Endophytic fungi isolated from medicinal plants: future prospects of bioactive natural products from Tabebuia/Handroanthus endophytes

Antioxidant Potential and Chemical Evaluation of Extracts from Endophytic Fungus Lasiodiplodia sp

Antioxidants are compounds that can eliminate free radicals and are known to prevent cell damage and health disorders, in turn, improving the quality of life of human beings. This study aims to evaluate the presence of antioxidants in ethyl acetate (EtOAc) extracts from Lasiodiplodia endophyte, which was previously isolated and cultivated by our research group, given its ability to produce a variety of metabolites with different chemical and biological properties. The antioxidant activities were determined using ABTS+⋅, DPPH and FRAP. Total phenolic content (TPC) and total flavonoid content (TFC) were evaluated, as well as the NMR metabolomics of extracts. All extracts showed promising antioxidant activity, and optimal results were achieved between the sixth and eleventh days of fungus cultivation. Furthermore, one of the extracts showed no in vivo toxicity against Galleria mellonella for all tested concentrations. The 1H-NMR spectra showed that there are two distinct groups of molecules present in EtOAc extracts obtained from Lasiodiplodia cultivation, and the data corroborate the results concerning antioxidant activity for TPC and TFC. This suggests that it is possible to monitor the chemical profile of fungal extracts using NMR, and to correlate compounds within days of fungus cultivation, along with their antioxidant activities.

Endophytic Fungi Co-Culture: An Alternative Source of Antimicrobial Substances

Antimicrobial resistance is becoming a critical issue due to the widespread and indiscriminate use of antibiotics and antifungals to treat common infections, leading to a growing shortage of effective drugs. Moreover, the increase in antimicrobial resistance is enhancing the pathogenicity and virulence of various pathogens. Microorganisms are key sources of chemically diverse specialized metabolites, which are produced in the final stages of their growth cycle. These metabolites hold significant value in chemical, pharmaceutical, and agrochemical industries. One of the major challenges researchers face in this field is the frequent isolation of already-known substances when classical protocols are used. To address this, several innovative strategies have been developed. The co-culture approach is a powerful tool for activating silent biosynthetic gene clusters, as it simulates natural microbial environments by creating artificial microbial communities. This method has shown promising results, with new compounds being isolated and the yields of target substances being improved. In this context, this review provides examples of antimicrobial compounds obtained from co-cultures of endophytic fungi, conducted in both liquid and solid media. Additionally, the review discusses the advantages and challenges of the co-culture technique. Significance and Impact of the Study: Microbial co-culture is a valuable strategy for discovering new natural products with antimicrobial activity, as well as for scaling up the production of target substances. This review aims to summarize important examples of endophyte co-cultures and highlights the potential of endophytic fungi co-culture for pharmacological applications.

Physiological, transcriptomic, and metabolomic analyses reveal that Pantoea sp. YSD J2 inoculation improves the accumulation of flavonoids in Cyperus esculentus L. var. sativus

Plant growth-promoting microorganisms (PGPMs), such as Pantoea sp. YSD J2, promote plant development and stress resistance, while their role in flavonoids accumulation still needs to be further understood. To investigate the complex flavonoid biosynthesis pathway of Cyperus esculentus L. var. sativus (tigernut), we compared Pantoea sp. YSD J2 inoculation (YSD J2) and water inoculation (CK) groups. YSD J2 significantly elevated the content of indole-3-acetic acid (IAA) and orientin. Furthermore, when analyzing flavonoid metabolome, YSD J2 caused increased levels of uralenol, petunidin-3-O-glucoside-5-O-arabinoside, luteolin-7-O-glucuronide-(2 → 1)-glucuronide, kaempferol-3-O-neohesperidoside, cyanidin-3-O-(2″-O-glucosyl)glucoside, kaempferol-3-O-glucuronide-7-O-glucoside, quercetin-3-O-glucoside, luteolin-7-O-glucuronide-(2 → 1)-(2″-sinapoyl)glucuronide, and quercetin-4'-O-glucoside, which further enhanced antioxidant activity. We then performed RNA-seq and LC-MS/MS, aiming to validate key genes and related flavonoid metabolites under YSD J2 inoculation, and rebuild the gene-metabolites regulatory subnetworks. Furthermore, the expression patterns of the trans cinnamate 4-monooxygenase (CYP73A), flavonol-3-O-L-rhamnoside-7-O-glucosyltransferase (UGT73C6), shikimate O-hydroxycinnamoyltransferase (HCT), chalcone isomerase (CHI), flavonol synthase (FLS), and anthocyanidin synthase (ANS) genes were confirmed by qRT-PCR. Additionally, 4 transcription factors (TF) (especially bHLH34, Cluster-37505.3) under YSD J2 inoculation are also engaged in regulating flavonoid accumulation. Moreover, the current work sheds new light on studying the regulatory effect of Pantoea sp. YSD J2 on tigernut development and flavonoid biosynthesis.

Aromatic components and endophytic fungi during the formation of agarwood in Aquilaria sinensis were induced by exogenous substances

The process of formation of aromatic components for agarwood in Aquilaria sinensis is closely related to endophytic fungi and the result of complex multiple long-term joint interactions with them. However, the interactions between the aromatic components and endophytic fungi remain unclear during the formation of agarwood. In this study, precise mixed solution of hormones, inorganic salts, and fungi was used to induce its formation in A. sinensis, and sample blocks of wood were collected at different times after inoculation. This study showed that the aromatic compounds found in the three treatments of A. sinensis were primarily chromones (31.70-33.65%), terpenes (16.68-27.10%), alkanes (15.99-23.83%), and aromatics (3.13-5.07%). Chromones and terpenes were the primary components that characterized the aroma. The different sampling times had a more pronounced impact on the richness and diversity of endophytic fungal communities in the A. sinensis xylem than the induction treatments. The species annotation of the operational taxonomic units (OTUs) demonstrated that the endophytic fungi were primarily composed of 18 dominant families and 20 dominant genera. A linear regression analysis of the network topology properties with induction time showed that the interactions among the fungal species continued to strengthen, and the network structure tended to become more complex. The terpenes significantly negatively correlated with the Pielou evenness index (p < 0.05), while the chromones significantly positively correlated with the OTUs and Shannon indices.

Plant-Entomopathogenic Fungi Interaction: Recent Progress and Future Prospects on Endophytism-Mediated Growth Promotion and Biocontrol

Entomopathogenic fungi, often acknowledged primarily for their insecticidal properties, fulfill diverse roles within ecosystems. These roles encompass endophytism, antagonism against plant diseases, promotion of the growth of plants, and inhabitation of the rhizosphere, occurring both naturally and upon artificial inoculation, as substantiated by a growing body of contemporary research. Numerous studies have highlighted the beneficial aspects of endophytic colonization. This review aims to systematically organize information concerning the direct (nutrient acquisition and production of phytohormones) and indirect (resistance induction, antibiotic and secondary metabolite production, siderophore production, and mitigation of abiotic and biotic stresses) implications of endophytic colonization. Furthermore, a thorough discussion of these mechanisms is provided. Several challenges, including isolation complexities, classification of novel strains, and the impact of terrestrial location, vegetation type, and anthropogenic reluctance to use fungal entomopathogens, have been recognized as hurdles. However, recent advancements in biotechnology within microbial research hold promising solutions to many of these challenges. Ultimately, the current constraints delineate potential future avenues for leveraging endophytic fungal entomopathogens as dual microbial control agents.

Diversity and Isolation of Endophytic Fungi in Panax japonicus and Biotransformation Activity on Saponins

OBJECTIVE

This study reports the diversity and community structure differences of the endophytic fungi of Panax japonicus of different ages to obtain novel endophytic fungi with glycoside hydrolytic activity for rare saponins production.

METHODS

This study used the high-throughput sequencing method to analyze the diversity and community structure of endophytic fungi of P. japonicus. The endophytic fungi were processed by traditional isolation, culture, conservation, and ITS rDNA sequence analyses. Then the total saponins of P. japonicus were used as the substrate to evaluate the glycoside hydrolytic activity.

RESULTS

The composition analysis of the community structure showed that the abundance, evenness, and diversity of endophytic fungi of nine-year-old P. japonicus were the best among all samples. A total of 210 endophytic fungi were isolated from P. japonicus samples and further annotated by sequencing the internal transcribed spacer. Then the biotransformation activity of obtained strains was further examined on total saponins of P. japonicus (TSPJ), with a strain identified as Fusarium equiseti (No.30) from 7-year-old P. japonicus showing significant glycoside hydrolytic activity on TSPJ, including ginsenoside Ro→zinglbroside R1, pseudoginsenoside RT1→pseudoginsenoside RP1, chikusetsusaponin IV→tarasaponin VI and chikusetsusaponin IVa →calenduloside E.

CONCLUSION

These results reveal the diversity and community structure differences of the endophytic fungi of P. japonicus with different ages and establish a resource library of endophytic fungi of P. japonicus. More importantly, we identified a valuable endophytic fungus with glycoside hydrolytic activity and provided a promising convenient microbial transformation approach to produce minor deglycosylated ginsenosides.

Diversity, Antimicrobial, Antioxidant, and Anticancer Activity of Culturable Fungal Endophyte Communities in Cordia dichotoma

Endophytic fungi are a significant source of secondary metabolites, which are chemical compounds with biological activities. The present study emphasizes the first-time isolation and identification of such fungi and their pharmacological activities from the medicinal plant Cordia dichotoma, which is native to Jammu, India. The Shannon Wiener diversity index revealed a wide range of fungal endophytes in root (1.992), stem (1.645), and leaf (1.46) tissues. A total of 19 endophytic fungi belonging to nine different genera were isolated from this plant and the majority belonged to the Ascomycota phylum. ITS rRNA gene sequencing was used to identify the fungal strains and they were submitted in NCBI GenBank. The most potent fungal isolate Cladosporium cladosporioides OP870014 had strong antimicrobial, antioxidant, and anticancer activity against MCF-7, HCT-116, and PC-3 cancer cell lines. The LC-MS and GC-MS analyses of the ethyl acetate extract of C. cladosporioides were examined to identify the bioactive metabolites. The major compounds of the crude extract derived from C. cladosporioides OP870014, according to GC-MS, are spiculisporic acid; dibutyl phthalate; phenylethyl alcohol; cyclohexanone, 2,3,3-trimethyl-2-3-methylbutyl; pyrrolo[1,2-a]pyrazine-1,4-dione,hexahydro-3-(phenylmethyl);2,5-piperazinedione,3,6-bis(2-methylpropyl); and heneicosane which possessed antimicrobial, anticancerous, and antioxidant activities. The findings revealed that C. dichotoma has the capacity to host a wide variety of fungal endophytes and that secondary metabolites from the endophytic fungus may be a source of alternative naturally occurring antimicrobial, antioxidant, and cytotoxic compounds.

Current Scenario and Future Prospects of Endophytic Microbes: Promising Candidates for Abiotic and Biotic Stress Management for Agricultural and Environmental Sustainability

Globally, substantial research into endophytic microbes is being conducted to increase agricultural and environmental sustainability. Endophytic microbes such as bacteria, actinomycetes, and fungi inhabit ubiquitously within the tissues of all plant species without causing any harm or disease. Endophytes form symbiotic relationships with diverse plant species and can regulate numerous host functions, including resistance to abiotic and biotic stresses, growth and development, and stimulating immune systems. Moreover, plant endophytes play a dominant role in nutrient cycling, biodegradation, and bioremediation, and are widely used in many industries. Endophytes have a stronger predisposition for enhancing mineral and metal solubility by cells through the secretion of organic acids with low molecular weight and metal-specific ligands (such as siderophores) that alter soil pH and boost binding activity. Finally, endophytes synthesize various bioactive compounds with high competence that are promising candidates for new drugs, antibiotics, and medicines. Bioprospecting of endophytic novel secondary metabolites has given momentum to sustainable agriculture for combating environmental stresses. Biotechnological interventions with the aid of endophytes played a pivotal role in crop improvement to mitigate biotic and abiotic stress conditions like drought, salinity, xenobiotic compounds, and heavy metals. Identification of putative genes from endophytes conferring resistance and tolerance to crop diseases, apart from those involved in the accumulation and degradation of contaminants, could open new avenues in agricultural research and development. Furthermore, a detailed molecular and biochemical understanding of endophyte entry and colonization strategy in the host would better help in manipulating crop productivity under changing climatic conditions. Therefore, the present review highlights current research trends based on the SCOPUS database, potential biotechnological interventions of endophytic microorganisms in combating environmental stresses influencing crop productivity, future opportunities of endophytes in improving plant stress tolerance, and their contribution to sustainable remediation of hazardous environmental contaminants.

Diversity analysis of endophytes with antimicrobial and antioxidant potential from Viola odorata: an endemic plant species of the Himalayas

Viola odorata, also known as "Banafshah" in high altitudes of Himalayas, is well known for its pharmaceutical importance in Ayurvedic and Unani medicinal system. The plant is a source of various drugs for its anti-inflammatory, diaphoretic, diuretic, emollient, expectorant, antipyretic, and laxative properties. The endophytes of plants have been reported for their role in modulating various physiological and biological processes of the host plants. In the present study, a total of 244 endophytes were isolated in pure cultures from the roots of Viola odorata, and genetic diversity was evaluated using amplified ribosomal DNA restriction analysis (ARDRA) and enterobacterial repetitive intergenic consensus (ERIC). The molecular fingerprinting revealed variation among various rRNA types among morphologically different endophytes based on ARDRA and ERIC-PCR. The screening of endophytes showed antimicrobial activity of 11 bacterial isolates and one actinomycete SGA9 against various pathogens Bacillus cereus, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. The antioxidant activity revealed the majority of the bacterial isolates able to scavenge the free radical in the range of 10-50% and 8 bacterial isolates in the range of 50-85%. Principal component analysis separated eight isolates away from the central eclipse and form a separate group based on antimicrobial and antioxidant potential. The identification of these eight isolates showed affiliation with different species of the genus Enterobacter, Microbacterium, Pseudomonas, Rhizobium, and Streptomyces. This is the first report on the characterization of endophytic bacteria and actinomycetes from endemic Viola odorata. Results suggested that these endophytes could be explored for the production of antimicrobial and antioxidant products.

Bioactive Metabolite from Endophytic Aspergillus versicolor SB5 with Anti-Acetylcholinesterase, Anti-Inflammatory and Antioxidant Activities: In Vitro and In Silico Studies

Endophytic fungi are a highly unpredictable group of microorganisms that can create a diverse range of secondary metabolites with biological activity. These metabolites enhance the host's ability to tolerate stress caused by various factors, such as disease, insects, pathogens, and herbivores. The secondary metabolites produced by endophytic fungi may have potential applications in agriculture, pharmacy, and medicine. The purpose of this study was to examine the anti-acetylcholinesterase activity of secondary metabolites extracted from endophytic fungi. Aspergillus versicolor SB5 was one of the many endophytic fungi isolated from Juncus rigidus and identified genetically with accession number ON872302. Our study utilized fermentation and microbial cultivation techniques to obtain secondary metabolites. During the course of our investigation, we isolated a compound called Physcion (C1) from the endophytic fungus Aspergillus versicolor SB5. We subsequently identified that C1 possesses inhibitory activity against COX-2 and LOX-1, with IC50 values of 43.10 and 17.54 µg/mL, respectively, making it an effective anti-inflammatory agent. Moreover, we found that C1 also exhibited potent anticholinesterase activity (86.9 ± 1.21%). In addition to these promising therapeutic properties, our experiments demonstrated that C1 possesses strong antioxidant capacity, as evidenced by its ability to scavenge DPPH, ABTS, O2 radicals, and NO and inhibit lipid peroxidation. To further investigate the molecular mechanisms underlying C1 pharmacological properties, we employed SwissADME web tools to predict the compound's ADME-related physicochemical properties and used Molecular Operating Environment and PyMOL for molecular docking studies.

Metabolites of medicine food homology-derived endophytic fungi and their activities

Medicine food homology (MFH) substances not only provide essential nutrients as food but also have corresponding factors that can prevent and help treat nutritional imbalances, chronic disease, and other related issues. Endophytic fungi associated with plants have potential for use in drug discovery and food therapy. However, the endophytic fungal metabolites from MFH plants and their effects have been overlooked. Therefore, this review focuses on the various biological activities of 108 new metabolites isolated from 53 MFH-derived endophytic fungi. The paper explores the potential nutritional and medicinal value of metabolites of MFH-derived endophytic fungi for food and medical applications. This research is important for the future development of effective, safe, and nontoxic therapeutic nutraceuticals for the prevention and treatment of human diseases.

Global regulatory factor AaLaeA upregulates the production of antitumor substances in the endophytic fungus Alternaria alstroemeria

The global regulatory factor LaeA has been shown to be involved in the biosynthesis of secondary metabolites in various fungi. In a previous work, we isolated an endophytic fungus from Artemisia annua, and its extract had a significant inhibitory effect on the A549 cancer cell line. Phylogenetic analysis further identified the strain as Alternaria alstroemeria. Overexpression of AalaeA gene resulted in significantly increased antitumor activity of this strain's extract. The 3-(4, 5- dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay results showed that the inhibition rate of the AalaeA^OE29 mutant extract on A549 cancer cells was significantly higher than that of the WT extract, as the IC₅₀ decreased from 195.0 to 107.4 μg/ml, and the total apoptosis rate was enhanced. Overexpression of the AalaeA gene significantly increased the contents of myricetin, geraniol, ergosterol, and 18 other antitumor compounds as determined by metabolomic analysis. Transcriptomic analysis revealed significant changes in 95 genes in the mutant strain, including polyketide synthases, nonribosomal peptide synthases, cytochrome P450s, glycosyltransferases, acetyl-CoA acetyltransferases, and others. These results suggested that AaLaeA mediated the antitumor activity of the metabolites in A. alstroemeria by regulating multiple metabolic pathways.

Zinc Oxide Nanoparticles as Potential Delivery Carrier: Green Synthesis by Aspergillus niger Endophytic Fungus, Characterization, and In Vitro/In Vivo Antibacterial Activity

We aimed to synthesize zinc oxide nanoparticles (ZnO NPs) using the endophytic fungal extract of Aspergillus niger. The prepared ZnO NPs were characterized, and their in vitro and in vivo antibacterial activity was investigated. Isolated endophytic fungus identification was carried out using 18S rRNA. A. niger endophytic fungal extract was employed for the green synthesis of ZnO NPs. The in vitro antibacterial activity of the prepared ZnO NPs was elucidated against Staphylococcus aureus using the broth microdilution method and quantitative real-time polymerase chain reaction (qRT-PCR). Additionally, the in vivo antibacterial activity was elucidated using a systemic infection model in mice. The biosynthesized ZnO NPs showed a maximum optical density at 380 nm with characteristic peaks on the Fourier-transform infrared spectrum. The X-ray diffraction pattern was highly matched with a standard platform of zinc oxide crystals. Energy-dispersive X-ray analysis confirmed that the main composition of nanoparticles was zinc and oxygen atoms. Scanning and transmission electron microscopies showed spherical geometry with a smooth surface. Zeta potential measurements (26.6 ± 0.56 mV) verified the adequate stability of ZnO NPs. Minimum inhibitory concentrations of ZnO NPs against S. aureus isolates ranged from 8 to 128 µg/mL. Additionally, ZnO NPs revealed antibiofilm activity, resulting in the downregulation of the tested biofilm genes in 29.17% of S. aureus isolates. Regarding the in vivo experiment, ZnO NPs reduced congestion and fibrosis in liver and spleen tissues. They also improved liver function, increased the survival rate, and significantly decreased inflammatory markers (p < 0.05). ZnO NPs synthesized by A. niger endophytic fungus revealed a promising in vivo and in vitro antibacterial action against S. aureus isolates.

Endophytic fungi and their bioactive secondary metabolites in medicinal leguminosae plants: Nearly untapped medical resources

There are many species of Chinese traditional leguminosae family plants that are well known for their medicinal applications, such as Astragalus membranaceus, Catsia tora, Glycyrrhiza uralensis, Sophora flavescens and Albacia acacia. Their unique bioactive composition and internal phenological environment contribute to the formation of specific and unique endophytic fungal communities, which are important resources for new compounds used in a variety of pharmacological activities. Nonetheless, they have not been systematically studied. In the last decade, nearly 64 genera and thousands of species of endophytic fungi have been discovered from leguminosae plants, as well as 138 secondary metabolites (with 34 new compounds) including flavonoid, alkaloids, phenol, anthraquinone, macrolide, terpenoid, phytohormone and many more. They were shown to have diverse applications and benefits, such as antibacterial, antitumor, antioxidative, immunoregulatory and neuroprotective properties. Here, we provide a summarized overview with the aim of raising awareness of endophytic fungi from medicinal leguminosae plants and providing a comprehensive review of the discoveries of new natural products that may be of medicinal and pharmaceutical importance.

Optimizing the Culture Medium of Lasiodiplodia sp. to Improve the Yield of Ethyl Acetate Extract as an Antimicrobial Source

Endophytes often inhabit plant tissues and cause no disease symptoms. Lasiodiplodia is generally considered a pathogenic fungus, but such a genus is capable of producing high-value bioactive molecules, such as enzymes, secondary metabolites including antimicrobials. Therefore, Lasiodiplodia sp. endophyte was cultivated in static mode for 12 days and EtOAc extracts were obtained and evaluated against pathogens afterward. Fermentation parameters (glucose, sucrose and NaNO₃) were optimized by the factorial design and response surface methodology, as these are powerful tools to provide reliable information about fungal culture conditions and EtOAc extract yields were considered as response variables. Lasiodiplodia growth curve indicated that optimal production of EtOAc extract mass was achieved after 12 days of fermentation (284 mg 300 mL^-1 broth), which is in agreement with values obtained from validation tests. Minimum Inhibitory Concentration (MIC) and Minimum Microbicidal Concentration (MMC) essays suggested that the endophyte produce substances presenting antimicrobial and antifungal activities against ATCC Staphylococcus aureus and Candida albicans strains at optimum point under evaluated conditions. MIC values ranged between 50 and 100 µg mL^-1 for both pathogens, while MMC of C. albicans ranged from 100 to 200 µg mL^-1, which evidence its fungicidal effect. Furthermore, it was found that the EtOAc extract yield can be increased by optimizing carbon and nitrogen sources in endophyte cultivation, and there was good agreement between predicted and experimental values under optimized conditions. Thus, Lasiodiplodia fungi are promising sources of antimicrobials and changes in carbon and nitrogen sources can improve the yield of secondary metabolites according to the factorial design.

The Fusaric Acid Derivative qy17 Inhibits Staphylococcus haemolyticus by Disrupting Biofilm Formation and the Stress Response via Altered Gene Expression

Staphylococcus haemolyticus (S. haemolyticus) is the second most commonly isolated coagulase-negative staphylococcus (CoNS) in patients with hospital-acquired infections. It can produce phenol-soluble modulin (PSM) toxins and form biofilms. Compared with the wealth of information on Staphylococcus aureus and Staphylococcus epidermidis, very little is known about S. haemolyticus. There is an urgent need to find an effective preparation to combat the harm caused by S. haemolyticus infection. Chinese herbs have been utilized to cure inflammation and infectious diseases and have a long history of anticancer function in China. Here, we modified fusaric acid characterized from the metabolites of Gibberella intermedia, an endophyte previously isolated from Polygonum capitatum. This study shows that fusaric acid analogs (qy17 and qy20) have strong antibacterial activity against S. haemolyticus. In addition, crystal violet analyses and scanning electron microscopy observations demonstrated that qy17 inhibited biofilm formation and disrupted mature biofilms of S. haemolyticus in a dose-dependent manner. Additionally, it reduced the number of live bacteria inside the biofilm. Furthermore, the antibiofilm function of qy17 was achieved by downregulating transcription factors (sigB), transpeptidase genes (srtA), and bacterial surface proteins (ebp, fbp) and upregulating biofilm-related genes and the density-sensing system (agrB). To further elucidate the bacteriostatic mechanism, transcriptomic analysis was carried out. The following antibacterial mechanisms were uncovered: (i) the inhibition of heat shock (clpB, groES, groL, grpE, dnaK, dnaJ)-, oxidative stress (aphC)- and biotin response (bioB)-related gene expression, which resulted in S. haemolyticus being unable to compensate for various stress conditions, thereby affecting bacterial growth; and (ii) a reduction in the expression of PSM-beta (PSMβ1, PSMβ2, PSMβ3) toxin- and Clp protease (clpP, clpX)-related genes. These findings could have major implications for the treatment of diseases caused by S. haemolyticus infections. Our research reveals for the first time that fusaric acid derivatives inhibit the expression of biofilm formation-related effector and virulence genes of S. haemolyticus. These findings provide new potential drug candidates for hospital-acquired infections caused by S. haemolyticus.

Isolation of endophytic bacteria from the medicinal, forestal and ornamental tree Handroanthus impetiginosus

Plant interactions with endophytic bacteria produce mutual benefits and contribute to environmental sustainability. Handroanthus impetiginosus (Mart. ex DC.) Mattos 'pink lapacho' (syn. Tabebuia impetiginosa, Bignoniaceae) is a medicinal, ornamental and forestal native tree from South and Mesoamerica. Plant growth promoting bacteria (PGPB) isolated from pink lapacho are scarcely described. The aim of this work was to isolate and characterize native endophytic bacteria from pink lapacho. Ten bacterial strains were isolated from leaves and six from roots of naturally growing trees in Luján (Central-Eastern region of Argentina). Endophytes were identified as Bacillus, Paenibacillus, Pseudomonas, Rhizobium, Rummeliibacillus and Methylobacterium genera, according to 16S rRNA gene sequencing and phylogenetic analysis. In the present study, a strain of the Rummelibacillus genus (L14) has been first ever reported as endophyte. This strain was capable of growing in Nfb medium and exhibited zinc solubilization ability. A high percentage of strains showed PGPB traits; namely 88% fixed nitrogen, 63% solubilized zinc, 69% solubilized phosphate and 63% produced indole compounds such as IAA. Most strains were salt tolerant that confer them a potential competitive advantage to survive in saline conditions. To the best of our knowledge, this is the first study reporting an approach to assess the diversity of cultivable endophytic bacteria of H. impetiginosus tree and its plant growth promoting capacity. The knowledge about this kind of associations could contribute to environmental sustainability by developing effective biofertilizers that minimize the use of chemical fertilizers and pesticides.

A New Source of Diterpene Lactones From Andrographis paniculata (Burm. f.) Nees—Two Endophytic Fungi of Colletotrichum sp. With Antibacterial and Antioxidant Activities

Endophytic fungi of medicinal plants are abundant, and their metabolites often have antioxidant, antibacterial, and antitumor effects and can produce secondary metabolites identical or similar to those of their hosts, which can mitigate the problem of insufficient supply of medicinal plants. In this study, we screened endophytic fungi for strains that produce the same diterpene lactones as Andrographis paniculata based on their biological activity. Firstly, the dominant group of endophytic fungi of Andrographis paniculata was screened and pathogenicity was studied using Koch’s rule. Secondly, DPPH, ABTS, OH, PTIO radical scavenging, and FRAP assays were used to detect the antioxidant activity of the extracellular extracts of the strains, and total phenol and total flavonoid contents of the strains with high antioxidant capacity were determined. S. aureus, B. subtilis, E. coli, and P. aeruginosa were used to determine the antibacterial activity of the mycelial extracts of the strains. Finally, the secondary metabolites of the mycelial extracts of the strains were examined by high-performance liquid chromatography. The results showed that 32 strains of Andrographis paniculata were relatively isolated > 70% and non-pathogenic. Extracellular extracts of strains AP-1 and AP-4 showed vigorous antioxidant activity, and AP-4, AP-12, AP-47, and AP-48 showed antibacterial activity against four strains of bacteria. The HPLC results indicated that the mycelial extracts of AP-4 and AP-12 contained diterpene lactones. The two endophytic fungi were recognized as Colletotrichum sp. The study successfully obtained diterpene lactones from the endophytic fungus of Andrographis paniculata and confirmed the feasibility of using endophytic fungal strains to produce active substances consistent with the host. It was also useful for exploring endophytic fungi and medicinal plants. The relationship provides theoretical guidance.

Huoshanmycins A‒C, New Polyketide Dimers Produced by Endophytic Streptomyces sp. HS-3-L-1 From Dendrobium huoshanense

Three new polyketide dimers named huoshanmycins A‒C (1–3) were isolated from a plant endophytic Streptomyces sp. HS-3-L-1 in the leaf of Dendrobium huoshanense, which was collected from the Cultivation base in Jiuxianzun Huoshanshihu Co., Ltd. The dimeric structures of huoshanmycins were composed of unusual polyketides SEK43, SEK15, or UWM4, with a unique methylene linkage. Their structures were elucidated through comprehensive 1D-/2D-NMR and HRESIMS spectroscopic data analysis. The cytotoxicity against MV4-11 human leukemia cell by the Cell Counting Kit-8 (CCK8) method was evaluated using isolated compounds with triptolide as positive control (IC₅₀: 1.1 ± 0.4 μM). Huoshanmycins A and B (1, 2) displayed moderate cytotoxicity with IC₅₀ values of 32.9 ± 7.2 and 33.2 ± 6.1 μM, respectively.

Screening saikosaponin d (SSd)-producing endophytic fungi from Bupleurum scorzonerifolium Willd

Saikosaponin d (SSd) is an important bioactive compound of traditional Chinese medicinal plant Bupleurum scorzonerifolium Willd. and exhibits many effects, such as anti-tumor, anti-inflammation and immunomodulatory. Since endophytic fungi possess the natural capacity to produce the similar secondary metabolite to that of their host plants, they are promising as alternative sources of plant bioactive natural products. In this study, in order to search for SSd-producing strains, endophytes were isolated from B. scorzonerifolium and were authenticated by the ITS sequence and the translation elongation factor-1alpha gene (TEF-1α) sequence analysis. The profile of metabolites present in the crude exacts was carried out by ultra performance liquid chromatography time-of-flight mass spectrometry (UPLC/Q-TOF-MS) analysis. The results showed that two strains, CHS₂ and CHS₃ from B. scorzonerifolium could produce SSd by UPLC/Q-TOF-MS analysis, and the amount of SSd produced by strain CHS₂ and CHS₃ were about 2.17 and 2.40 µg/mL, respectively. CHS₂ and CHS₃ showed a close phylogenetic relationship to Fusarium oxysporum and Fusarium acuminatum, respectively. According to our concern, no endophytic fungi capable of producing SSd from B. scorzonerifolium have been found before. Our clear intention was to isolate and identify these endophytic fungi that produce important active secondary metabolites, and then study the strains that produce this compound on a large scale through fermentation or even genetic study, to provide a feasible and more convenient way for the production of SSd.

Natural Biocidal Compounds of Plant Origin as Biodegradable Materials Modifiers

The article presents a literature review of the plant origin natural compounds with biocidal properties. These compounds could be used as modifiers of biodegradable materials. Modification of polymer material is one of the basic steps in its manufacturing process. Biodegradable materials play a key role in the current development of materials engineering. Natural modifiers are non-toxic, environmentally friendly, and renewable. The substances contained in natural modifiers exhibit biocidal properties against bacteria and/or fungi. The article discusses polyphenols, selected phenols, naphthoquinones, triterpenoids, and phytoncides that are natural antibiotics. Due to the increasing demand for biodegradable materials and the protection of the natural environment against the negative effects of toxic substances, it is crucial to replace synthetic modifiers with plant ones. This work mentions industries where materials containing natural modifying additives could find potential applications. Moreover, the probable examples of the final products are presented. Additionally, the article points out the current world's pandemic state and the use of materials with biocidal properties considering the epidemiological conditions.

Diversity and Interactomics of Bacterial Communities Associated with Dominant Trees During Tropical Forest Recovery

Bacterial communities have been identified as functional key members in soil ecology. A deep relation with these communities maintains forest coverture. Trees harbor particular bacteriomes in the rhizosphere, endosphere, or phyllosphere, different from bulk-soil representatives. Moreover, the plant microbiome appears to be specific for the plant-hosting species, varies through season, and responsive to several environmental factors. This work reports the changes in bacterial communities associated with dominant pioneer trees [Tabebuia rosea and Handroanthus chrysanthus [(Bignoniaceae)] during tropical forest recovery chronosequence in the Mayan forest in Campeche, Mexico. Massive 16S sequencing approach leads to identifying phylotypes associated with rhizosphere, bulk-soil, or recovery stage. Lotka-Volterra interactome modeling suggests the presence of putative regulatory roles of some phylotypes over the rest of the community. Our results may indicate that bacterial communities associated with pioneer trees may establish more complex regulatory networks than those found in bulk-soil. Moreover, modeled regulatory networks predicted from rhizosphere samples resulted in a higher number of nodes and interactions than those found in the analysis of bulk-soil samples.

Diversity and community structure of endophytic Bacillus with antagonistic and antioxidant activity in the fruits of Xisha Wild Noni (Morinda citrifolia L.)

Noni (Morinda citrifolia L.) is a tropical crop with strong antibacterial, antioxidant and other abilities, and its fruit has a strong potential for adjuvant treatment of diseases. This study aimed to explore the dynamic change of endophytic bacteria in Noni fruit at different stages and the correlation between the antagonistic and antioxidant activity of the Bacillus which was screened and the change of the host's growth stage. In this study, though the high-throughput sequencing technology (HTS), 106 endophytic bacteria species were found in A, B, C, D, E and F stages of Noni fruit, among which the dominant group were Pantoea (0.3%-20.9%), and Candidatus_Uzinura (2.3%-35.2%) etc. The endophytic bacteria were isolated by culture-dependent method. Through their antagonistic experiments on Staphylococcus aureus and Escherichia coli, the results of 16S polyphasic taxonomic identification showed that the 34 antagonistic strains belonged to Bacillus. Five species of these Bacillus were identified by gyrA polyphase taxonomy, including Bacillus subtilis (76% of all Bacillus), Bacillus licheniformis (9%), Bacillus amyloliquefaciens (6%), Bacillus velezensis (6%) and Bacillus mojavensi (3%), and the RAPD showed these Bacillus are no signs of stable passage. In C, D, E and F stages, the average total antioxidant activity of Bacillus endophytic antagonists against Noni was 7.812 U/mL, 8.144 U/mL, 7.817 U/mL and 7.144 U/mL, which was much higher than that of Noni fruit, and antioxidant activity of Noni juice and Bacillus bacterial liquid vary with host's growth period showed the same trend, both rose slowly at first, and reached the highest in period E, then declined slightly in period F, it showed that the antagonistic Bacillus of Noni had synergistic function with Noni fruit. This study clarified the relationship of function between Noni fruit and endophytic bacteria, and laid a foundation for future study on the dynamic change of endophytic flora succession and efficacy.

Penpolonin A-E, cytotoxic α-pyrone derivatives from Penicillium polonicum

Five new α-pyrone derivatives, named penpolonin A-E (1-5), together with two known compounds (6-7) were acquired from the endophytic fungus Penicillium polonicum isolated from the roots of Camptotheca acuminata Decne. Their structures were established by combination of NMR and HRESIMS data and the absolute configurations of 1-5 were determined by NMR calculations and comparison of experimental and calculated ECD data. Compounds 3 and 7 exhibited moderate cytotoxicity against Hep-2, TU212 human laryngeal cancer cells with IC₅₀ values ranging from 31.6 to 45.1 μg/ml, compound 4 showed weak cytotoxicity against the Hep-2 and TU212 cell lines with IC₅₀ values of 69.2 and 68.7 μg/ml.

Identification and Bioactivities of Secondary Metabolites Derived from Endophytic Fungi Isolated from Ethnomedicinal Plants of Tujia in Hubei Province: A Review

Tujia is a national minority, inhabiting in the mountainous Wuling area in China. Since 1978, Tujia medicine has been studied, summarized and developed, leading to numerous achievements by Chinese researchers, such as the publishing of approximately 30 monographs of Tujia medicine. These publications are focused on summarizing and improving the theory of Tujia medicine and developing clinical therapies from this system of medicine. The shortage of natural medicinal plants used in Tujia medicine has created the need to discover new resources to replace them and protect endangered natural plant species. Endophytic fungi are one of the conservation options, are considered a source of new bioactive natural products, and are a renewable and inexhaustible source of new drugs and agrochemicals. This review summarizes 260 compounds from endophytic fungi that have been previously isolated from the medicinal plants of Tujia. These compounds include steroids, terpenoids, meroterpenoids, polyketides, alkaloids, peptides, aliphatic compounds, aromatic compounds, and heterocyclic compounds.

Pharmacological Potential of Fungal Endophytes Associated with Medicinal Plants: A Review

Endophytic microbes are microorganisms that colonize the intracellular spaces within the plant tissues without exerting any adverse or pathological effects. Currently, the world population is facing devastating chronic diseases that affect humans. The resistance of pathogens to commercial antibiotics is increasing, thus limiting the therapeutic potential and effectiveness of antibiotics. Consequently, the need to search for novel, affordable and nontoxic natural bioactive compounds from endophytic fungi in developing new drugs with multifunction mechanisms to meet human needs is essential. Fungal endophytes produce invaluable bioactive metabolic compounds beneficial to humans with antimicrobial, anticancer, antidiabetic, anti-inflammatory, antitumor properties, etc. Some of these bioactive compounds include pestacin, taxol, camptothecin, ergoflavin, podophyllotoxin, benzopyran, isopestacin, phloroglucinol, tetrahydroxy-1-methylxanthone, salidroside, borneol, dibenzofurane, methyl peniphenone, lipopeptide, peniphenone etc. Despite the aforementioned importance of endophytic fungal metabolites, less information is available on their exploration and pharmacological importance. Therefore, in this review, we shall elucidate the fungal bioactive metabolites from medicinal plants and their pharmacological potential.

Discovery of a Novel Lineage Burkholderia cepacia ST 1870 Endophytically Isolated from Medicinal Polygala paniculata Which Shows Potent In Vitro Antileishmanial and Antimicrobial Effects

In this study, we report the isolation and identification of an endophytic strain of Burkholderia cepacia (COPS strain) associated with Polygala paniculata roots. Polygala plants are rich sources of promising microbiomes, of which the literature reports several pharmacological effects, such as trypanocidal, antinociceptive, anesthetic, anxiolytics, and anticonvulsant activities. B. cepacia COPS belongs to a new sequence type (ST 1870) and harbors a genome estimated in 8.3 Mbp which exhibits the aminoglycosides and beta-lactams resistance genes aph(3′)-IIa and bla_TEM-116, respectively. Analysis performed using MLST, average nucleotide identity, and digital DNA-DNA hybridization support its species-level identification and reveals its novel housekeeping genes alleles gyrB, lepA, and phaC. The root endophyte B. cepacia COPS drew our attention from a group of 14 bacterial isolates during the primary screening for being potentially active against Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212, Micrococcus luteus ATCC 9341, Escherichia coli ATCC 25922, and Candida albicans ATCC 10231 and exhibited the broad-spectrum activity against phytopathogenic fungi. In addition, COPS strain showed production of protease, lipase, and esterase in solid media, and its natural product extract showed potent inhibition against fungal plant pathogens, such as Moniliophthora perniciosa, whose antagonism index (89.32%) exceeded the positive control (74.17%), whereas Sclerotinia sclerotiorum and Ceratocystis paradoxa showed high percentages of inhibition (85.53% and 82.69%, respectively). COPS crude extract also significantly inhibited S. epidermidis ATCC 35984, E. faecium ATCC 700221 (MIC values of 32 μg/mL for both), E. faecalis ATCC 29212 (64 μg/mL), and S. aureus ATCC 25923 (128 μg/mL). We observed moderate antagonistic activity against A. baumannii ATCC 19606 and E. coli ATCC 25922 (both at 512 μg/mL), as well as potent cytotoxic effects on Leishmania infantum and Leishmania major promastigote forms with 78.25% and 57.30% inhibition. In conclusion, this study presents for the first time the isolation of an endophytic B. cepacia strain associated with P. paniculata and enough evidence that these plants may be considered a rich source of microbes for the fight against neglected diseases.

Beauveria bassiana Endophytic Strain as Plant Growth Promoter: The Case of the Grape Vine Vitis vinifera

The common grape vine, Vitis vinifera, is a widely known plant with commercial and pharmacological value. The plant hosts a variety of microorganisms known as endophytes that can live within the tissues of the plant for a considerable time period, or even their whole life cycle. The fungus Beauveria bassiana is a well-studied endophyte which can colonize a variety of plants in many ways and in different parts of the plant. In this study, we examined the effect of the endophytic fungus B. bassiana on the growth of V. vinifera. The results demonstrated not only a successful colonization of the endophyte, but also a noteworthy impact on the growth of the V. vinifera root without harming the plant in any way. The fungus was also re-isolated from the parts of the plant using inst bait method. Overall, the study demonstrates the capability of B. bassiana to colonize V. vinifera plants, adding to the already existing knowledge of its endophytic activity, and highlighting its beneficial impact on the root growth.

Cadinane- and drimane-type sesquiterpenoids produced by Paecilomyces sp. TE-540, an endophyte from Nicotiana tabacum L., are acetylcholinesterase inhibitors

Sesquiterpenoids with diverse skeleton types are regarded as potential lead compounds in pharmacological and other applications. Herein, we report the discovery of two new cadinane-type sesquiterpenoids, paecilacadinol A (1) and B (2); two new drimane-type sesquiterpenoids, ustusol D (3) and ustusol E (4); and six known analogs (5-10) from the endophytic fungus Paecilomyces sp. TE-540, enriching the structural diversity of naturally occurring sesquiterpenoids. Their planar structures were determined on the basis of detailed interpretation of 1D and 2D NMR spectroscopy and HRESIMS data, while their stereochemical structures were established by X-ray crystallographic analyses for 1 and 3-8 and theoretical calculations for 2. Notably, compounds 1 and 2 represent novel examples of cadinane-type sesquiterpenoids with ether bonds formed by intramolecular dehydration. Compounds 5 and 6 showed moderate activities against acetylcholinesterase (AChE), with IC50 values of 43.02 ± 6.01 and 35.97 ± 2.12 μM, respectively. Docking analysis predicted that 5 bound well in the catalytic pocket of AChE via hydrophobic interactions with Trp84, Gly117, Ser122, and Tyr121 residues, while 6 was located with Asp72 and Ser122 residues.

Phaeosphaones: Tyrosinase Inhibitory Thiodiketopiperazines from an Endophytic Phaeosphaeria fuckelii

Phaeosphaeria fuckelii, an endophytic fungus associated with the herbal medicine Phlomis umbrosa, produced four new thiodiketopiperazine alkaloids, phaeosphaones A-D (1-4), featuring an unusual β-(oxy)thiotryptophan motif, along with four known analogues, phaeosphaone E (5), chetoseminudin B (6), polanrazine B (7), and leptosin D (8). Their structures were elucidated by extensive spectroscopic data analysis, and their absolute configurations were determined by single-crystal X-ray diffraction and ECD calculations. Compounds 4, 6, and 8 were found to display mushroom tyrosinase inhibitory activity with IC₅₀ values of 33.2 ± 0.2, 31.7 ± 0.2, and 28.4 ± 0.2 μM, respectively, more potent than that of the positive control, kojic acid (IC₅₀ = 40.4 ± 0.1 μM). A molecular-docking study disclosed the π-π stacking interaction between the indole moiety of 8 and the His243 residue of tyrosinase.

New peptidendrocins and anticancer chartreusin from an endophytic bacterium of Dendrobium officinale

Background

Endophyte has now become a potential source for the discovery of novel natural products, as they participate in biochemical pathways of their hosts and produce analogous or novel bioactive compounds. As an epiphytic plant, Dendrobium officinale is one of precious Chinese medicines with various activities. It is well known for containing diverse endophytes, but so far not much is known about their secondary metabolites.

Methods

the plant tissues were cut and cultured on agar plates to isolate and purify the endophytic bacteria from Dendrobium officinale. Taxonomical identification of strains was performed by 16s rRNA. At the same time, the crude extracts of the strains were tested for antibacterial and cytotoxic activities to screen out one endophyte, Streptomyces sp. SH-1.2-R-15 for further study. After scale-up fermentation, isolation, purification and structure elucidation by using MS, 1D/2D-NMR spectroscopic method, secondary metabolites were identified and submitted for biological activity test.

Results

Fifty-eight endophytic strains representing 9 genera were obtained, with 50% of strains were Streptomyces. One of the most active strain, Streptomyces sp. 1.2-R-15, was selected for bioassay-guided isolation, which led to the discovery of two new peptide-type compounds 1 and 2, as well as a bioactive chartreusin, and four other known natural products. Their structures were determined by comprehensive spectroscopic techniques. Chartreusin showed potent cytotoxicity against Hep3B2.1-7 (IC₅₀ =18.19 µM) and H1299 (IC₅₀ =19.74 µM) cancer cell lines, and antibacterial activity against S. aureus (IC₅₀ =23.25 µM).

Conclusions

This study highlights the endophytic bacteria from medical plant D. officinale have potential bioactivity and natural product diversity, thus implicates them as a valuable source for new anticancer and antibiotics agents.

Insecticidal Endostemonines A-J Produced by Endophytic Streptomyces from Stemona sessilifolia

The discovery of new, safe, and effective pesticides is one of the main means for modern crop protection and parasitic disease control. During the search for new insecticidal secondary metabolites from endophytes in Stemona sessilifolia (a traditional Chinese medicine with a long history as an insecticide), 10 new insecticidal endostemonines A-J (1-10) were identified from an endophytic Streptomyces sp. BS-1. Their structures were determined by comprehensive spectroscopic analysis. Endostemonines A-J represent the first reported naturally occurring pyrrole-2-carboxylic ester derivatives, which consisted of different fatty acid chains at the C-2 of pyrrole ring were produced by traditional Chinese medicine endophytic microbes. All new tested compounds exhibited strong lethal activity against Aphis gossypii (LC₅₀ value range of 3.55-32.00 mg/L after 72 h). This research highlighted the discovery of pesticide natural products from insecticidal medicinal plant endophytes for the first time, paving a new pathway for the development of pest control.

Four New Chromone Derivatives from Colletotrichum gloeosporioides

Four previously unreported chromones, 5-hydroxy-2-(hydroxymethyl)-8-methoxy-4H-chromen-4-one (1), (5R,7S)-5,7-dihydroxy-2-propyl-5,6,7,8-tetrahydro-4H-chromen-4-one (2), (5R,7S)-5,7-dihydroxy-2-methyl-5,6,7,8-tetrahydro-4H-chromen-4-one (3), and (5R,7S)-5,7-dihydroxy-2-[(E)-prop-1-en-1-yl]-5,6,7,8-tetrahydro-4H-chromen-4-one (4), as well as one known analogue 5-hydroxy-2-methyl-4H-chromen-4-one (5) were isolated from the fermentation broth of the endophytic fungus Colletotrichum gloeosporioides derived from the mangrove Ceriops tagal. Their structures were elucidated based on extensive spectroscopic analyses. The absolute configurations of 2-4 were determined by comparison the experimental and calculated electronic circular dichroism (ECD) spectra. Compound 2 showed cytotoxic activity against A549 cell line with the IC₅₀ value of 0.094 mm.

Isolation of Antibiotic 3R,5R-Dihydroxyhexanoate Polymers From Endophytic Fungi

The extracts of two isolates in our library of fungal endophytes, Annulohypoxylon multiforme (TC2-046) from the medicinal plant Juniperus communis and a sterile filamentous isolate (KP1-131DD) from the marine alga Scytosiphon lomentaria, displayed similar antimicrobial bioactivity profiles with notable high activity against Staphylococcus aureus. Bioassay-guided fractionation led to the isolation of poly(3 R,5 R-dihydroxyhexanoic acid) oligomers ranging from the trimer to the 29-mer that exhibited significant and selective inhibition of S. aureus and Mycobacterium tuberculosis H37Ra in vitro.

Agricultural and Other Biotechnological Applications Resulting from Trophic Plant-Endophyte Interactions

Endophytic microbiota plays a role not only in supplying plants with the basic nutrients indispensable for their growth, but also helps them in the mechanisms of adaptation to various environmental stresses (i.e., salinity, drought), which is important in the aspect of crop yields. From the agricultural and biotechnological points of view, the knowledge of endophytes and their roles in increasing crop yields, plant resistance to diseases, and helping to survive environmental stress is extremely desirable. This paper reviews some of the beneficial plant–microbe interactions that might be potentially used in both agriculture (plant growth stimulation effect, adaptation of host organisms in salinity and drought conditions, and support of defense mechanisms in plants), and in biotechnology (bioactive metabolites, application of endophytes for bioremediation and biotransformation processes, and production of biofertilizers and biopreparations). Importantly, relatively recent reports on endophytes from the last 10 years are summarized in this paper.

Fusarubin and Anhydrofusarubin Isolated from A Cladosporium Species Inhibit Cell Growth in Human Cancer Cell Lines

Cladosporium species are endophytic fungi that grow on organic matter and are considered food contaminants. The anti-microbial and anti-tumor naphthoquinones fusarubin (FUS) and anhydrofusarubin (AFU) were isolated using column chromatography from a Cladosporium species residing inside Rauwolfia leaves. The impact of FUS and AFU on cell growth was assessed in acute myeloid leukemia (OCI-AML3) and other hematologic tumor cell lines (HL-60, U937, and Jurkat). Treatment with FUS or AFU reduced the number of OCI-AML3 cells as evaluated by a hemocytometer. Flow cytometry analyses showed that this effect was accompanied by diverse impairments in cell cycle progression. Specifically, FUS (20 or 10 μg/mL significantly decreased the percentage of cells in S phase and increased the percentage of cells in G2/M phase, whereas AFU increased the percentage of cells in G0/G1 phase (50 and 25 μg/mL) and decreased the percentage of cells in S (50 μg/mL) and G2/M (50 and 25 μg/mL) phases. Both substances significantly increased apoptosis at higher concentrations. The effects of FUS were more potent than those of AFU, with FUS up-regulating p21 expression in a p53-dependent manner, as detected by Western blot analyses, likely the consequence of decreased ERK phosphorylation and increased p38 expression (both of which increase p21 stability). FUS also decreased Akt phosphorylation and resulted in increased Fas ligand production and caspase-8/3-dependent apoptosis. These results suggest that FUS and AFU inhibit proliferation and increase apoptosis in cell lines derived from hematological cancers.