Antibiofilm potential of medicinal plants against Candida spp. oral biofilms: a review

The use of natural products to promote health is as old as human civilization. In recent years, the perception of natural products derived from plants as abundant sources of biologically active compounds has driven their exploitation towards the search for new chemical products that can lead to further pharmaceutical formulations. Candida fungi, being opportunistic pathogens, increase their virulence by acquiring resistance to conventional antimicrobials, triggering diseases, especially in immunosuppressed hosts. They are also pointed to as the main pathogens responsible for most fungal infections of the oral cavity. This increased resistance to conventional synthetic antimicrobials has driven the search for new molecules present in plant extracts, which have been widely explored as alternative agents in the prevention and treatment of infections. This review aims to provide a critical view and scope of the in vitro antimicrobial and antibiofilm activity of several medicinal plants, revealing species with inhibition/reduction effects on the biofilm formed by Candida spp. in the oral cavity. The most promising plant extracts in fighting oral biofilm, given their high capacity to reduce it to low concentrations were the essential oils extracted from Allium sativum L., Cinnamomum zeylanicum Blume. and Cymbopogon citratus (DC) Stapf.The authors wish to acknowledge financial support from the project “AquaValor—Centro de Valorização e Transferência de Tecnologia da Água” (NORTE-01-0246-FEDER-000053), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). The authors are also grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020); and L. Barros is grateful for her contract through the institutional scientific employment program-contract.info:eu-repo/semantics/publishedVersio

Biological Activities of Essential Oils: From Plant Chemoecology to Traditional Healing Systems

Essential oils are complex mixtures of hydrocarbons and their oxygenated derivatives arising from two different isoprenoid pathways. Essential oils are produced by glandular trichomes and other secretory structures, specialized secretory tissues mainly diffused onto the surface of plant organs, particularly flowers and leaves, thus exerting a pivotal ecological role in plant. In addition, essential oils have been used, since ancient times, in many different traditional healing systems all over the world, because of their biological activities. Many preclinical studies have documented antimicrobial, antioxidant, anti-inflammatory and anticancer activities of essential oils in a number of cell and animal models, also elucidating their mechanism of action and pharmacological targets, though the paucity of in human studies limits the potential of essential oils as effective and safe phytotherapeutic agents. More well-designed clinical trials are needed in order to ascertain the real efficacy and safety of these plant products

Fungal Biofilms 2020

Fungal infections are an important and increasing global threat, carrying not only high morbidity and mortality rates, but also high healthcare costs. Without an effective response, it is predicted that 10 million people will die per year as a result of multi-drug-resistant pathogens. A high percentage of the mortalities caused by fungi are known to be biofilm-related.This Special Issue, “Fungal Biofilms 2020”, is intended to cover the state of fungal biofilm research, from virulence and pathogenicity, to new compounds with antibiofilm and antifungal activity. We welcome reviews and original research articles covering the development/evaluation/validation of recent studies, especially those regarding multidrug resistance

Essential oils as antimicrobials and antifungals

Die antimikrobielle Wirkung von ätherischen Ölen wird in diesem Review unter Berücksichtigung von Studien, die in der Zeitspanne von 2008 bis September 2010 veröffentlicht wurden, diskutiert. Außerdem werden die wichtigsten Methoden zur Bestimmung der antimikrobiellen Wirksamkeit von ätherischen Ölen präsentiert. Die Studien werden in die folgenden drei Gruppen unterteilt, abhängig von der Aktivität des verwendeten ätherischen Öls gegen die Testkeime: antimikrobielle, antifungale Wirkstoffe und Substanzen, die das Wachstum von Hefen hemmen. Verschiedene interessante Anwendungsmöglichkeiten werden aufgezeigt, wie zum Beispiel die Anwendung von ätherischen Ölen an Stelle von synthetischen Wirkstoffen, um die ansteigende Resistenz von einigen Pathogenen zu umgehen. Außerdem können sie nicht nur zur Therapie von infektiösen Erkrankungen eingesetzt werden, sondern auch als Konservierungsmittel in der Lebensmittelindustrie. Eine weitere Möglichkeit ist unter anderem die Anwendung von ätherischen Ölen in Hautprodukten, um dermale Infektionen zu behandeln oder zu vermeiden. Des Weiteren sind die vorherrschenden Bestandteile der einzelnen antimikrobiell wirksamen ätherischen Öle ausgearbeitet.The antimicrobial activity of essential oils is discussed in this review taking in account studies which were published in the period of time from 2008 until September 2010. Furthermore, the most important methods to examine the antimicrobial efficiency of essential oils are presented. The studies are divided into the following three groups depending on the activity of the applied essential oil against the test microorganisms: antimicrobial, antifungal active agents and substances which inhibit the growth of yeasts. Various interesting possible applications are revealed such as the use of essential oils instead of synthetic drugs to circumvent the increasing resistance of some pathogens. Moreover, they could not only be used for the therapy of infectious illnesses, but also as preservatives in the food industry. A further possibility is among others the application of essential oils in skin products in order to treat or avoid dermal infections. Additionally, the prevalent constituents of the individual antimicrobial active essential oils are elaborated

Biological activities of essential oils from leaves of paramignya trimera (Oliv.) guillaum and limnocitrus littoralis (miq.) swingle

The present study aimed to determine the bioactivities of essential oils extracted from the leaves of Paramignya trimera and Limnocitrus littoralis, including cytotoxicity, antiviral, antibacterial, antimycotic, and antitrichomonas effects. Herein, it was indicated that P. trimera and L. littoralis oils showed no cytotoxicity on normal cells, namely MT-4, BHK-21, MDBK, and Vero-76. P. trimera oil (i) exhibited the strongest inhibition against Staphylococcus aureus with MIC and MLC values of 2% (v/v); (ii) showed MIC and MLC values of 8% (v/v) in Candida parapsilosis; and (iii) in the remaining strains, showed MIC and MLC values greater than or equal to 16% (v/v). On the other hand, L. littoralis oil (i) displayed the strongest inhibition against Candida tropicalis and Candida parapsilosis with 2% (v/v) of MIC and MLC; and (ii) in the remaining strains, possessed MIC and MLC greater than or equal to 16% (v/v). In addition, antitrichomonas activities of the oils were undertaken, showing IC50, IC90, MLC values, respectively, at 0.016%, 0.03%, and 0.06% (v/v) from P. trimera, and 0.03%, 0.06%, 0.12% (v/v) from L. littoralis, after 48 h of incubation. The oils were completely ineffective against ssRNA+ (HIV-1, YFV, BVDV, Sb-1, CV-B4), ssRNA- (RSV, VSV), dsRNA (Reo-1), and dsDNA (HSV-1, VV) viruses. This is the first report describing the cytotoxicity, antiviral, antibacterial, antimycotic, and antitrichomonas activities of the essential oils of P. trimera and L. littoralis

Candida Infections and Therapeutic Strategies: Mechanisms of Action for Traditional and Alternative Agents

The Candida genus comprises opportunistic fungi that can become pathogenic when the immune system of the host fails. Candida albicans is the most important and prevalent species. Polyenes, fluoropyrimidines, echinocandins, and azoles are used as commercial antifungal agents to treat candidiasis. However, the presence of intrinsic and developed resistance against azole antifungals has been extensively documented among several Candida species. The advent of original and re-emergence of classical fungal diseases have occurred as a consequence of the development of the antifungal resistance phenomenon. In this way, the development of new satisfactory therapy for fungal diseases persists as a major challenge of present-day medicine. The design of original drugs from traditional medicines provides new promises in the modern clinic. The urgent need includes the development of alternative drugs that are more efficient and tolerant than those traditional already in use. The identification of new substances with potential antifungal effect at low concentrations or in combination is also a possibility. The present review briefly examines the infections caused by Candida species and focuses on the mechanisms of action associated with the traditional agents used to treat those infections, as well as the current understanding of the molecular basis of resistance development in these fungal species. In addition, this review describes some of the promising alternative molecules and/or substances that could be used as anticandidal agents, their mechanisms of action, and their use in combination with traditional drugs

Essential Oils

Over the years, natural products such as essential oils have been gaining more and more prominence due to their perceived health benefits. Plants rich in essential oils represent a viable source of biomolecules for use in the most varied human activities, such as agricultural, cosmetic, and pharmaceutical applications. Essential oils are natural volatile fractions extracted from aromatic plants that are formed by classes of substances such as fatty acid esters, mono and sesquiterpenes, phenylpropanoids, and aldehyde alcohols, and in some cases, aliphatic hydrocarbons, among others. In this context, this book includes twelve chapters that present new information on the extraction and application of essential oils in various industrial segments. It is divided into three sections that discuss the general concepts of essential oils and techniques for their extraction, topics in food science and technology, and essential oils and their pharmacological properties in various activities and applications

Monoterpenes as Medicinal Agents: Exploring the Pharmaceutical Potential of p-Cymene, p-Cymenene, and γ-Terpinene

This review highlights the therapeutic propeties of monoterpenes, particularly γ-terpinene, p-cymene, and p-cymenene, found in essential oils derived from various plants. These compounds are known for their analgesic, anticancer, anti-inflammatory, and antimicrobial properties. γ-Terpinene is recognized for its potent antioxidant propeties and is a constituent of oils from plants such as cumin and thyme. p-cymene, found in over 100 plant species, is noted for its antiviral and antibacterial properties and is considered safe by IFRA standards. p-Cymenene, with its distinct aroma, is detected in parsley and turmeric oils and is known for its antibacterial and antioxidant activities. The antimicrobial properties of γ-terpinene and p-cymene are highlighted, demonstrating their effectiveness in treating various skin conditions and reducing airborne microbes. Their selective antimicrobial activity preserves the integrity of the microbiome, offering a balanced approach to infection control. The anti-inflammatory properties of γ-terpinene are emphasized, with studies indicating its role in modulating cytokine production, underscoring its potential in the treatment of inflammation. Additionally, its antinociceptive effects suggest that it is a safe analgesic. In cancer treatment, the antiproliferative effects of γ-terpinene and p-cymene are being explored, highlighting their potential for targeted cancer therapy. This review aims to consolidate knowledge about these monoterpenes and promote a deeper understanding of their medical applications and safety. The knowledge gained is expected to stimulate further research, potentially leading to innovative applications in pharmaceutical and medical fields and harnessing the potential of -terpinene, p-cymene, and p-cymenene

Natural Products: Therapeutic Properties and Beyond II

Bioactive compounds have a range of chemical structures and biological activities. Recently, new advances regarding natural compounds were achieved, leading to their application in several areas related to human therapies. New computational methods that analyze the pharmacological potential of natural products have led to its its conversion into low toxicity molecules. This Special Issue has collected the most recent innovations in scientific research on natural products, together with the application of bioactive compounds in human health. It acts as a reference for academic researchers and health and industry professionals, particularly those working in the fields of medicinal chemistry, toxicology, phytochemistry, and natural product chemistry

Phytochemical Composition and Antimicrobial Properties of Four Plants Indicated for Traditional Medicine Use

The rapid development of seriously drug-resistant pathogen strains has created a dangerous problem to public health. The discovery of new effective antimicrobials remains an urgent task to control microbial resistance. Natural products can offer special stereochemistry and unlimited diversity of natural leads which are biologically active or ready for development and structure optimization strategies. Four medicinal plants Cylicodiscus gabunensis (CG), Pogostemon cablin (PC), Perilla frutescens (PF) and Magnolia biondii (MB) were selected for investigation of their phytochemical composition and antiplasmodial and/or antibacterial properties. A bioassay guided fractionation method has been followed to characterize the antiplasmodial and antibacterial constituents of CG. Flash column chromatography and preparative HPLC were used to obtain the bioactive compounds. GC-MS, LC-MS, and NMR have been used for chemical analysis purposes. For evaluation of the antibacterial activity, disk diffusion assay, alamar blue microplate assay, time kill kinetic and scanning electron microscopy (SEM) methods have been used. The work led to the isolation of the most potent antiplasmodial fraction of CG with IC50 of 4.