Endophytic Fungi: An Effective Alternative Source of Plant-Derived Bioactive Compounds for Pharmacological Studies

A review of the pharmaceutical applications of endophytic fungal secondary metabolites

A major challenge to human health is the emergence of drug-resistant pathogenic strains of organisms. Studies have found ecologically friendly, cost-effective, and innocuous alternative sources of bioactive compounds capable of managing drug-resistant menace. This review x-rays the endophytic fungal community and the pharmaceutical applications of their secondary metabolites. Endophytic fungi house biologically active compounds, which makes them a good pharmaceutical alternative. Also, their intrinsic ability to produce such an avalanche of bioactive compounds could be attributed to their mutualistic interaction with the plant's host. Secondary metabolites harvested from endophytic fungi have been identified and categorised: steroids, xanthones, terpenoids, isocoumarins, phenols, tetralones, benzopyranones, and enniatrines. This review also highlights optimisation strategy, co-culture method, chemical epigenetic remodelling, and molecular method as approaches adopted to boost the production of bioactive compounds. The numerous applications of endophytic fungal secondary metabolites were equally presented, which include their bioactive properties, as well as their use in industries.

Investigating the antimicrobial and anticancer potential of culturable fungal endophytes isolated from the stems of Kirkia acuminata Oliv

Background

Fungal endophytes produce various structurally and chemically diverse bioactive secondary metabolites including those that are similar to their host plants. However, fungal endophytes from South African medicinal plants are relatively under-explored. The medicinal plant, Kirkia acuminata Oliv., is on the decline in the natural environment due to overharvesting. This necessitates the search for novel alternatives to sustainably obtain the plant’s bioactive metabolites. Thus, fungal endophytes may serve as suitable candidates as they can produce host-similar bioactive compounds.

Results

Eighteen morphologically distinct fungal endophytes were isolated from the surface-sterilised stems of K. acuminata Oliv. Sequencing of the internal transcribed spacer (ITS) region revealed that the isolates were distributed among three genera, namely Diaporthe , Neofusicoccum and Pseudofusicoccum . The broth micro-dilution assay showed that 17 of the 18 ethyl acetate crude extracts exhibited inhibitory activity with minimum inhibitory concentration (MIC) values ranging from 0.31 to 2.5 mg/mL and 1.25 to 2.5 mg/mL against bacterial pathogens and Candida albicans , respectively. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay revealed that most of the crude extracts had dose-dependent cytotoxicity against non-cancerous human embryonic kidney (HEK-293) cells, with the crude extracts of the N . parvum KaS-3, D. macadamiae KaS-4, P . olivaceum KaS-5 and D . neotheicola KaS-6 isolates demonstrating safety against the non-cancerous cells. The alamarBlue assay revealed that the four non-cytotoxic crude extracts had moderate anticancer activity against cervical cancer ME-180 and melanoma A375 cancerous cell lines. Moreover, mycochemical analysis of the non-cytotoxic crude extracts using colourimetric quantification methods revealed that the observed cytotoxic effect could be attributed to the high total phenolic content in the crude extracts.

Conclusion

The study highlights that the fungal endophytes inhabiting the stems of K. acuminata Oliv. produce secondary metabolites that may serve as leads for novel antimicrobial and non-toxic anticancer agents.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-025-03964-y.

Colonization effect of Beauveria bassiana (Bals.) Vuill. on tomato plant and Bemisia tabaci

Whitefly (Bemisia tabaci) is an insect threatening tomato production in Egypt. This study investigated the impacts of the entomopathogenic fungi species, Beauveria bassiana, isolate against B. tabaci on tomato plants under natural conditions in two seasons (2023-2024). Conidial powder was directly applied to the soil. Fungus was added to the fertilization treatments (BF) and was compared with fertilization (CF) and control (C0). The findings indicated notable significant variations in the population densities of B. tabaci in comparison to the other groups in two seasons. This fungus can also be used as a growth enhancer besides being a biopesticide for tomato crops. Tomato leaf samples were collected in three growth phases: vegetative, flowering, and fruiting phases in addition to ripe tomato fruits. Collected leaves were dried and used to detect defense mechanisms through estimating phenolic compounds such as tannins and flavonoids and total protein content, while tomato fruits were used to estimate ascorbic acid level as a growth promotion indicator in the tested tomato plants. B. bassiana -treated plants showed a significant increase in total tannins compared to fertilization-treated plants and non-significant increase compared to control. While Total Protein Content (TPC) was significantly higher in fertilization-treated plants than in B. bassiana -treated plants and control it was only increased significantly in the bioagent treatment than in the control. For total flavonoids, a non-significant increase was detected in total flavonoids content in B. bassiana-treated plants than in fertilization- treated plants and controls. Beauveria bassiana -treated tomato fruits recorded the highest value of ascorbic acid content, which significantly increased than fertilization treatment and non-significantly increased compared to the control. Generally, the interaction between treatments and growth phases in total tannin content, total protein content, and total flavonoid content was not statistically significant, which means there is no behavior for B. bassiana treatment on the plant resistance mechanism during the different growth stages, and the highest level for each was recorded in the flowering phase compared to the vegetative and fruiting phases. Also, the findings indicated the highest yield was represented by adding B. bassiana to the soil. The obtained results from this study refer to the beneficial role of B. bassiana in systemic resistance induction stimulated by tannin content in the tested tomato plants against whitefly attacks.

Lonicera maackii (Rupr.) Maxim: a review of its phytochemistry, pharmacological activities and clinical application

Lonicera maackii (Rupr.) Maxim (hereinafter referred to as L. maackii) is a perennial deciduous that has been used as a medicinal plant, ornamental tree, and green plant in China. Phytochemical studies have shown that L. maackii contains 223 bioactive compounds, including volatile oils, flavonoids, iridoids, organic acids, polysaccharides and other compounds. Pharmacological studies have shown that the extract of L. maackii has a variety of biological activities, such as antibacterial, antitumor, antioxidant, anti-inflammatory, hepatoprotective and hypoglycaemic effects. L. maackii preparations are widely used to treat respiratory and inflammatory diseases, especially paediatric bronchopneumonia and bronchitis, with significant efficacy. Novel nanomaterials prepared from the fruits of L. maackii have potential for a wide range of applications in medical imaging, sensing, anticounterfeiting, and environmental monitoring. This review summarises the information available in the scientific literature on L. maackii, covering its pharmacognostic identification, chemical constituents, pharmacological activities and clinical applications.

The endophytic fungus Cosmosporella sp. VM-42 from Vinca minor is a source of bioactive compounds with potent activity against drug-resistant bacteria

Medicinal plants serve as valuable resources for the isolation of endophytic fungi. Vinca minor is a well-known producer of important vinca alkaloids and emerges as a promising source of endophytic fungi with antibacterial potential and biosynthetic capacity. In this study, we isolated an endophytic fungus from V. minor and identified it as Cosmosporella sp. VM-42. To date, relatively little is known about this fungal genus. The ethyl acetate extract of this isolate selectively inhibited Gram-positive bacteria, such as methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA). Therefore, we isolated the most abundant compound from the crude extract and identified it as nectriapyrone with MIC and MBC values ranging from 125 to 62.5 µg/mL against MSSA and MRSA strains. We further sequenced and annotated the 39.07 Mb genome of the isolate, revealing that it encodes 9842 protein-coding genes, including 415 genes for carbohydrate-active enzymes and various biosynthetic gene clusters. Our untargeted metabolomic analysis shows that the fungus produces various secondary metabolites, including cyclodepsipeptides, dimeric naphtho-γ-pyrones, and macrolactones, which are known to have antifungal and antibacterial activities. In addition, we used small-molecule epigenetic modulators to activate the expression of silent biosynthetic gene clusters to broaden the chemical profile of Cosmosporella sp. VM-42. Taken together, we provide a first systematic analysis of Cosmosporella sp. VM-42, and our results show that it is a promising source of compounds with pharmacological potential against drug resistant bacteria.

Two new alkaloids from the endophytic fungus Aspergillus fumigatus SAS10 isolated from the mangrove tree Sonneratia apetala

Two new alkaloids designated aspernigrin E (1) and pyranonigrin L (2) were isolated from mangrove endophytic fungus Aspergillus fumigatus SAS10, together with the known alkaloid compounds pyranonigrin A (3), asperazine (4), (+)-iso-pestalazine A (5), pestalazine A (6), and pestalazine B (7). The planar structures of the new compounds were elucidated by HR-MS and NMR spectroscopic data analyses. The absolute configurations of compounds 1 and 2 were determined by comparison of the electronic circular dichroic (ECD) spectra with the calculated ECD spectra. All these compounds were tested for anti-bacterial activity.

A comprehensive analysis of Ardisia crenata Sims from endophytes and rhizosphere soil microorganisms

Introduction

Endophytic and rhizosphere microorganisms play crucial roles in influencing the quality and secondary metabolite accumulation of traditional Chinese medicinal.

Methods

Endophytic and rhizosphere microorganisms play crucial roles in influencing the quality and secondary metabolite accumulation of traditional Chinese medicinal.

Results and discussion

A total of 8,514,557 highquality reads were generated from 140 plant and soil sample in A. crenata Sims based on high-throughput sequencing. The fungal species composition within the endophytic and rhizosphere soil samples of A. crenata Sims is rich and varied, exhibiting notable disparities across different geographical regions of the plant. The alpha diversity and beta diversity indicated significant differences in microbial diversity and community structure between soil and plants. As for endophytic fungi, the dominant phyla in both plants and soil were Ascomycota and Basidiomycota, with different dominant genera between the two compartments. LEfSe analysis at the genus level identified 80 and 124 fungal indicator taxa associated with plants and soil, respectively, including Aspergillus, Acremonium, Fusarium, among others. Co-occurrence network analysis demonstrated intimate interactions among soil fungal microorganisms. Examination of soil physicochemical factors and the primary active constituent (bergenin) across different regions of A. crenata Sims indicated that the highest bergenin concentration is found in the Guangxi region, whereas the Guizhou region boasts relatively abundant soil nutrient components. Correlation analysis revealed that Aspergillus, Fusarium, Penicillium, Tausonia, and Trichoderma are correlated with soil physicochemistry or active compounds. These findings hint at a potential role for endophytic and rhizosphere microorganisms in the accumulation of active compounds within medicinal plants, thereby furnishing a scientific rationale for guiding the cultivation practices of A. crenata Sims.

Remedying SARS-CoV-2 through nature: a review highlighting the potentiality of herbs, trees, mushrooms, and endophytic microorganisms in controlling Coronavirus

MAIN CONCLUSION

Medicinal plants, mushrooms, and endophytes offer a rich source of secondary metabolites (SMs), including flavonoids, alkaloids, tannins, and terpenoids, with proven antiviral properties against SARS-CoV-2. Plant-associated microorganisms that colonize in living tissues of different parts of a plant possess the ability to produce SMs of immense therapeutic value and this biological interaction between plants and microbes can be exploited to develop antiviral drugs against SARS-CoV-2. The unprecedented lethality of the SARS-CoV-2 virus during the recent global pandemic has prompted extensive research into new treatment options and preventive strategies for COVID-19. Phytochemicals, particularly those derived from medicinal plants, microbes, and mushrooms, show promising results in combating the virus when combined with synthetic components. These natural compounds include terpenes, phenolics, flavonoids, and alkaloids that possess antiviral properties. Medicinal plants and their endophytic microbes, and mushrooms, offer a rich source of secondary metabolites (SMs) with potential antiviral effects against SARS-CoV-2. Given the urgency of addressing the swift spread of the new coronavirus strain, exploring and understanding these SMs could lead to the development of innovative and potent antiviral drugs. This review provides a comprehensive overview of plant-, microbial- and mushroom-derived SMs, their classification, and their applications in treating diseases caused by the coronavirus family, offering insights into the potential future production of natural medicines.

Advanced fermentation techniques enhance dioxolanone type biopesticide production from Phyllosticta capitalensis

In the current work, the production of dioxolanone and meroterpene type secondary metabolites under different fermentation conditions by the endophytic fungus Phyllosticta capitalensis (isolate YCC4) isolated from the leaves of the endemic plant Persea indica has been evaluated. Different techniques, such as microparticle-enhanced culture (MPEC: bentonite, talcum powder) and surface adhesion fermentation (SAF: metallic mesh and glass wool) were applied to the culture medium. Ethyl acetate extracts from different fermentations of the isolate YCC4 were analyzed for their content and revealed the following dioxolanone derivatives: metguignardic acid (1), guignardianone C (2), ethyl guignardate (3), guignardianone D (4) and phenguignardic acid methyl ester (5), and meroterpenes: guignardone A (6) and B (7), guignarenone C (8), guignarenone B (9) and guignardone I (10). Additionally, the biological activity of extracts was tested against the aphid Myzus persicae and the root-knot nematode Meloidogyne javanica. Our study revealed significant variations in the production of the target metabolites as well as notable differences in biopesticide activity influenced by the presence of inert supports. Overall, the findings indicate that glass wool (GW) is a high-performance material to improve the production of dioxolanone derivatives. These findings underscore the significance of innovative cultivation methods such MPEC and SAF as drivers to produce valuable secondary metabolites from fungal organisms.

Bioorganic compounds in quorum sensing disruption: strategies, Mechanisms, and future prospects

Recent research has shed light on the complex world of bacterial communication through quorum sensing. This sophisticated intercellular signalling mechanism, driven by auto-inducers, regulates crucial bacterial community behaviours such as biofilm formation, expression of virulence factors, and resistance mechanisms. The increasing threat of antibiotic resistance, coupled with quorum sensing mediated response, necessitates alternative strategies to combat bacterial infections. Quorum quenching has emerged as a promising approach, utilizing quorum quenching enzymes and quorum sensing inhibitors to disrupt quorum sensing signalling pathways, thus reducing virulence and biofilm formation. This review focuses on natural and synthetic bioorganic compounds that act as quorum-sensing inhibitors, providing insights into their mechanisms, structure-activity relationships, and potential as anti-virulence agents. The review also explores the communication languages of bacteria, including AHLs in gram-negative bacteria, oligopeptides in gram-positive bacteria, and LuxS, a universal microbial language. By highlighting recent advancements and prospects in bioorganic QSIs, this article underscores their crucial role in developing effective anti-virulence therapies and combating the growing threat of antimicrobial resistance.

New Isocoumarins from an Endophytic Fungal Strain Diaporthe arengae M2 and their Antibacterial Activities

Four new isocoumarin derivatives 12-O-acetyl-isocitreoisocoumarinol (1), (+)-(10R)-O-acetyl-diaportinol (2-a), (-)-(10S)-O-acetyl-diaportinol (2-b), peyroisocoumarin E (3) and new stereoconfigurations of three isocoumarin derivatives desmethyldichlorodiaportinol A (4), threo-monochlorodiaportinol A (5-a), erytheo-monochlorodiaportinol A (5-b), together with nine known ones (6-14), were separated from the rice fermentation of endophytic fungus Diaporthe arengae M2 isolated from Camellia oleifera. The structures of new compounds were determined by extensive spectroscopic analyses including nuclear magnetic resonance (NMR) and high resolution electrospray ionization mass spectroscopy (HR-ESI-MS). Compounds 4, 7, 8, 12, 13 exhibited definite inhibition against five strains of bacteria with the MIC values range from 16 μg/mL to 64 μg/mL.

Botryorhodine J, a new anti-MRSA depsidone isolated from endophytic fungus Alternaria alternata Pas11

A new depsidone derivative botryorhodine J (1), along with six known compounds (2-7) were obtained from solid rice cultures of Alternaria alternata Pas11 that was isolated from leaves of Phragmites australis. The structure of the new compound was elucidated on the basis of combination of NMR spectroscopic data and high resolution mass spectrometry (HRMS). All the isolated compounds were evaluated for their antibacterial activities against a panel of Gram-positive bacterial strains (methicillin-resistant Staphylococcus aureus [MRSA], Bacillus subtilis and S. aureus). Compounds 1 and 6 displayed antibacterial activity against the three bacterial strains with the minimum inhibitory concentration values (MICs) of 14 - 32 μg/mL, while compound 5 showed good antibacterial activity against above bacterial strains with MIC values of 5 - 8 μg/mL.

Exploring endophytic fungi from Cynodon dactylon: GC-MS profiling and biological activity

The rapid decline of significant plant species due to deforestation and slow regrowth has endangered many trees that are crucial for producing life-saving medications. This dual crisis of conserving plant biodiversity while meeting pharmaceutical demands necessitates innovative solutions. Endophytic fungi, naturally occurring symbionts within plants, present an eco-friendly and economically viable alternative. These fungi can produce a wide range of bioactive compounds, offering a sustainable source of pharmaceuticals. This study investigated endophytic fungi isolated from the inflorescence, leaf, and culm of Cynodon dactylon, a perennial medicinal grass. The research involved the isolation of endophytic fungi on potato dextrose agar (PDA) and water agar (WA), extracting secondary metabolites, and performing antimicrobial and antioxidant assays and gas chromatography-mass spectroscopy (GC-MS) profiling. A total of 21 endophytic fungi were isolated, with species of Alternaria, Aspergillus, and Cladosporium being predominant. These fungi were identified through morphological and molecular (internal transcribed sequences-ITS) characterization. Based on factors such as fungal dominance and specificity, five fungi (Aspergillus chevalieri, Aspergillus stellatus, Hypoxylon sp., and Xylaria apiculate) were selected and they exhibited significant activity against plant pathogens (Sclerotium rolfsii and Aspergillus niger) and radical scavenging properties in DPPH assays. GC-MS analysis revealed over twenty bioactive compounds in each fungal extract. These findings underscore the potential of endophytic fungi as sustainable sources of novel pharmaceuticals and effective biocontrol agents, offering a promising approach to address the current ecological and medicinal challenges.

Characterization of Spirobisnaphthalenes from an Endophytic Fungus Edenia sp. Associated with Drymaria cordata and Insights into Their Biological Activity

Fungal secondary metabolites have been increasingly sought after as an alternative strategy to herbicides and a source of new medicines. Twenty spirobisnaphthalenes (SBNs) were isolated from the fermentation broth of Edenia sp. YUD20003 from the herb Drymaria cordata (L.) Willd. in China, including eight new SBNs (1-8) and a new phenolic dinaphthoether (9). Their chemical structures and absolute configurations were elucidated on the basis of comprehensive spectroscopic analyses. The biosynthetic pathway of these SBNs was proposed. The insight into biological activity showed that these SBNs not only demonstrated significant cytotoxicity against five human cancer cell lines but also exhibited potent antimicrobial activities against both Candida albicans and Staphylococcus aureus. Notably, 3, 5-7, and 9 demonstrated an inhibitory effect on acetylcholinesterase that was on par with tacrine. Additionally, compound 7 effectively inhibited the germination of the weed Setaria viridis, suggesting its potential as a biological herbicide. The research highlights the potential of these SBNs as bioactive natural products with agrochemical and pharmaceutical applications.

Endophytic fungi: nature's solution for antimicrobial resistance and sustainable agriculture

The growing threat of antimicrobial resistance (AMR) has underlined the need for a sustained supply of novel antimicrobial agents. Endophyte microorganism that reside within plant tissues as symbionts have been the source of potential antimicrobial substances. However, many novel and potent antimicrobials are yet to be discovered from these endophytes. The present study investigates the potential of endophytic fungi as a source of novel bioactive chemicals with antibacterial capabilities. These fungi synthesize secondary metabolites such as polyketides and peptides via polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) pathways. Notable substances, like prenylated indole alkaloids and fumaric acid, have shown promising antibacterial and antifungal properties against multidrug-resistant infectious agents. This review also emphasizes the symbiotic link between endophytes and their host plants, which is critical for secondary metabolite production. The study focuses on the significance of isolation methods for endophytes and proposes their use in for sustainable agriculture, bioremediation, and medicine. Future research combining endophytic biodiversity analysis with next-generation sequencing (NGS) and nanotechnology could provide novel techniques for combating AMR and contributing to sustainability across multiple industries.

Diversity of cultivable endophytic fungi in a decumbent subshrub endemic of the Brazilian tropical savanna

The diversity of cultivable endophytic fungi in native subshrubs of the Brazilian Cerrado is largely unknown. This study investigated the cultivable endophytic mycobiome of stems, leaves, and flowers of Peltaea polymorpha (Malvaceae). In total, 208 endophytic fungi were isolated, 95 from stems, 65 from leaves, and 48 from flowers. The isolates were classified as ascomycetes belonging to three classes, eight orders, ten families, 12 genera, and 31 species. Diaporthe, Nigrospora, and Colletotrichum were the dominant genera in the three analyzed organs. The richness estimators suggested that the number of species might be slightly higher than observed. The highest values for the Shannon and Simpson diversity indices were observed in stems. Beta diversity showed overlapping of fungal communities in different organs, with a high rate of sharing of taxa. Furthermore, the dominant primary fungal lifestyles were plant pathogens and saprobes. Our findings show that the cultivable endophytic fungal community of P. polymorpha is species-rich and that communities in different organs share genera and species.

In Vitro and In Vivo Antitumor Activity of Lophocereus marginatus (DC.) S. Arias & Terrazas Endophytic Aspergillus versicolor and Metarhizium anisopliae Extracts Against the Murine Lymphoma L5178Y-R

Cancer belongs to a group of diseases characterized by uncontrolled cell growth. The search for new effective treatments for cancer has led to the discovery of different molecules from plants, bacteria, and fungi with pharmacological use. Plant endophytic fungi are large producers of metabolites with antitumor properties. We aimed to evaluate the in vitro and in vivo antitumor potential of extracts from Lophocereus marginatus endophytic fungi. We obtained ethyl acetate and hexane extracts from the L. marginatus endophytes Metarhizium anisopliae and Aspergillus versicolor and evaluated their antitumor activity against murine L5178Y-R lymphoma cells and human peripheral blood mononuclear cells, using the 3-(4,5-dimethylthiazol-2-yl)-2-diphenyltetrazolium bromide reduction colorimetric technique. M. anisopliae and A. versicolor ethyl acetate extracts showed IC50 values of 9.168 ± 1.21 μg/mL and 13.51 ± 1.62, respectively, and selectivity indices > 30. We also observed that the maximum tolerated dose (100 mg/kg) of ethyl acetate extracts and the vehicle in BALB/c mice did not cause hepatotoxicity. In addition, we evaluated the effects of ethyl acetate extracts on survival and tumor volume in the L5178Y-R lymphoma tumor model. An increase in survival (17 d) was observed in mice treated with A. versicolor extract. Furthermore, it did not increase tumor volume during 10 d, as compared with the control groups without treatment, vehicle, and M. anisopliae extract, which had a maximum survival of 10 d. A. versicolor ethyl acetate extract showed in vitro and in vivo antitumor activity against lymphoma L5178Y-R, increasing mice survival.

Antibacterial Activity and Multi-Targeted Mechanism of Action of Suberanilic Acid Isolated from Pestalotiopsis trachycarpicola DCL44: An Endophytic Fungi from Ageratina adenophora

Methicillin-resistant Staphylococcus aureus (MRSA) is a highly threatening foodborne pathogen capable of causing severe organ and life-threatening diseases. Over the past years, various commercial antibiotics have been used to treat MRSA infections. However, these commercial antibiotics have not yielded efficient results and also cause other side effects; therefore, there is a need for the development of effective alternatives to replace these commercial antibiotics. Suberanilic acid, an amide alkaloid obtained from the endophytic fungus Pestalotiopsis trachycarpicola DCL44, has been identified as a significant antimicrobial agent. However, its antibiotic properties on multi-drug-resistant bacteria such as MRSA have not been fully explored. Therefore, to investigate the potential antimicrobial mechanism of suberanilic acid against MRSA, a quantitative proteomics approach using tandem mass tagging (TMT) was used. The results obtained in the study revealed that suberanilic acid targets multiple pathways in MRSA, including disruption of ribosome synthesis, inhibition of membrane translocation for nutrient uptake (ABC transporter system), and causing dysregulation of carbohydrate and amino acid energy metabolism. These results provide new insights into the mechanism of action of suberanilic acid against MRSA and offer technical support and a theoretical basis for the development of novel food antimicrobial agents derived from endophytic fungal origin.

Exploring Endophytic Fungi as Natural Antagonists against Fungal Pathogens of Food Crops

The yield and quality of cultivated food crops are frequently compromised by the prevalent threat from fungal pathogens that can cause widespread damage in both the pre-harvest and post-harvest stages. This paper investigates the challenges posed by fungal pathogens to the sustainability and yield of essential food crops, leading to significant economic and food security repercussions. The paper critiques the long-standing reliance on synthetic fungicides, emphasizing the environmental and health concerns arising from their widespread and occasionally inappropriate use. In response, the paper explores the potential of biological control agents, specifically endophytic fungi in advancing sustainable agricultural practices. Through their diverse symbiotic relationships with host plants, these fungi exhibit strong antagonistic capabilities against phytopathogenic fungi by producing various bioactive compounds and promoting plant growth. The review elaborates on the direct and indirect mechanisms of endophytic antagonism, such as antibiosis, mycoparasitism, induction of host resistance, and competition for resources, which collectively contribute to inhibiting pathogenic fungal growth. This paper consolidates the crucial role of endophytic fungi, i.e., Acremonium, Alternaria, Arthrinium, Aspergillus, Botryosphaeria, Chaetomium, Cladosporium, Cevidencealdinia, Epicoccum, Fusarium, Gliocladium, Muscodor, Nigrospora, Paecilomyces, Penicillium, Phomopsis, Pichia, Pochonia, Pythium, Ramichloridium, Rosellinia, Talaromyces, Trichoderma, Verticillium, Wickerhamomyces, and Xylaria, in biological control, supported by the evidence drawn from more than 200 research publications. The paper pays particular attention to Muscodor, Penicillium, and Trichoderma as prominent antagonists. It also emphasizes the need for future genetic-level research to enhance the application of endophytes in biocontrol strategies aiming to highlight the importance of endophytic fungi in facilitating the transition towards more sustainable and environmentally friendly agricultural systems.

Endophytic Fungi for Crops Adaptation to Abiotic Stresses

Endophytic fungi (EFs) have emerged as promising modulators of plant growth and stress tolerance in agricultural ecosystems. This review synthesizes the current knowledge on the role of EFs in enhancing the adaptation of crops to abiotic stress. Abiotic stresses, such as drought, salinity, and extreme temperatures, pose significant challenges to crop productivity worldwide. EFs have shown remarkable potential in alleviating the adverse effects of these stresses. Through various mechanisms, including the synthesis of osmolytes, the production of stress-related enzymes, and the induction of plant defense mechanisms, EFs enhance plant resilience to abiotic stressors. Moreover, EFs promote nutrient uptake and modulate the hormonal balance in plants, further enhancing the stress tolerance of the plants. Recent advancements in molecular techniques have facilitated the identification and characterization of stress-tolerant EF strains, paving the way for their utilization in agricultural practices. Furthermore, the symbiotic relationship between EFs and plants offers ecological benefits, such as improved soil health and a reduced dependence on chemical inputs. However, challenges remain in understanding the complex interactions between EFs and host plants, as well as in scaling up their application in diverse agricultural systems. Future research should focus on elucidating the mechanisms underlying endophytic-fungal-mediated stress tolerance and developing sustainable strategies for harnessing their potential in crop production.

Transcriptome analysis revealing the effect of Bupleurum scorzonerifolium Willd association with endophytic fungi CHS3 on the production of saikosaponin D

Saikosaponin D (SSd) is a naturally active product with strong pharmacological activity found in Bupleurum scorzonerifolium Willd. Studies have shown that endophytic fungi have great potential as sources of natural medicines. Fusarium acuminatum (CHS3), an SSd-producing endophytic fungus, was isolated from B. scorzonerifolium. To elucidate the effect of host plants on the production of SSd in CHS3, CHS3 was co-cultured with suspension cells of B. scorzonerifolium and SSd was detected using high-performance liquid chromatography (HPLC). Transcriptome sequencing (RNA-Seq) of CHS3 before and after co-culture was performed using an Illumina HiSeq 2500 platform. The results indicated that the content of SSd synthesised by CHS3 increased after co-culture with suspension cells of B. scorzonerifolium. Transcriptome analysis of CHS3 with differentially expressed genes (DEGs) showed that 1202 and 1049 genes were upregulated and downregulated, respectively, after co-culture. Thirty genes associated with SSd synthesis and 11 genes related to terpene backbone biosynthesis were annotated to the Kyoto Encyclopaedia of Genes and Genomes (KEGG). Combined with transcriptome data, it was speculated that the mevalonate (MVA) pathway is a possible pathway for SSd synthesis in CHS3, and the expression of key enzyme genes (HMGR, HMGCS, GGPS1, MVK, FDFT1, FNTB) was validated by qRT-PCR. In conclusion, the endophytic fungus CHS3 can form an interactive relationship with its host, thereby promoting SSd biosynthesis and accumulation by upregulating the expression of key enzyme genes in the biosynthesis pathway.

In silico prediction of polyketide biosynthetic gene clusters in the genomes of Hypericum-borne endophytic fungi

BACKGROUND

The search for new bioactive natural compounds with anticancer activity is still of great importance. Even though their potential for diagnostics and treatment of cancer has already been proved, the availability is still limited. Hypericin, a naphthodianthrone isolated essentially from plant source Hypericum perforatum L. along with other related anthraquinones and bisanthraquinones belongs to this group of compounds. Although it has been proven that hypericin is synthesized by the polyketide pathway in plants, none of the candidate genes coding for key enzymes has been experimentally validated yet. Despite the rare occurrence of anthraquinones in plants, their presence in microorganisms, including endophytic fungi, is quite common. Unlike plants, several biosynthetic genes grouped into clusters (BGCs) in fungal endophytes have already been characterized.

RESULTS

The aim of this work was to predict, identify and characterize the anthraquinone BGCs in de novo assembled and functionally annotated genomes of selected endophytic fungal isolates (Fusarium oxysporum, Plectosphaerella cucumerina, Scedosporium apiospermum, Diaporthe eres, Canariomyces subthermophilus) obtained from different tissues of Hypericum spp. The number of predicted type I polyketide synthase (PKS) BGCs in the studied genomes varied. The non-reducing type I PKS lacking thioesterase domain and adjacent discrete gene encoding protein with product release function were identified only in the genomes of C. subthermophilus and D. eres. A candidate bisanthraquinone BGC was predicted in C. subthermophilus genome and comprised genes coding the enzymes that catalyze formation of the basic anthraquinone skeleton (PKS, metallo-beta-lactamase, decarboxylase, anthrone oxygenase), putative dimerization enzyme (cytochrome P450 monooxygenase), other tailoring enzymes (oxidoreductase, dehydrogenase/reductase), and non-catalytic proteins (fungal transcription factor, transporter protein).

CONCLUSIONS

The results provide an insight into genetic background of anthraquinone biosynthesis in Hypericum-borne endophytes. The predicted bisanthraquinone gene cluster represents a basis for functional validation of the candidate biosynthetic genes in a simple eukaryotic system as a prospective biotechnological alternative for production of hypericin and related bioactive anthraquinones.

Biological and Medicinal Properties of Natural Chromones and Chromanones

Emerging threats to human health require a concerted effort to search for new treatment therapies. One of the biggest challenges is finding medicines with few or no side effects. Natural products have historically contributed to major advances in the field of pharmacotherapy, as they offer special characteristics compared to conventional synthetic molecules. Interest in natural products is being revitalized, in a continuous search for lead structures that can be used as models for the development of new medicines by the pharmaceutical industry. Chromone and chromanones are recognized as privileged structures and useful templates for the design of diversified therapeutic molecules with potential pharmacological interest. Chromones and chromanones are widely distributed in plants and fungi, and significant biological activities, namely antioxidant, anti-inflammatory, antimicrobial, antiviral, etc., have been reported for these compounds, suggesting their potential as lead drug candidates. This review aims to update the literature published over the last 6 years (2018-2023) regarding the natural occurrence and biological activity of chromones and chromanones, highlighting the recent findings and the perspectives that they hold for future research and applications namely in health, cosmetic, and food industries.

Novel Alkaloids from Aspergillus fumigatus VDL36, an Endophytic Fungus Associated with Vaccinium dunalianum

Eleven alkaloids (1-11) including seven new ones, 1-7, were isolated from the solid fermentation of Aspergillus fumigatus VDL36, an endophytic fungus isolated from the leaves of Vaccinium dunalianum Wight (Ericaceae), a perennial evergreen shrub distributed across the Southwest regions of China, Myanmar, and Vietnam. Their structures were elucidated on the basis of extensive spectroscopic methods. The isolates were evaluated for in vitro antifungal activities against five phytopathogenic fungi (Fusarium oxysporum, Coriolus versicolor, Fusarium solani, Botrytis cinerea, Fusarium graminearum). As a result, the new compounds fumigaclavine I (1), 13-ethoxycyclotryprostatin A (5), 13-dehydroxycyclotryprostatin A (6), and 12β-hydroxy-13-oxofumitremorgin C (7) exhibited antifungal activities with MIC values of 7.8-62.5 μg/mL which were comparable to the two positive controls ketoconazole (MIC = 7.8-31.25 μg/mL) and carbendazim (MIC = 1.95-7.8 μg/mL). Furthermore, compounds 1 and 5 demonstrated potent protective and curative effects against the tomato gray mold in vivo. Preliminary structure-activity relationships of the tested indole diketopiperazine alkaloids indicate that the introduction of a substituent group at position C-13 enhances their biological activities.

Exploring the antioxidant potential of endophytic fungi: a review on methods for extraction and quantification of total antioxidant capacity (TAC)

Endophytic fungi have emerged as a significant source of natural products with remarkable bioactivities. Recent research has identified numerous antioxidant molecules among the secondary metabolites of endophytic fungi. These organisms, whether unicellular or micro-multicellular, offer the potential for genetic manipulation to enhance the production of these valuable antioxidant compounds, which hold promise for promoting health, vitality, and various biotechnological applications. In this study, we provide a critical review of methods for extracting, purifying, characterizing, and estimating the total antioxidant capacity (TAC) of endophytic fungi metabolites. While many endophytes produce metabolites similar to those found in plants with established symbiotic associations, we also highlight the existence of novel metabolites with potential scientific interest. Additionally, we discuss how advancements in nanotechnology have opened new avenues for exploring nanoformulations of endophytic metabolites in future studies, offering opportunities for diverse biological and industrial applications.

Anti-inflammatory Polyketides from an Endophytic Fungus Chaetomium sp. UJN-EF006 of Vaccinium bracteatum

Seven new polyketides including three chromone derivatives (1-3) and four linear ones incorporating a tetrahydrofuran ring (4-7), along with three known compounds (8-10), were obtained from the fermentation of an endophytic fungus (Chaetomium sp. UJN-EF006) isolated from the leaves of Vaccinium bracteatum. The structures of these fungal metabolites have been elucidated by spectroscopic means including MS, NMR and electronic circular dichroism. A preliminary anti-inflammatory screening with the lipopolysaccharide (LPS) induced RAW264.7 cell model revealed moderate NO production inhibitory activity for compounds 1 and 4. In addition, the expression of three LPS-induced inflammatory factors IL-6, iNOS and COX-2 was also blocked by 1 and 4.

The antifungal metabolites from coculture of Aspergillus fumigatus and Alternaria alternata associated with Coffea arabica

One new cyclohexenone derivative, asperfumtone A (1) along with six known compounds were obtained from the coculture of Aspergillus fumigatus and Alternaria alternata associated with Coffea arabica. The configuration of 2 was first reported in the research. The structures were determined by extensive spectroscopic analyses, and ECD calculation. Compounds 3, 4 and 7 showed significant antifungal activities against coffee phytopathogens A. alternata and Fusarium incarnatum with MICs of 1 μg/mL. Compounds 1 and 2 showed weak antifungal activities against A. alternata and F. incarnatum with MICs of 32-64 μg/mL.

Fungal Endophytes as Mitigators against Biotic and Abiotic Stresses in Crop Plants

The escalating global food demand driven by a gradually expanding human population necessitates strategies to improve agricultural productivity favorably and mitigate crop yield loss caused by various stressors (biotic and abiotic). Biotic stresses are caused by phytopathogens, pests, and nematodes, along with abiotic stresses like salt, heat, drought, and heavy metals, which pose serious risks to food security and agricultural productivity. Presently, the traditional methods relying on synthetic chemicals have led to ecological damage through unintended impacts on non-target organisms and the emergence of microbes that are resistant to them. Therefore, addressing these challenges is essential for economic, environmental, and public health concerns. The present review supports sustainable alternatives, emphasizing the possible application of fungal endophytes as innovative and eco-friendly tools in plant stress management. Fungal endophytes demonstrate capabilities for managing plants against biotic and abiotic stresses via the direct or indirect enhancement of plants' innate immunity. Moreover, they contribute to elevated photosynthesis rates, stimulate plant growth, facilitate nutrient mineralization, and produce bioactive compounds, hormones, and enzymes, ultimately improving overall productivity and plant stress resistance. In conclusion, harnessing the potentiality of fungal endophytes represents a promising approach toward the sustainability of agricultural practices, offering effective alternative solutions to reduce reliance on chemical treatments and address the challenges posed by biotic and abiotic stresses. This approach ensures long-term food security and promotes environmental health and economic viability in agriculture.

Enhancing dendrobine production in Dendrobium nobile through mono-culturing of endophytic fungi, Trichoderma longibrachiatum (MD33) in a temporary immersion bioreactor system

INTRODUCTION

Dendrobine, a valuable alkaloid found in Dendrobium nobile, possesses significant pharmaceutical potential.

METHODS

In this study, we explored innovative approaches to enhance dendrobine production by utilizing endophytic fungi in a Temporary Immersion Bioreactor System (TIBS, Nanjing BioFunction Co. Ltd., China) and traditional test bottles. Dendrobine was unequivocally identified and characterised in D. nobile co-culture seedlings through UHPLC analysis and LC-MS qTOF analysis, supported by reference standards.

RESULTS

The CGTB (control group) and EGTB (experimental group) 12-month-old D. nobile seedlings exhibited similar peak retention times at 7.6±0.1 minutes, with dendrobine identified as C16H25NO2 (molecular weight 264.195). The EGTB, co-cultured with Trichoderma longibrachiatum (MD33), displayed a 2.6-fold dendrobine increase (1804.23 ng/ml) compared to the CGTB (685.95 ng/ml). Furthermore, a bioanalytical approach was applied to investigate the mono-culture of T. longibrachiatum MD33 with or without D. nobile seedlings in test bottles. The newly developed UHPLC-MS method allowed for dendrobine identification at a retention time of 7.6±0.1 minutes for control and 7.6±0.1 minutes for co-culture. Additionally, we explored TIBS to enhance dendrobine production. Co-culturing D. nobile seedlings with Trichoderma longibrachiatum (MD33) in the TIBS system led to a substantial 9.7-fold dendrobine increase (4415.77 ng/ml) compared to the control (454.01 ng/ml) after just 7 days. The comparative analysis of dendrobine concentration between EGTB and EGTIBS highlighted the remarkable potential of TIBS for optimizing dendrobine production. Future research may focus on scaling up the TIBS approach for commercial dendrobine production and investigating the underlying mechanisms for enhanced dendrobine biosynthesis in D. nobile. The structural elucidation of dendrobine was achieved through 1H and 13C NMR spectroscopy, revealing a complex array of proton environments and distinct carbon environments, providing essential insights for the comprehensive characterization of the compound.

DISCUSSION

These findings hold promise for pharmaceutical and industrial applications of dendrobine and underline the role of endophytic fungi in enhancing secondary metabolite production in medicinal plants.

Unveiling the cytotoxic and anti-proliferative potential of green-synthesized silver nanoparticles mediated by Colletotrichum gloeosporioides

Fungal endophytes are a putative source of bioactive metabolites that have found significant applications in nanomedicine due to their metabolic versatility. In the present study, an aqueous extract of the fungal endophyte, Colletotrichum gloeosporioides associated with a medicinal plant Oroxylum indicum, has been used for the fabrication of green silver nanoparticles (CgAgNPs) and further evaluated their cytotoxic and anti-proliferative activity. Bioanalytical techniques including UV-Vis spectral analysis revealed a sharp band at 435 nm and functional molecules from the aqueous extract involved in the synthesis of CgAgNPs were evidenced through FTIR. Further, the crystalline nature of CgAgNPs was determined through XRD analysis and microscopy techniques including AFM, TEM and FESEM demonstrated the spherical shape of CgAgNPs exhibiting a crystalline hexagonal lattice and the size was found to be in the range of 9-29 nm. The significant cytotoxic potential of CgAgNPs was observed against breast cancer cells, MDA-MB-231 and MCF-7 with IC50 values of 18.398 ± 0.376 and 38.587 ± 1.828 μg mL-1, respectively. The biochemical study revealed that the treatment of MDA-MB-231 and MCF-7 cells with CgAgNPs reduces glucose uptake, suppresses cell proliferation, and enhances LDH release, indicating reduced cell viability and progression. Moreover, our research revealed differential expression of genes associated with apoptosis, cell cycle inhibition and metastasis suppression, evidencing anti-proliferative activity of CgAgNPs. The main objective of the present study is to harness anti-breast cancer activity of novel biogenic nanoparticles synthesized using the aqueous extract of O. indicum associated C. gloeosporioides and study the underlying mechanistic pathway exerted by these mycogenic nanoparticles.

Genome sequencing and molecular networking analysis of the wild fungus Anthostomella pinea reveal its ability to produce a diverse range of secondary metabolites

BACKGROUND

Filamentous fungi are prolific producers of bioactive molecules and enzymes with important applications in industry. Yet, the vast majority of fungal species remain undiscovered or uncharacterized. Here we focus our attention to a wild fungal isolate that we identified as Anthostomella pinea. The fungus belongs to a complex polyphyletic genus in the family of Xylariaceae, which is known to comprise endophytic and pathogenic fungi that produce a plethora of interesting secondary metabolites. Despite that, Anthostomella is largely understudied and only two species have been fully sequenced and characterized at a genomic level.

RESULTS

In this work, we used long-read sequencing to obtain the complete 53.7 Mb genome sequence including the full mitochondrial DNA. We performed extensive structural and functional annotation of coding sequences, including genes encoding enzymes with potential applications in biotechnology. Among others, we found that the genome of A. pinea encodes 91 biosynthetic gene clusters, more than 600 CAZymes, and 164 P450s. Furthermore, untargeted metabolomics and molecular networking analysis of the cultivation extracts revealed a rich secondary metabolism, and in particular an abundance of sesquiterpenoids and sesquiterpene lactones. We also identified the polyketide antibiotic xanthoepocin, to which we attribute the anti-Gram-positive effect of the extracts that we observed in antibacterial plate assays.

CONCLUSIONS

Taken together, our results provide a first glimpse into the potential of Anthstomella pinea to provide new bioactive molecules and biocatalysts and will facilitate future research into these valuable metabolites.

Interaction with the entomopathogenic fungus Beauveria bassiana influences tomato phenome and promotes resistance to Botrytis cinerea infection

Plants are central to complex networks of multitrophic interactions. Increasing evidence suggests that beneficial microorganisms (BMs) may be used as plant biostimulants and pest biocontrol agents. We investigated whether tomato (Solanum lycopersicum) plants are thoroughly colonized by the endophytic and entomopathogenic fungus Beauveria bassiana, and how such colonization affects physiological parameters and the phenotype of plants grown under unstressed conditions or exposed to the pathogenic fungus Botrytis cinerea. As a positive control, a strain of the well-known biocontrol agent and growth inducer Trichoderma afroharzianum was used. As multitrophic interactions are often driven by (or have consequences on) volatile organic compounds (VOCs) released by plants constitutively or after induction by abiotic or biotic stresses, VOC emissions were also studied. Both B. bassiana and T. afroharzianum induced a significant but transient (one to two-day-long) reduction of stomatal conductance, which may indicate rapid activation of defensive (rejection) responses, but also limited photosynthesis. At later stages, our results demonstrated a successful and complete plant colonization by B. bassiana, which induced higher photosynthesis and lower respiration rates, improved growth of roots, stems, leaves, earlier flowering, higher number of fruits and yield in tomato plants. Beauveria bassiana also helped tomato plants fight B. cinerea, whose symptoms in leaves were almost entirely relieved with respect to control plants. Less VOCs were emitted when plants were colonized by B. bassiana or infected by B. cinerea, alone or in combination, suggesting no activation of VOC-dependent defensive mechanisms in response to both fungi.

Antioxidant and Antidiabetic Activities, and UHPLC-ESI-QTOF-MS-Based Metabolite Profiling of an Endophytic Fungus Nigrospora sphaerica BRN 01 Isolated from Bauhinia purpurea L

Diabetes-associated postprandial hyperglycemia is a major risk factor in cardiovascular disease. Since enzyme α-glucosidase is primarily responsible for glucose release during digestion, inhibiting it mitigates post-meal spike in blood glucose level. Metabolites from endophytic fungi could be potential natural inhibitors of this enzyme. Endophytic fungi isolated from Bauhinia purpurea L. were screened for their potential antioxidant and antidiabetic activities. Ethyl acetate extract of Nigrospora sphaerica BRN 01 (NEE) displayed high antioxidant activity with an IC50 value of 9.72 ± 0.91 µg/ml for DPPH assay and ferric reducing antioxidant power (FRAP) of 1595 ± 0.23 µmol AAE g-1 DW. NEE also showed high degree of inhibition of α-glucosidase activity with an IC50 value of 0.020 ± 0.001 mg/ml, significantly greater than the standard drug acarbose (0.494 ± 0.009 mg/ml). Metabolite profiling of NEE was carried using ultra-high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS) and 21 metabolites identified based on the MS/MS fragmentation patterns. Docking analysis of all 21 identified metabolites was carried out. Of these, 6 showed binding energies higher than acarbose (- 6.6 kcal/mol). Based on the analysis of interactions of feruloyl glucose with active site residues of the enzyme, it could be a potential α-glucosidase inhibitor. Metabolites of Nigrospora sphaerica BRN 01, therefore, could be potential lead molecules for design and development of antidiabetic drugs.

Chemical constituents from the medicinal herb-derived fungus Chaetomium globosum Km1226

BACKGROUND

Endophytic fungi have proven to be a rich source of novel natural products with a wide-array of biological activities and higher levels of structural diversity.

RESULTS

Chemical investigation on the liquid- and solid-state fermented products of Chaetomium globosum Km1226 isolated from the littoral medicinal herb Atriplex maximowicziana Makino resulted in the isolation of compounds 1-14. Their structures were determined by spectroscopic analysis as three previously undescribed C13-polyketides, namely aureonitol C (1), mollipilins G (2), and H (3), along with eleven known compounds 4-14. Among these, mollipilin A (5) exhibited significant nitric oxide production inhibitory activity in LPS-induced BV-2 microglial cells with an IC50 value of 0.7 ± 0.1 µM, and chaetoglobosin D (10) displayed potent anti-angiogenesis property in human endothelial progenitor cells (EPCs) with an IC50 value of 0.8 ± 0.3 µM.

CONCLUSIONS

Three previously unreported compounds 1-3 were isolated and identified. Mollipilin A (5) and chaetoglobosin D (10) could possibly be developed as anti-inflammatory and anti-angiogenic lead drugs, respectively.

Bioactive Alkaloids as Secondary Metabolites from Plant Endophytic Aspergillus Genus

Alkaloids represent a large family of natural products with diverse structures and bioactivities. These compounds and their derivatives have been widely used in clinics to treat various diseases. The endophytic Aspergillus is a filamentous fungus renowned for its extraordinary ability to produce active natural products of high therapeutic value and economic importance. This review is the first to focus on Aspergillus-derived alkaloids. Through an extensive literature review and data analysis, 263 alkaloids are categorized according to their structural features into those containing cytochalasans, diketopiperazine alkaloids, quinazoline alkaloids, quinoline alkaloids, indole alkaloids, pyrrolidine alkaloids, and others. These metabolites exhibited diverse biological activities, such as antibacterial activity, cytotoxicity, anti-inflammatory activity, and α-glucosidase, ACE, and DPPH inhibitory activities. The bioactivity, structural diversity, and occurrence of these alkaloids are reviewed in detail.

Health-Promoting Effects of Bioactive Compounds from Plant Endophytic Fungi

The study examines the intricate relationship between plants and the endophytic fungi inhabiting their tissues. These fungi harmoniously coexist with plants, forming a distinct symbiotic connection that has caught scientific attention due to its potential implications for plant health and growth. The diverse range of bioactive compounds produced by these fungi holds significant promise for human health. The review covers various aspects of this topic, starting by introducing endophytic microorganisms, explaining their colonization of different plant parts, and illuminating their potential roles in enhancing plant defense against diseases and promoting growth. The review emphasizes the widespread occurrence and diversity of these microorganisms among plant species while highlighting the complexities and significance of isolating and extracting bioactive compounds from them. It focuses on the health benefits of these bioactive compounds, including their capacity to exhibit antioxidant, anti-inflammatory, antimicrobial, and anticancer effects. The review delves into the mechanisms behind these health-promoting effects, spotlighting how the compounds interact with cellular receptors, signaling pathways, and gene expression. In conclusion, the review provides a comprehensive overview of health-promoting bioactive compounds from plant endophytic fungi. It outlines their multifaceted impact, potential applications, and future research avenues in health and medicine.

Natural Products as Mite Control Agents in Animals: A Review

Mites have been a persistent infectious disease affecting both humans and animals since ancient times. In veterinary clinics, the primary approach for treating and managing mite infestations has long been the use of chemical acaricides. However, the widespread use of these chemicals has resulted in significant problems, including drug resistance, drug residues, and environmental pollution, limiting their effectiveness. To address these challenges, researchers have shifted their focus towards natural products that have shown promise both in the laboratory and real-world settings against mite infestations. Natural products have a wide variety of chemical structures and biological activities, including acaricidal properties. This article offers a comprehensive review of the acaricidal capabilities and mechanisms of action of natural products like plant extracts, natural compounds, algae, and microbial metabolites against common animal mites.

Endophytic fungal species Nigrospora oryzae and Alternaria alternata exhibit antimicrobial activity against gram-positive and gram-negative multi-drug resistant clinical bacterial isolates

BACKGROUND

The emergence of multidrug-resistant pathogens and the lack of new antimicrobial drugs is a major public health concern that needs urgent and innovative solutions. Endophytic fungi living in unique niches such as in endosymbiosis with plants are increasingly drawing attention as alternative sources of novel and chemically diverse compounds with unique mechanisms of action.

METHODS

In the present study, ten endophytic fungi isolated from the medicinal plant, Sclerocarya birrea were screened for bioactivity against a panel of indicator bacteria. Three bioactive endophytic fungi (strains P02PL2, P02MS1, and P02MS2A) were selected and identified through ITS-rDNA sequencing. The whole broth extracts of the three selected isolates were further screened against contemporary drug-resistant bacterial pathogens. This was followed by partial purification by solid phase extraction and GC-MS analysis of bioactive fractions.

RESULTS

The bioactive endophytic fungi were identified as Alternaria alternata species (strains P02PL2 and P02MS1) and Nigrospora oryzae (strain P02MS2A). The whole broth extracts from N. oryzae P02MS2A exhibited a MIC of one μg/mL and 16 μg/mL against gram-negative, MDR Pseudomonas 5625574 and gram-positive MRSA 25775 clinical isolates, respectively. After partial purification and GC-MS analysis of whole broth extract from A. alternaria PO2MS1, 2-fluorobenzoic acid heptadecyl was putatively identified as the active compound in fraction C of this extract. This compound was also putatively identified in fraction E of A. alternata P02PL2, fraction B of A. alternata P02MS1 and fraction B of N. oryzae P02MS2A, and interestingly, all these fractions retained activity against the two MDR clinical isolates.

CONCLUSION

The putative identification of 2-fluorobenzoic acid heptadecyl compound showing a broad-spectrum of activity, more especially against gram-negative MDR contemporary pathogens is highly encouraging in the initiative at developing novel drugs to combat multi-drug resistance.

Antimicrobial and Cytotoxic Activities of the Secondary Metabolites of Endophytic Fungi Isolated from the Medicinal Plant Hyssopus officinalis

According to the World Health Organization, it is estimated that by 2050, drug-resistant infections could cause up to 10 million deaths annually. Therefore, finding a new generation of antibiotics is crucial. Natural compounds from endophytic fungi are considered a potential source of new-generation antibiotics. The antimicrobial and cytotoxic effects of ethyl acetate extracts of nine endophytic fungal isolates obtained from Hyssopus officinalis were investigated for bioassay-guided isolation of the natural compounds. An extract of isolate VII showed the highest antimicrobial activities against Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus (30.12 ± 0.20 mm and 35.21 ± 0.20 mm) and Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa (30.41 ± 0.23 mm and 25.12 ± 0.25 mm) among the tested extracts of isolates. Molecular identification of isolate VII confirmed it as Chaetomium elatum based on sequencing of its ITS genes, and it was discovered that this was the first time C. elatum had been isolated from H. officinalis. This isolate was cultured at a large scale for the isolation and identification of the active compound. Penicillic acid was isolated for the first time from C. elatum and its chemical structure was established by NMR spectroscopy. The penicillic acid showed strong antibacterial activities against Bacillus subtilis and Staphylococcus aureus with 20.68 mm and 25.51 mm inhibition zones, respectively. In addition, MIC and MBC values and antibiofilm activities of penicillic acid were determined. It was found that penicillic acid reduced the level of biofilms in proportion to antibacterial activity.

Endophytic Fungi as a Promising Source of Anticancer L-Asparaginase: A Review

L-asparaginase is a tetrameric enzyme from the amidohydrolases family, that catalyzes the breakdown of L-asparagine into L-aspartic acid and ammonia. Since its discovery as an anticancer drug, it is used as one of the prime chemotherapeutic agents to treat acute lymphoblastic leukemia. Apart from its use in the biopharmaceutical industry, it is also used to reduce the formation of a carcinogenic substance called acrylamide in fried, baked, and roasted foods. L-asparaginase is derived from many organisms including plants, bacteria, fungi, and actinomycetes. Currently, L-asparaginase preparations from Escherichia coli and Erwinia chrysanthemi are used in the clinical treatment of acute lymphoblastic leukemia. However, they are associated with low yield and immunogenicity problems. At this juncture, endophytic fungi from medicinal plants have gained much attention as they have several advantages over the available bacterial preparations. Many medicinal plants have been screened for L-asparaginase producing endophytic fungi and several studies have reported potent L-asparaginase producing strains. This review provides insights into fungal endophytes from medicinal plants and their significance as probable alternatives for bacterial L-asparaginase.

Broad spectrum bioactivity of a novel β-glucan rich heteropolysaccharide, Pestalopine isolated from endophytic fungi Pestalotiopsis chamaeropsis CEL6

A biologically potent exopolysaccharide (EPS), Pestalopine was produced by Pestalotiopsis chamaeropsis CEL6, an endophytic fungal isolate of Chloranthus elatior Sw. Pestalopine is composed of glucose, arabinose, fucose, rhamnose, and galactose in a molar ratio of nearly 10:1:2:2:4 having an Mw ∼ 3.29 × 105 Da. Pestalopine exhibited a radical scavenging effect and significantly increased antioxidant parameters (malondialdehyde, superoxide dismutase, glutathione peroxidase, reduced glutathione oxidized glutathione) in peritoneal macrophage cells in a concentration-dependent manner, with a maximum effect at 500 mg mL-1. Pestalopine is hepatoprotective in nature and improves the liver function profiles-total bilirubin, direct bilirubin, hepatic enzymes: alkaline phosphatase, gamma-glutamyl transferase, aspartate aminotransferase, alanine transaminase of liver fibrosis induced (through thioacetamide) male Wistar rats in comparison to control. Pestalopine-fed rats are reported to have higher counts of beneficial Lactobacillus sp. Present findings suggest that Pestalopine, a novel compound may have promise as a non-toxic exogenous antioxidant with hepatoprotective and probiotic efficacies.

Towards further understanding the applications of endophytes: enriched source of bioactive compounds and bio factories for nanoparticles

The most significant issues that humans face today include a growing population, an altering climate, an growing reliance on pesticides, the appearance of novel infectious agents, and an accumulation of industrial waste. The production of agricultural goods has also been subject to a great number of significant shifts, often known as agricultural revolutions, which have been influenced by the progression of civilization, technology, and general human advancement. Sustainable measures that can be applied in agriculture, the environment, medicine, and industry are needed to lessen the harmful effects of the aforementioned problems. Endophytes, which might be bacterial or fungal, could be a successful solution. They protect plants and promote growth by producing phytohormones and by providing biotic and abiotic stress tolerance. Endophytes produce the diverse type of bioactive compounds such as alkaloids, saponins, flavonoids, tannins, terpenoids, quinones, chinones, phenolic acids etc. and are known for various therapeutic advantages such as anticancer, antitumor, antidiabetic, antifungal, antiviral, antimicrobial, antimalarial, antioxidant activity. Proteases, pectinases, amylases, cellulases, xylanases, laccases, lipases, and other types of enzymes that are vital for many different industries can also be produced by endophytes. Due to the presence of all these bioactive compounds in endophytes, they have preferred sources for the green synthesis of nanoparticles. This review aims to comprehend the contributions and uses of endophytes in agriculture, medicinal, industrial sectors and bio-nanotechnology with their mechanism of action.

Genomic and Metabolomic Analysis of the Endophytic Fungus Fusarium sp. VM-40 Isolated from the Medicinal Plant Vinca minor

The genus Fusarium is well-known to comprise many pathogenic fungi that affect cereal crops worldwide, causing severe damage to agriculture and the economy. In this study, an endophytic fungus designated Fusarium sp. VM-40 was isolated from a healthy specimen of the traditional European medicinal plant Vinca minor. Our morphological characterization and phylogenetic analysis reveal that Fusarium sp. VM-40 is closely related to Fusarium paeoniae, belonging to the F. tricinctum species complex (FTSC), the genomic architecture and secondary metabolite profile of which have not been investigated. Thus, we sequenced the whole genome of Fusarium sp. VM-40 with the new Oxford Nanopore R10.4 flowcells. The assembled genome is 40 Mb in size with a GC content of 47.72%, 15 contigs (≥50,000 bp; N 50~4.3 Mb), and 13,546 protein-coding genes, 691 of which are carbohydrate-active enzyme (CAZyme)-encoding genes. We furthermore predicted a total of 56 biosynthetic gene clusters (BGCs) with antiSMASH, 25 of which showed similarity with known BGCs. In addition, we explored the potential of this fungus to produce secondary metabolites through untargeted metabolomics. Our analyses reveal that this fungus produces structurally diverse secondary metabolites of potential pharmacological relevance (alkaloids, peptides, amides, terpenoids, and quinones). We also employed an epigenetic manipulation method to activate cryptic BGCs, which led to an increased abundance of several known compounds and the identification of several putative new compounds. Taken together, this study provides systematic research on the whole genome sequence, biosynthetic potential, and metabolome of the endophytic fungus Fusarium sp. VM-40.

Diversity, chemical constituents and biological activities of endophytic fungi from Alisma orientale (Sam.) Juzep

The dried tuber of Alisma orientale (Sam.) Juzep. (AOJ) is a traditional Chinese medicine with high medicinal value. The endophytic fungi of medicinal plants are a treasure house of natural compounds. However, there is a lack of research on the diversity and biological activity of endophytic fungi of AOJ. In this study, high-throughput sequencing technology was used to study the diversity of endophytic fungi in the roots and stems of AOJ, and endophytic fungi with a high output of phenols and flavonoids were screened by chromogenic reaction, and the antioxidant and antibacterial activities and chemical constituents of crude extracts of their fermentation broth were studied. A total of 3,426 amplicon sequence variants (ASVs) belonging to 9 phyla, 27 classes, 64 orders, 152 families, and 277 genera were identified from AOJ. There were significant differences in the endophytic fungal communities of AOJ roots and stems, as well as in the endophytic fungal communities of triangular AOJ and circular AOJ. In addition, 31 strains of endophytic fungi were isolated from AOJ, of which 6 strains had good antioxidant and antibacterial activities. The crude extract of YG-2 had the strongest free radical scavenging ability and bacteriostatic ability, and its IC50 DPPH, IC50 ABTS, and IC50⋅OH values were 0.009 ± 0.000 mg/mL, 0.023 ± 0.002 mg/mL, and 0.081 ± 0.006 mg/mL, respectively. The results of LC-MS showed that the main component of the crude extract of YG-2 was caffeic acid (10.12 μmol/g). Overall, the results of this study preliminarily elucidated the diversity and community composition of endophytic fungi of AOJ, indicating that AOJ endophytic fungi have abundant secondary metabolites and good antioxidant and antibacterial activities. This study provides an important reference for further research, development and utilization of AOJ endophytic fungi and a theoretical basis for the further development of the endophytic fungus YG-2 (Chaetomium globosum) as a source of antioxidants.

Wild Rosa Endophyte M7SB41-Mediated Host Plant's Powdery Mildew Resistance

Our previous studies indicated that endophyte M7SB41 (Seimatosporium sp.) can significantly enhance host plants powdery mildew (PM) resistance. To recover the mechanisms, differentially expressed genes (DEGs) were compared between E+ (endophte-inoculated) and E- (endophyte-free) plants by transcriptomics. A total of 4094, 1200 and 2319 DEGs between E+ and E- were identified at 0, 24, and 72 h after plants had been infected with PM pathogen Golovinomyces cichoracearum, respectively. Gene expression pattern analysis displayed a considerable difference and temporality in response to PM stress between the two groups. Transcriptional profiling analysis revealed that M7SB41 induced plant resistance to PM through Ca²⁺ signaling, salicylic acid (SA) signaling, and the phenylpropanoid biosynthesis pathway. In particular, we investigated the role and the timing of the SA and jasmonic acid (JA)-regulated defensive pathways. Both transcriptomes and pot experiments showed that SA-signaling may play a prominent role in PM resistance conferred by M7SB41. Additionally, the colonization of M7SB41 could effectively increase the activities and the expression of defense-related enzymes under PM pathogen stress. Meanwhile, our study revealed reliable candidate genes from TGA (TGACG motif-binding factor), WRKY, and pathogenesis-related genes related to M7SB41-mediate resistance. These findings offer a novel insight into the mechanisms of endophytes in activating plant defense responses.

Bioactive Compounds Produced by Endophytic Microorganisms Associated with Bryophytes—The “Bryendophytes”

The mutualistic coexistence between the host and endophyte is diverse and complex, including host growth regulation, the exchange of substances like nutrients or biostimulants, and protection from microbial or herbivore attack. The latter is commonly associated with the production by endophytes of bioactive natural products, which also possess multiple activities, including antibacterial, insecticidal, antioxidant, antitumor, and antidiabetic properties, making them interesting and valuable model substances for future development into drugs. The endophytes of higher plants have been extensively studied, but there is a dearth of information on the biodiversity of endophytic microorganisms associated with bryophytes and, more importantly, their bioactive metabolites. For the first time, we name bryophyte endophytes “bryendophytes” to elaborate on this important and productive source of biota. In this review, we summarize the current knowledge on the diversity of compounds produced by endophytes, emphasizing bioactive molecules from bryendophytes. Moreover, the isolation methods and biodiversity of bryendophytes from mosses, liverworts, and hornworts are described.

Anti-Alzheimer's Natural Products Derived from Plant Endophytic Fungi

Alzheimer's is the most common cause of dementia worldwide and seriously affects patients' daily tasks. Plant endophytic fungi are known for providing novel and unique secondary metabolites with diverse activities. This review focuses primarily on the published research regarding anti-Alzheimer's natural products derived from endophytic fungi between 2002 and 2022. Following a thorough review of the literature, 468 compounds with anti-Alzheimer's-related activities are reviewed and classified based on their structural skeletons, primarily including alkaloids, peptides, polyketides, terpenoids, and sterides. The classification, occurrences, and bioactivities of these natural products from endophytic fungi are summarized in detail. Our results provide a reference on endophytic fungi natural products that may assist in the development of new anti-Alzheimer's compounds.

Chemical Profile and Biological Activities of Fungal Strains Isolated from Piper nigrum Roots: Experimental and Computational Approaches

The current report describes the chemical investigation and biological activity of extracts produced by three fungal strains Fusarium oxysporum, Penicillium simplicissimum, and Fusarium proliferatum isolated from the roots of Piper nigrum L. growing in Vietnam. These fungi were namely determined by morphological and DNA analyses. GC/MS identification revealed that the EtOAc extracts of these fungi were associated with the presence of saturated and unsaturated fatty acids. These EtOAc extracts showed cytotoxicity towards cancer cell lines HepG2, inhibited various microbacterial organisms, especially fungus Aspergillus niger and yeast Candida albicans (the MIC values of 50-100 μg/mL). In α-glucosidase inhibitory assay, they induced the IC₅₀ values of 1.00-2.53 μg/mL were better than positive control acarbose (169.80 μg/mL). The EtOAc extract of F. oxysporum also showed strong anti-inflammatory activity against NO production and PGE-2 level. Four major compounds linoleic acid (37.346 %), oleic acid (27.520 %), palmitic acid (25.547 %), and stearic acid (7.030 %) from the EtOAc extract of F. oxysporum were selective in molecular docking study, by which linoleic and oleic acids showed higher binding affinity towards α-glucosidase than palmitic and stearic acids. In subsequent docking assay with inducible nitric oxide synthase (iNOS), palmitic acid, oleic acid and linoleic acid could be moderate inhibitors.

Endophytic Fungi Isolated from Ageratina adenophora Exhibits Potential Antimicrobial Activity against Multidrug-Resistant Staphylococcus aureus

Multidrug-resistant bacteria such as Staphylococcus aureus (MRSA) cause infections that are difficult to treat globally, even with current available antibiotics. Therefore, there is an urgent need to search for novel antibiotics to tackle this problem. Endophytes are a potential source of novel bioactive compounds; however, the harnessing of novel pharmacological compounds from endophytes is infinite. Therefore, this study was designed to identify endophytic fungi (from Ageratina adenophora) with antibacterial activity against multidrug-resistant bacteria. Using fungal morphology and ITS-rDNA, endophytic fungi with antibacterial activities were isolated from A. adenophora. The results of the ITS rDNA sequence analysis showed that a total of 124 morphotype strains were identified. In addition, Species richness (S, 52), Margalef index (D/, 7.3337), Shannon-Wiener index (H/,3.6745), and Simpson's diversity index (D, 0.9304) showed that A. adenophora have abundant endophytic fungi resources. Furthermore, the results of the agar well diffusion showed that the Penicillium sclerotigenum, Diaporthe kochmanii, and Pestalotiopsis trachycarpicola endophytic fungi's ethyl acetate extracts showed moderate antibacterial and bactericidal activities, against methicillin-resistant Staphylococcus aureus (MRSA) SMU3194, with a MIC of 0.5-1 mg/mL and a MBC of 1-2 mg/mL. In summary, A. adenophora contains endophytic fungi resources that can be pharmacologically utilized, especially as antibacterial drugs.