Antifungal and Herbicidal Effects of Fruit Essential Oils of Four Myrtus communis Genotypes

Antibacterial Activity of Plants in Cirsium: A Comprehensive Review

As ethnic medicine, the whole grass of plants in Cirsium was used as antimicrobial. This review focuses on the antimicrobial activity of plants in Cirsium, including antimicrobial components, against different types of microbes and bacteriostatic mechanism. The results showed that the main antimicrobial activity components in Cirsium plants were flavonoids, triterpenoids and phenolic acids, and the antimicrobial ability varied according to the species and the content of chemicals. Among them, phenolic acids showed a strong antibacterial ability against Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterococcus faecium. The antibacterial mechanisms include: (1) damaging the cell membrane, cell walls, mitochondria and nucleus of bacteria; (2) inhibiting the synthesis of proteins and nucleic acids; (3) suppressing the synthesis of enzymes for tricarboxylic acid cycle pathways and glycolysis, and then killing the bacteria via inhibition of energy production. Totally, most research results on antimicrobial activity of Cirsium plants are reported based on in vitro assays. The evidence from clinical data and comprehensive evaluation are needed.

The therapeutic value of Myrtus communis L.: an updated review

Myrtus communis L. (Family: Myrtaceae) is naturally found in the western part of Asia, Southern Europe, and North Africa. It has been reportedly applied in pharmaceutical industry, traditional medicine, cosmetics, spices, and food. Pubmed, Google scholar, Web of Science, and Scopus were utilized to seek out relevant content concerning the therapeutic potential of M. communis. Subsequently, we conducted a review to identity noteworthy updates pertaining to M. communis. Myrtle berries, leaves, seeds, and essential oils are natural sources of several nutrients and bioactive compounds with marked health effects. The chemical analysis showed that M. communis contained oils, alkaloids, flavonoids, phenolics, coumarins, saponosides, tannins, quinines, and anthraquinones. A pharmacological investigation revealed that M. communis possessed anti-inflammatory, analgesic, antimicrobial, antiparasitic, antioxidant, antidiabetic, anticancer, antimutagenic, immunomodulatory, dermatological, cardiovascular, central nervous system, and gastrointestinal protective effects, among numerous other biological effects. This current review focused on the biochemical, pharmacological, therapeutic effects, and various biological activities of different parts of M. communis. It signifies that M. communis is a therapeutic plant with numerous applications in medicine and could be used as a drug isolate based on its safety and effectiveness.

Liposomal Formulations to Improve Antioxidant Power of Myrtle Berry Extract for Potential Skin Application

Many substances in plant extracts are known for their biological activities. These substances act in different ways, exerting overall protective effects against many diseases, especially skin disorders. However, plant extracts’ health benefits are often limited by low bioavailability. To overcome these limitations, drug delivery systems can be employed. In this study, we evaluated the antioxidant power of an ethanolic extract from Myrtus communis L. (myrtle) berries through colorimetric tests (DPPH and FRAP). The antioxidant activity was also verified by using fibroblast cell culture through cellular Reactive Oxygen Species (ROS) levels measurements. Moreover, the myrtle extract was formulated in phospholipid vesicles to improve its bioavailability and applicability. Myrtle liposomes were characterized by size, surface charge, storage stability, and entrapment efficiency; visualized by using cryo-TEM images; and assayed for cytocompatibility and anti-ROS activity. Our results suggest that myrtle liposomes were cytocompatible and improved the extract’s antioxidant power in fibroblasts, suggesting a potential skin application for these formulations and confirming that nanotechnologies could be a valid tool to enhance plant extracts’ potentialities.

Efficacy of Four In Vitro Fungicides for Control of Wilting of Strawberry Crops in Puebla-Mexico

Strawberry wilt is an established disease of strawberry crops caused by fungus Fusarium solani. In Mexico, strawberry cultivation represents an important productive activity for several rural areas; however, wilt disease affects producers economically. The objectives of this research were: (a) to identify and morphologically characterize strain “MA-FC120” associated with root rot and wilting of strawberry crops in Santa Cruz Analco, municipality of San Salvador el Verde, Puebla-Mexico; (b) to evaluate the potential of single and multiple applications of four broad-spectrum fungicides used against F. solani in vitro. Plant tissue samples were collected from strawberry crops in Puebla-Mexico with presence of symptoms of desiccation and root rot. Strain “MA-FC120” was identified as F. solani, being the causal agent of wilt and root rot in strawberry plants from Santa Cruz Analco. Fungicide Benomyl 50® showed the highest percentage of inhibition on F. solani (100%) under in vitro conditions. The fungicide Mancosol 80® and Talonil 75® at low concentration (600 and 450 mg L−1) showed no toxicity, being harmless to strain MA-FC120. However, fungicide Talonil 75® showed slight toxicity at the dose recommended by the manufacturer and moderate toxicity in high concentration (1350 mg L−1). Likewise, Captan 50® in its three concentrations evaluated showed slight toxicity, obtaining around 50% on the classification scale established by International Organization for Biological Control (IOBC).

Botanic Garden as a Factory of Molecules: Myrtus communis L. subsp. communis as a Case Study

A novel perception of botanic gardens as complex “factories of molecules” (Lombardy Region Project–Lr. 25/2016, year 2021), that mediate plant–environment interactions, and are the basis of their utility for humans, is presented. The core-topic is the medicinal plant heritage of the Ghirardi Botanic Garden (Toscolano Maderno, Brescia, Italy) of the University of Milan. In this work, we studied Myrtus communis L. subsp. communis (Myrtaceae) at multiple scale levels: macro- and micromorphological, with special emphasis on the secretory structures responsible for the production of secondary metabolites; phytochemical, with the analysis of the essential oil (EO) composition from leaves (fresh, dried, stored at −20 °C and at −80 °C) and fruits over two consecutive years (2018 and 2019); bio-ecological, with a focus, based on literature data, on the ecology and biological activity of the main EO components. The occurrence of secretory cavities producing terpenes, along with flavonoids, was proven. A high level of chemical variability across the obtained EO profiles emerged, especially that concerning quantitative data. However, regardless of the different conservation procedures, the examined plant part, or the phenological stage, we detected the presence of three ubiquitous compounds: α-pinene, 1,8-cineole, and linalool. The overall results will serve to enrich the Ghirardi Botanic Garden with novel labeling showing accurate and updated scientific information in an Open science perspective.

The application of essential oils as a next-generation of pesticides: recent developments and future perspectives

The overuse of synthetic pesticide, a consequence of the rush to increase crop production, led to tremendous adverse effects, as they constitute a major pollutant for both soils and water, with a high toxicity towards humans and animals and, at the same time, led to development of pest resistance. In the last period, the researches were directed towards finding new solutions with a lower toxicity, less damaging behaviour towards the environment, and a better specificity of action. In this context, the use of essential oils, a complex and unique mixture of compounds, can be considered for the next-generation pesticides. This review aims to present the main applications of the essential oils as insecticides, herbicides, acaricides, and nematicides, as they emerged from the scientific literature published in the last 5 years (2015 to present). From the identified articles within the time period, only those dealing with essential oils obtained by the authors (not commercially available) were selected to be inserted in the review, characterized using established analytical techniques and employed for the envisaged applications. The review is concluded with a chapter containing the main conclusions of the literature study and the future perspectives, regarding the application of essential oils as next-generation pesticides.

Sesamol-based terpenoids as promising bio-sourced crop protection compounds against the wheat pathogen Zymoseptoria tritici

BACKGROUND

Research into environmentally friendly alternatives to conventional plant protection products, to promote sustainable agriculture and healthy food, is strongly encouraged.

RESULTS

In this context, 20 naturally occurring terpenoids and phenolic compounds were selected and evaluated in vitro as crop protection compounds against Zymoseptoria tritici, the causal agent of Septoria tritici blotch of wheat. After selection of the most active compounds, some hemisynthetic modifications were conducted to modify their lipophilicity. These modifications led to the discovery of sesamol esters as promising antifungal agents, with IC₅₀ around 10 μg/mL and a total absence of cytotoxicity against human cells.

CONCLUSION

These sesamol-based derivatives should be selected for further evaluations in planta to validate their use as wheat crop protection agents. Moreover, the importance of a balanced hydrophily/lipophilicity ratio should be further studied. © 2021 Society of Chemical Industry.

Antifungal Properties of Essential Oils and Their Compounds for Application in Skin Fungal Infections: Conventional and Nonconventional Approaches

Essential oils (EOs) are known to have varying degrees of antimicrobial properties that are mainly due to the presence of bioactive compounds. These include antiviral, nematicidal, antifungal, insecticidal and antioxidant properties. This review highlights the potential of EOs and their compounds for application as antifungal agents for the treatment of skin diseases via conventional and nonconventional approaches. A search was conducted using three databases (Scopus, Web of Science, Google Scholar), and all relevant articles from the period of 2010-2020 that are freely available in English were extracted. In our findings, EOs with a high percentage of monoterpenes showed strong ability as potential antifungal agents. Lavandula sp., Salvia sp., Thymus sp., Citrus sp., and Cymbopogon sp. were among the various species found to show excellent antifungal properties against various skin diseases. Some researchers developed advanced formulations such as gel, semi-solid, and ointment bases to further evaluate the effectiveness of EOs as antifungal agents. To date, most studies on the application of EOs as antifungal agents were performed using in vitro techniques, and only a limited number pursued in vivo and intervention-based research.

Chemical Composition and Biological Activities of the Essential Oils of Leptospermum petersonii and Eucalyptus gunnii

The aim of this study was to characterize the chemical composition and to evaluate the antimicrobial and phytotoxic properties of the essential oils (EOs) obtained from leaves of Leptospermum petersonii chemotype "Variety B" and Eucalyptus gunnii, native to Australia. Geranyl acetate, γ-terpinene, geraniol, terpinolene, α-pinene, p-cimene, and linalool were the main components in L. petersonii EO, confirming also the existence of several chemotypes in such taxa; on the other hand, 1,8-cineole, trans-sabinene hydrate acetate, globulol, longicyclene, terpinolene, and camphene were present in major amounts in the E. gunnii EO. Chemical analysis of L. petersonii revealed that it belongs to the variety "B." E. gunnii EO showed good antibacterial activity, with an MIC of 0.5 and 2 μg/mL against Staphylococcus aureus, and Pectobacterium carotovorum, respectively. The activity of E. gunnii EO was stronger than L. petersonii EO, whose maximum MIC reached 5 μg/mL. E. gunnii and L. petersonii EOs were particularly effective in inhibiting the biofilm formation by S. aureus, already at a concentration of 0.01 μg/mL. The other strains were resistant to both EOs up to a dose of 0.05 μg/mL. The maximum inhibition on biofilm formed by P. carotovorum was recorded for E. gunnii EO, reaching a value of 93.12% at 1.0 μg/mL. This is the first manuscript which studies the biofilm inhibition by EOs and evaluates their effects on biofilm metabolism. Both EOs were more effective against P. carotovorum. In addition, even though L. petersonii EO 0.1 μg/mL was unable to inhibit biofilm formation by Escherichia coli, it decreased the metabolic activity of the biofilm to 78.55% compared to control; furthermore, despite it inducing a relatively low inhibition (66.67%) on biofilm formation, it markedly affected metabolic activity, which decreased to 16.09% with respect to the control. On the contrary, L. petersonii EO 0.5 μg/mL induced a 79.88% inhibition of S. aureus biofilm, maintaining a high metabolic activity (90.89%) compared to the control. Moreover, this EO showed inhibitory activity against radical elongation of Solanum lycopersicum and the germination of radish. On the contrary, E. gunnii EO showed no phytotoxic activity.

The Fight Against Panax notoginseng Root-Rot Disease Using Zingiberaceae Essential Oils as Potential Weapons

The root of Panax notoginseng (P. notoginseng) is one of the most highly valuable medicinal herbs in China owing to its pronounced hemostatic and restorative properties. Despite this important fact, growing P. notoginseng is seriously limited by root-rot diseases. In studies aimed at developing a solution to this problem, environment-friendly essential oils (EOs) of five medicinal plants of the family Zingiberaceae were tested for their inhibitory effects on the growth of three main soil pathogens associated with the root-rot diseases of P. notoginseng. The results showed that the EOs of Alpinia katsumadai Hayata and Zingiber officinale Roscoe promote significant reductions in the mycelium growth of the pathogen in vitro at a concentration of 50 mg mL-1, which is much higher than that needed (5 mg mL-1) to reduce growth by the positive control, flutriafol. Furthermore, the chemical components of the two EOs were determined by using GC-MS analysis. Eucalyptol was found to account for more than 30% of the oils of the two plants, with the second major components being geranyl acetate and α-terpineol. These substances display different degrees of fungistasis in vitro. To further determine the effects of the EO of Zingiber officinale (Z. officinale) in vivo, soilless cultivation of P. notoginseng with pathogen inoculation was conducted in a greenhouse. Addition of the petroleum ether extract (approximately equal to EO) of Z. officinale to the culture matrix causes a large decrease in both the occurrence and severity of the P. notoginseng root-rot disease. The decreasing trend of net photosynthetic rate (Pn), stomatal conductance (gs), intercellular CO2 concentration (Ci), and transpiration rate (Tr) were all alleviated. In addition, the activities of catalase (CAT), peroxidase (POD), and the malondialdehyde (MDA) content were also largely reduced after pathogen infection, with the root activity being higher than that of the control. Taken together, the findings reveal that the EOs from plants might serve as promising sources of eco-friendly natural pesticides with less chemical resistance.

Antifungal activity of Myrtus communis against Malassezia sp. isolated from the skin of patients with pityriasis versicolor

The increasing incidence of fungal infections and antifungal resistance has prompted the search for novel antifungal drugs and alternative agents. We explored the antifungal activity of Myrtus communis essential oil (EO) against Malassezia sp. isolated from the skin of patients with pityriasis versicolor. These broad-spectrum antimicrobial activities of M. communis EO and its potent inhibiting activity on Malassezia growth deserve further research with aim to considerate this EO as candidate for topical use in treatment of skin diseases.

Ethnobotanical, Ethnopharmacological, and Phytochemical Studies of Myrtus communis Linn: A Popular Herb in Unani System of Medicine

Myrtus communis L (Myrtaceae) is one of the popular drugs being used in the Unani system of phytomedicine since ancient Greece period. From time immemorial, different parts of this plant and essential oil have been used for a variety of purposes such as cosmetics (hair fall control), flavoring of food and drinks as well as extensive therapeutic purposes. Ethnobotanical information revealed that M communis L has been a folkloric repute for the treatment of several diseases like gastric ulcer, diarrhea, dysentery, cancer, rheumatism, hemorrhage, deep sinuses, leucorrhoea, hemorrhoid, inflammation, dyspepsia, anxiety, insomnia, diabetes, hypertension, pulmonary disorders, and skin diseases. Moreover, ethnopharmacological studies revealed that the plant is endowed with extensive pharmacological activities, including antimicrobial, antidiarrheal, antidiabetic, antispasmodic, vasodilator, antiulcer, antioxidant, anticancer, anxiolytic, sedative-hypnotic, and anti-inflammatory activities, among others. The plant has been known to contain phenolic acids, tannins, flavonoids, glycosides, and terpenes. The myrtle oil was also found to be rich in a variety of bioactive monoterpenes and sesquiterpenes with their derivatives. Most of these studies validate the aforementioned traditional claims of this medicinal plant. Further studies are needed to unravel other pharmacological activities of this plant in the long run.

A complex game of hide and seek: the search for new antifungals

Fungal infections directly affect millions of people each year. In addition to the invasive fungal infections of humans, the plants and animals that comprise our primary food source are also susceptible to diseases caused by these eukaryotic microbes. The need for antifungals, not only for our medical needs, but also for use in agriculture and livestock causes a high demand for novel antimycotics. Herein, we provide an overview of the most commonly used antifungals in medicine and agriculture. We also present a summary of the recent progress (from 2010-2016) in the discovery/development of new agents against fungal strains of medical/agricultural relevance, as well as information related to their biological activity, their mode(s) of action, and their mechanism(s) of resistance.