In vitro antimicrobial activity of extracts and isolated constituents of Rubus ulmifolius

Metabolite Profiling and Biological Activity Assessment of Paeonia ostii Anthers and Pollen Using UPLC-QTOF-MS

Paeonia ostii is an important economic oil and medicinal crop. Its anthers are often used to make tea in China with beneficial effects on human health. However, the metabolite profiles, as well as potential biological activities of P. ostii anthers and the pollen within anthers have not been systematically analyzed, which hinders the improvement of P. ostii utilization. With comprehensive untargeted metabolomic analysis using UPLC-QTOF-MS, we identified a total of 105 metabolites in anthers and pollen, mainly including phenylpropanoids, polyketides, organic acids, benzenoids, lipids, and organic oxygen compounds. Multivariate statistical analysis revealed the metabolite differences between anthers and pollen, with higher carbohydrates and flavonoids content in pollen and higher phenolic content in anthers. Meanwhile, both anthers and pollen extracts exhibited antioxidant activity, antibacterial activity, α-glucosidase and α-amylase inhibitory activity. In general, the anther stage of S4 showed the highest biological activity among all samples. This study illuminated the metabolites and biological activities of anthers and pollen of P. ostii, which supports the further utilization of them.

Protective effects of Rubus tereticaulis leaves ethanol extract on rats with ulcerative colitis and bio-guided isolation of its active compounds: A combined in silico, in vitro and in vivo study

The aim of this study was to evaluate the therapeutic effect of active ethanol extract obtained from the leaves of Rubus tereticaulis (RTME) against colitis, and to purify major compounds from this extract by bioassay-directed isolation. Rats with colitis induced via intra-rectal acetic acid administration (5%, v/v) received RTME or sulfasalazine for three consecutive days. On day four, all rats were decapitated, and the colonic tissue samples were collected for macroscopic score, colon weight, reduced glutathione (GSH), myeloperoxidase (MPO), and malondialdehyde (MDA) analyses. The active compounds and chemical composition of RTME were determined by bio-guided isolation and LC-MS/MS, respectively. Compared to the colitis group, the rats treated with RTME displayed significantly lowered macroscopic scores and colon wet weights (p < 0.001). These effects were confirmed biochemically by a decrease in colonic MPO activity (p < 0.001), MDA levels (p < 0.001), and an increase in GSH levels (p < 0.001). Kaempferol-3-O-β-d-glucuronide (RT1) and quercetin-3-O-β-d-glucuronide (RT2) were found to be the major compounds of RTME, as evidenced by in vitro anti-inflammatory and antioxidant activity-guided isolation. Their anti-inflammatory/antioxidant activities were also predicted by docking simulations. Additionally, quinic acid, 5-caffeoylquinic acid, quercetin pentoside, quercetin glucoside, quercetin-3-O-β-d-glucuronide, kaempferol-3-O-β-d-glucuronide, and kaempferol rutinoside were identified in RTME via using LC-MS/MS. RT2, along with other compounds, may be responsible for the observed protective action of RTME against colitis. This study represents the first report on the beneficial effects of RTME in an experimental model of colitis and highlights the potential future use of RTME as a natural alternative to alleviate colitis.

Novel approaches for the treatment of infections due to multidrug-resistant bacterial pathogens

Antimicrobial resistance (AMR), which is a major challenge for global healthcare, emerging because of several reasons including overpopulation, increased global migration and selection pressure due to enhanced use of antibiotics. Antibiotics are the widely used therapeutic options to combat infectious diseases; however, unfortunately, inadequate and irregular antibiotic courses are also major contributing factors in the emergence of AMR. Additionally, persistent failure to develop and commercialize new antibiotics has created the scarcity of effective anti-infective drugs. Thus, there is an urgent need for a new class of antimicrobials and other novel approaches to curb the menace of AMR. Besides the conventional approaches, some novel approaches such as the use of antimicrobial peptides, bacteriophages, immunomodulation, host-directed therapy and antibodies have shown really promising potentials.

Gentians, natural remedies for future of visceral pain control; an ethnopharmacological review with an in silico approach

Different gentian preparations are used as traditional remedies for internal pain control in: Persian traditional medicine (PTM), Chinese traditional medicine (CTM) and Ancient Greek medicine (AGM) from the time of the Roman Empire. Objective: To present a survey of the ethnopharmacological applications of gentians recorded as being used in Eastern and Western traditional medical systems (PTM, CTM and AGM) and their pharmacological effects, chemical composition as well as an in silico investigation of the possible active component/s for the alleviation of internal pain via molecular docking studies. Major traditional medicine literature (PTM, CTM and AGM, 50 AD- 1770) and ethnobotanical studies for the application of gentians were reviewed. Nine European species representing 5 of the 13 sections currently attributed to Gentiana were selected. Chemical compounds and pharmacological activity data of these species were gathered from different databases including Google Scholar, PubChem, PubMed and Web of Science (between 1972 and 2020). The possible active constituents of gentians on visceral pain receptors were investigated, in silico. In all investigated literature, traditional uses of gentian were indicated to have anti-nociceptive effects on visceral pain and possess diuretic action. According to our computational study, acylated flavonoid glycosides, viz. trans-feruloyl-2"-isovitexin (33), trans-feruloyl-2"-isovitexin-4'-O-β-D-glucoside (34), iso-orientin-4'-O-glucoside (38), trans-caffeoyl-2"-iso-orientin-4'-O-β-D-glucoside (39), iso-orientin-2"-O-β-D-glucoside (40) and isoscoparin (41), might be responsible for visceral pain reduction by interacting with the purinergic receptor (P2X₃) and vanilloid receptor 1 (TrpV₁). This finding shows a good correlation with different traditional gentian uses in Persian, Chinese and European ethnomedicine for visceral pain control.

Antibacterial, Antioxidant and Melanogenesis Inhibitory Activity of Auraptene, a Coumarin from Ferula szowitsiana Root

The auraptene is a geranyloxyn coumarin found in the Ferula species. The plant is endemic in Central Asia and it is used as a medicinal food in Iran. This research aimed to evaluate the antibacterial, antioxidant, and anti-melanogenic properties of auraptene, a coumarin from Ferula szowitsiana root. The results revealed that auraptene possessed antibacterial activity with minimum inhibitory and minimum bactericidal concentrations ranged from 2.5 up to 10 mg/ml against human pathogenic bacteria (Escherichia coli, Salmonella typhimurium, Salmonella paratyphi, Clostridium perfringens, Staphylococcus aureus). The nitric oxide scavenging activity (IC₅₀: 670.9 µg/ml) showed its moderate antioxidant potential. Similarly, the results of ferric thiocyanate and thiobarbituric acid assays reconfirmed the moderate antioxidant activity of auraptene and indicated the percentage inhibitions of hydroxyl radicals to be 31.87 and 14%, respectively. The cell-based antioxidant evaluation confirmed the antioxidant activity of auraptene through up-regulation of the antioxidant-related genes including superoxide dismutase, catalase, and glutathione peroxidase in the human foreskin fibroblast (HFF). The auraptene has also displayed the anti-melanogenic activity through direct tyrosinase enzyme inhibition (IC₅₀ of 29.7 µg/ml) and could modulate the expression of major melanogenesis-related genes including tyrosinase, tyrosinase-related protein 1, and dopachrome tautomerase in the murine melanoma cell line. The auraptene from Ferula szowitsiana root exhibited antibacterial, antioxidant, and melanogenesis inhibitory activities.

Evaluation of Antioxidant, Antimicrobial and Potential Food Preserving Properties of Rubus Discolor (Rosaceae) Fruit Extracts

The presented study was aimed at exploring the bioactive properties (antioxidant, antimicrobial and food preserving) and chemical composition of R. discolor fruits collected from 2 geographically distinct wild-growing populations and extracted by using different solvents (methanol, ethanol, acetone and water). The total phenol (TPC), flavonoid (TFC) and anthocyanin (TAC) content varied from 52.7 to 186.8 mg GAE/g, 3.5 to 7.0 mg QE/g and 11.1 to 28.2 mg/g dry weight (dw), respectively. HPLC-DAD analysis identified cyanidin-3-glucoside (Cy-3-Glu) as the dominant anthocyanin that ranged in concentration from 18.4 to 32.2 mg/g dw. The acetone extract revealed the highest antioxidant activity through the ferric reducing antioxidant power (FRAP), total reducing power (TRC) and ß-carotene bleaching in vitro methods. The examined extracts showed antimicrobial activity, being more effective against Gram-positive (G+) than Gram-negative (G-) bacteria. Furthermore, Candida glabrata was the most susceptible among the pathogenic yeasts. The ethanol fruit extract was the most active against Listeria monocytogenes and thus chosen for incorporation in yoghurt and further analyses regarding its food preserving properties, which confirmed its efficacy towards this food-borne pathogen. Additionally, panelists gave high marks to the novel product regarding color, taste, texture flavor and overall acceptance. The obtained results indicated that R. discolor fruit extracts exhibits notable bioactivity and might therefore be considered as a good platform for the development of new preparations to be used in the food industry.

Design, Synthesis, Antiviral Bioactivity, and Mechanism of the Ferulic Acid Ester-Containing Sulfonamide Moiety

Tobacco mosaic virus (TMV) has caused huge economic losses to tobacco, pepper, cucumber, and ornamental crops all over the world. However, few effective antiviral agents were developed and applied to control such plant disease. It is challenging to find an anti-TMV agent which is highly effective, less toxic, and environmentally friendly. In this work, a series of ferulic acid ester-containing sulfonamide moieties were designed and synthesized, and the antiviral activities of these compounds against TMV were evaluated. The anti-TMV biological activity test showed that the target compounds showed excellent anti-TMV activity in vitro and in vivo. In particular, compound 2 has excellent anti-TMV activity at 500 μg/mL, which is higher than that of the control drug ribavirin. The preliminary mechanism research results showed that compound 2 can obviously destroy the morphology of the virions to show excellent activity. The results show that the ferulic acid ester-containing sulfonamide moiety deserves further research and development.

A review of the antimicrobial potential of herbal drugs used in popular Italian medicine (1850s-1950s) to treat bacterial skin diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Before the advent of modern antibiotics, microbial infections were treated with herbal medicine or cauterization. Literature from the latter half of the nineteenth to the early mid-twentieth century, when antibiotics became widely available, arguably holds the most progressive information about herbal remedies to treat bacterial skin diseases. The corpus of literature produced in Italy during that period is not easily accessible and mostly out of print.

MATERIAL AND METHODS

Plant-based remedies utilized in popular Italian medicine to treat anthrax, boils, erysipelas, impetigo, pustules, and whitlow were sourced from literature indexed in and available through the National Library Service website of the Italian Libraries Network. The remedies are assessed for their antimicrobial potential based on a detailed search of the herbal drug species in scientific databases.

RESULTS

A considerable part of the reviewed recipes included specific excipients (41 out of 139) and others were produced with fresh plant material (48 out of 139). Out of the 52 identified herbal drug species used in popular Italian medicine against dermatologic infections, extracts of 43 were shown to have moderate in vitro activity against Gram-positive and Gram-negative bacteria.

CONCLUSION

The antibacterial activity of the extracts and pure compounds as reported in the reviewed literature is mostly based on in vitro assays and generally does not encourage follow up studies. The effectiveness of the reported recipes, which include fresh plant material and excipients can only be assessed through in vivo studies. Those remedies including herbal drugs with reported antimicrobial activity might have the potential as complementary therapies. The reviewed plant based antimicrobial recipes might serve as inspirations in the search for alternative topical antibacterial strategies and the search for their synergistic and potentiating ingredients.

Effects of Chestnut Tannin Extract, Vescalagin and Gallic Acid on the Dimethyl Acetals Profile and Microbial Community Composition in Rumen Liquor: An In Vitro Study

The addition of polyphenol extracts in ruminant diets is an effective strategy to modulate rumen microflora. The aim of this in vitro trial was to study the effects of chestnut tannin extract (CHT), vescalagin (VES) and gallic acid (GAL) on dietary fibre degradability and on the dimethyl acetals (DMA) profile and microbial community composition of rumen liquor. Four diets (basal diet; basal diet plus CHT; basal diet plus VES; basal diet plus GAL) were fermented for 24 h using ewe rumen liquor. At the end of the fermentation, the microbial communities were characterized by sequencing the 16S rRNA gene. The DMA profile was analyzed by gas chromatography. Chestnut tannin extract did not affect fibre degradability, whereas VES and GAL showed a detrimental effect. The presence of CHT, VES and GAL influenced the concentration of several DMA (i.e., 12:0, 13:0, 14:0, 15:0, 18:0 and 18:1 trans-11), whereas the composition of the microbial community was marginally affected. The inclusion of CHT led to the enrichment of the genera Anaerovibrio, Bibersteinia, Escherichia/Shigella, Pseudobutyrivibrio and Streptococcus. The results of this study support the hypothesis that the activity of CHT is due to the synergistic effect of all components rather than the property of a single component.

Rubus ulmifolius Schott fruits: A detailed study of its nutritional, chemical and bioactive properties

There is a growing interest in wild edible species that represent a source of several health-promoting compounds, providing a potential strategy to diversify and enrich the daily diet. The aim of the present work was to characterize the nutritional and chemical composition of Rubus ulmifolius Schott fruits. Furthermore, their antimicrobial activity, non-anthocyanin and anthocyanin phenolic profile were also determined. According to the obtained results, R. ulmifolius fruits exhibited a high concentration in carbohydrates and a low fat content, in comparison with the other nutrients and non-nutrients detected in this sample. The colour parameters demonstrated differences in a* and b* parameters after lyophilisation process. Glucose and fructose were the most abundant free sugars detected and quinic acid showed the highest content compared to the other five organic acids identified. The fatty acids profile revealed 25 compounds, being mostly represented by polyunsaturated fatty acids and evidencing linolenic and α-linolenic acid as the most abundant. All tocopherol isoforms were detected, revealing γ-tocopherol with highest amount. Cyanidin-3-O-glucoside, ellagic acid pentoside, ellagic acid glucuronide and sanguiin H-10 were the main phenolic compounds present, which could be related to the antimicrobial activity (MIC values ranging between 5 and 20 mg/mL) revealed by R. ulmifolius fruits. These results showed that this fruit is a good source of nutrients as also non-nutrient compounds, with human health benefits.

Litter Inhibitory Effects on Soil Microbial Biomass, Activity, and Catabolic Diversity in Two Paired Stands of Robinia pseudoacacia L. and Pinus nigra Arn

Research Highlights: Plant cover drives the activity of the microbial decomposer community and affects carbon (C) sequestration in the soil. Despite the relationship between microbial activity and C sequestration in the soil, potential inhibition of soil microbial activity by plant cover has received little attention to date. Background and Objectives: Differences in soil microbial activity between two paired stands on soil at a very early stage of formation and a common story until afforestation, can be traced back to the plant cover. We hypothesized that in a black locust (Robinia pseudoacacia L.) stand the high-quality leaf litter of the tree, and that of the blackberry (Rubus fruticosus L.) understory had an inhibitory effect on soil microbial community resulting in lower mineralization of soil organic matter compared to the paired black pine (Pinus nigra Arn.) stand. Materials and Methods: We estimated potential mineralization rates (MR), microbial (MB), and active fungal biomass (AFB) of newly-shed litter, forest floor, and mineral soil. We tested the effects of litters’ water extracts on soil MR, MB, AFB and its catabolic response profile (CRP). Results: Newly-shed litter of black locust had higher MR than that of blackberry and black pine; MR, MB, and AFB were higher in forest floor and in mineral soil under black pine than under black locust. Water extracts of black locust and blackberry litter had a negative effect on the amount, activity of microorganisms, and CRP. Conclusions: The results demonstrate the potential for black locust and blackberry litter to have a marked inhibitory effect on decomposer microorganisms that, in turn, reduce organic matter mineralization with possible consequences at the ecosystem level, by increasing C sequestration in mineral soil.

A Review on the Dietary Flavonoid Tiliroside

Among flavonoid derivatives, tiliroside is a flavonoid contained in several edible plants or specific plant parts (fruits, leaves, or roots). These parts are often widely used as both food and medicines, in the treatment of various ailments and, in some cases, as food supplements. Considering the easy access to many publications concerning tiliroside and the lack of a review that summarizes the current progress in studies on its safety, efficacy, and presence in the plant kingdom, we present here a review paper on tiliroside and its principal derivatives. The paper also highlights the basic knowledge regarding this molecule, its derivatives, and the analytical approaches used for extraction and quantification, as well as reports on the biological activities against different key enzymes linked to various human diseases. The reported information is also devoted to highlighting the concept "learn from nature to discover new products," particularly in the development of new drugs, food supplements, and nutraceuticals, starting from a natural lead compound such as tiliroside and improving its biological activities (and selectivities) against a specific target for therapeutic purposes.

Phytochemical Screening of Quaking Aspen (Populus tremuloides) Extracts by UPLC-QTOF-MS and Evaluation of their Antimicrobial Activity

The continual emergence of pathogen resistance is a recurring challenge and pushes for the development of antimicrobial compounds. Here, we investigated compounds from quaking aspen trees (Populus tremuloides) as potential antimicrobial agents. Several extractions using different solvents were realized, and corresponding antimicrobial activity was tested against eight microorganisms. Results revealed that polar extraction solvents including water, ethanol and methanol gave the best extraction yields (>15.07%). Minimal inhibition concentration (MIC) and minimal bactericidal/fungicidal concentration (MBC/MFC) demonstrated that water extracts had the best antimicrobial activity by a weak to moderate inhibition of growth of all eight tested microorganisms in addition to having a bactericidal effect on three of them. The quaking aspen methanol extract also displayed antimicrobial activity but to a lower level than the water extract. Ultra-performance liquid chromatography quadrupole time-of flight mass spectrometry (UPLC-QTOF-MS) analysis led to the identification of 92 compounds, mainly polyphenols in both extracts, with 22 molecules previously known for their antimicrobial properties. According to the relative abundance, 4-hydroxybenzaldehyde (5.44% in methanol extract) and kaempferol (5.03% in water extract) were the most abundant antimicrobial compounds. Among antimicrobial molecules identified, nine were from the flavonoid family. The results of our study demonstrate the interest of using quaking aspen as source of antimicrobial compounds.

Identification of Ellagic Acid Rhamnoside as a Bioactive Component of a Complex Botanical Extract with Anti-biofilm Activity

Staphylococcus aureus is a leading cause of hospital-acquired infections. It is listed among the top "serious threats" to human health in the USA, due in large part to rising rates of resistance. Many S. aureus infections are recalcitrant to antibiotic therapy due to their ability to form a biofilm, which acts not only as a physical barrier to antibiotics and the immune system, but results in differences in metabolism that further restricts antibiotic efficacy. Development of a modular strategy to synthesize a library of phenolic glycosides allowed for bioactivity testing and identification of anti-biofilm compounds within an extract of the elmleaf blackberry (Rubus ulmifolius). Two ellagic acid (EA) derivatives, EA xyloside and EA rhamnoside, have been identified as components of the Rubus extract. In addition, EA rhamnoside has been identified as an inhibitor of biofilm formation, with activity comparable to the complex extract 220D-F2 (composed of a mixture of EA glycosides), and confirmed by confocal laser scanning microscopy analyses.

Pharmacological profile of the aerial parts of Rubus ulmifolius Schott

Background

As aerial parts of Rubus ulmifolius contains phytochemicals like flavonoids and tannins. And whereas flavonoids and tannins have antioxidant and antipyretic activity, hence, current work is carried out to screen crude methanolic extract of aerial parts of Rubus ulmifolius (Ru.Cr) and crude flavonoids rich extract of Rubus ulmifolius (Ru.F) for possible antioxidant and antipyretic activity. Ru.Cr and Ru.F are also tested for brine shrimps lethality bioassay. Ru.F is tested for the first time for possible antioxidant and antipyretic activity.

Methods

Preliminary phytochemical screening of Ru.Cr and Ru.F was performed as it provides rapid finger printing for targeting a pharmacological activity. Acute toxicity and Brine shrimps’ cytotoxicity studies of Ru.Cr and Ru.F were performed to determine its safe dose range. Antioxidant and antipyretic studies were also performed as per reported procedures.

Results

Ru.Cr tested positive for presence of tannins, alkaloids, flavonoids and steroids. Ru.Cr is safe up to 6 g/kg following oral doses for acute toxicity study. Ru.Cr is safe up to 75 μg/kg (p.o), LC₅₀ for Ru.Cr and Ru.F are 16.7 ± 1.4 μg/ml 10.6 ± 1.8 μg/ml, respectively (n = 3). Both Ru.Cr and Ru.F demonstrated comparable antioxidant activity using vitamin C as standard (p ≤ 0.05). In test dose of 300 mg of Ru.Cr, rectal temperature was reduced by 74% (p ≤ 0.05) on 4^th hour of the administration. More, Ru.F produced 72% reduction in pyrexia (p ≤ 0.05) on 4^th hour of administration of paracetamol in Westar rats.

Conclusions

The current work confirms that aerial parts of Rubus ulmifolius contain flavonoids that are safe up to 6 g/kg (p.o). Crude methanolic extract and flavonoids rich fraction of Rubus ulmifolius have significant antioxidant and antipyretic activity. Further work is required to isolate the pharmacologically active substances for relatively safe and effective antipyretics and antioxidants.

Comparison of Phytochemical Composition and Biological Activities of Rubus ulmifolius Extracts Originating from Four Regions of Tunisia

In the current study, the phenolic composition, antioxidant and antimicrobial activities of extracts from Rubus ulmifolius Schott leaves harvested in four localities (Sejnen, Tabarka, Faija and Ain drahem) in Tunisia were investigated for the first time. Great differences were found for the chemical composition, total phenol contents and biological activities among the evaluated extracts. HPLC analysis of methanolic extracts showed that the dominant compounds were kaempferol 3-O-rutinoside and naringenine. In addition, significant correlations were observed between antioxidant activities and phenolic contents. In fact, leaves collected from Sejnen presented higher total phenol content (53.32 mg GAE/g DW) and antioxidant activities (IC₅₀ = 39.40 mg/l) than the others samples. All extracts showed significant antimicrobial activity against six used bacteria with the inhibition zones diameters and minimal inhibitory concentration values were in the range of 8 - 16 mm and 6.25 - 25 mg/ml, respectively. The highest antimicrobial activities were recorded in Sejnen extract against Gram-positive bacteria.

Aroma Profile of Rubus ulmifolius Flowers and Fruits During Different Ontogenetic Phases

The chemical composition of spontaneous volatile emission from Rubus ulmifolius flowers and fruits during different stages of development was evaluated by HS-SPME-GC/MS. In total, 155 chemical compounds were identified accounting 84.6 - 99.4% of whole aroma profile of flowers samples and 92.4 - 96.6% for fruit samples. The main constituents were α-copaene, β-caryophyllene, germacrene D, (E,E)-α-farnesene, 1,7-octadien-3-one,2-methyl-6-methylene, tridecane, (E)-2-hexenol acetate, (E)-3-hexenol acetate and cyperene. The results give a chemotaxonomic contribution to the characterization of the VOCs emitted from flowers and fruits during their ontogenic development.

A bioactivity guided study on the antibacterial activity of Hertia cheirifolia L. extracts

This study was carried out with the objective to investigate the antibacterial activity of Hertia cheirifolia L. extracts against Gram-positive and Gram-negative strains including Staphylococcus aureus (ATCC 6538), Bacillus subtilis (ATCC 6633), Bacillus licheniformis, Esherichia coli (ATCC 8739), Pseudomonas aeruginosa (ATCC 9027), Salmonella enterica (CIP 8039) and Salmonella typhimirium. The results of this antibacterial screening showed that the ethyl acetate (EtOAc) extracts had the best activity against the tested microorganisms. A bioassay-oriented fractionation approach for the more active extract (roots ethyl acetate extract) led to the obtaining five sub-fractions. Furthermore, these sub-fractions were also tested for antimicrobial activity and the best results were obtained for the roots EtOAc sub-fraction (C) with MICs values between 0.039 and 0.156 mg/mL. Reversed-phase high performance liquid chromatography (RP-HPLC) analysis indicated that the major phenolic components of active (EtOAc) extracts and sub-fraction (C) are fisetin hydrate (82.06%), trans cinnamic acid (63.66%), gallic acid (38.97%) and myricetin (20.92%). These results may help to improve these natural antibacterial substances that could serve as selective agents for bacterial diseases.

Synthesis and Anticancer Activities of Glycyrrhetinic Acid Derivatives

A total of forty novel glycyrrhetinic acid (GA) derivatives were designed and synthesized. The cytotoxic activity of the novel compounds was tested against two human breast cancer cell lines (MCF-7, MDA-MB-231) in vitro by the MTT method. The evaluation results revealed that, in comparison with GA, compound 42 shows the most promising anticancer activity (IC₅₀ 1.88 ± 0.20 and 1.37 ± 0.18 μM for MCF-7 and MDA-MB-231, respectively) and merits further exploration as a new anticancer agent.

Biomolecules and Natural Medicine Preparations: Analysis of New Sources of Bioactive Compounds from Ribes and Rubus spp. Buds

It is well known that plants are important sources for the preparation of natural remedies as they contain many biologically active compounds. In particular, polyphenols, terpenic compounds, organic acids, and vitamins are the most widely occurring groups of phytochemicals. Some endemic species may be used for the production of herbal preparations containing phytochemicals with significant bioactivity, as antioxidant activity and anti-inflammatory capacities, and health benefits. Blackberry sprouts and blackcurrant buds are known to contain appreciable levels of bioactive compounds, including flavonols, phenolic acids, monoterpenes, vitamin C, and catechins, with several clinical effects. The aim of this research was to perform an analytical study of blackcurrant and blackberry bud-preparations, in order to identify and quantify the main biomarkers, obtaining a specific phytochemical fingerprint to evaluate the single botanical class contribution to total phytocomplex and relative bioactivity, using a High Performance Liquid Chromatograph−Diode Array Detector; the same analyses were performed both on the University laboratory and commercial preparations. Different chromatographic methods were used to determine concentrations of biomolecules in the preparations, allowing for quantification of statistically significant differences in their bioactive compound content both in the case of Ribes nigrum and Rubus cultivated varieties at different harvest stages. In blackcurrant bud-extracts the most important class was organic acids (50.98%) followed by monoterpenes (14.05%), while in blackberry preparations the main bioactive classes were catechins (50.06%) and organic acids (27.34%). Chemical, pharmaceutical and agronomic-environmental knowledge could be important for obtaining label certifications for the valorization of specific genotypes, with high clinical and pharmaceutical value: this study allowed to develop an effective tool for the natural preparation quality control and bioactivity evaluation through the chemical fingerprinting of bud preparations.

Agents that inhibit bacterial biofilm formation

In the biofilm form, bacteria are more resistant to various antimicrobial treatments. Bacteria in a biofilm can also survive harsh conditions and withstand the host's immune system. Therefore, there is a need for new treatment options to treat biofilm-associated infections. Currently, research is focused on the development of antibiofilm agents that are nontoxic, as it is believed that such molecules will not lead to future drug resistance. In this review, we discuss recent discoveries of antibiofilm agents and different approaches to inhibit/disperse biofilms. These new antibiofilm agents, which contain moieties such as imidazole, phenols, indole, triazole, sulfide, furanone, bromopyrrole, peptides, etc. have the potential to disperse bacterial biofilms in vivo and could positively impact human medicine in the future.

Drug resistance of bacterial dental biofilm and the potential use of natural compounds as alternative for prevention and treatment

Oral diseases, such as dental caries and periodontal disease are directly linked with the ability of bacteria to form biofilm. The development of dental caries involves acidogenic and aciduric Gram-positive bacteria colonizing the supragingival biofilm (Streptococcus, Lactobacillus and Actinomycetes). Periodontal diseases have been linked to anaerobic Gram-negative bacteria forming a subgingival plaque (Porphyromonas gingivalis, Actinobacillus, Prevotella and Fusobacterium). Cells embedded in biofilm are up to 1000-fold more resistant to antibiotics compared to their planctonic ones. Several mechanisms have been proposed to explain biofilms drug resistance. Given the increased bacterial resistance to antibiotics currently used in dentistry, a great importance is given to natural compounds for the prevention of oral bacterial growth, adhesion and colonization. Over the past decade, interest in drugs derived from medicinal plants has markedly increased. It has been well documented that medicinal plants and natural compounds confer considerable antibacterial activity against various microorganisms including cariogenic and periodontal pathogens. This paper provides a review of the literature focusing on the studies on (i) biofilm in the oral cavity, (ii) drug resistance of bacterial biofilm and (iii) the potential use of plant extracts, essential oils and natural compounds as biofilm preventive agents in dentistry, involving their origin and their mechanism of biofilm inhibition.

Fatty acid composition, antioxidant and antibacterial properties of the microwave aqueous extract of three varieties of Labisia pumila Benth

Background

The present study was conducted in order to evaluate the fatty acid profile, anti-oxidant and anti-bacterial activities from the microwave aqueous extract of the leaves of three different varieties of Labisia pumila Benth.

Results

The chemical analysis of the extract showed that fatty acids (palmitic, palmitoleic, stearic, oleic, linoleic and α-linolenic) acid as the main components in three varieties of L. pumila leaves. Furthermore, the obtained results of the anti-oxidant revealed that L. pumila var. alata contained higher anti-oxidative activities compared to var. pumila and var. lanceolata. However, these values were lower than the tested anti-oxidant standards. On the other hand, the aqueous leaf extracts in all three varieties of L. pumila were also found to inhibit a variable degree of antibacterial activities against eight bacteria (four Gram-positive and four Gram-negative bacteria).

Conclusions

In this study, it was observed the leaves of three varieties of L. pumila exhibited variable patterns of fatty acids and the microwave aqueous extraction possess anti-oxidant and anti-bacterial activities.

Phytochemical, analgesic, antibacterial, and cytotoxic effects of Alpinia nigra (Gaertn.) Burtt leaf extract

This research evaluated the phytochemical contents as well as the analgesic, cytotoxic, and antimicrobial effects of the methanolic extract of Alpinia nigra leaf. Phytochemical analysis was carried out using established methods. The analgesic effects of the extract were measured with the formalin test and tail immersion test. The antibacterial activity of the extract was evaluated using the disc diffusion technique. Cytotoxicity was assessed with the brine shrimp lethality bioassay. Data were analyzed with one-way analysis of variance using statistical software (SPSS, Version 19.0). The qualitative phytochemical screening of A. nigra leaf extract showed the presence of medicinally active secondary metabolites such as alkaloids, glycosides, cardiac glycosides, flavonoids, steroids, tannins, anthraquinone glycosides, and saponins. The extract at a dose of 200 mg/kg revealed a prevailed central nociception increasing the reaction time in response to thermal stimulation. The extract also showed a response to chemical nociceptors, causing pain inhibition in the late phase. The leaf extract (2 mg/disc) showed mild antibacterial activity compared to tetracycline (50 μg/disc). In the brine shrimp lethality bioassay, the LC₅₀ (lethal concentration 50) value of the extract was found to be 57.12 μg/mL, implying a promising cytotoxic effect. The results evidenced the moderate analgesic and antibacterial effects with pronounced cytotoxic capability.

Investigation of in vivo neuropharmacological effect of Alpinia nigra leaf extract

OBJECTIVE

To analyze in vivo neuro-pharmacological effects of Alpinia nigra as anxiety is a particular form of behavioral inhibition that occurs in response to novel environmental events.

METHODS

In present study, the extract of Alpinia nigra was evaluated for its central nervous system depressant effect using mice behavioral models, such as hole cross, open field and thiopental sodium induced sleeping time tests for its sedative properties and an elevated plus-maze test for its anxiolytic potential, respectively.

RESULTS

In anxiolytic study, the extract displayed increased percentage of entry into open arm at the dose of 400 and 200 mg/kg. The extract produced a significant (P<0.01) increase in sleeping duration and reduction of onset of sleep compared to sodium thiopental at both doses (200 and 400 mg/kg). The extract (200 and 400 mg/kg) also showed a dose-dependent suppression of motor activity and exploratory activity of the mice in both open field and hole cross test.

CONCLUSION

This study demonstrates that the treated extract has significant central nervous system depressant effect. Further studies on active constituent of the extract can provide approaches for therapeutic intervention.

Antibacterial potential of northeastern Portugal wild plant extracts and respective phenolic compounds

The present work aims to assess the antibacterial potential of phenolic extracts, recovered from plants obtained on the North East of Portugal, and of their phenolic compounds (ellagic, caffeic, and gallic acids, quercetin, kaempferol, and rutin), against bacteria commonly found on skin infections. The disk diffusion and the susceptibility assays were used to identify the most active extracts and phenolic compounds. The effect of selected phenolic compounds on animal cells was assessed by determination of cellular metabolic activity. Gallic acid had a higher activity, against gram-positive (S. epidermidis and S. aureus) and gram-negative bacteria (K. pneumoniae) at lower concentrations, than the other compounds. The caffeic acid, also, showed good antibacterial activity against the 3 bacteria used. The gallic acid was effective against the 3 bacteria without causing harm to the animal cells. Gallic and caffeic acid showed a promising applicability as antibacterial agents for the treatment of infected wounds.

Spectroscopic (FT-IR, FT-Raman, 1H, 13C NMR, UV/VIS), thermogravimetric and antimicrobial studies of Ca(II), Mn(II), Cu(II), Zn(II) and Cd(II) complexes of ferulic acid

The molecular structure of Mn(II), Cu(II), Zn(II), Cd(II) and Ca(II) ferulates (4-hydroxy-3-methoxycinnamates) was studied. The selected metal ferulates were synthesized. Their composition was established by means of elementary and thermogravimetric analysis. The following spectroscopic methods were used: infrared (FT-IR), Raman (FT-Raman), nuclear magnetic resonance ((13)C, (1)H NMR) and ultraviolet-visible (UV/VIS). On the basis of obtained results the electronic charge distribution in studied metal complexes in comparison with ferulic acid molecule was discussed. The microbiological study of ferulic acid and ferulates toward Escherichia coli, Bacillus subtilis, Candida albicans, Pseudomonas aeruginosa, Staphylococcus aureus and Proteus vulgaris was done.

Antibacterial and anti-inflammatory effects of Syzygium jambos L. (Alston) and isolated compounds on acne vulgaris

BACKGROUND

Acne vulgaris is a chronic skin disorder leading to inflammation as a result of the production of reactive oxygen species due to the active involvement of Propionibacterium acnes (P. acnes) in the infection site of the skin. The current study was designed to assess the potential of the leaf extract of Syzygium jambos L. (Alston) and its compounds for antibacterial and anti-inflammatory activity against the pathogenic P. acnes.

METHODS

The broth dilution method was used to assess the antibacterial activity. The cytotoxicity investigation on mouse melanocyte (B16-F10) and human leukemic monocyte lymphoma (U937) cells was done using sodium 3'-[1-(phenyl amino-carbonyl)-3,4-tetrazolium]-bis-[4-methoxy-6-nitrobenzene sulfonic acid hydrate (XTT) reagent. The non-toxic concentrations of the samples was investigated for the suppression of cytokines interleukin 8 (IL 8) and tumour necrosis factor (TNF α) by testing the supernatants in the co-culture of the human U937 cells and heat killed P. acnes using enzyme immunoassay kits (ELISA). The statistical analysis was done using the Graph Pad Prism 4 program.

RESULTS

Bioassay guided isolation of ethanol extract of the leaves of S. jambos led to the isolation of three known compounds namely; squalene, an anacardic acid analogue and ursolic acid which are reported for the first time from this plant. The ethanol extract of S. jambos and one of the isolated compound namely, anacardic acid analogue were able to inhibit the growth of P. acnes with a noteworthy minimum inhibitory concentration (MIC) value of 31.3 and 7.9 μg/ml, respectively. The ethanol extract and three commercially acquired compounds namely; myricetin, myricitrin, gallic acid exhibited significant antioxidant activity with fifty percent inhibitory concentration (IC50) ranging between 0.8-1.9 μg/ml which was comparable to that of vitamin C, the reference antioxidant agent. The plant extract, compounds ursolic acid and myricitrin (commercially acquired) significantly inhibited the release of inflammatory cytokines IL 8 and TNF α by suppressing them by 74 - 99%. TEM micrographs showed the lethal effects of selected samples against P. acnes.

CONCLUSIONS

The interesting antibacterial, antioxidant and anti-inflammatory effects of S. jambos shown in the present study warrant its further investigation in clinical studies for a possible alternative anti-acne agent.

Cytotoxicity evaluation of Curcuma zedoaria (Christm.) Roscoe fluid extract used in oral hygiene products

OBJECTIVE

This in vitro study evaluated the cytotoxic effects of the Curcuma zedoaria (Christm.) Roscoe (popular name: zedoary) fluid extract, as used in preparations for oral hygiene, mostly for anti-septic purposes.

MATERIALS AND METHODS

The cell viability and cell growth were assessed by Trypan blue dye exclusion assay using the LMF cell line derived from oral mucosa. Cell viability (short-term assay) was measured 0, 6, 12 and 24 h after contact with the fluid extract. Cell growth (long-term assay) was analyzed in 1, 3, 5 and 7 days. The experimental groups were those testing the fluid extract obtained from the zedoary rhizome and the extractor liquid (ethanol 70° GL) in the concentrations of 0.01-0.0001% v/v. Fresh DMEM were used in the control cultures.

RESULTS

Short-term assay-all studied cultures maintained stable cell viability; Long-term assay-there was progressive cell growth in all studied cultures.

CONCLUSION

According to the results, the zedoary fluid extract presents low cytotoxicity and probably can be used in the oral hygiene products.

Comparative analyses of seeds of wild fruits of Rubus and Sambucus species from Southern Italy: fatty acid composition of the oil, total phenolic content, antioxidant and anti-inflammatory properties of the methanolic extracts

Fruit seeds are byproducts from fruit processing. Characterisation of the bioactive compounds present in seeds and evaluation of their potential biological properties is therefore of particular importance in view of a possible valorisation of seeds as a source of health beneficial components. In this work, we have analysed the seeds of Sambucus and Rubus species in order to identify their bioactive components and to determine the antioxidant and anti-inflammatory activities of the extracts. We first analysed their oil content, in order to assess the fatty acid profile and tocopherol content. Moreover, the methanolic extracts of the seeds were analysed for their total phenolic contents and antioxidant capacities. Polyphenols were identified by HPLC-ESI-MS/MS analysis. Furthermore, extracts were evaluated for their inhibitory effects on the production of LPS-induced inflammatory mediators (NO, CCL-20) in RAW 264.7 cells. Our findings show that the methanolic extracts from Rubus seeds have strong antioxidant and anti-inflammatory properties and could therefore represent an attractive source of bioactive compounds for food, cosmetic, or pharmaceutical applications.

Inhibitory effect of carob (Ceratonia siliqua) leaves methanolic extract on Listeria monocytogenes

In recent years, there has been great development in the search for new natural compounds for food preservation aimed at a partial or total replacement of currently popular antimicrobial chemicals. Carob (Ceratonia siliqua) offers a natural promising alternative for food safety and bioconservation. In this work, the methanolic extract of carob leaves (MECL) was tested for the ability to inhibit the growth of a range of microorganisms. MECL inhibited the growth of Listeria monocytogenes at 28.12 μg/mL by the broth microdilution method. The effect of this bacteriostatic concentration on the growth of this bacterium revealed a pattern of inhibition characterized by (a) a resumed growth phase, which showed a lower rate of growth if compared with controls; and (b) first a lag and then a stationary phase at a lower bacterium concentration. The study of the chemical composition of MECL by high-performance liquid chromatography and liquid chromatography/mass spectrometry showed the presence of gallic acid, (-)-epigallocatechin-3-gallate, myricitrin, isoquercitin, catechin, chlorogenic acid, and malic acid. L. monocytogenes growth inhibition was recorded for myricitrin and gallic acid at 450 μg/mL and for (-)-epigallocatechin-3-gallate and isoquercitin, respectively, at 225 and 112.5 μg/mL. Taking into account that proline is a ligand of proline dehydrogenase (PDH), the use of this compound leads us to hypothesize the mode of action of MECL constituents.

Microbiological and Pharmacological Evaluation of the Micropropagated Rubus liebmannii Medicinal Plant

Rubus liebmannii is an endemic species from Mexico used in traditional medicine primarily to treat dysentery and cough. The in vitro activity against Giardia lamblia and Entamoeba histolytica that produces the ethanolic extract of the aerial parts of the plant led us to expand the pharmacological and phytochemical research of this species. Gastrointestinal disorders including amebiasis remain one of the health problems that need to be addressed and it is of interest to find alternatives that improve their treatment. Also, it is important to emphasize that R. liebmannii grows wild in the country and is not found in abundance; therefore, alternatives that avoid overexploitation of the natural resource are mandatory. Ongoing with the evaluation of the potentialities that R. liebmannii possesses for treating infectious gastrointestinal diseases, the aim of the present study was to evaluate the biological effects and the chemical composition of the micropropagated plant.

Aqueous extracts of yerba mate (Ilex paraguariensis) as a natural antimicrobial against Escherichia coli O157:H7 in a microbiological medium and pH 6.0 apple juice

Ilex paraguariensis is popularly used in the preparation of a tea infusion (yerba mate), most commonly produced and consumed in the South American countries of Uruguay, Paraguay, Argentina, and Brazil. In this study, aqueous extracts of commercial tea, derived from the holly plant species I. paraguariensis were evaluated for their ability to inhibit or inactivate Escherichia coli O157:H7 in a microbiological medium and modified apple juice. Dialyzed, lyophilized aqueous extracts were screened for antimicrobial activity against E. coli O157:H7 strains ATCC 43894 and 'Cider' in tryptic soy broth (TSB) and apple juice (adjusted to pH 6.0 to allow for growth of the bacterium). A mixture of the two strains was used as the inoculum when apple juice was used as the medium. MBCs were determined to be ca. 5 and 10 mg/ml for ATCC 43894 and 'Cider', respectively, in TSB. Higher concentrations of the extract were required to inactivate E. coli O157:H7 in pH-adjusted apple juice. An approximate 4.5-log reduction was observed for E. coli O157:H7 treated with 40 mg/ml extract. It was concluded that aqueous extracts from commercial yerba mate have potential to be used as antimicrobials in foods and beverages against pathogenic E. coli O157:H7.

Ellagic acid derivatives from Rubus ulmifolius inhibit Staphylococcus aureus biofilm formation and improve response to antibiotics

BACKGROUND

Biofilms contribute to the pathogenesis of many forms of Staphylococcus aureus infection. Treatment of these infections is complicated by intrinsic resistance to conventional antibiotics, thus creating an urgent need for strategies that can be used for the prevention and treatment of biofilm-associated infections.

METHODOLOGY/PRINCIPAL FINDINGS

This study demonstrates that a botanical natural product composition (220D-F2) rich in ellagic acid and its derivatives can limit S. aureus biofilm formation to a degree that can be correlated with increased antibiotic susceptibility. The source of this composition is Rubus ulmifolius Schott. (Rosaceae), a plant used in complementary and alternative medicine in southern Italy for the treatment of skin and soft tissue infections. All S. aureus clonal lineages tested exhibited a reduced capacity to form a biofilm at 220D-F2 concentrations ranging from 50-200 µg/mL, which were well below the concentrations required to limit bacterial growth (530-1040 µg/mL). This limitation was therapeutically relevant in that inclusion of 220D-F2 resulted in enhanced susceptibility to the functionally-distinct antibiotics daptomycin, clindamycin and oxacillin. Testing with kidney and liver cell lines also demonstrated a lack of host cell cytotoxicity at concentrations of 220D-F2 required to achieve these effects.

CONCLUSIONS/SIGNIFICANCE

These results demonstrate that extract 220D-F2 from the root of Rubus ulmifolius can be used to inhibit S. aureus biofilm formation to a degree that can be correlated with increased antibiotic susceptibility without toxic effects on normal mammalian cells. Hence, 220D-F2 is a strong candidate for development as a botanical drug for use in the prevention and treatment of S. aureus biofilm-associated infections.

Biological treatment of eucalypt spent sulphite liquors: a way to boost the production of second generation bioethanol

The fermentation of reducing sugars from hardwood (eucalypt) spent sulphite liquor (HSSL) into ethanol by Pichia (Scheffersomyces) stipitis is hindered by concomitant inhibitors of microbial metabolism. The conditions for the HSSL biological treatment step by Paecilomyces variotii were evaluated and optimised. Two different strategies of reactor operation were compared using single batch (B) and sequential batch reactor (SBR). Biological treatment of HSSL in the SBR revealed the best results with respect to the removal of microbial inhibitors. Also, most of inhibitory compounds, acetic acid, gallic acid, pyrogallol, amongst others, were removed from HSSL by P. variotii before the ethanol fermentation. The bio-detoxified HSSL was subjected to a successful fermentation by P. stipitis, attaining a maximum ethanol concentration of 2.4 g L(-1) with a yield of 0.24 g ethanol g sugars(-1).