Further antibacterial diterpenes from the bark and leaves of Juniperus procera hochst. ex Endl

The bark of Juniperus procera yielded three antibacterial diterpenoids, (+)-E-communic acid (1), (+)-Z-communic acid (2) and (+)-totarol (3). Compound 2 exhibited significant activity against Gram-positive bacteria, while 1 was found to be less active. Compound 3, on the other hand, demonstrated potent activity against Mycobacterium organisms, while its corresponding 3β-hydroxy-derivative 4 was found to be inactive. The chromatographic separation of (+)-Z-communic acid (2) from (+)-E-communic acid (1) and those previously unreported spectral data of 1 and 2 are described. In addition, the leaves yielded (+)-8α-acetoxyelemol, β-peltatin A methyl ether and deoxypodophyllotoxin.     

Antibacterial diterpenes from the leaves and seeds of Juniperus excelsa M. Bieb

Two diterpenes from Juniperus excelsa, obtained by bioautography-guided isolation technique, were found to possess significant antibacterial activity in a two-fold serial dilution assay. (+)-Ferruginol (abieta-8,11,13-triene-12-ol) (1) and (?)-sandaracopimeric acid (isopimara-8(14), 15-diene-18-oic acid) (2) exhibited significant activity against Bacillus subtilis, Staphylococcus aureus and Streptococcus durans, while their corresponding 3β-hydroxy derivatives [(hinokiol (3) and 3β-hydroxysandaracopimeric acid (4), also isolated from J. excelsa)] were found to be inactive. (+)-Ferruginol, in addition, demonstrated strong activity against Mycobacterium smegmatis, M. intracellulare, M. xenopi and M. cheloni. The minimum inhibitory concentrations were determined for all compounds isolated from the active bioautographic zones, and were compared to those of the standard antibiotics chloramphenicol and streptomycin sulphate.     

A Preliminary Investigation on the Antimicrobial Activity of Listerine®, Its Components,and of Mixtures Thereof

Listerine® is one of the most popular mouthwashes worldwide and claims to combat harmful bacteria. In the past century, its recipe was changed from an essential oil mouthwash to a five‐component mixture (thymol, menthol, eucalyptol, and methyl salicylate dissolved in 27% ethanol). The aim of this study was to get preliminary information about the antimicrobial activities of individual Listerine® components and their mixtures. We tested the bacterial strains Streptococcus mutans, Enterococcus faecalis, and Eikenella corrodens and the yeast Candida albicans. The established minimum inhibitory concentration (MIC) assay and the minimum bactericidal/fungicidal concentration (MBC/MFC) assay were applied. None of the combinations of two phenols at the concentrations contained within Listerine® were associated with either an additive or synergistic effect. Thymol had lower MIC and MBC/MFC values than the other Listerine® components and Listerine® against E. corrodens and C. albicans. The mixtures consisting of eucalyptol, methyl salicylate, and thymol were the most effective against S. mutans and E. faecalis and more effective than Listerine®. Our results demonstrate that the phenols and their concentrations as contained within Listerine® could be further optimized in terms of selecting those which increase their general effectiveness, at concentrations that do not induce harm. Copyright © 2015 John Wiley & Sons, Ltd.     

Acetylcholinesterase Inhibition,Antioxidant, Antiinflammatory,Antimicrobial and Phytochemical Properties of Huernia hystrix

Huernia species are typical famine‐food plants consumed in southern Ethiopia. H. hystrix is a heavily exploited ethnomedicinal succulent plant traded in traditional medicine systems especially on South Africa's eastern seaboard. This study investigated the acetylcholinesterase (AChE) inhibition, antioxidant, antiinflammatory and antimicrobial properties of extracts obtained from the stems and roots of this plant. At the same concentration level (625.0, 312.5 or 156.3 µg/mL), the whole plant extract showed higher AChE inhibitory activity when compared with the stem and root extracts; a finding suggesting the presence of AChE inhibitors acting additively or synergistically in the whole plant extract. The roots showed strong antioxidant activity (in DPPH and β‐carotene assays) comparable to that of butylated hydroxytoluene (BHT), indicating the presence of potent antioxidant compound(s) that can be exploited as alternatives for use in the food and cosmetic industries and/or as nutraceuticals. All the petroleum ether (PE) (except root PE) and dichloromethane (DCM) extracts demonstrated good inhibitory activity (> 70%) in cyclooxygenase (COX‐1 and COX‐2) assays at a 0.25 µg/μL concentration. Most of the extracts showed broad‐spectrum inhibitory and lethal activities against the microorganisms used in this study. The observed biological activities might be due to the iridoid, phenolic and flavonoid contents of the plants. Copyright © 2011 John Wiley & Sons, Ltd.     

Antimicrobial activities of Asian ginseng,American ginseng,and notoginseng

Asian ginseng (Panax ginseng C.A. Meyer), American ginseng (Panax quinquefolius) and notoginseng (Panax notoginseng) are the three most commonly used ginseng botanicals in the world. With the increasing interests on antimicrobial properties of plants, the antimicrobial activities of ginseng species have been investigated by a number of researchers worldwide. This overview interprets our present knowledge of the antimicrobial activities of the three ginseng species and some of their bioactive components against pathogenic bacteria (Pseudomonas aeruginosa, Helicobacter pylori, Staphylococcus aureus, Escherichia coli, Propionibacterium acnes, et al.) and fungi (Candida albicans, Fusarium oxysporum, et al). Ginsenosides, polysaccharides, essential oil, proteins, and panaxytriol are all might responsible for the antimicrobial activities of ginseng. The antimicrobial mechanisms of ginseng components could be summarized to the following points: (a) inhibit the microbial motility and quorum‐sensing ability; (b) affect the formation of biofilms and destroy the mature biofilms, which can weaken the infection ability of the microbes; (c) perturb membrane lipid bilayers, thus causing the formation of pores, leakages of cell constituents and eventually cell death; (d) stimulate of the immune system and attenuate microbes induced apoptosis, inflammation, and DNA damages, which can protect or help the host fight against microbial infections; and (e) inhibit the efflux of antibiotics that can descend the drug resistance of the microbial. The collected information might facilitate and guide further studies needed to optimize the use of ginseng and their components to improve microbial food safety and prevent or treat animal and human infections.     

Antimicrobial activity of extracts and phthalides occurring in Apiaceae plants

Apiaceae plants exhibit a broad spectrum of activities, for instance, antithrombotic, hypotensive, antioxidant, and insecticidal. They also provide a source of phthalides, which display antimicrobial activity. Considering the fact of rising resistance of both bacteria and fungi against commonly used antibiotics, developing of new naturally derived compounds is undeniably attractive approach. To our best knowledge, there are no other reviews concerning this subject in the literature. In view of above, an attempt to summarize an antimicrobial potential of isolated compounds and extracts from Apiaceae plants has been made, by specifying techniques of activity determination and methods of extraction. Techniques of antimicrobial activity evaluation are mainly based on bioautography, diffusion, and dilution methods. Therefore, we focused on in vitro data described in literature so far.     

Growth inhibitory activity of biflavonoids and diterpenoids from the leaves of the Libyan Juniperus phoenicea against human cancer cells

Three biflavonoids [cupressuflavone ( 1 ), amentoflavone ( 2 ), and sumaflavone ( 3 )], four diterpenoids [13‐epi‐cupressic acid ( 4 ), imbricatholic acid ( 5 ), 3‐hydroxy‐sandaracopimaric acid ( 6 ), and dehydroabietic acid ( 7 )], and one lignan [β‐peltatin methyl ether ( 8 )] were isolated from the cytotoxic fractions of the extracts of the leaves of the Libyan Juniperus phoenicea L. The structures of these compounds were elucidated by spectroscopic means. Cytotoxicity of compounds 1 – 6 were assessed against the human lung cancer cell line A549 using the MTT assay. Compounds 1 and 3 showed cytotoxicity against the A549 cells (IC₅₀ = 65 and 77 μM, respectively), whereas compound 2 did not show any activity. Diterpenes 4 – 6 exhibited weak cytotoxicity against the A549 cells with the IC₅₀ values of 159, 263, and 223 μM, respectively. The cytotoxicity of each compound was compared with the anticancer drug, etoposide (IC₅₀ = 61 μM). Cupressuflavone ( 1 ) was evaluated also for cytotoxicity against both the human PC3 cancer cell line and the normal prostate cell line (PNT2), and this compound revealed a high degree of cytotoxic selectivity towards the prostate cancer cells (PC3), with IC₅₀ value of 19.9 μM, without any evidence of cytotoxicity towards the normal prostate cell line (PNT2).     

Antimicrobial potential of two different Hypericum species available in India

The antimicrobial activity of extracts of the leaves and stems of two different varieties of Hypericum was evaluated by the disc diffusion method. Petroleum ether, acetone, chloroform and methanol extracts of Hypericum mysorense and Hypericum patulum stems and leaves were investigated for their antimicrobial activity against six different strains of bacteria and fungi by the zone of inhibition method (ZIM). The results showed that both the stem and leaf extracts of both species have a very broad spectrum of antibacterial activity. The petroleum ether and acetone extract of the leaves and stems of H. mysorense did not show antifungal effects against any of the six fungal organisms tested but other extracts showed a potential antifungal effect which was comparable to that of griseofulvin, the standard antifungal agent. Thus these results demonstrate that the leaf and stem extracts of both the Hypericum species have a very broad spectrum of activity and suggest that they may be useful in the treatment of various microbial infections.     

Antibacterial and antifungal activity of juniper berry oil and its selected components

Juniper berry oil is stated to possess a wide spectrum of pharmacological activities and its monographs are included in some National Pharmacopoeias. The antibacterial and antifungal activity of the oil was reported by some authors. In our study we estimated the antibacterial and antifungal activity of three different juniper berry oils and their main components. All the micro-organisms used in this experiment were isolated from patients of Regional Hospital of Gdańsk and some of them showed resistance against commonly used antibiotics. Only one of the oils (labelled A) revealed good antimicrobial properties. None of the single oil components was a stronger antibacterial and antifungal inhibitor than the oil A itself. Our data suggest that the antimicrobial activity of juniper oil A is the result of either the specific composition of the oil A (highest concentration of (-)-alpha-pinene, p-cymene and beta-pinene) or activity of a single non-identified compound. The presence of an adulterant in the oil was excluded.     

Essential Oil of Juniperus communis subsp. alpina (Suter) Čelak Needles: Chemical Composition,Antifungal Activity and Cytotoxicity

Essential oils are known to possess antimicrobial activity against a wide spectrum of bacteria and fungi. In the present work the composition and the antifungal activity of the oils of Juniperus communis subsp. alpina (Suter) ?elak were evaluated. Moreover, the skin cytotoxicity, at concentrations showing significant antifungal activity, was also evaluated. The oils were isolated by hydrodistillation and analysed by gas chromatography and gas chromatography–mass spectrometry. Minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) were used to evaluate the antifungal activity of the oil against dermatophytes (Epidermophyton floccosum, Microsporum canis, M. gypseum, Trichophyton mentagrophytes, T. mentagrophytes var. interdigitale, T. rubrum, T. verrucosum), yeasts (Candida albicans, C. guillermondii, C. krusei, C. parapsilosis, C. tropicalis, Cryptococcus neoformans) and Aspergillus species (Aspergillus flavus, A. fumigatus, A. niger). Cytotoxicity was tested in HaCaT keratinocytes through the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay. Essential oil of J. communis subsp. alpina needles was predominantly composed of monoterpene hydrocarbons (78.4%), with the main compounds being sabinene (26.2%), α‐pinene (12–9%) and limonene (10.4%). Results concerning the antifungal activity demonstrated the potential of needle oil against dermatophytes, particularly for Microsporum canis and Trichophyton rubrum with MIC and MLC of 0.32 μL/mL. Furthermore, evaluation of cell viability showed no significant cytotoxicity in HaCaT keratinocytes at concentrations between 0.32 and 0.64 μL/mL. These results show that it is possible to find appropriate doses of J. communis subsp. alpina oil with both antifungal activity and a very low detrimental effect on keratinocytes. Copyright © 2012 John Wiley & Sons, Ltd.     

Antimicrobial properties of the essential oil of Artemisia asiatica Nakai

The antibacterial and antifungal activity of the essential oil of Artemisia asiatica Nakai, its main constituents: 1,8-cineole and selin-11-en-4alpha-ol and monoterpene alcohols fraction were determined against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Rhodotorula rubra and Aspergillus fumigatus. The oil exhibited a good inhibitory activity against bacteria and fungi. The monoterpene alcohols fraction showed the highest antibacterial activity.     

The antioxidant activity of the essential oils of Artemisia afra, Artemisia abyssinica and Juniperus procera

The essential oils of Artemisia afra Jacq., Artemisia abyssinica Schultz-Bip. and Juniperus procera Hoechst ex Endl. were examined for their potential radical scavenging activities. First a rapid evaluation of antioxidants was made using a TLC screening method. The abilities of the volatile oils to act as nonspecific donors for hydrogen atoms or electrons were checked in the diphenylpicrylhydrazyl assay. Oils from all three species showed positive results and were examined further. The oils of A. afra and J. procera were also effective hydroxyl radical scavenging agents when assessed in the deoxyribose degradation assay, whilst oils from A. abyssinica exhibited a paradoxical effect. In the in vitro assay for non-enzymatic lipid peroxidation in liposomes, the oils of A. afra and J. procera also displayed antioxidant potential. It was not possible to measure the effect of A. abyssinica oil in this system because certain components, e.g. alk-2-enals, interfered with the assay. The compounds that contribute to the radical scavenging activities of A. afra and J. procera were identified and then assessed for their effects in the various test systems. Finally, the qualitative and quantitative compositions of the essential oils were studied by GC-MS.     

Antiprotozoal screening and cytotoxicity of extracts and fractions from the leaves,stem bark and root bark of Alstonia congensis

Ethnopharmacological relevance

To evaluate the antiprotozoal activity and cytotoxicity of extracts and fractions from the leaves, root bark and stem bark of Alstonia congensis (Apocynaceae), used in traditional medicine against parasitic diseases.

Materials and methods

The aqueous and 80% MeOH extracts, and a series of fractions and subfractions from the leaves, stem and root bark of Alstonia congensis were tested in vitro for their antiprotozoal activity against Trypanosoma brucei brucei, Trypanosoma cruzi, Lesihamania infantum and the chloroquine and pyrimethamine-resistant K1 strain of Plasmodium falciparum. Their cytotoxicity on MRC-5 cells (human lung fibroblasts) was evaluated as well.

Results

The aqueous and 80% MeOH extracts and a series of subfractions of each plant part exhibited pronounced antiprotozoal activity against the K1 strain of Plasmodium falciparum with IC₅₀ values ranging from 2 to 5 µg/ml, and good activity against Trypanosoma brucei brucei and Trypanosoma cruzi with IC₅₀ values ranging between 5 and 10 µg/ml. The residual 80% MeOH extract from the leaves, and the total alkaloid extract from stem and root bark were the only subfractions active against Leishmania infantum with IC₅₀ values <10 µg/ml. None of the samples from the root bark was cytotoxic against MRC-cell lines (CC₅₀>64 µg/ml). In general, the aqueous extract (traditional decoction) showed the highest selectivity, especially against Plasmodium falciparum.

Conclusion

These results can partly support and justify the traditional use of these plant parts of Alstonina congensis as raw materials for the preparation of traditional remedies to treat parasitic diseases such as malaria and trypanosomiasis.     

Antifungal,antioxidant and larvicidal activities of compounds isolated from the heartwood of Mansonia gagei

Eleven compounds isolated from the heartwood of Mansonia gagei were tested for their antifungal activities against Cladosporium cucumerinum and Candida albicans, as well as for their larvicidal activities against Aedes aegypti and radical scavenging properties in a DPPH assay. Mansonone C (4) was found to be the most interesting compound with antifungal activities against Cladosporium cucumerinum and Candida albicans as well as for its larvicidal properties against Aedes aegypti. Mansonone E (5) was active against Cladosporium cucumerinum and Candida albicans. Two coumarin derivatives, mansorin A (1) and mansorin B (2) were also found to be active against Cladosporium cucumerinum, while mansonone N (9) was the only isolated product to show radical scavenging properties.     

Antimicrobial activity of seed extracts and bondenolide from Caesalpinia bonduc (L.) Roxb

The antibacterial and antifungal activities, along with a phytotoxicity test of the newly isolated diterpene bondenolide (1), of a methanol extract, ethylacetate fraction and water soluble part of the methanol extract of Caesalpinia bonduc (L.) Roxb. were assayed.     

芳香型植物抑菌护肤洗脚液的制备及其抑菌作用评价

制备芳香型植物抑菌护肤洗脚液,并考察其对引起足癣真菌和足部易感染细菌的抑菌效果.洗脚液以苦参和白鲜皮为主要原料,添加芦荟提取物、芳香精油、表面活性剂等制备而成,采用悬液定量法考察了洗脚液的抑菌活性.制成的洗脚液有清香味,可产生泡沫,对主要引起足癣的致病真菌和脚上易感染细菌的抑菌率均达90%以上.芳香型植物抑菌护肤洗脚液制备工艺操作简单,有明显地抑菌作用.     

Enzyme inhibition,antioxidant and immunomodulatory activities,and brine shrimp toxicity of extracts from the root bark,stem bark and leaves of Terminalia macroptera

Ethnopharmacological relevance

The root bark, stem bark and leaves of Terminalia macroptera have been traditionally used against a variety of ailments such as wounds, hepatitis, malaria, fever, cough, and diarrhea as well as tuberculosis and skin diseases in African folk medicine. Boiling water extracts of Terminalia macroptera, administered orally, are the most common preparations of this plant used by the traditional healers in Mali. This study aimed to investigate the inhibition of the activities of α-glucosidase, 15-lipoxygenase and xanthine oxidase, DPPH scavenging activity, complement fixation activity and brine shrimp toxicity of different extracts obtained by boiling water extraction (BWE) and by ASE (accelerated solvent extraction) with ethanol, ethanol–water and water as extractants from different plant parts of Terminalia macroptera.

Materials and methods

27 different crude extracts were obtained by BWE and ASE from root bark, stem bark and leaves of Terminalia macroptera. The total phenolic and carbohydrate contents, enzyme inhibition activities (α-glucosidase, 15-lipoxygenase and xanthine oxidase), DPPH scavenging activity, complement fixation activity and brine shrimp toxicity of these extracts were evaluated. Principal component analysis (PCA) was applied for total biological activities evaluation.

Results

Several of the extracts from root bark, stem bark and leaves of Terminalia macroptera obtained by BWE and ASE showed potent enzyme inhibition activities, radical-scavenging properties and complement fixation activities. None of the extracts are toxic against brine shrimp larvae in the test concentration. Based on the results from PCA, the ASE ethanol extracts of root bark and stem bark and the low molecular weight fraction of the 50% ethanol–water extract of leaves showed the highest total biological activities. The boiling water extracts were less active, but the bark extracts showed activity as α-glucosidase inhibitors and radical scavengers, the leaf extract being less active.

Conclusion

The observed enzyme inhibition activities, radical scavenging properties and complement fixation activities may explain some of the traditional uses of this medicinal tree, such as in wound healing and against diabetes.     

蘘荷提取物抗氧化能力及抑菌作用

目的:以新鲜蘘荷Zingiber mioga花蕾为原料,探讨蘘荷花蕾不同提取部位的抗氧化作用,并筛选其有效抑菌部位。方法:蘘荷花蕾用甲醇提取浓缩,依次萃取得到石油醚、二氯甲烷、乙酸乙酯、正丁醇和水等5个萃取部位后,采用1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除模型评价不同萃取部位抗氧化能力,用打孔扩散法考察萃取部位对大肠埃希菌、沙门氏菌、金黄色葡萄球菌和铜绿假单胞菌的体外抑菌活性。结果:加热回流法提取蘘荷花蕾,提取率为3.1%,其中乙酸乙酯部位DPPH自由基清除能力最高,半数抑制率(IC50)达到(26.22±1.12)mg·L-1,对铜绿假单胞菌的抑菌圈达到(10±1)mm,石油醚部位抑菌活性最高,对金黄色葡萄球菌的最低抑菌浓度(MIC)最低,达到25.0 mg·L-1。结论:蘘荷花蕾各部位均有一定的抗氧化能力,综合抑菌效果比较石油醚部位二氯甲烷部位乙酸乙酯部位甲醇提取物,为蘘荷花蕾抗氧化产品、抑菌剂的开发利用提供理论基础。     

Antimicrobial activities of methanol extract and compounds from stem bark of Vismia rubescens

Ethnopharmacological relevance

The plant, Vismia rubescens (Guttiferae) is popularly used in Cameroon and in several parts of Africa as febrifugal and for the treatment of various microbial infections (skin diseases, diarrhoea and venereal diseases).

Aim of the study

This study was mapped out to evaluate the antimicrobial activities of the methanol extract and compounds from the stem bark of Vismia rubescens.

Materials and methods

Structures of the compounds obtained after column chromatography of the methanol-soluble fraction were determined by spectroscopy and in comparison with published data. The broth micro-dilution method was used to evaluate the antimicrobial activities against three bacteria species (Salmonella typhi, Stahylococcus aureus and Pseudomonas aeruginosa) and four yeast species (Candida albicans, Candida tropicalis, Candida parapsilosis and Cryptococcus neoformans).

Results

Chemical analysis of the methanol extract from the stem bark of Vismia rubescens yielded five known compounds 1,4,8-trihydroxyxanthone (1), 1,7-dihydroxyxanthone (2), physcion (3), friedelin (4) and friedelanol (5). The crude extract and compounds 1, 2 and 3 exhibited both antibacterial and antifungal activities that varied between the microbial species (MIC = 3.12–1000 μg/ml). Compounds 2 and 3 were the most active (MIC = 3.12–100 μg/ml) while Stahylococcus aureus and Pseudomonas aeruginosa were sensitive to all the tested compounds. The antimicrobial activity of this plant as well as that of compounds 1 and 2 is being reported here for the first time.

Conclusion

These results provide promising baseline information for the potential use of this plant as well as some of the isolated compounds in the treatment of skin diseases and diarrhoea.     

In vitro cytotoxic,antiprotozoal and antimicrobial activities of medicinal plants from Vanuatu

Sixty‐three extracts obtained from 18 plants traditionally used in the South Pacific archipelago Vanuatu for the treatment of infectious diseases were screened for antimicrobial and antiprotozoal activities. In addition, the extracts were subjected to a detailed analysis on cytotoxic effects toward a panel of human cancer cell lines, designed as a smaller version of the NCI60 screen. Intriguingly, 15 plant extracts exhibited strong cytotoxic effects specific for only one cancer cell line. Extracts of the leaves of Acalypha grandis Benth . significantly affected Plasmodium falciparum without showing obvious effects against the other protozoa tested. The leaves of Gyrocarpus americanus Jacq . displayed significant activity against Trypanosoma b. brucei and the leaves of Tabernaemontana pandacaqui Lam . I as well as the stems of Macropiper latifolium (L.f .) against Trypanosoma cruzi. In contrast none of the extracts showed relevant antibacterial or antifungal activity. Copyright © 2009 John Wiley & Sons, Ltd.