Compounds from Olea europaea and Pistacia lentiscus inhibit oral microbial growth

Biological Activities of Novel Oleanolic Acid Derivatives from Bioconversion and Semi-Synthesis

Oleanolic acid (OA) is a vegetable chemical that is present naturally in a number of edible and medicinal botanicals. It has been extensively studied by medicinal chemists and scientific researchers due to its biological activity against a wide range of diseases. A significant number of researchers have synthesized a variety of analogues of OA by modifying its structure with the intention of creating more potent biological agents and improving its pharmaceutical properties. In recent years, chemical and enzymatic techniques have been employed extensively to investigate and modify the chemical structure of OA. This review presents recent advancements in medical chemistry for the structural modification of OA, with a special focus on the biotransformation, semi-synthesis and relationship between the modified structures and their biopharmaceutical properties.

Microbiome-driven anticancer therapy: A step forward from natural products

Human microbiomes, considered as a new emerging and enabling cancer hallmark, are increasingly recognized as critical effectors in cancer development and progression. Manipulation of microbiome revitalizing anticancer therapy from natural products shows promise toward improving cancer outcomes. Herein, we summarize our current understanding of the human microbiome-driven molecular mechanisms impacting cancer progression and anticancer therapy. We highlight the potential translational and clinical implications of natural products for cancer prevention and treatment by developing targeted therapeutic strategies as adjuvants for chemotherapy and immunotherapy against tumorigenesis. The challenges and opportunities for future investigations using modulation of the microbiome for cancer treatment are further discussed in this review.

Effects of Oleanolic Acid Derived from Wine Pomace on Periodontopathic Bacterial Growth in Healthy Individuals: A Randomized Placebo-Controlled Study

Periodontal disease is caused by oral pathogenic bacteria and is associated with systemic disease and frailty. Therefore, its prevention is crucial in extending healthy life expectancy. This study aimed to evaluate the effect of orally administered oleanolic acid, extracted from wine pomace, on periodontopathic bacterial growth in healthy individuals. In this randomized, placebo-controlled, double-blind, parallel-group comparison study, 84 healthy adults were assigned to a placebo (n = 29), low-dose (n = 29, 9 mg oleanolic acid), or high-dose (n = 26, 27 mg oleanolic acid) groups. The number of oral bacteria in their saliva, collected before and 5 h after administration, was determined using the polymerase chain reaction-invader technique. The proportion of periodontopathic bacteria among the total oral bacteria in the saliva was calculated. Oleanolic acid significantly decreased the proportion of Porphyromonas gingivalis among the total oral bacteria in a dose-dependent manner (p = 0.005 (low-dose) and p = 0.003 (high-dose) vs. placebo, Williams' test). Moreover, high-dose oleanolic acid decreased the proportion of Tannerella forsythia (p = 0.064 vs. placebo, Williams' test). Periodontopathic bacteria are closely associated with the development and progression of periodontal disease; thus, the continuous daily intake of oleanolic acid derived from pomace may be helpful in maintaining a healthy oral microbiome by controlling the proportion of periodontopathic bacteria.

Biological Activities of Virgin Coconut and Virgin Olive Oil Mixture against Oral Primary Colonizers: An In Vitro Study

AIM AND BACKGROUND

This study aimed to explore the potential synergistic interaction of virgin coconut oil (VCO) and virgin olive oil (VOO) mixture against Streptococcus sanguinis, Streptococcus mutans, and Lactobacillus casei in a single and mixture species through the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), antiadherence, and antibiofilm activities.

MATERIALS AND METHODS

The broth microdilution technique was used to individually determine the MIC of both oils and an oil mixture (in the ratio of 1:1) in a 96-well microtiter plate. As for the MBC, the subcultured method was used. The fractional inhibitory concentration index (ΣFIC) was determined to identify the interaction types between both oils. The oil mixture at its MIC was then tested on its antibiofilm and antiadherence effect.

RESULTS

The MIC of the oil mixture against the tested microbiota was 50-100%. The oil mixture was bactericidal at 100% concentration for all the mentioned microbes except S. mutans. The ΣFIC value was 2 to 4, indicating that the VCO and VOO acted additively against the microbiota. Meanwhile, the oil mixture at MIC (50% for S. sanguinis and L. casei; 100% for S. mutans and mixture species) exhibited antiadherence and antibiofilm activity toward the microbiota in mixture species.

CONCLUSION

The oil mixture possesses antibacterial, antibiofilm, and antiadherence properties toward the tested microbiota, mainly at 50-100% concentration of oil mixture. There was no synergistic interaction found between VCO and VOO.

CLINICAL SIGNIFICANCE

Children and individuals with special care may benefit from using the oil mixture, primarily to regulate the biofilm formation and colonization of the bacteria. Furthermore, the oil mixture is natural and nontoxic compared to chemical-based oral healthcare products. How to cite this article: Ng YM, Sockalingam SNMP, Shafiei Z, et al. Biological Activities of Virgin Coconut and Virgin Olive Oil Mixture against Oral Primary Colonizers: An In Vitro Study. J Contemp Dent Pract 2024;25(3):260-266.

Evaluation of the antifungal effect of plant extracts on oral Candidaspp. - a critical methodological analysis of the last decade

INTRODUCTION

In 2022, the World Health Organization published a report encouraging researchers to focus on Candida spp. to strengthen the global response to fungal oral infections and antifungal resistance. In the context of innovative research, it seems pertinent to investigate the antifungal potential of natural extracts of plants and the methodology involved in the recent reports. The aim of this systematic review is to identify the current state of in vitro research on the evaluation of the ability of plant extracts to inhibit Candida spp.

MATERIAL AND METHODS

A bibliographic search has been developed to on a 10-year period to identify which plant extracts have an antifungal effect on the Candida spp. found in the oral cavity.

RESULTS

A total of 20 papers were reviewed and fulfilled all the selection criteria and were included in the full data analysis.

DISCUSSION

Plants have been tested in a wide range of states - whole extracts, extraction of particular components such as flavonoids or polyphenols, or even using the plant to synthesize nanoparticles. Of forty-five plants tested, five of them did not show any effect against Candida spp., which weren't part of the same family. There is a wide range of plant that exhibit antifungal proprieties.

CONCLUSION

Many plants have been tested in a wide range of states - whole extracts, extraction of components such as flavonoids or polyphenols, or even using the plant to synthetize nanoparticles. The combination of plants, the addition of plants to a traditional antifungal and the interference with adhesion provided by some plants seem to be promising strategies. Nonetheless, on contrary to drugs, there is a critical lack of standardization on methodologies and protocols, which makes it difficult to compare data and, consequently, to conclude, beyond doubts, about the most promising plants to fight Candida spp. oral infections.

Olea europaea L-derived secoiridoids: Beneficial health effects and potential therapeutic approaches

Over the years, health challenges have become increasingly complex and global and, at the beginning of the 21st century, chronic diseases, including cardiovascular, neurological, and chronic respiratory diseases, as well as cancer and diabetes, have been identified by World Health Organization as one of the biggest threats to human health. Recently, antimicrobial resistance has also emerged as a growing problem of public health for the management of infectious diseases. In this scenario, the exploration of natural products as supplementation or alternative therapeutic options is acquiring great importance, and, among them, the olive tree, Olea europaea L, specifically leaves, fruits, and oil, has been increasingly investigated for its health promoting properties. Traditionally, these properties have been largely attributed to the high concentration of monounsaturated fatty acids, although, in recent years, beneficial effects have also been associated to other components, particularly polyphenols. Among them, the most interesting group is represented by Olea europaea L secoiridoids, comprising oleuropein, oleocanthal, oleacein, and ligstroside, which display anti-inflammatory, antioxidant, cardioprotective, neuroprotective and anticancer activities. This review provides an overview of the multiple health beneficial effects, the molecular mechanisms, and the potential applications of secoiridoids from Olea europaea L.

The effect of mastic mouthwash on halitosis and oral hygiene in orthodontic patients: a randomized clinical trial

BACKGROUND/OBJECTIVES

The aim of this trial was to investigate the effect of mastic mouthwash on halitosis using as a proxy the levels of the Volatile Sulfur Compounds (VSCs), and the effect on plaque and gingival indices in adolescents undergoing orthodontic treatment with fixed conventional labial appliances.

SUBJECTS/METHODS

The study was a double-blinded, placebo-controlled, parallel-group, randomized clinical trial. Thirty patients with fixed orthodontic appliances were randomly allocated at a 1:1 ratio, to either the mastic-mouthwash or the placebo-mouthwash group. Eligibility criteria included ages between 13 and 18, active orthodontic treatment with fixed appliances, good general health, and total initial VSCs levels above 150 ppb. The primary outcome was the objective hydrogen sulfide (H2S) level, measured with the Oral ChromaTM device. The secondary outcomes were (1.) the methyl-mercaptan (CH3SH) and (2.) dimethyl sulfide [(CH3)2S] levels, measured with the same device, (3.) the subjective perception of the own malodour via questionnaires, and (4.) the oral hygiene assessed with the use of the Modified Silness and Löe Plaque Index (PI-M) and the Silness and Löe Gingival Index (GI) at baseline (T0) and after 2 weeks (T1). Stratified randomization by gender was used, and allocation was concealed with opaque numbered sealed envelopes.

RESULTS

H2S level dropped from 221.00 ppb (T0) to 125.00 ppb (T1), and the difference between treatment groups was statistically significant in favour of the mastic group (coef: 72.34, 95% CI: 8.48, 136.27, P = 0.03). The levels of the other VSCs, the subjective measurements of oral malodour, and the oral hygiene indices did not differ between treatment arms.

LIMITATIONS

The objective organoleptic assessment by a calibrated examiner was not performed.

CONCLUSIONS/IMPLICATIONS

Mastic mouthwashes could be an alternative treatment for adolescent patients suffering from halitosis during orthodontic treatment with fixed appliances.

REGISTRATION

The trial was registered at ClinicalTrials.gov (identifier: NCT05647369).

Extra Virgin Olive Oil-Based Formulations: A "Green" Strategy against Chlamydia trachomatis

In recent decades, antibiotic misuse has emerged as an important risk factor for the appearance of multi-drug-resistant bacteria, and, recently, antimicrobial resistance has also been described in Chlamydia trachomatis as the leading cause of bacterial sexually transmitted diseases worldwide. Herein, we investigated, for the first time, the antibacterial activity against C. trachomatis of a polyphenolic extract of extra virgin olive oil (EVOO), alongside purified oleocanthal and oleacein, two of its main components, in natural deep eutectic solvent (NaDES), a biocompatible solvent. The anti-chlamydial activity of olive-oil polyphenols (OOPs) was tested in the different phases of chlamydial developmental cycle by using an in vitro infection model. Transmission and scanning electron microscopy analysis were performed for investigating potential alterations of adhesion and invasion, as well as morphology, of chlamydial elementary bodies (EBs) to host cells. The main result of our study is the anti-bacterial activity of OOPs towards C. trachomatis EBs down to a total polyphenol concentration of 1.7 μg/mL, as shown by a statistically significant decrease (93.53%) of the total number of chlamydial-inclusion-forming units (p < 0.0001). Transmission and scanning electron microscopy analysis supported its anti-chlamydial effect, suggesting that OOP might damage the chlamydial outer layers, impairing their structural integrity and hindering EB capability to infect the host cell. In conclusion, OOPs may represent an interesting alternative therapeutic option toward C. trachomatis, although further studies are necessary for exploring its clinical applications.

Antimicrobial Efficiency of Pistacia lentiscus L. Derivates against Oral Biofilm-Associated Diseases-A Narrative Review

Pistacia lentiscus L. (PlL) has been used for centuries in traditional medicine. The richness in antimicrobial biomolecules of Pll derivates can represent an alternative to chemically formulated agents used against oral infections. This review summarizes the knowledge on the antimicrobial activity of PlL essential oil (EO), extracts, and mastic resin against microorganisms being of relevance in oral biofilm-associated diseases. Results demonstrated that the potential of PlL polyphenol extracts has led to increasing scientific interest. In fact, the extracts are a significantly more effective agent than the other PlL derivates. The positive findings regarding the inhibition of periodontal pathogens and C. albicans, together with the antioxidant activity and the reduction of the inflammatory responses, suggest the use of the extracts in the prevention and/or reversal of intraoral dysbiosis. Toothpaste, mouthwashes, and local delivery devices could be effective in the clinical management of these oral diseases.

Mastic (Pistacia lentiscus) gum and oral health: a state-of-the-art review of the literature

The aim of this state-of-the-art review is to provide a comprehensive overview of the various therapeutic effects of Mastic (Pistacia lentiscus) gum on oral health. The search of the literature was conducted across thirteen databases for relevant publications published through May 2022 in English, Arabic, or Greek using a combination of keywords and phrases. Out of 246 papers, the search procedure identified 14 papers for inclusion. Mastic gum displayed antibacterial and antimicrobial properties and inhibited plaque accumulation, constituting a beneficial adjuvant in caries prevention. In the treatment and prevention of periodontal diseases, Pistacia lentiscus essential oil provided effective antibacterial activity against a variety of periodontal bacteria as well as anti-inflammatory properties. For oral cancer, several clinical trials revealed interesting results against cell proliferation, induction of apoptosis, and regulation of intracellular signaling pathways. This indicates the potential of Mastic gum to serve as a preventive and therapeutic agent for oral mucosa inflammation and oral cancer. No notable toxic or side effects were reported in the clinical trials reviewed. This review highlights the various beneficial effects of Mastic gum in the prevention and potential treatment of oral diseases. Further research targeting Pistacia lentiscus products is required in order to validate and utilize these products to prevent and to treat oral health diseases.

Randomized clinical trial on the clinical effects of a toothpaste containing extra virgin olive oil, xylitol, and betaine in gingivitis

To determine the effects on gingival bleeding, dental biofilm, and salivary flow and pH in patients with gingivitis of using toothpaste with extra-virgin olive oil (EVOO), xylitol, and betaine in comparison to a placebo or commercial toothpaste. This controlled, double blinded, and multicenter randomized clinical trial included patients with gingivitis randomly assigned to one of three groups: test group (EVOO, xylitol, and betaine toothpaste), control group 1 (placebo toothpaste), or control group 2 (commercial toothpaste). Percentage supragingival biofilm and gingival bleeding were evaluated at baseline (T0), 2 months (T2), and 4 months (T4), measuring non-stimulated salivary flow and salivary pH. Comparisons were performed between and within groups. The final study sample comprised 20 in the test group, 21 in control group 1, and 20 in control group 2. In comparison to control group 1, the test group showed significantly greater decreases in gingival bleeding between T4 and T0 (p = 0.02) and in biofilm between T2 and T0 (p = 0.02) and between T4 and T0 (p = 0.01). In the test group, salivary flow significantly increased between T2 and T0 (p = 0.01), while pH alkalization was significantly greater between T4 and T0 versus control group 2 (p = 0.01) and close-to-significantly greater versus control group 1 (p = 0.06). The toothpaste with EVOO, xylitol, and betaine obtained the best outcomes in patients with gingivitis, who showed reductions in gingival bleeding and supragingival biofilm and an increase in pH at 4 months in comparison to a commercial toothpaste.

Evaluation of Chitosan-Oleuropein Nanoparticles on the Durability of Dentin Bonding

Purpose

To evaluate the effects of dentin pretreatment with chitosan-loaded oleuropein nanoparticles (CONPs) on the durability of resin-dentin bonding interfaces.

Methods

Eighty freshly extracted non-carious human third molars were randomly divided into four groups (n = 20 each): a de-ionized water (DW) group, a chitosan (CS) group, a chlorhexidine (CHX) group and a CONP group. The dentin in the DW, CS, CHX, and CONP groups were pretreated with de-ionized water, 1.0 mg/L CS solution, 2% chlorhexidine solution, and CONP suspension (prepared with 100 mg/L oleuropein), respectively, followed by the universal adhesive and resin composites. The bonded teeth of each group were randomly divided into two subgroups: an immediate subgroup and an aged subgroup. The bonded teeth of each group were then cut into the bonded beams. We measured their microtensile bond strength (μTBS), observed the characteristics of bonding interface by atomic force microscope, calculated the percentage of silver particles in a selected area for interfacial nanoleakage analysis, and evaluated the endogenous gelatinase activity within the bonding interface for in-situ zymogram analysis. Data were analyzed with two-way ANOVA and LSD multiple comparison test (P < 0.05).

Results

Regardless of after 24 h or after thermocycling, CONP exhibited better μTBS (P < 0.05) than the other three groups except that there was not a statistical significance (P > 0.05) in the CONP and CHX groups after 24 h. Besides, the CONP group presented significantly higher modulus of elasticity in the hybrid layers (P < 0.05), lower expression of nanoleakage (P < 0.05), and better inhibitory effect of matrix metalloproteinases than the other three groups before and after thermocycling.

Conclusion

Altogether, the CONPs had the potential to act as a dentin primer, which could effectively improve the dentin-resin binding durability.

A Review of Pistacia lentiscus Polyphenols: Chemical Diversity and Pharmacological Activities

Pistacia lentiscus (lentisk) is a plant species of the Anacardiaceae family. It is a medicinal plant that grows wild in the Mediterranean region. This review aims to update the existing knowledge regarding P. lentiscus polyphenols by consulting references dated from 1996 to 2022. The data are organized and analyzed as follows: (i) to show the chemical diversity of phenolic products from P. lentiscus; (ii) to summarize the variability in phenolic composition and quantity; this could be attributed to plant origin, environmental conditions, phenological stage, and the polarity of the extraction solvents; (iii) to present the pharmacological properties in agreement with the traditional uses of this plant; and (iv) to demonstrate the correlation between the chemical profile and the pharmacological effect. Various compositions were observed, including phenolic acids, flavonoid glycosides, anthocyanins, catechins, and their derivatives. The biological and therapeutic potentials of lentisk extracts have been evaluated in terms of antioxidant, antimicrobial, and anti-inflammatory activities. Most of these activities are related to the phenolic composition of this plant. The content of this review will undoubtedly contribute to the choice of techniques for isolating the different bioactive molecules contained in the P. lentiscus. It is also of significance for the potential development of a micro-industrial sector based on the valorization of lentisk polyphenols.

Effect of chitosan-oleuropein nanoparticles on dentin collagen cross-linking

BACKGROUND

The integrity and stability of collagen are crucial for the dentin structure and bonding strength at dentin-resin interface. Natural plant-derived polypehenols have been used as collagen crosslinkers.

OBJECTIVE

The aims of the study were to develop novel chitosan oleuropein nanoparticles (CS-OL-NPs), and to investigate the CS-OL-NPs treated dentin's the resistance to enzymatic degradation and mechanic property.

METHODS

CS-OL-NPs were developed using the ionotropic gelation method. Release and biocompatibility of the CS-OL-NPs were tested. Twenty demineralized dentin collage specimens were randomized into four interventions groups: A, Deionized Water (DW); B, 5% glutaraldehyde solution (GA); C, 1 mg/ml chitosan (CS); and D, 100 mg/L CS-OL-NPs. After 1-min interventions, dentin matrix were evaluated by the micro-Raman spectroscopy for the modulus of elasticity test. Collagen degradation was assessed using hydroxyproline (HYP) assay.

RESULTS

CS-OL-NPs were spherical core-shape with a size of 161.29 ± 8.19 nm and Zeta potential of 19.53 ± 0.26 mV. After a burst release of oleuropein in the initial 6 h, there was a long-lasting steady slow release. CS-OL-NPs showed a good biocompatibility for the hPDLSCs. The modulus of elasticity in the crosslinked groups were significantly higher than that in the control group (P< 0.05 for all). The specimens treated with CS-OL-NP showed a greater modulus of elasticity than those treated with GA and CS (P< 0.05 for both). The release of HYP in the crosslinked group was significantly lower than that in the non-crosslinked groups (P< 0.05 for all).

CONCLUSION

CS-OL-NPs enhanced the dentin mechanical property and resistance to biodegradation, with biocompatibility and potential for clinical application.

Strategies to Combat Caries by Maintaining the Integrity of Biofilm and Homeostasis during the Rapid Phase of Supragingival Plaque Formation

Bacteria in the oral cavity, including commensals and opportunistic pathogens, are organized into highly specialized sessile communities, coexisting in homeostasis with the host under healthy conditions. A dysbiotic environment during biofilm evolution, however, allows opportunistic pathogens to become the dominant species at caries-affected sites at the expense of health-associated taxa. Combining tooth brushing with dentifrices or rinses combat the onset of caries by partially removes plaque, but resulting in the biofilm remaining in an immature state with undesirables’ consequences on homeostasis and oral ecosystem. This leads to the need for therapeutic pathways that focus on preserving balance in the oral microbiota and applying strategies to combat caries by maintaining biofilm integrity and homeostasis during the rapid phase of supragingival plaque formation. Adhesion, nutrition, and communication are fundamental in this phase in which the bacteria that have survived these adverse conditions rebuild and reorganize the biofilm, and are considered targets for designing preventive strategies to guide the biofilm towards a composition compatible with health. The present review summarizes the most important advances and future prospects for therapies based on the maintenance of biofilm integrity and homeostasis as a preventive measure of dysbiosis focused on these three key factors during the rapid phase of plaque formation.

Extra Virgin Olive Oil-Based Green Formulations With Promising Antimicrobial Activity Against Drug-Resistant Isolates

Extra virgin olive oil (EVOO) from Olea europaea L. drupes, a cornerstone in the Mediterranean diet, is well known for its nutritional and health properties, especially for prevention of cardiovascular diseases and metabolic disorders. Traditionally, beneficial health effects have been largely attributed to the high concentration of monounsaturated fatty acids, and in recent years, these have also been related to other components including oleacein and oleocanthal. Here, we evaluated, for the first time, the antimicrobial activity of different green extra virgin olive oil-based formulations in natural deep eutectic solvents (NaDESs) emerging as powerful and biocompatible solvents. Specifically, the antimicrobial activity of the EVOO extract, as well as purified oleocanthal and oleacein in two NaDESs (choline/glycerol and choline/propylene glycol), against several drug-resistant clinical isolates and standard microbial strains has been evaluated. The main result was the inhibitory activity of the EVOO extract in choline/glycerol as well as oleacein in choline/propylene glycol toward drug-resistant Gram-positive and -negative strains. Specifically, the EVOO extract in choline/glycerol showed the highest antibacterial activity against several clinical strains of Staphylococcus aureus, whereas oleacein in choline/propylene glycol was the most effective toward various clinical strains of Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. In addition, all the formulations tested were effective against Candida spp. In conclusion, our results suggest EVOO-based formulations in NaDESs as an interesting strategy that may help in reducing the risk of development of drug resistance. Under this perspective, the usage of NaDESs for the preparation of new antimicrobial formulations may represent a promising approach.

The antimicrobial effect of Rosmarinus officinalis extracts on oral initial adhesion ex vivo

Objective

In the last few decades, there has been a growing worldwide interest in the use of plant extracts for the prevention of oral diseases. The main focus of this interest lies in the identification and isolation of substances that limit the formation of microbial biofilm which plays a major role in the development of caries, periodontitis, and peri-implantitis. In this clinical ex vivo study, we investigated the antimicrobial effects of Rosmarinus officinalis extract against oral microorganisms within in situ initial oral biofilms.

Materials and methods

Initial in situ biofilm samples (2 h) from six healthy volunteers were treated ex vivo with R. officinalis extract at concentrations of 20 mg/ml and 30 mg/ml. The number of viable bacterial cells was determined by counting the colony-forming units. All surviving bacteria were isolated in pure cultures and identified using MALDI-TOF and biochemical testing procedures. Additionally, live/dead staining in combination with epifluorescence microscopy was used for visualizing the antimicrobial effects in the initial biofilms.

Results

The number of colony-forming units in the R. officinalis–treated biofilms was significantly lower than in the untreated controls (p < 0.001). The reduction range of log10 was 1.64–2.78 and 2.41–3.23 for aerobic and anaerobic bacteria, respectively. Regarding the bacterial composition, large intra- and interindividual variability were observed. Except for Campylobacter spp., the average amount of all bacterial taxa was lower after treatment with R. officinalis than in the untreated biofilms. A total of 49 different species were detected in the untreated biofilms, while only 11 bacterial species were detected in the R. officinalis–treated biofilms. Live/dead staining confirmed that the R. officinalis–treated biofilms had significantly lower numbers of surviving bacteria than the untreated biofilms.

Conclusions

The treatment with R. officinalis extract has a significant potential to eliminate microbial oral initial biofilms.

Clinical relevance

The results of this study encourage the use of R. officinalis extracts in biofilm control and thus in the treatment of caries and periodontitis as a herbal adjuvant to synthetic substances.

First report of isolation of antibacterial ceramides from the leaves of Euclinia longiflora Salisb

Two phytosphingosine-type ceramides (euclinide A (1) and B (2)) were isolated alongside one fatty acid (geddic acid (3)), one fatty acid-1-glyceride ((2 S)-1- O-hentriacontanoyl glycerol (4)), ten triterpenes ( α-amyrin (5), α-amyrin acetate (6), ursolic acid (7), β-amyrin (8), β-amyrin acetate (9), β-amyrin palmitate (10), oleanic acid (11), maslinic acid (12), betulinic acid (13) and cylicodiscic acid (14)) and four sterols ( β -sitosterol (15), stigmasterol (17), and their glucosylated derivatives β-sitosterol-3-O- β-glucopyranoside (16) and stigmasterol-3-O- β-glucopyranoside (18)) from the methanol extract of the leaves of Euclinia longiflora Salisb. using routine chromatographic methods. The structures of the new ceramides and known compounds were determined by analyses of HR-FAB-MS, 1D and 2D NMR (HSQC, HMBC, and NOESY) data and confirmed, where applicable, by comparison with data reported in literature. The methanolic extract and the ceramides were evaluated for their antibacterial activities against different bacterial strains using microdilution method and the MIC values ranged from 6.25 to 50 μg/mL and were considered as moderate activity compared to ciprofloxacin. It is the first report of ceramides in Euclinia longiflora.

Ca' Granda, Hortus simplicium: Restoring an Ancient Medicinal Garden of XV-XIX Century in Milan (Italy)

This work is based on the study of 150 majolica vases dated back to the mid XVII century that once preserved medicinal remedies prepared in the ancient Pharmacy annexed to the Ospedale Maggiore Ca' Granda in Milan (Lombardy, Italy). The Hortus simplicium was created in 1641 as a source of plant-based ingredients for those remedies. The main objective of the present work is to lay the knowledge base for the restoration of the ancient Garden for educational and informative purposes. Therefore, the following complementary phases were carried out: (i) the analysis of the inscriptions on the jars, along with the survey on historical medical texts, allowing for the positive identification of the plant ingredients of the remedies and their ancient use as medicines; (ii) the bibliographic research in modern pharmacological literature in order to validate or refute the historical uses; (iii) the realization of the checklist of plants potentially present in cultivation at the ancient Garden, concurrently with the comparison with the results of a previous in situ archaeobotanical study concerning pollen grains. For the species selection, considerations were made also regarding drug amounts in the remedies and pedoclimatic conditions of the study area. Out of the 150 vases, 108 contained plant-based remedies, corresponding to 148 taxa. The remedies mainly treated gastrointestinal and respiratory disorders. At least one of the medicinal uses was validated in scientific literature for 112 out of the 148 examined species. Finally, a checklist of 40 taxa, presumably hosted in the Hortus simplicium, was assembled.

Antifungal Activity of Isolated Compounds from the Leaves of Combretum erythrophyllum (Burch.) Sond. and Withania somnifera (L.) Dunal against Fusarium Pathogens

Crop diseases caused by Fusarium pathogens, among other microorganisms, threaten crop production in both commercial and smallholder farming. There are increasing concerns about the use of conventional synthetic fungicides due to fungal resistance and the associated negative effects of these chemicals on human health, livestock and the environment. This leads to the search for alternative fungicides from nature, especially from plants. The objectives of this study were to characterize isolated compounds from Combretum erythrophyllum (Burch.) Sond. and Withania somnifera (L.) Dunal leaf extracts, evaluate their antifungal activity against Fusarium pathogens, their phytotoxicity on maize seed germination and their cytotoxicity effect on Raw 264.7 macrophage cells. The investigation led to the isolation of antifungal compounds characterized as 5-hydroxy-7,4'-dimethoxyflavone, maslinic acid (21-hydroxy-3-oxo-olean-12-en-28-oic acid) and withaferin A (4β,27-dihydroxy-1-oxo-5β,6β-epoxywitha-2-24-dienolide). The structural elucidation of the isolated compounds was established using nuclear magnetic resonance (NMR) spectroscopy, mass spectroscopy (MS) and, in comparison, with the available published data. These compounds showed good antifungal activity with minimum inhibitory concentrations (MIC) less than 1.0 mg/mL against one or more of the tested Fusarium pathogens (F. oxysporum, F. verticilloides, F. subglutinans, F. proliferatum, F. solani, F. graminearum, F. chlamydosporum and F. semitectum). The findings from this study indicate that medicinal plants are a good source of natural antifungals. Furthermore, the isolated antifungal compounds did not show any phytotoxic effects on maize seed germination. The toxicity of the compounds A (5-hydroxy-7,4'-dimethoxyflavone) and AI (4β,27-dihydroxy-1-oxo-5β,6β-epoxywitha-2-24-dienolide) was dose-dependent, while compound B (21-hydroxy-3-oxo-olean-12-en-28-oic acid) showed no toxicity effect against Raw 264.7 macrophage cells.

Porphyromonas gingivalis: where do we stand in our battle against this oral pathogen?

Periodontal diseases, such as gingivitis and periodontitis, are inflammatory diseases triggered by pathogenic bacteria that lead to damage of the soft tissue and bone supporting the teeth. Amongst the identified oral periodontopathogenic bacteria, Porphyromonas gingivalis is able to enhance oral dysbiosis, which is an imbalance in the beneficial commensal and periodontal pathogenic bacteria that induces chronic inflammation. Given the critical role of oral pathogenic bacteria like P. gingivalis in the pathogenesis of periodontitis, local and/or systemic antibacterial therapy has been suggested to treat this disease, especially in its severe or refractory forms. Nevertheless, the majority of the antibacterial agents currently used for the treatment of periodontal diseases are broad-spectrum, which harms beneficial bacterial species that are critical in health, inhibit the growth of pathogenic bacteria, contribute in protecting the periodontal tissues to damage and aid in its healing. Thus, the development of more effective and specific antibacterial agents is needed to control oral pathogens in a polymicrobial environment. The strategies for the development of novel antibacterial agents include natural product isolation as well as synthetic and semi-synthetic methodologies. This review presents an overview of the periodontal diseases gingivitis and periodontitis along with current antibacterial treatment options (i.e., classes of antibacterial agents and the mechanism(s) of resistance that hinder their usage) used in periodontal diseases that specifically target oral pathogens such as P. gingivalis. In addition, to help medicinal chemists gain a better understanding of potentially promising scaffolds, this review provides an in-depth coverage of the various families of small molecules that have been investigated as potential anti-P. gingivalis agents, including novel families of compounds, repositioned drugs, as well as natural products.

Effects of virgin olive oil and grape seed oil on physicochemical and antimicrobial properties of pectin-gelatin blend emulsified films

The active emulsified blend films based on gelatin-pectin (5% w/w) containing virgin olive oil (VOO) (0.1-0.3 g/g biopolymer) and grape seed oil (GSO) (0.1-0.3 g/g biopolymer) were prepared by casting method. GSO showed slightly more decreasing effect than VOO on ultimate tensile strength (UTS) and strain at break (SAB) of blend films however; VOO had more reducing effect than GSO on the water vapor permeability (WVP). The scanning electron microscopy (SEM) images showed that incorporating 0.3 g GSO and VOO oils had not considerable effect on the morphology of the emulsified films. Atomic force microscopy (AFM) topography images indicated that adding of oils considerably could increase roughness of emulsified film. Fourier transforms infrared (FTIR) revealed that no new chemical bond formed by adding oils into biopolymer matrix. The minimum inhibitory concentration (MIC) of VOO, GSO and Savory essential oil (SEO) against four important spoilage bacteria showed that GSO had higher antibacterial effect than VOO however; both showed very lower antimicrobial effect than SEO. All active films showed lower inhibitory zone for S. aureus than S. typhimurium and P. fluorescence. The chicken breast fillets wrapped in the films containing VOO-GSO-SEO (0.15-0.15-0.02 g/g polymer) showed considerably lower total viable count (TVC), Pseudomonas spp., Enterobacteriaceae, E. coli 157:H7 and S. typhimurium count than the control one during 12 days storage. Also, it caused significant decrease in peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and total volatile basic nitrogen (TVB-N) of fillet samples.

Aqueous Leaf Extract of Pistacia lentiscus Improves Acute Acetic Acid-Induced Colitis in Rats by Reducing Inflammation and Oxidative Stress

We investigate the antioxidant activity and protective effects of the aqueous leaf extract of Pistacia lentiscus (AELPL) against ulcerative colitis induced by acetic acid infusion through the rectum in Wistar rats. Phytochemical analyses allowed the identification of numerous phenolic compounds in P. lentiscus leaves such as flavonoids (isoquercetin and luterolin), flavonols (catechin, rutin, and kaempferol), phenolic acids (ellagic and dicaffeoylquinic), and tanins. Acetic acid exposure induced macroscopic colonic mucosal lesions with hemorrhage, congestion, edema, and the development of an expected oxidative stress state revealed by an increase in lipoperoxidation and carbonylation of proteins and a decrease in sulfhydryl (SH) group levels and antioxidant enzyme activities such as superoxide dismutase, catalase, glutathione-S-peroxidase, and glutathione transferase, as well as an increase in the inflammatory cytokine, interleukin-6, in the colon and plasma. Administration of acetic acid also increased plasma and tissue levels of hydrogen peroxide and rates of iron and free calcium, whereas AELPL significantly and dose-dependently attenuated all the previous biochemical alterations and intracellular mediator perturbations. In conclusion, the AELPL exhibited a potent cytoprotective effect against acetic acid-induced colitis in rats, mainly through its antioxidant and anti-inflammatory activities.

Antibacterial activity of plant species used for oral health against Porphyromonas gingivalis

Porphyromonas gingivalis is the keystone pathogen of periodontitis, a chronic inflammatory disease which causes tooth loss and deterioration of gingiva. Medicinal plants have been traditionally used for oral hygiene and health and might play a role as antibacterial agents against oral pathogens. In this work, we aimed to evaluate the antibacterial activity of plants used for oral hygiene or symptoms of periodontitis against P. gingivalis. We first reviewed the literature to identify plant species used for oral hygiene or symptoms of periodontitis. Then, we cross-checked this species list with our in-house library of plant extracts to select extracts for testing. Antibacterial activity tests were then performed for each plant extract against P. gingivalis, and their cytotoxicity was assessed on HaCaT cells. The selectivity index (SI) was then calculated. A total of 416 plant species belonging to 110 families and 305 genera were documented through our literature search, and 158 plant species were noted as being used by North American Native peoples Once cross-checked with the extracts contained in our library of natural products, 30 matches were identified and 21 were defined as high priority. Of the 109 extracts from 21 plant species selected and tested, 21 extracts from 11 plants had higher than 90% inhibition on P. gingivalis at 64 μg/mL and were further selected for MIC (Minimum Inhibitory Concentration) assays. Out of 21 plant extracts, 13 extracts (7 plant species) had a SI > 10. Pistacia lentiscus fruits showed the best MIC with value of 8 μg/mL, followed by Zanthoxylum armatum fruits/seeds with a MIC of 16 μg/mL. P. lentiscus fruits also showed the highest SI of 256. Most of the extracts tested present promising antibacterial activity and low cytotoxicity. Further testing for biofilm eradication and examination of activity against other dental pathogens and oral commensals should be performed to confirm the potential of these extracts as antibacterial agents. Future work will focus on application of a bioassay-guided fractionation approach to isolating and identifying the most active natural products in the top performing extracts. This study can serve as a basis for their future development as ingredients for oral hygiene products.

The Pharmaceutical Ability of Pistacia lentiscus L. Leaves Essential Oil Against Periodontal Bacteria and Candida sp. and Its Anti-Inflammatory Potential

BACKGROUND

Given the increasing request for natural pharmacological molecules, this study assessed the antimicrobial capacity of Pistacia lentiscus L. essential oil (PLL-EO) obtained from the leaves of wild plants growing in North Sardinia (Italy) toward a wide range of periodontal bacteria and Candida, including laboratory and clinical isolates sp., together with its anti-inflammatory activity and safety.

METHODS

PLL-EO was screened by gas chromatography/mass spectrometry. The minimal inhibitory concentration (MIC) was determined. The anti-inflammatory activity was measured by cyclooxygenase (COX-1/2) and lipoxygenase (LOX) inhibition, while the antioxidant capacity was determined electro-chemically and by the MTT assay. The WST-1 assay was used to ascertain cytotoxicity toward four lines of oral cells.

RESULTS

According to the concentrations of terpens, PLL-EO is a pharmacologically-active phytocomplex. MICs against periodontal bacteria ranged between 3.13 and 12.5 µg/ml, while against Candida sp. they were between 6.25 and 12.5 µg/mL. Oxidation by COX-1/2 and LOX was inhibited by 80% and 20% µg/mL of the oil, respectively. Antioxidant activity seemed negligible, and no cytotoxicity arose.

CONCLUSIONS

PLL-EO exhibits a broad-spectrum activity against periodontal bacteria and Candida, with an interesting dual inhibitory capacity toward COX-2 and LOX inflammatory enzymes, and without side effects against oral cells.

Biofilm inhibiting properties of compounds from the leaves of Warburgia ugandensis Sprague subsp ugandensis against Candida and staphylococcal biofilms

ETHNOPHARMACOLOGICAL RELEVANCE

Warburgia ugandensis Sprague subspecies ugandensis is a plant widely distributed in Eastern, Central and Southern Africa. In humans, it is used to treat respiratory infections, tooth aches, malaria, skin infections, venereal diseases, diarrhea, fevers and aches.

AIM OF THE STUDY

This study aims to identify the bioactive compounds against clinically important biofilm-forming strains of Candida and staphylococci that are responsible for tissue and implanted device-related infections.

METHODS

Using a bioassay-guided fractionation approach, hexane -, ethanol -, acetone - and water extracts from the leaves of W. ugandensis, their subsequent fractions and isolated compounds were tested against both developing and preformed 24 h-biofilms of Candida albicans SC5314, Candida glabrata BG2, Candida glabrata ATCC 2001, Staphylococcus epidermidis 1457 and Staphylococcus aureus USA 300 using microtiter susceptibility tests. Planktonic cells were also tested in parallel for comparison purposes. Confocal scanning laser microscopy was also used to visualize effects of isolated compounds on biofilm formation.

RESULTS

Warburganal, polygodial and alpha-linolenic acid (ALA) were the major bioactive compounds isolated from the acetone extract of W. ugandensis. For both warburganal and polygodial, the biofilm inhibitory concentration that inhibits 50% of C. albicans developing biofilms (BIC₅₀) was 4.5 ± 1 and 10.8 ± 5 μg/mL respectively. Against S. aureus developing biofilms, this value was 37.9 ± 8 μg/mL and 25 μg/mL with warburganal and ALA respectively. Eradication of preformed 24 h biofilms was also observed. Interestingly, synergy between the sesquiterpenoids and azoles against developing C. albicans biofilms resulted in an approximately ten-fold decrease of the effective concentration required to completely inhibit growth of the biofilms by individual compounds. The hydroxyl group in position C-9 in warburganal was identified as essential for activity against staphylococcal biofilms. We also identified additional promising bioactive sesquiterpenoids; drimenol and drimendiol from the structure-activity relationship (SAR) studies.

CONCLUSIONS

ALA and four sesquiterpenoids: polygodial, warburganal, drimenol and drimendiol, have shown biofilm-inhibitory activity that has not been reported before and is worth following up. These compounds are potential drug candidates to manage biofilm-based infections, possibly in combination with azoles.

Antibacterial Activity of Three Extra Virgin Olive Oils of the Campania Region, Southern Italy, Related to Their Polyphenol Content and Composition

Production of extra virgin olive oil (EVOO) represents an important element for the economy of Southern Italy. Therefore, EVOO is recognized as a food with noticeable biological effects. Our study aimed to evaluate the antimicrobial activity exhibited by the polyphenolic extracts of EVOOs, obtained from three varieties of Olea europea L. (Ruvea antica, Ravece, and Ogliarola) cultivated in the village of Montella, Avellino, Southern Italy. The study evaluated the inhibiting effect of the extracts against some Gram-positive and Gram-negative bacteria. Statistical analysis, used to relate values of antimicrobial activity to total polyphenols and phenolic composition, revealed a different behavior among the three EVOO polyphenol extracts. The method applied could be useful to predict the influence of singular metabolites on the antimicrobial activity.