Chemical Composition, Antimicrobial and Antioxidant Activities of the Volatile Oil of Ganoderma pfeifferi Bres

Nature's Own Pharmacy: Mushroom-Based Chemical Scaffolds and Their Therapeutic Implications

Mushrooms are new potential sources of valuable medicines, long neglected because of difficulties experienced in their cultivation. There is a large variety of medicinal mushrooms which possess significant therapeutic properties and are used as medications for various diseases because they contain several novel highly bioactive components. Medicinal mushrooms can be identified based on their morphology, size, mass, and the color of the stalk, cap and spore, and attachment to the stalk. Medicinal mushrooms possess a variety of important biological activities and are used as antioxidants, hepatoprotectors, anticancer, antidiabetic, anti-inflammatory, antiaging, antiviral, antiparasitic, and antimicrobial agents, among others. This review provides a basic overview of the chemical scaffolds present in mushrooms and their therapeutic implications in the human body.

Do Ganoderma Species Represent Novel Sources of Phenolic Based Antimicrobial Agents?

Ganoderma species have been recognized as potential antimicrobial (AM) agents and have been used in traditional Chinese medicine (TCM) for a long time. The aim of this study is to examine the AM potential of autochthonous Ganoderma species (G. applanatum, G. lucidum, G. pfeifferi and G. resinaceum) from Serbia. The extraction of fungal material was prepared in different solvents (ethanol-EtOH, water-H₂O, chloroform-CHCl₃). Antibacterial activity (ABA) was determined using disk-diffusion, agar-well diffusion, and micro-dilution method, while for antifungal properties disk-diffusion and pour plate method were applied. Antiviral activity was tested on model DNA virus LK3 and determined by plaque assay. Statistical PCA analysis was applied for detection of correlation effects of phenolics and AM activities, while LC-MS/MS was performed for phenolics quantification. G. resinaceum CHCl₃ extract expressed the most potent ABA against P. aeruginosa (MIC = 6.25 mg/mL), probably due to presence of flavonoids and 2,5-dihydroxybenzoic acid. Among H₂O extracts, the highest ABA was determined for G. pfeifferi against both E. coli and S. aureus (21 and 19 mm, respectively). EtOH extracts of G. pfeifferi and G. resinaceum were the most effective against A. niger (23.8 and 20.15 mm, respectively), with special impact of phenolic acids and flavonoid isorhamnetin, while C. albicans showed the lowest susceptibility. The most potent antiviral inhibitor was G. lucidum (70.73% growth inhibition) due to the high amount of phenolic acids. To the best of our knowledge, this is the first report of a methodical AM profile of G. pfeifferi and G. resinaceum from the Balkan region including PCA analysis.

Why Do These Yeasts Smell So Good? Volatile Organic Compounds (VOCs) Produced by Malassezia Species in the Exponential and Stationary Growth Phases

Malassezia synthesizes and releases volatile organic compounds (VOCs), small molecules that allow them to carry out interaction processes. These lipid-dependent yeasts belong to the human skin mycobiota and are related to dermatological diseases. However, knowledge about VOC production and its function is lacking. This study aimed to determine the volatile profiles of Malassezia globosa, Malassezia restricta, and Malassezia sympodialis in the exponential and stationary growth phases. The compounds were separated and characterized in each growth phase through headspace solid-phase microextraction (HS-SPME) and gas chromatography–mass spectrometry (GC–MS). We found a total of 54 compounds, 40 annotated. Most of the compounds identified belong to alcohols and polyols, fatty alcohols, alkanes, and unsaturated aliphatic hydrocarbons. Unsupervised and supervised statistical multivariate analyses demonstrated that the volatile profiles of Malassezia differed between species and growth phases, with M. globosa being the species with the highest quantity of VOCs. Some Malassezia volatiles, such as butan-1-ol, 2-methylbutan-1-ol, 3-methylbutan-1-ol, and 2-methylpropan-1-ol, associated with biological interactions were also detected. All three species show at least one unique compound, suggesting a unique metabolism. The ecological functions of the compounds detected in each species and growth phase remain to be studied. They could interact with other microorganisms or be an important clue in understanding the pathogenic role of these yeasts.

Chemical Composition, Antibacterial Test, and Antioxidant Activity of Essential Oils from Fresh and Dried Stropharia rugosoannulata

The essential oils, respectively, from fresh and dried Stropharia rugosoannulata fruiting bodies, an important edible mushroom, have been studied for their chemical composition, antibacterial capacity, and antioxidant activity. The essential oils were obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS) combined with Kovats retention index. The oils’ antibacterial test was evaluated by the microdilution method against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, and antioxidant activity was determined through DPPH radical scavenging activity and ferric reducing power. Twenty-nine components were identified from the fresh mushroom, and the compositions were mainly dominated by hydrocarbons (54.72%), acids (32.99%), esters (5.07%), and terpenic compounds (0.96%). Thirty-five components were identified from the dried sample, and acids (31.22%), terpenic compounds (28.7%), alcohols (12.7%), and ketones (10.48%) were the major compounds. Strong antibacterial capacity and obvious antioxidant activity were observed for both essential oils from the fresh and dried mushrooms.

Skin Microbiome, Metabolome and Skin Phenome, from the Perspectives of Skin as an Ecosystem

Skin is a complex ecosystem colonized by millions of microorganisms, including bacteria, fungi, and viruses. Skin microbiota is believed to exert critical functions in maintaining host skin health. Profiling the structure of skin microbial community is the first step to overview the ecosystem. However, the community composition is highly individualized and extremely complex. To explore the fundamental factors driving the complexity of the ecosystem, namely the selection pressures, we review the present studies on skin microbiome from the perspectives of ecology. This review summarizes the following: (1) the composition of substances/nutrients in the cutaneous ecological environment that are derived from the host and the environment, highlighting their proposed function on skin microbiota; (2) the features of dominant skin commensals to occupy ecological niches, through self-adaptation and microbe-microbe interactions; (3) how skin microbes, by their structures or bioactive molecules, reshape host skin phenotypes, including skin immunity, maintenance of skin physiology such as pH and hydration, ultraviolet (UV) protection, odor production, and wound healing. This review aims to re-examine the host-microbe interactions from the ecological perspectives and hopefully to give new inspiration to this field.

Genus Barleria L. (Acanthaceae): a review of its taxonomy, cytogenetics, phytochemistry and pharmacological potential

OBJECTIVES

Barleria, a large genus of the Acanthaceae family, comprises more than 300 species with diverse taxonomy, cytogenetics, phytochemistry and pharmacological potential. Therefore, the aim of this review is to critically assess the research on Barleria and provide guidance for future investigations.

METHODS

The data were obtained from different sources, such as books, theses, journals and some of the websites and internet-based searches, published from 1901 to 2020. Data obtained from PubMed, Google Scholar, ScienceDirect, online electronic journals, SpringerLink, Wiley, etc. have also been used.

KEY FINDINGS

The species of this genus exhibit considerable medicinal properties. Cytogenetical data are scantily available with chromosome counts available for only 24 species. The most common chromosome number is 2n = 2x = 40. So far, 187 compounds are reported from Barleria species. The active principles, their uses, toxicity and pharmacological effects are discussed. Essential oils, flavones, flavonoids, glycosides, terpenes and terpenoids form the major compounds.

SUMMARY

It is highly recommended that the pharmacological and economic potential of Barleria species should be exploited and more detailed studies and attention be geared towards its utilization and conservation. In addition, to ensure maximum pharmacological benefits and sustainable use, it is necessary to have empirical information explaining its ethnobotanical values as well as commercial potential.

Bacterial type III effector-induced plant C8 volatiles elicit antibacterial immunity in heterospecific neighbouring plants via airborne signalling

Upon sensing attack by pathogens and insect herbivores, plants release complex mixtures of volatile compounds. Here, we show that the infection of lima bean (Phaseolus lunatus L.) plants with the non-host bacterial pathogen Pseudomonas syringae pv. tomato led to the production of microbe-induced plant volatiles (MIPVs). Surprisingly, the bacterial type III secretion system, which injects effector proteins directly into the plant cytosol to subvert host functions, was found to prime both intra- and inter-specific defense responses in neighbouring wild tobacco (Nicotiana benthamiana) plants. Screening of each of 16 effectors using the Pseudomonas fluorescens effector-to-host analyser revealed that an effector, HopP1, was responsible for immune activation in receiver tobacco plants. Further study demonstrated that 1-octen-3-ol, 3-octanone and 3-octanol are novel MIPVs emitted by the lima bean plant in a HopP1-dependent manner. Exposure to synthetic 1-octen-3-ol activated immunity in tobacco plants against a virulent pathogen Pseudomonas syringae pv. tabaci. Our results show for the first time that a bacterial type III effector can trigger the emission of C8 plant volatiles that mediate defense priming via plant-plant interactions. These results provide novel insights into the role of airborne chemicals in bacterial pathogen-induced inter-specific plant-plant interactions.

Phytomedicine from Middle Eastern Countries: An Alternative Remedy to Modern Medicine against Candida spp Infection

Candida spp are capable of infecting both normal and immunocompromised individuals. More recently, Candida infections have spread considerably in healthcare settings, especially in intensive care units, where it is the most frequently encountered pathogen. Candida albicans is the commonest species encountered, although infections by non-albicans species have also risen in the past few years. The pathogenicity of Candida is credited to its aptitude to change between yeast and hyphal modes of growth. Candida spp produce biofilms on synthetic materials that protect them and facilitate drug resistance and act as a source for chronic and recurrent infections. Primarily, azoles antifungal agents are utilized to treat Candida infection that targets the ergosterol synthesis pathway in the cell wall. The development of antifungal resistance in Candida species is a major reason for treatment failure, and hence, there is a need to develop newer antifungal molecules and/or modifications of existing antifungals to make them more effective and less toxic. This has led researchers to oversee the plants to discover newer antimicrobials. Middle Eastern countries are well known for their landscape ranging from dry and sandy deserts to snow-capped mountains. However, they comprise enormous plant diversity with over 20,000 different species showing various types of bioactivities, such as anticancer, antidiabetic, and antimicrobial activities. Especially, the antifungal potential of these phytoproducts could be exploited in the clinical setting for therapy. The present review examines some of the promising alternative natural compounds that have been tested and found effective in treating Candida infections in vitro in some Middle Eastern countries.

Learning about microbial language: possible interactions mediated by microbial volatile organic compounds (VOCs) and relevance to understanding Malassezia spp. metabolism

BACKGROUND

Microorganisms synthesize and release a large diversity of small molecules like volatile compounds, which allow them to relate and interact with their environment. Volatile organic compounds (VOCs) are carbon-based compounds with low molecular weight and generally, high vapor pressure; because of their nature, they spread easily in the environment. Little is known about the role of VOCs in the interaction processes, and less is known about VOCs produced by Malassezia, a genus of yeasts that belongs to the human skin mycobiota. These yeasts have been associated with several dermatological diseases and currently, they are considered as emerging opportunistic yeasts. Research about secondary metabolites of these yeasts is limited. The pathogenic role and the molecular mechanisms involved in the infection processes of this genus are yet to be clarified. VOCs produced by Malassezia yeasts could play an important function in their metabolism; in addition, they might be involved in either beneficial or pathogenic host-interaction processes. Since these yeasts present differences in their nutritional requirements, like lipids to grow, it is possible that these variations of growth requirements also define differences in the volatile organic compounds produced in Malassezia species.

AIM OF REVIEW

We present a mini review about VOCs produced by microorganisms and Malassezia species, and hypothesize about their role in its metabolism, which would reveal clues about host-pathogen interaction.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Since living organisms inhabit a similar environment, the interaction processes occur naturally; as a result, a signal and a response from participants of these processes become important in understanding several biological behaviors. The efforts to elucidate how living organisms interact has been studied from several perspectives. An important issue is that VOCs released by the microbiota plays a key role in the setup of relationships between living micro and macro organisms. The challenge is to determine what is the role of these VOCs produced by human microbiota in commensal/pathogenic scenarios, and how these allow understanding the species metabolism. Malassezia is part of the human mycobiota, and it is implicated in commensal and pathogenic processes. It is possible that their VOCs are involved in these behavioral changes, but the knowledge about this remains overlocked. For this reason, VOCs produced by microorganisms and Malassezia spp. and their role in several biological processes are the main topic in this review.

Traditional uses, chemical components and pharmacological activities of the genus Ganoderma P. Karst.: a review

In recent years, some natural products isolated from the fungi of the genus Ganoderma have been found to have anti-tumor, liver protection, anti-inflammatory, immune regulation, anti-oxidation, anti-viral, anti-hyperglycemic and anti-hyperlipidemic effects. This review summarizes the research progress of some promising natural products and their pharmacological activities. The triterpenoids, meroterpenoids, sesquiterpenoids, steroids, alkaloids and polysaccharides isolated from Ganoderma lucidum and other species of Ganoderma were reviewed, including their corresponding chemical structures and biological activities. In particular, the triterpenes, polysaccharides and meroterpenoids of Ganoderma show a wide range of biological activities. Among them, the hydroxyl groups on the C-3, C-24 and C-25 positions of the lanostane triterpenes compound were the necessary active groups for the anti-HIV-1 virus. Previous study showed that lanostane triterpenes can inhibit human immunodeficiency virus-1 protease with an IC₅₀ value of 20–40 μM, which has potential anti-HIV-1 activity. Polysaccharides can promote the production of TNF α and IFN-γ by macrophages and spleen cells in mice, and further inhibit or kill tumor cells. Some meroterpenoids contain oxygen-containing heterocycles, and they have significant antioxidant activity. In addition, Ganoderma has been used as a medicine to treat diseases for more than 2000 years, and we also reviewed its traditional uses.

In recent years, some natural products isolated from the fungus of the genus Ganoderma have been found to have anti-tumor, liver protection, anti-inflammatory, immune regulation, anti-oxidation, anti-viral, anti-hyperglycemic and anti-hyperlipidemic effects.

Purification, characterization, and antitumor activity of a novel glucan from the fruiting bodies of Coriolus Versicolor

Cancer is one of the most common causes of deaths worldwide. Herein, we report an efficient natural anticancer glucan (CVG) extracted from Coriolus Versicolar (CV). CVG was extracted by the hot water extraction method followed by ethanol precipitation and purified using gas exclusion chromatography. Structural analysis revealed that CVG has a linear α-glucan chain composed of only (1→ 6)-α-D-Glcp. The antitumor activity of CVG on Sarcoma-180 cells was investigated in vitro and in vivo. Mice were treated with three doses of CVG (40, 100, 200 mg/kg body weight) for 9 days. Tumor weight, relative spleen, thymus weight, and lymphocyte proliferation were studied. A significant increase (P< 0.01) in relative spleen and thymus weight and a decrease (P< 0.01) in tumor weight at the doses of 100 and 200 mg/kg were observed. The results obtained demonstrate CVG has antitumor activity towards Sarcoma-180 cells by its immunomodulation activity.