39 research outputs found

    Фитохемикалије из бриофита: структура и биолошке активности

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    Little attention has been paid to the bryophytes as sources for human diet despite the presence of 23,000 species in the world. Some mosses contain Vitamin B1, tocopherols, prostaglandin-like highly unsaturated fatty acids and phenolic compounds. On the other hand, liverworts contain enantiomeric mono-, sesqui- and diterpenoids similar to those found in vascular plants. Additionally, they possess bibenzyls, bis-bibenzyls and polyketides, many of them showing various bioactivity, such as antimicrobial, antiviral, anti-inf­lam­matory, cytotoxicity against cancer cell lines, muscle relaxing, antioxidant and others. In this paper, the structures of phytochemicals from bryophytes and their biological activities are discussed.На бриофите као изворе за људску исхрану се обраћа мала пажња иако их има преко 23000 врста. Неке маховине садрже витамин Б1, токофероле, простагландинима слична једињења, вишеструко незасићене масне киселине и фенолна једињења. С друге стране, јетрењаче садрже моно-, сескви- и дитерпеноиде енентиомерне онима пронађеним у васкуларним биљкама. Поред њих, оне садрже и бибензиле, бис-бибензиле и поликетиде, од којих многи показују антимикробну, антивирусну, анти-инфламаторну, цитотоксичну на ћелије рака, миорекласантску, антиоксидативну и друге. У овом раду су продискутоване структуре и биолошка активност фитохемикалија из јетрењача.Part of the theme issue honoring Professor Emeritus Slobodan Milosavljevićs 80th birthday

    Management of Diabetic Bacterial Foot Infections with Organic Extracts of Liverwort Marchantia debilis from Cameroon

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    Diabetic bacterial foot infections (DBFIs) are limb-threatening complications in patients with diabetes mellitus, accounting for 50% of diabetes related lower limb amputations in developing countries, representing approximately 20 percent of all diabetes-related hospital admissions with significant healthcare-related costs involved. The widespread problem of bacterial resistance to most commonly used antibiotics places a huge economic burden on the healthcare system, with both increased morbidity and mortality among diabetic patients with foot infections. In this study, the antibacterial activity of organic extracts of the fresh liverwort Marchantia debilis from the North West Region of Cameroon is reported. An exit pool system, where patients presenting with DBFIs consented to be involved in the use of phytomedicines, after long term treatment of ulcers with antibiotics and not yielding significant long term benefit, presented themselves at the Phytobiotechnology Research clinic (PRF). Continuous culture of swabs from foot and toe wounds from 30 infected patients on nutrient agar and MacConkey agars in triplicate as well as Gram stain microscopy, revealed the presence of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis and Bacillus species. Light petroleum and methanol extracts of the whole bryophyte plants at 100% concentration were tested. In vitro inhibition of the tested bacterial isolates from the diabetic foot ulcers by M debilis was observed only with the light petroleum extract. No inhibition by the extracts was observed for the Pseudomonas aeruginosa isolate. The light petroleum extract of M debilis was formulated into a petroleum oil based cream named BryoCream (TM). This was administered to 20 of the patients with 90% cure rate in a three week time period. The main nonpolar components were determined by GCMS as lepidozene and beta-barbatene, and by NMR. as stigmasterol and beta-sitosterol. In conclusion, nonpolar extracts from bryophytes from Cameroon could, potentially, be used to treat diabetic bacterial foot infections

    Bis-bibenzyls from the Cameroon Liverwort Marchantia debilis

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    Liverworts are rich sources of terpenoids and aromatic compounds among which bis-bibenzyls are well known for their wide spectrum of biological activities. This is the first report of chemical analysis of the African liverwort Marchantia debilis Goebel. From the methanol extract marchantinquinone-l'-methyl ether was newly isolated together with three known bis-bibenzyls, marchantin C, marchantinquinone and perrottetin E. The presence of bis-bibenzyls with a quinone moiety is noted for the first time in the Marchantia genus

    Eucalyptus essential oil as a natural food preservative: in vivo and in vitro antiyeast potential

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    In this study, the application of eucalyptus essential oil/vapour as beverages preservative is reported. The chemical composition of eucalyptus oil was determined by gas chromatography-mass spectrometry (GC-MS) and solid phase microextraction GC-MS (SPME/GC-MS) analyses. GC-MS revealed that the major constituents were 1,8-cineole (80.5%), limonene (6.5%), \u3b1-pinene (5%), and \u3b3-terpinene (2.9%) while SPME/GC-MS showed a relative reduction of 1,8-cineole (63.9%) and an increase of limonene (13.8%), \u3b1-pinene (8.87%), and \u3b3-terpinene (3.98%). Antimicrobial potential of essential oil was initially determined in vitro against 8 different food spoilage yeasts by disc diffusion, disc volatilization, and microdilution method. The activity of eucalyptus vapours was significantly higher than the eucalyptus oil. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) varied from 0.56 to 4.50\u2009mg/mL and from 1.13 to 9\u2009mg/mL, respectively. Subsequently, the combined efficacy of essential oil and thermal treatment were used to evaluate the preservation of a mixed fruit juice in a time-dependent manner. These results suggest eucalyptus oil as a potent inhibitor of food spoilage yeasts not only in vitro but also in a real food system. Currently, this is the first report that uses eucalyptus essential oil for fruit juice preservation against food spoiling yeast

    Essential Oils and Their Combination with Lactic Acid Bacteria and Bacteriocins to Improve the Safety and Shelf Life of Foods: A Review

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    The use of plant extracts (e.g., essential oils and their active compounds) represents an interesting alternative to chemical additives and preservatives applied to delay the alteration and oxidation of foods during their storage. Essential oils (EO) are nowadays considered valuable sources of food preservatives as they provide a healthier alternative to synthetic chemicals while serving the same purpose without affecting food quality parameters. The natural antimicrobial molecules found in medicinal plants represent a possible solution against drug-resistant bacteria, which represent a global health problem, especially for foodborne infections. Several solutions related to their application on food have been described, such as incorporation in active packaging or edible film and direct encapsulation. However, the use of bioactive concentrations of plant derivatives may negatively impact the sensorial characteristics of the final product, and to solve this problem, their application has been proposed in combination with other hurdles, including biocontrol agents. Biocontrol agents are microbial cultures capable of producing natural antimicrobials, including bacteriocins, organic acids, volatile organic compounds, and hydrolytic enzymes. The major effect of bacteriocins or bacteriocin-producing LAB (lactic acid bacteria) on food is obtained when their use is combined with other preservation methods. The combined use of EOs and biocontrol agents in fruit and vegetables, meat, and dairy products is becoming more and more important due to growing concerns about potentially dangerous and toxic synthetic additives. The combination of these two hurdles can improve the safety and shelf life (inactivation of spoilage or pathogenic microorganisms) of the final products while maintaining or stabilizing their sensory and nutritional quality. This review critically describes and collects the most updated works regarding the application of EOs in different food sectors and their combination with biocontrol agents and bacteriocins

    Assessment of the chemical composition and in vitro antimicrobial potential of extracts of the liverwort Scapania aspera.

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    The chemical composition of Scapania aspera extracts was determined by solid phase micro extraction gas chromatography–mass spectrometry (SPME GC-MS) and 96 constituents were identified. The dominant compounds in the methanol extract were β-barbatene (25.1%), o-cymene (14.0%), α-barbatene (5.7%), allo-aromadendrene (4.9%) and β-bourbonene, while in the ethanol extract, o-cymene (17.8%), β-barbatene (17.6%), α-thujene (6.7%), octen-1-ol acetate (4.9%) and β-bazzanene (2.4%) were the major components. In the ethyl acetate extract, β-barbatene (14.3%), undecane (11.8%), 2-methyldecane (11.2%), decane (10.9%) and o-cymene (3.6%) were major components. The antimicrobial activity of the different extracts was evaluated against pathogenic and food spoilage microorganisms using disc diffusion and micro-broth dilution methods. The minimal inhibitory concentration (MIC) of extracts of S. aspera varied from 0.4 to 1.5 mg/mL and 1 to 3 mg/mL for yeast and bacterial strains, respectively. The zone of inhibition of the methanol extract for yeast strains was higher than that for bacterial strains. The results suggest that S. aspera extracts have potential as natural antimicrobial agents

    Management of Diabetic Bacterial Foot Infections with Organic Extracts of Liverwort Marchantia debilis from Cameroon

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    Diabetic bacterial foot infections (DBFIs) are limb-threatening complications in patients with diabetes mellitus, accounting for 50% of diabetes related lower limb amputations in developing countries, representing approximately 20 percent of all diabetes-related hospital admissions with significant healthcare-related costs involved. The widespread problem of bacterial resistance to most commonly used antibiotics places a huge economic burden on the healthcare system, with both increased morbidity and mortality among diabetic patients with foot infections. In this study, the antibacterial activity of organic extracts of the fresh liverwort Marchantia debilis from the North West Region of Cameroon is reported. An exit pool system, where patients presenting with DBFIs consented to be involved in the use of phytomedicines, after long term treatment of ulcers with antibiotics and not yielding significant long term benefit, presented themselves at the Phytobiotechnology Research clinic (PRF). Continuous culture of swabs from foot and toe wounds from 30 infected patients on nutrient agar and MacConkey agars in triplicate as well as Gram stain microscopy, revealed the presence of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis and Bacillus species. Light petroleum and methanol extracts of the whole bryophyte plants at 100% concentration were tested. In vitro inhibition of the tested bacterial isolates from the diabetic foot ulcers by M debilis was observed only with the light petroleum extract. No inhibition by the extracts was observed for the Pseudomonas aeruginosa isolate. The light petroleum extract of M debilis was formulated into a petroleum oil based cream named BryoCream (TM). This was administered to 20 of the patients with 90% cure rate in a three week time period. The main nonpolar components were determined by GCMS as lepidozene and beta-barbatene, and by NMR. as stigmasterol and beta-sitosterol. In conclusion, nonpolar extracts from bryophytes from Cameroon could, potentially, be used to treat diabetic bacterial foot infections

    Unravelling the Potential of Lactococcus lactis Strains to Be Used in Cheesemaking Production as Biocontrol Agents

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    This research, developed within an exchange program between Italy and Canada, represents the first step of a three-year project intended to evaluate the potential of nisin-producing Lactococcus lactis strains isolated from Italian and Canadian dairy products to select a consortium of strains to be used as biocontrol agents in Crescenza and Cheddar cheese production. In this framework, the acidification and the production of nisin in milk, and the volatile molecule profiles of the fermented milk, were recorded. The strains were further tested for their anti-Listeria monocytogenes activity in milk. The data obtained highlighted good potential for some of the tested strains, which showed production of nisin beginning within 12 h after the inoculation and reaching maximum levels between 24 and 48 h. The highest inactivation levels of L. monocytogenes in milk was reached in the presence of the strains 101877/1, LBG2, 9FS16, 11FS16, 3LC39, FBG1P, UL36, UL720, UL35. The strains generated in milk-specific volatile profiles and differences in the presence of fundamental aromatic molecules of dairy products, such as 2-butanone and diacetyl. The results highlight the interesting potential of some L. lactis strains, the producer of nisin, to be further used as biocontrol agents, although the strains need to be tested for interaction with traditional thermophilic starters and tested in real cheesemaking conditions

    Micromeria thymifolia Essential Oil Suppresses Quorum-sensing Signaling in Pseudomonas aeruginosa

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    The chemical composition, antimicrobial and antiquorum sensing activity of the essential oil of Micromeria thymifolia (Scop.) Fritsch were investigated. Limonene, piperitone epoxide and piperitenone epoxide were found as the main constituents using a gas chromatography-mass spectrometry technique. In vitro antimicrobial activity of the oil was tested against six bacterial and seven fungal strains and high antimicrobial potential was noticed. Minimum inhibitory concentration varied from 0.031 mg/mL to 0.5 mg/mL for bacterial and 0.062 mg/mL to 0.5 mg/mL for fungal strains. The antiquorum properties of the essential oil were evaluated on Pseudomonas aeruginosa PAO1. The oil was tested at subMiC concentrations for anti-quorum sensing activity. The analyses on quorum-sensing functions have been carried out by evaluating twitching and swarming of bacterial cultures and the total amount of pyocyanin production produced by P. aeruginosa. This study showed that M thymifolia essential oil exhibited antiquorum sensing activity and may be used as an antipathogenic drug
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