemical characterization of VANP was performed by using transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray powder diffraction, and Zetasizer. No significant differences were observed between VANP and ANP in terms of size and morphology as both samples were cubic shaped with sizes of approximately 35 nm. The Fourier transform infrared spectroscopy of VANP indicated a weak noncovalent interaction between ANP and vancomycin, while the zeta potential values were slightly increased from -19.4±3.3 to -21.2±5.7 mV after vancomycin loading. VANP displayed 120 hours (5 days) release profile of vancomycin that exhibited high antibacterial effect against methicillin-resistant Staphylococcus aureus ATCC 29213. The cell proliferation assay showed 80% cell viability of human fetal osteoblast cell line 1.19 treated with the highest concentration of VANP (250 µg/mL), indicating good biocompatibility of VANP. In summary, VANP is a potential formulation for the development of an LADS against osteomyelitis with optimal antibacterial efficacy, good bone resorbability, and biocompatibility.

In vitro activity of xanthorrhizol isolated from the rhizome of Javanese turmeric (Curcuma xanthorrhiza Roxb.) against Candida albicans biofilms.

The purpose of this study was to investigate the activity of xanthorrhizol isolated from Curcuma xanthorrhiza Roxb. on Candida albicans biofilms at adherent, intermediate, and mature phase of growth. C. albicans biofilms were formed in flat-bottom 96-well microtiter plates. The biofilms of C. albicans at different phases of development were exposed to xanthorrhizol at different concentrations (0.5 µg/mL-256 µg/mL) for 24 h. The metabolic activity of cells within the biofilms was quantified using the XTT reduction assay. Sessile minimum inhibitory concentrations (SMICs) were determined at 50% and 80% reduction in the biofilm OD490 compared to the control wells. The SMIC50 and SMIC80 of xanthorrhizol against 18 C. albicans biofilms were 4--16 µg/mL and 8--32 µg/mL, respectively. The results demonstrated that the activity of xanthorrhizol in reducing C. albicans biofilms OD490 was dependent on the concentration and the phase of growth of biofilm. Xanthorrhizol at concentration of 8 µg/mL completely reduced in biofilm referring to XTT-colorimetric readings at adherent phase, whereas 32 µg/mL of xanthorrhizol reduced 87.95% and 67.48 % of biofilm referring to XTT-colorimetric readings at intermediate and mature phases, respectively. Xanthorrhizol displayed potent activity against C. albicans biofilms in vitro and therefore might have potential therapeutic implication for biofilm-associated candidal infections.

Effect of Agrobacterium rhizogenes and elicitation on the asiaticoside production in cell cultures of Centella asiatica.

BACKGROUND: Centella asiatica (L.) Urb. (Apiaceae) is an important medicinal plant, and it has been using to prepare herbal medicines. The compounds responsible for the biological activity of C. asiatica are triterpenoids such as asiaticoside. Asiaticoside is also important as a marker for standardization of C. asiatica. Due to the low content, there is a need to enhance the production of asiaticoside of C. asiatica. The biotechnological approach is one of the methods that can be used to enhance its production. OBJECTIVES: This study was designed to enhance the production of asiaticoside from C. asiatica using A. rhizogenes and elicitation experiments. MATERIALS AND METHODS: Callus cultures were initiated using Murashige and Skoog (MS) medium supplemented with 1.0 mg/L indole-3-acetic acid (IAA) and 1.0 mg/L 6-benzylaminopurin (BAP). All media were supplemented with 4% (w/w) sucrose and solidified with 0.9% agar. Elicitations were done using pectin, methyl jasmonate, and Cu(2+) ions. Transformed hairy root cultures were performed using A. rhizogenes. RESULTS: Callus culture of C. asiatica was successfully initiated. Enhancement of the production of asiaticoside in the callus culture by elicitors pectin was up to 31%; methyl jasmonate (50 µM) in cell suspension cultures at day 14 was up to 171% compared to explant and 494% compared to control callus; copper ion (25 µM) at day 21 was up to 144% compared to explant, and 676% compared to control cell suspension cultures. While enhancement by genetic transformation using A. rhizogenes was 166-172% compare to untransformed roots CONCLUSION: Elicitation and genetically transformed hairy root cultures of C. asiatica produced asiaticoside up to 172% higher than untreated callus.

Activity of panduratin A isolated from Kaempferia pandurata Roxb. against multi-species oral biofilms in vitro.

The formation of dental biofilm caused by oral bacteria on tooth surfaces is the primary step leading to oral diseases. This study was performed to investigate the preventive and reducing effects of panduratin A, isolated from Kaempferia pandurata Roxb., against multi-species oral biofilms consisting of Streptococcus mutans, Streptococcus sanguis and Actinomyces viscosus. Minimum inhibitory concentration (MIC) of panduratin A was determined by the Clinical and Laboratory Standards Institute (CLSI) broth microdilution assay. Prevention of biofilm formation was performed on 96-well microtiter plates by coating panduratin A in mucin at 0.5-40 microg/ml, followed by biofilm formation at 37 degrees C for 24 h. The reducing effect on the preformed biofilm was tested by forming the biofilm at 37 degrees C for 24 h, followed by treatment with panduratin A at 0.2-10 microg/ml for up to 60 min. Panduratin A showed a MIC of 1 microg/ml for multi-species strains. Panduratin A at 2 x MIC for 8 h exhibited bactericidal activity against multi-species planktonic cells for 8 h. At 8 x MIC, panduratin A was able to prevent biofilm formation by > 50%. Biofilm mass was reduced by > 50% after exposure to panduratin A at 10 microg/ml for 15 min. Panduratin A showed a dose-dependent effect in preventing and reducing the biofilm. These results suggest that panduratin A is applicable as a natural anti-biofilm agent to eliminate oral bacterial colonization during early dental plaque formation.

Antibacterial activity of xanthorrhizol isolated from Curcuma xanthorrhiza Roxb. against foodborne pathogens.

Xanthorrhizol, isolated from the ethanol extract of Curcuma xanthorrhiza Roxb., is a sesquiterpene compound with a molecular weight of 218. The aim of this study was to investigate the antibacterial activity of xanthorrhizol against foodborne pathogens. The antibacterial activity of xanthorrhizol was measured in terms of the MIC and the MBC. MICs and MBCs of xanthorrhizol against Bacillus cereus, Clostridium perfringens, Listeria monocytogenes, Staphylococcus aureus, Salmonella Typhimurium, and Vibrio parahaemolyticus were 8, 16, 8, 8, 16, 8 microg/ml and 16, 32, 16, 16, 16, 16 microg/ml, respectively. The bactericidal study, as determined by the viable cell count method, revealed that xanthorrhizol treatment at 4 x MIC reduced viable cells by at least 6 to 8 log for all six foodborne pathogens in 4 h. Xanthorrhizol maintained its antibacterial activity after thermal treatments (121 degrees C, 15 min) under various pH ranges (pH 3.0, 7.0, and 11.0). These results strongly suggest that xanthorrhizol, conferring strong antibacterial activity with thermal and pH stability, can be effectively used as a natural preservative to prevent the growth of foodborne pathogens.

Screening of Thai medicinal plants for anticandidal activity.

Medicinal plants are often used in the treatment of various ailments. In this study, 23 of Thai medicinal plants were screened for their anticandidal activity against six pathogenic Candida species: C. albicans, C. glabrata, C. guilliermondii, C. krusei, C. parapsilosis and C. tropicalis. The methanol extract of Hibiscus sabdariffa L. fruit, Trigonostemon reidioides (Kurz) Craib root, Usnea siamensis Vain whole plant, Boesenbergia rotunda (L.) Mansf. rhizome, and Albizia myriophylla Benth. stem showed anticandidal activity against one or more species of Candida. Among them, A. myriophylla Benth. showed broad anticandidal activity. The susceptibility tests of A. myriophylla Benth. extract, in terms of minimal inhibitory concentrations (MIC) and minimal fungicidal concentration (MFC), were performed by the broth microdilution techniques as described by the Clinical Laboratory Standard Institute. MICs of A. myriophylla Benth. extract to all Candida species was ranged 100-500 mug ml(-1). The killing activity of A. myriophylla Benth. extract was fast acting against all Candida tested; the reduction in the number of CFU ml(-1) was >3 log(10) units (99.9%) in 2 h. This study indicates that A. myriophylla Benth. extract has considerable anticandidal activity, deserving further investigation for clinical applications for the treatment of candidiasis.

In vitro anti-biofilm activity of macelignan isolated from Myristica fragrans Houtt. against oral primary colonizer bacteria.

In early dental plaque formation, oral primary colonizers such as Streptococcus mutans, Streptococcus sanguis and Actinomyces viscosus are initially attached to the pellicle-coated tooth surface to form a biofilm. The study aimed to determine the efficacy of macelignan, isolated from nutmeg (Myristica fragrans Houtt.), in removing each single oral primary biofilm in vitro on a polystyrene 96-well microtiter plate. Four biofilm growth phases (4, 12, 20 and 24 h) were evaluated in this study after treatment with macelignan at various concentrations (0.2, 2 and 10 microg/mL) and exposure times (5, 10 and 30 min). Anti-biofilm activity of macelignan was measured as the percentage of the remaining biofilm absorbance after macelignan treatment in comparison with the untreated control. At 24 h of biofilm growth, S. mutans, A. viscosus and S. sanguis biofilms were reduced by up to 30%, 30% and 38%, respectively, after treatment with 10 microg/mL macelignan for 5 min. Increasing the treatment time to 30 min resulted in a reduction of more than 50% of each of the single primary biofilms. The results indicate that macelignan is a potent natural anti-biofilm agent against oral primary colonizers.

In Vitro antimycotic activity of xanthorrhizol isolated from Curcuma xanthorrhiza Roxb. against opportunistic filamentous fungi.

Xanthorrhizol was isolated from the rhizome of Curcuma xanthorrhiza (Zingiberaceae) and its in vitro activity against opportunistic filamentous fungi was evaluated using the NCCLS (M38-A) standard method. Xanthorrhizol was found to be active against all the species tested, namely Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Fusarium oxysporum, Rhizopus oryzae and Trichophyton mentagrophytes: the MICs being 2.0, 2.0, 2.0, 4.0, 1.0 and 1.0 microg/mL, while the MFCs were 4.0, 4.0, 4.0, 8.0, 2.0 and 2.0 microg/mL, respectively. The susceptibility of six species of filamentous fungi to xanthorrhizol was comparable to that of the commercial antifungal, amphotericin B. Xanthorrhizol also has activity to inhibit the conidial germination of all tested species. The results strongly suggest that xanthorrhizol can be developed as a natural antifungal agent.