In vitro antioxidant activity and total phenolic content of endophytic fungi isolated from Eugenia jambolana Lam

Phytochemical Analysis and Antioxidant Activity of Endophytic Fungi Isolated from Dillenia indica Linn

Endophytic fungi live symbiotically inside plants and are hidden source of natural bioactive molecules. The present study was carried out to investigate the phytochemical analysis and antioxidant activity of endophytic fungi isolated from the ethnomedicinal plant Dillenia indica L. The ethyl acetate crude extracts of the endophytic fungal strains were preliminarily evaluated for their phytochemical analysis, and the results showed the presence of alkaloids, flavonoids, phenolics, terpene, and saponins. The crude extracts of more than 60% of the isolates showed 50-90% antioxidant activity by DPPH and H2O2 assay. The inhibition percentage of ethyl acetate extracts ranges from 34.05 to 91.5%, whereas IC50 values vary from 72.2 to 691.14%. Among all the strains, Fomitopsis meliae crude extract showed a maximum inhibition percentage, i.e., 91.5%, with an IC50 value of 88.27 µg/mL. Chaetomium globosum showed significant activity having an inhibition percentage of 89.88% and an IC50 value of 74.44 µg/mL. The total phenolic and flavonoid content in the crude extract of Chaetomium globosum was 37.4 mg gallic acid equivalent (GAE)/g DW and 31.0 mg quercetin equivalent (GAE)/g DW. GC-MS analysis of crude extract of C. globosum revealed different compounds, such as squalene; butanoic acid, 2-methyl-; hexadecanoic acid; 2-propanone, 1-phenyl-; 5-oxo-pyrrolidine-2-carboxylic acid methyl ester; 9,12-octadecadienoic acid (z)- etc. Many of these belong to phenolics, which are natural antioxidant compounds. The findings suggested that endophytic fungi associated with Dillenia indica L. can be a potential source of novel antioxidant compounds.

Molecular and morphological diversity, qualitative chemical profile and antioxidant activity of filamentous fungi of the digestive tract of Phylloicus sp. (Trichoptera: Calamoceratidae)

Abstract This study aimed to identify by molecular analysis, morphology, chemistry and antioxidant extracts of filamentous fungi isolated from the digestive tract of Phylloicus sp, an aquatic insect that lives on leaf packages in tropical streams and participates together with fungi of the decomposition of plant substrates in aquatic habitats. Insect larvae of Phylloicus sp. were collected in streams in the state of Tocantins, Brazil. Fungi were isolated from the digestive tract of larvae after disinfection and dissection, then described and purified for identification purposes and testing for antioxidant activity. Molecular identity was performed of ITS1 and ITS4, TUB e TEF sequencing. Fungal extracts were produced in 70% ethanol solution and later lyophilized. For analysis of chemical groups of extracts, thin layer chromatography (TLC) was performed in two mobile phases and different developers. Morphology was performed by optical microscopy stained with Toluidine Blue and measurement performed using the ImageJ program. Antioxidant activity performed in TLC and by quantitative method for DPPH and hydrogen peroxide (H2O2) radicals. Four fungi were identified: Endomelanconiopsis endophytica, Myxospora musae, Neopestalotiopsis cubana and Fusarium pseudocircinatum. The TLC showed several spots with acetone/chloroform mobile phase and UV 254 nm developers and I2 vapor. Fungal extracts demonstrate antioxidant action to reduce the DPPH free radical and especially for H2O2 above 50%, E. endophytica 91.6%, M. musae 87.8%, N. cubana 89.5% and 92.3% for F. pseudocircinatum. This study demonstrated that the molecular technique by PCR was satisfactory for identifying fungi, and extracts with numerous chemical groups and potent reducing agents. Thus future work, should be carried out evaluating these four species for industrial use.

Fungi-derived natural antioxidants

In humans, exogenous antioxidants aid the endogenous antioxidant system to detoxify excess ROS generated during oxidative stress, thereby protecting the body against various diseases and stressful conditions. The majority of natural antioxidants available on the consumer market are plant-based; however, fungi are being recognized as alternative sources of various natural antioxidants such as polysaccharides, pigments, peptides, sterols, phenolics, alkaloids, and flavonoids. In addition, some exogenous antioxidants are exclusively found in fungi. Fungi-derived antioxidants exhibit scavenging activities against DPPH, ABTS, hydroxyl, superoxide, hydrogen peroxide, and nitric oxide radicals in vitro. Furthermore, in vivo models, application of fungal-derived antioxidants increase the level of various antioxidant enzymes, such as catalases, superoxide dismutases, and glutathione peroxidases, and reduce the level of malondialdehyde. Therefore, fungi-derived antioxidants have potential to be used in the food, cosmetic, and pharmaceutical industries. This review summarizes the antioxidant potential of different fungi (mushrooms, yeasts, and molds)-derived natural compounds such as polysaccharides, pigments, peptides, ergothioneine, ergosterol, phenolics, alkaloids, etc.

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.

Endophytic fungi: hidden treasure chest of antimicrobial metabolites interrelationship of endophytes and metabolites

Endophytic fungi comprise host-associated fungal communities which thrive within the tissues of host plants and produce a diverse range of secondary metabolites with various bioactive attributes. The metabolites such as phenols, polyketides, saponins, alkaloids help to mitigate biotic and abiotic stresses, fight against pathogen attacks and enhance the plant immune system. We present an overview of the association of endophytic fungal communities with a plant host and discuss molecular mechanisms induced during their symbiotic interaction. The overview focuses on the secondary metabolites (especially those of terpenoid nature) secreted by endophytic fungi and their respective function. The recent advancement in multi-omics approaches paved the way for identification of these metabolites and their characterization via comparative analysis of extensive omics datasets. This study also elaborates on the role of diverse endophytic fungi associated with key agricultural crops and hence important for sustainability of agriculture.

Fungal Endophytes: Microfactories of Novel Bioactive Compounds with Therapeutic Interventions; A Comprehensive Review on the Biotechnological Developments in the Field of Fungal Endophytic Biology over the Last Decade

The seminal discovery of paclitaxel from endophytic fungus Taxomyces andreanae was a milestone in recognizing the immense potential of endophytic fungi as prolific producers of bioactive secondary metabolites of use in medicine, agriculture, and food industries. Following the discovery of paclitaxel, the research community has intensified efforts to harness endophytic fungi as putative producers of lead molecules with anticancer, anti-inflammatory, antimicrobial, antioxidant, cardio-protective, and immunomodulatory properties. Endophytic fungi have been a valuable source of bioactive compounds over the last three decades. Compounds such as taxol, podophyllotoxin, huperzine, camptothecin, and resveratrol have been effectively isolated and characterized after extraction from endophytic fungi. These findings have expanded the applications of endophytic fungi in medicine and related fields. In the present review, we systematically compile and analyze several important compounds derived from endophytic fungi, encompassing the period from 2011 to 2022. Our systematic approach focuses on elucidating the origins of endophytic fungi, exploring the structural diversity and biological activities exhibited by these compounds, and giving special emphasis to the pharmacological activities and mechanism of action of certain compounds. We highlight the tremendous potential of endophytic fungi as alternate sources of bioactive metabolites, with implications for combating major global diseases. This underscores the significant role that fungi can play in the discovery and development of novel therapeutic agents that address the challenges posed by prevalent diseases worldwide.

Phytochemical profiling, anti-hyperglycemic, antifungal, and radicals scavenging potential of crude extracts of Athyrium asplenioides- an in-vitro approach

This research was aimed to evaluate the phytochemical profile, antifungal, anti-hyperglycemic, as well as antioxidant activity competence of different extracts of Athyrium asplenioides through in-vitro approach. The A. asplenioides crude methanol extract contained considerable quantity of pharmaceutically precious phytochemicals (saponins, tannins, quinones, flavonoid, phenols, steroid, and terpenoids) than others (acetone, ethyl acetate, and chloroform). Interestingly, the crude methanol extract showed remarkable antifungal activity against Candida species (C. krusei: 19.3 ± 2 mm > C. tropicalis: 18.4 ± 1 mm > C. albicans: 16.5 ± 1 mm > C. parapsilosis: 15.5 ± 2 mm  >  C. glabrate: 13.5 ± 2 mm > C. auris: 7.6 ± 1 mm) at a concentration of 20 mg mL-1. The crude methanol extract also showed remarkable anti-hyperglycemic activity on concentration basis. Surprisingly, remarkable free radicals scavenging potential against DPPH (76.38%) and ABTS (76.28%) free radicals at a concentration of 20 mg mL-1. According to the findings, the A. asplenioides crude methanol extract contains pharmaceutically valuable phytochemicals and may be useful for drug discovery.

Plant-growth promoting activity of three fungal endophytes isolated from plants living in dehesas and their effect on Lolium multiflorum

Endophytic fungi have been demonstrated to produce bioactive secondary metabolites, some of which promote plant growth. Three endophytic fungi isolated from healthy plants living in dehesas of Extremadura (Spain) were identified and evaluated for their ability to produce phytohormone-like substances, antioxidant activity, total polyphenol content, phosphate solubilization ability and siderophore and ammonia production. The filtrates and extracts produced by the three endophytes were applied to Lolium multiflorum seeds and seedlings under both in vitro and greenhouse conditions, to analyse their influence on plant growth traits such as germination, vigour index, chlorophyll data, number and length of leaves and roots, and dry weight. All three endophytes, which were identified as Fusarium avenaceum, Sarocladium terricola and Xylariaceae sp., increased the germination of L. multiflorum seeds by more than 70%. Shoot and root length, plant dry weight and the number of roots were positively affected by the application of fungal filtrates and/or extracts, compared with controls. The tentative HPLC-MS identification of phytohormone-like substances, such as gibberellin A2 and zeatin, or the antioxidant acetyl eugenol, may partially explain the mechanisms of L. multiflorum plant growth promotion after the application of fungal filtrates and/or extracts.

Growth-Promoting Characteristics of Fungal and Bacterial Endophytes Isolated from a Drought-Tolerant Mint Species Endostemon obtusifolius (E. Mey. ex Benth.) N. E. Br

Endophytes are primarily endosymbiotic bacteria and fungi that colonize the interior tissues of their host plant. They enhance the host plant's growth and attenuate adverse effects of biological stress. Endophytic species of many indigenous plants are an untapped resource of plant growth-promoting microorganisms that can mitigate abiotic stress effects. Thus, this study aimed to isolate endophytes from the roots and leaves of the medicinal plant Endostemon obtusifolius to evaluate their in vitro growth-promoting capacities and drought tolerance and to characterize the most promising species. Twenty-six endophytes (fourteen bacteria and twelve fungi) were isolated and cultured from the roots and leaves of E. obtusifolius. All 26 endophytes produced flavonoids, and 14 strains produced phenolic compounds. Of the 11 strains that displayed good free radical scavenging capability (low IC₅₀) in the 1-1-diphenyl-1-picryhydrazyl radical scavenging assay, only three strains could not survive the highest drought stress treatment (40% polyethylene glycol). These 11 strains were all positive for ammonia and siderophore production and only one strain failed to produce hydrogen cyanide and solubilize phosphate. Seven isolates showed aminocyclopropane-1-carboxylate deaminase activity and differentially synthesized indole-3-acetic acid. Using molecular tools, two promising symbiotic, drought stress tolerant, and plant growth-enhancing endophytic species (EORB-2 and EOLF-5) were identified as Paenibacillus polymyxa and Fusarium oxysporum. The results of this study demonstrate that P. polymyxa and F. oxysporum should be further investigated for their drought stress mitigation and plant growth enhancement effects as they have the potential to be developed for use in sustainable agricultural practices.

Comparative Analysis of the Antioxidant, Antidiabetic, Antibacterial, Cytoprotective Potential and Metabolite Profile of Two Endophytic Penicillium spp

The current study assessed the metabolite abundance, alpha (α)-amylase and α-glucosidase inhibitory, antioxidant, and antibacterial activity of the ethyl acetate extract (EAE) of endophytic Penicillium lanosum (PL) and Penicillium radiatolobatum (PR). A higher extract yield was found in EAE-PR with a total phenolic content of 119.87 ± 3.74 mg of GAE/g DW and a total flavonoid content of 16.26 ± 1.95 mg of QE/g DW. The EAE-PR inhibited α-amylase and scavenged ABTS+ radicals with a half-maximal inhibitory concentration (IC₅₀) of 362.5 and 37.5 µg/mL, respectively. Compared with EAE-PL, EAE-PR exhibited higher antibacterial activity against Gram-positive and Gram-negative pathogens. Treatment with EAE-PR (1000 µg/mL) did not cause significant toxicity in the HEK-293 cell line compared to the control cells (p < 0.05). EAE-PR treatments (250-1000 µg/mL) showed higher cytoprotective effects toward H₂O₂-stressed HEK-293 cells compared with ascorbic acid (AA). The UHPLC-Q-TOF-MS/MS analysis revealed the presence of thiophene A (C₁₃H₈S), limonene (C₁₀H₁₆), and phenylacetic acid (C₈H₈O₂) in EAE-PR. Furthermore, these compounds demonstrated substantial interactions with diabetes (α-amylase and α-glucosidase), oxidative stress (NADPH-oxidase), and bacteria (D-alanine D-alanine ligase)-related enzymes/proteins evidenced in silico molecular docking analysis.

Exploration of the chemical constituents and its antioxidant, antibacterial activities of endophytic fungi isolated from the medicinal plant Dillenia indica

Assam, India being the pool for ethnomedicinal plants harbors diverse endophytic fungi constituting major bioactive metabolites. The present study was designed to screen the antioxidant, antibacterial activities along with the chemical constituents of the endophytic fungi isolated from the fruits of Dillenia indica (commonly known as Otenga in Assam). Screening of such metabolic compounds and their antioxidant, antibacterial activities can have tremendous potential in suppressing certain diseases. Agar well diffusion method has been used to carry out the antibacterial assay against three pathogenic bacteria two gram positive [Bacillus subtilis (MTCC No. 441); Staphylococcus aureus (MTCC No. 740)] and one gram negative [Escherichia coli (MTCC No. 739)]. Aspergillus fumigatus of ethyl acetate extract showed a prominent activity against Staphylococcus aureus followed by Aspergillus flavus and Aspergillus niger. Antioxidants have the potential to neutralize and inhibit the action of free radicals. The highest scavenging activity was exhibited by ethyl acetate extract of Aspergillus fumigatus in DPPH assay. Furthermore, the phytochemical screening revealed the presence of flavonoids, alkaloids, terpenoids and saponins. Result showed that ethyl acetate extract of Aspergillus fumigatus showed the highest phenolic content (236.81 ± 0.2 mg.g^-1) and least was shown by Aspergillus flavus (92.12 ± 1.4 mg.g^-1). Total flavonoids content for Aspergillus fumigatus (39.08 ± 0.2 mg.g^-1) was found to be highest compared to other isolates. Molecular identification of the endophytic fungus showing highest activity was done based on 18S rRNA. The sequenced was submitted in Genbank with accession number MH540721 showing high similarities with Aspergillus fumigatus strain 3,162,954. A. fumigatus strain is subjected to GC/MS analysis that revealed the chemical constituents 2-isopropyl-5-methyl-1-heptanol, dodecane, 1-fluoro-pentanoic acid, 2-ethylhexyl ester, 1-octanol, 2-butyl-1-dodecanol. Thus, the present work reveals that endophytic fungi colonizing in ethnomedicinal plant Dillenia indica could be a promising source for antioxidant and antibacterial activity. Further work is needed to add value in various therapeutic and pharmaceutical fields.

Phytochemical screening and antioxidative property evaluation of lipid-producing fungi

The increased demands for natural bioactive compounds have induced the search for unusual sources. Microorganisms, especially fungi are a potent source of secondary metabolites, which could act mainly as antioxidant compounds to prevent oxidative stress. In the present study three soil-isolated fungi Aspergillus niger, Aspergillus heteromorphus and Aspergillus fumigatus, were screened for their oleaginous property as well as their potential for the production of bioactive compounds. Fungal biomasses were freeze dried and extracted with methanol using a cold percolation process for the production of intracellular metabolites and the fungal culture media after fermentation were examined for extracellular metabolites. Intracellular and extracellular extracts of the isolated fungi along with the single-cell oils extracted from those fungi were screened for phytochemicals, which showed the presence of alkaloids, flavonoides, glycosides, phenols, saponins and terpenoids. All strains showed potent antioxidant activity, determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and ferric reducing antioxidant power (FRAP) activity. Extracellular extract and single-cell oil of A. heteromorphus showed the highest antioxidant activity with maximum ABTS radical scavenging activity and reducing potential. Highest content of phenolic and flavonoid compounds within the isolated fungi was found to be 37.58 mg gallic acid equivalent (GAE)/g and 62.07 mg catechine equivalent (CE)/g, respectively. Chromatographic analysis of the intracellular and extracellular extracts of the fungi showed the presence of gallic acid, di-hydroxy benzoic acid, ferulic acid, quercetin, epigerin, kampferol, trans cinnamic acid, chlorogenic acid and rutin, which made them biologically important and beneficial for human health.

Phytochemistry and Biological Activities of Endophytic Fungi from the Meliaceae Family

Meliaceae plants are found worldwide in tropical or subtropical climates. They are important ethnobotanically as sources of traditional medicine, with 575 species and 51 genera. Previous research found that microorganisms are plant pioneers to produce secondary metabolites with diverse compound structures and bioactivities. Several plants of the Meliaceae family contain secondary metabolites isolated from endophytic fungi. Furthermore, related articles from 2002 to 2022 were collected from SciFinder, Google Scholar, and PubMed. About 276 compounds were isolated from endophytic fungi such as terpenoids, polyketides, lactones, pyrones, quinone, anthraquinones, xanthones, coumarines, isocoumarines, resorcylic acid lactones, cytochalasins, aromatics, ester, quinols, alkaloids, nitro compound, fatty acids, and sugars with bioactivities such as antioxidant, antibacterial, antifungal, anti-influenza, neuroprotective activities, anti-HIV, cytotoxic, allelopathic, anti-inflammatory, antifeedant effects, and BSLT toxicity. Meanwhile, secondary metabolites isolated from endophytic fungi were reported as one of the sources of active compounds for medicinal chemistry. This comprehensive review summarizes the ethnobotanical uses and secondary metabolites derived from Meliaceae endophytic fungi.

Fusarium oxysporum & Fusarium solani: Identification, Characterization, and Differentiation the Fungal Phenolic Profiles by HPLC and the Fungal Lipid Profiles by GC-MS

Fusarium is a famous genus including a numerous species of endophytic fungi as it is known as a productive source of secondary metabolites which had various bioactivities. Fungal secondary metabolites are defined as chemical compounds produced by fungus and not essential for it. The common secondary metabolites of Fusarium sp. (e.g., phenols, flavonoids, alkaloids, saponins, and terpenes) had a wide range of biological properties comprising antioxidant, antidiabetic, antibacterial, antifungal, and cytotoxic activities. In this way, the present study was performed to evaluate the phenolic compounds and flavonoids of Fusarium oxysporum and Fusarium solani qualitatively and quantitatively via high-performance liquid chromatography (HPLC). Moreover, lipid criteria of Fusarium oxysporum and Fusarium solani extracts had been displayed by gas chromatography-mass spectrometry (GC-MS) and their fatty acids had been identified to define the prolific species of the most biological and valuable fatty acids. In discrimination between phenols and flavonoids of Fusarium oxysporum and Fusarium solani as natural biological constituents analyzed by HPLC, the methanolic extracts of Fusarium species revealed that phenols level was elevated in F. oxysporum than its level in F. solani as well flavonoids level was advanced in F. oxysporum compared to F. solani. Furthermore, the HPLC chromatograph showed significant detection for some phenols in F. oxysporum extract were disappeared in F. solani extract and also some flavonoids were detected in F. oxysporum extract were vanished in F. solani extract. On the other side, the quantitative lipid analysis of Fusarium species chloroform extracts showed significant elevation in F. oxysporum lipid amount compared to F. solani, as the qualitative lipid analysis by GC-MS indicated that the concentration of saturated fatty acids was receded in F. oxysporum (29.18%) than its concentration in F. solani (40.11%) and the ratio of oxidation was 3.73% in F. oxysoporum while in F. solani was 4.23%. These displayed data illustrated conclusively that Fusarium oxysporum had a wide medicinal effectiveness as antioxidant, anticancer, anti-inflammation, and cardioprotective action due to its plentiful content from valuable phenols, flavonoids, and fatty acids in comparison with F. solani, as it may be elected as an alternative natural drug for some pharmaceutical applications.

Isolation and Identification of Endophytic Fungi from Syzygium cumini Linn and Investigation of Their Pharmacological Activities

This study was conducted to isolate and identify the endophytic fungi from the bark and leaves of the Syzygum cumini plant and investigate the pharmacological activities of endophytic fungi along with plant parts. After isolation, endophytic fungi were identified based on morphological characteristics and molecular identification. Antimicrobial, antioxidant, and cytotoxic activities were studied by a disc diffusion method, free radical scavenging DPPH assay, and brine shrimp lethality bioassay, respectively. A total of eight endophytic fungi were isolated and identified up to the genus level based on morphological characteristics and confirmed by molecular identification techniques. Among the eight isolates, three isolates were identified as Colletotrichum sp. (SCBE-2, SCBE-7, and SCLE-9), while the rest of the isolates belonged to Diaporthe sp. (SCBE-1), Pestalotiopsis sp. (SCBE-3), Penicillium sp. (SCBE-4), Phyllosistica sp. (SCLE-7), and Fusarium sp. (SCLE-8). The presence of flavonoids, anthraquinones, coumarins, and isocoumarins was assumed by the preliminary screening of the fungal and plant extracts by a thin-layer chromatographic technique under UV light. Fungal extracts of Pestalotiopsis sp. Penicillium sp. were found sensitive to all test bacteria, but only extracts from the leaf and bark showed significant antifungal activity along with their antimicrobial activity. Penicillium sp. The fungal extract showed the highest free radical scavenging activity (2.43 μg/mL) near that of ascorbic acid (2.42 μg/mL). Some fungal extracts showed cytotoxic activity that, in general, suggests their probable abundance of biological metabolites. This is the first approach to investigate the endophytic fungi of Syzygium cumini Linn. in Bangladesh, to find the pharmacological potential of endophytes, and to explore novel compounds from those endophytes.

Improved seed germination and plant growth mediated by compounds synthesized by endophytic Aspergillus niger (isolate 29) isolated from Albizia lebbeck (L.) Benth

Plant-microbe interactions are remarkably diverse and dynamic. These interactions can be in the form of endophytic association. Colonization of endophytic microflora in crop plants improves crop health leading to crop enhancement. They stimulate the overall growth of plants by facilitating nutrient uptake and regulating various hormones. This eventually improves the plant biomass and grain yield. Owing to the assistance of the endophytes to the host plants, augmentation of crop plants with potential fungal endophytes or their extracted bioactive compound can upsurge the overall crop production and provide promising solutions for environmentally sustainable agriculture. In this light, the present study deals with the prospects of bioactive metabolites produced by endophytic fungi in Albizia lebbeck (L.) Benth, a medicinal native plant of Rajasthan. The metabolomic analysis of a partially purified extract of Aspergillus niger (isolate 29) showed the presence of a total of 919 compounds using UHPLC-MS/MS. The metabolic pathway analysis revealed that these compounds were influencing super pathway of gibberellin and isoflavonoid biosynthesis. Significant increase in seed germination percentage (73-93%), seed vigour index (834.44-1498.21) and germination index (2.54-3.67 seeds/day) was found in treated seeds compared to untreated. There was a significant improvement in root (45-185%) and shoot length (215-295%) of wheat, barley and millet and a significant increase in root number (38-97%) in wheat and barley. Positive correlation was observed in the growth parameters of all the crops upon treatment. Overall, the results indicated that the partially purified fraction of A. niger (isolate 29) improved seed germination and promoted plant growth in cash crops. The results emphasize towards the importance of secondary metabolites in seed germination and enhancement of plant growth. These results also suggest a probable mutualistic role of endophyte with the host plant.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03332-x.

Screening of Bioactive Compounds from Endophytic Marine-Derived Fungi in Saudi Arabia: Antimicrobial and Anticancer Potential

Nowadays, endophytic fungi represent a rich source of biological active compounds. In the current study, twelve endophytic fungal species were isolated from Avicennia marina leaves. From the isolates, Aspergillus niger, Penicillium rubens and Alternaria alternata recorded the highest isolation frequency (80%), relative density (12.5%) and antimicrobial activity. The antimicrobial and anticancer activities of P. rubens were more effective than those of A. niger and A. alternata; therefore, its identification was confirmed via the ITS rRNA gene. Filtrate extracts of P. rubens, A. alternata and A. niger were analyzed using GC-MS and showed different detected constituents, such as acetic acid ethyl ester, N-(4,6-Dimethyl-2-pyrimidinyl)-4-(4-nitrobenzylideneamino) benzenesulfonamide, 1,2-benzenedicarboxylic acid, hexadecanoic acid and octadecanoic acid. Filtrate extract of P. rubens exhibited the presence of more compounds than A. alternata and A. niger. Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Aspergillus fumigatus were more inhibited by P. rubens extract than A. alternata or A. niger, with inhibition zones of 27.2 mm, 22.21 mm, 26.26 mm, 27.33 mm, 28.25 mm and 8.5 mm, respectively. We observed negligible cytotoxicity of P. rubens extract against normal cells of human lung fibroblasts (WI-38 cell line), unlike A. alternata and A. niger extracts. Proliferation of prostate cancer (PC-3) was inhibited using P. rubens extract, exhibiting mortality levels of 75.91% and 76.2% at 200 µg/mL and 400 µg/mL of the extract. Molecular docking studies against the crystal structures of C. albicans (6TZ6) and the cryo-EM structure of B. subtilis (7CKQ) showed significant interactions with benzenedicarboxylic acid and N-(4,6-dimethyl-2-pyrimidinyl)-4-(4-nitrobenzylideneamino) benzenesulfonamide as a constituent of P. rubens extract. N-(4,6-dimethyl-2-pyrimidinyl)-4-(4-nitrobenzylideneamino) benzenesulfonamide had the highest scores of −6.04905 kcal/mol and −6.590 kcal/mol towards (6tz6) and (7CKQ), respectively.

Effect of Fungal Fermentation on Enhancement of Nutritional Value and Antioxidant Activity of Defatted Oilseed Meals

Agro-industrial residues contain high nutritive value. Nowadays, various advanced researches have been done for the production of various value-added products, using these wastes as substrates in the fermentation media. Flaxseed, mustard, and rice bran meal, residues of oil industry, were used as substrates for fermentation. Submerged fermentation with soil-isolated fungal species of the genus Aspergillus sp. was done for oil production by using these substrates in the fermentation media. Effect of fermentation by the oleaginous species of Aspergillus on the nutritive value and functional properties of flaxseed, mustard, and rice bran meal has been discussed for the first time in the present study. After fermentation, the seed meals showed substantial increase in the protein and ash content. The fungal strains utilized the carbohydrate present in the seed meals for the production of highly nutritional metabolites, which decrease the sugar contents of the meals. The fungi also showed extracellular amylase and cellulase activities which helped to hydrolyze the carbohydrates present in these meals, to utilize them for their metabolism. The enhancement was also observed in terms of antioxidant activity of the meals. Increase in the total phenolic and flavonoid contents was observed after fermentation along with radical scavenging activity of 1,1-diphenyl-2-picrylhydrazyl and 2,2-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid reagents and ferric reduction potential. These effects of fermentation modify these cheap waste materials into nutrient dense substrates, which could be further used in the formulation of value-added products.

4a-methyl-dodecahydro-1H-pyrrolo[3,4-b]quinoline-6-one produced by Endophytic Fungi Aspergillus niger E12 obtained from Dodonaea viscosa Plant Leaves as a Novel Antibacterial Compound

Endophytic fungi were isolated from forty plant leaf samples from Gudiyam forest. The potent antibacterial strain Aspergillus niger E12 isolated from the plant Dodonaea viscosa showed maximal antibacterial activity against all the test organisms, viz., Staphylococcus aureus, Bacillus coagulans, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The production of the antibacterial compound was optimized using the yeast extract sucrose medium (2% YES) using response surface methodology (RSM). For the production, the optimal parameters were carbon/nitrogen (C:N) ratio, 9:1; temperature, 25 °C; pH, 5.7; incubation time, 240 h; and rpm, 30. A zone of inhibition of 19.33 mm was observed as maximal bioactivity against Pseudomonas aeruginosa. The antibacterial compound was purified by extraction with ethyl acetate, activity-guided fractionation, and preparative high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), Fourier transform infrared (FTIR) spectroscopy, and nuclear magnetic resonance (NMR) studies showed that the Aspergillus niger E12 bioactive substance is 4a-methyl-dodecahydro-1H-pyrrolo [3,4-b] quinoline-6-one.

Antioxidant, antibacterial, cytotoxicity, and phytochemical potentials of fungal bioactive secondary metabolites

The present study focuses on antioxidant, antibacterial, phytochemical potential, and cytotoxicity of secondary metabolites from Colletotrichum gloeosporioides, Fusarium proliferatum, Alternaria arborescens, and Pestalotiopsis vismiae. The scavenging effect of fungal metabolites was determined by 2, 2-diphenyl-1-picrylhydrazyl (DPPH), H₂ O₂ , O₂ -, and reducing power assays. Among the four fungi, A. arborescens have higher antioxidant activity of DPPH (81.12%), H₂ O₂ (74.83%), superoxide (75.74%), and reducing power (0.141) with standard ascorbic acid. Fungal metabolites were found to be significantly effective against all tested pathogens. A. arborescens showed significant amounts of phenolic (138.78 ± 3.70 mg/g of gallic acid equivalent), flavonoid (74.16 ± 3.58 mg/g of quercetin equivalent), as well as cytotoxicity effects in a cancer cell line (A549) with inhibitory concentration (IC₅₀  = 35 µg/ml at 24 and 48 h). The live and dead cells were analyzed by acridine orange/ethidium bromide staining methods. In addition, A. arborescens metabolites were characterized through gas chromatography-mass spectrometry analysis. The major compounds were found to be phenol, 4-(1,1,3,3-tetramethylbutyl)-, acetamide, N-(3-methylphenyl)-, dibutyl phthalate, and benzo[qr]naphtho[2,1,8,7-fghi] pentacene. The compounds were reported in A. arborescensis up to our knowledge this is the first report. Based on this study, all fungal strains have a significant bioactive capacity with A. arborescens strain exhibiting greater biological properties. Further purification and characterization of A. arborescens bioactive component could lead to an intriguing reservoir of novel pharmacological agents in the future.

Endophytic fungi of Brunfelsia uniflora: isolation, cryopreservation, and determination of enzymatic and antioxidant activity

Brunfelsia uniflora (Pohl.) D. Don (Solanaceae), commonly known as manacá-de-cheiro, is widely distributed in Brazil and used by local indigenous peoples as an antirheumatic, antisyphilitic, depurative, emetic, vermifuge, and purgative agent. Several studies have examined the biological activities and phytochemical profile of Brunfelsia; however, few have focused on the diversity of endophytic microorganisms that colonize members of the genus. This study aimed to isolate and cryopreserve endophytic fungi from B. uniflora and determine their cellulase, laccase, and antioxidant activities. Endophytic fungi were isolated from B. uniflora stems, cultured on wheat grains, immersed in a 150 g L^-1 aqueous sucrose solution, and cryopreserved at - 80 °C for 1 and 6 months. Cellulase activity was determined by a qualitative test using carboxymethylcellulose medium and laccase activity by a quantitative test based on the oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate). Prior to antioxidant activity assays, fungi were grown in malt extract broth for production of mycelial biomass. A methanolic extract was prepared for evaluation of DPPH· scavenging activity, FRAP activity, and total phenolic content. A total of 46 endophytic fungal isolates were obtained from B. uniflora stems and classified into 24 groups according to morphological similarities. B. uniflora was shown to harbor different genera of ascomycete fungi as endophytic organisms. Mycelial viability was observed after 1 and 6 months of cryopreservation at - 80 °C. Fungi exhibited cellulase and laccase activities. Isolate CE23 had the highest laccase activity after 7 days of cultivation. Twelve isolates were found to have low total phenolic contents and DPPH· and FRAP activities.

Pharmacological evaluation of anti-arthritic potential of terpinen-4-ol using in vitro and in vivo assays

Terpinen 4-ol, a phytochemical is a monoterpene which has been reported for its anti-inflammatory effect. Present research was planned to check its effect against arthritis through in vitro and in vivo models. Terpinen 4-ol was evaluated through in-vitro procedures including blocking of protein (BSA and egg albumin) denaturation and human RBC membrane stabilization. In in vivo study, terpinen 4-ol (15, 30 and 60 mg/kg) was evaluated using formaldehyde and CFA arthritic models. Terpinen 4-ol significantly inhibited increase in paw and joint swelling as compared to diseased group. Terpinen 4-ol showed remarkable antioxidant effect (SOD, reducing power) and also improved body weight, haematological, histopathological and radiological parameters in CFA model. Also, moreover, the excess production of IL-1β, TNF-α, IRAK, and NF-kB were noticeably attenuated in all terpinen 4-ol treated rats, however, IL-17 and IL-10 were distinctly increased compared to arthritic control rats in RT-PCR. Also, terpinen 4-ol showed promising antioxidant effect in DPPH assay. Henceforth, it might be concluded that terpinen 4-ol has anti-arthritic effect which can be attributed to the downregulation of pro-inflammatory cytokines.

Bioprospecting of fungal endophytes from Oroxylum indicum (L.) Kurz with antioxidant and cytotoxic activity

Oroxylum indicum (L.) Kurz, a medicinal plant, shows numerous pharmacological properties which may be attributed to the bioactive compounds produced by O. indicum or due to associated endophytes. In the present study, leaf of O. indicum was evaluated for the presence of associated fungal endophytes, and antioxidant and cytotoxic activities of bioactive compounds produced from them. Using culture-dependent approach, eight fungal endophytes belonging to five different genera were identified. Two endophytes Daldinia eschscholtzii and Ectophoma multirostrata have been reported for the first time from the leaf of O. indicum plant. High-performance thin-layer chromatography (HPTLC) of ethyl acetate (EA) extract of isolated fungal endophytes showed a distinct fingerprinting profile in EA extract of Colletotrichum gloeosporioides. Among identified endophytes, EA extract of C. gloeosporioides showed significant antioxidant activity against DPPH free radical, superoxide anion radical, nitric oxide radical and hydroxyl radical with EC50 values of 22.24±1.302 μg/mL, 67.46±0.576 μg/mL, 80.10±0.706 μg/mL and 61.55±1.360 μg/mL, respectively. EA extract of C. gloeosporioides exhibited potential cytotoxicity against HCT116, HeLa and HepG2 cancer cell lines with IC50 values of 76.59 μg/mL, 176.20 μg/mL and 1750.70 μg/mL, respectively. A comparative HPTLC fingerprinting and the antioxidant activity of C. gloeosporioides associated with two different hosts (leaf of O. indicum and dead twigs of other plant) showed that C. gloeosporioides produces bioactive compounds in a host-dependent manner.

Green synthesis of silver nanoparticles and its antibacterial activity using fungus Talaromyces purpureogenus isolated from Taxus baccata Linn

The present study is focused on the synthesis of silver nanoparticles (AgNPs) utilizing endophytic fungus Talaromyces purpureogenus, isolated from Taxus baccata Linn. Extracellular extract of Talaromyces purpureogenus has shown occurrence of secondary metabolites viz. terpenoids and phenols. Gas chromatography-mass spectroscopy analysis showed the presence of 16 compounds. Techniques like Ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, dynamic light scattering, field emission gun scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction were employed to characterize the synthesized AgNPs. UV–Vis spectroscopy showed sharp peaks at 380–470 nm which indicates the presence of metallic silver. FTIR analysis showed the presence of various functional groups like phenols, hydroxyl groups, and primary amines. In DLS, Z-average size and PdI of synthesized AgNPs were 240.2 r.nm and 0.720 respectively, with zeta potential − 19.6 mV. In FEG-SEM and HRTEM the spherical AgNPs showed diameter in the range of 30–60 nm. In EDS analysis the weight percent of Ag is 67.26% and atomic percent is 43.13%. From XRD analysis the size of AgNPs was found to be 49.3 nm with face-centered cubic crystalline nature of fungal synthesized AgNPs. These nanoparticles have shown significant antibacterial activity against tested strains viz. Listeria monocytogenes (13 ± 0.29 mm), Escherichia coli (17 ± 0.14 mm), Shigella dysenteriae (18 ± 0.21 mm) and Salmonella typhi (14 ± 0.13 mm). These synthesized AgNPs have shown effective free radical scavenging activity against 2,2′-diphenyl-1-picrylhydrazyl. The present study showed that the endophytic fungus Talaromyces purpureogenus can be used as a prominent source to synthesize AgNPs by using biological, ecofriendly, and in a non-toxic way accompanied by antibacterial and antioxidant properties which further can reduce the harvesting pressure faced by Taxus baccata.

Graphical Abstract

Withania somnifera Chemical Constituents' In Vitro Antioxidant Potential and Their Response on Spermatozoa Parameters

Background: Phytomedicine is becoming more acceptable as an alternative medicinal approach in the modern era. Objectives: The current study examined the antioxidant capacity and in vitro response of phytochemical constituents of Withania somnifera (Ashwagandha) on standard parameters of healthy volunteer semen. Methods: The phytochemicals and their pharmacological response in a hydroethanolic (30:70 v/v) extract of W. somnifera roots were determined using standard protocols. Results: The constituents included flavonoids, phenolic acids, alkaloids, and terpenoids were reported. High-performance liquid chromatography and Fourier-transform infrared spectroscopy determined a diverse array of biologically active chemical constituents in the extract. The extract of W. somnifera exhibits substantial antioxidant properties, including total antioxidant capacity, 2,2-diphenyl-1-picrylhydrazyl inhibition, H2O2 scavenging, and Fe3+ reducing potential (P < .05). The analysis of essential natural minerals explored adequate levels determined using atomic absorption spectrophotometer. Cytotoxic studies revealed significant thrombolytic, RBC membrane stabilization, and DNA damage protection activity (P < .05) while remaining non-mutagenic against Salmonella typhi TA98 and TA100. The best protective response of W. somnifera extract on human semen parameters (n = 30), such as total motility, progressive motility, and viability, demonstrated a significant (P < .05) improvement, particularly at the dose of 25 μg/mL and 50 μg/mL. Conclusion: The study concludes that W. somnifera possesses favorable in vitro characteristics that could aid in the preservation of sperm during intrauterine insemination and in vitro fertilization.

Desert soil fungi isolated from Saudi Arabia: cultivable fungal community and biochemical production

Desert soils harbor fungi that have survived under highly stressed conditions of high temperature and little available moisture. This study was designed to survey the communities of cultivable fungi in the desert soils of the Arabian Peninsula and to screen the fungi for the potentially valuable antioxidants (flavonoids, phenols, saponins, steroids, tannins, terpenoids, and alkaloids) and enzymes (cellulase, laccase, lipase, protease, amylase, and chitinase). Desert soil was sampled at 30 localities representing different areas of Saudi Arabia and studied for physico-chemical soil properties. Five types of soil texture (sand, loamy sand, sandy loam, silty loam, and sandy clay loam) were observed. A total of 25 saprotrophic species was identified molecularly from 68 isolates. Our survey revealed 13 culturable fungal species that have not been reported previously from Arabian desert soils and six more species not reported from Saudi Arabian desert soils. The most commonly recorded genera were Aspergillus (isolated from 20 localities) and Penicillium (6 localities). The measurements of biochemicals revealed that antioxidants were produced by 49 and enzymes by 52 isolates; only six isolates did not produce any biochemicals. The highest biochemical activity was observed for the isolates Fusarium brachygibbosum and A. phoenicis. Other active isolates were A. proliferans and P. chrysogenum. The same species, for instance, A. niger had isolates of both high and low biochemical activities. Principal component analysis gave a tentative indication of a relationship between the biochemical activity of fungi isolated from soil and soil texture variables namely the content of silt, clay and sand. However, any generalizable relation between soil properties and fungal biochemical activities cannot be suggested. Each fungal isolate is probable to produce several antioxidants and enzymes, as shown by the correlation within the compound groups. Desert soil warrants further research as a promising source of biochemicals.

Optimization and Characterization of Antimicrobial Agents Produced by Marine Aspergillus terreus She05 against Aeromonas hydrophila and other Applications

Seven morphologically distinct marine fungi were isolated from sediment and Seawater samples at different sites along Alexandria seashore. Antagonism effect against Aeromonas hydrophila on purpose and other pathogen was estimated. The most promising isolate giving the highest antibacterial activity (14 mm) against A. hydrophila was morphologically and genetically identified as Aspergillus terreus SHE05 and the corresponding sequence was recorded in the GenBank database with accession no. MW772239. Time course production of the antibacterial agents by A. terreus SHE05 against A. hydrophila was studied showing the highest productivity after 5 days incubation. Multi-factorial design in terms of Placket Burman design was implemented to predict the critical factors influencing the production of the antibacterial agents by A. terreus SHE05 against A. hydrophila. The obtained results showed that malt extract, pH and temperature were the key factors affecting the antimicrobial activity. Consequently, Box-Behnken design was applied to estimate the optimized levels of each independent variable showing that the optimized conditions were malt extract, 3 (g/l); peptone, 0.75 (g/l); salinity, 50%; pH, 4; culture age, 4 days; inoculum size, 0.5 ml; temperature 30°C and incubation time 5 days, which caused an increase in the antimicrobial activity to 25 mm, which denotes an approximately 1.8 fold increase comparing with the pre-optimized conditions. The potentiality of chloroform, hexane, petroleum ether and ethyl acetate for extraction of the active compounds was tested showing that ethyl acetate was the best. The extracted bioactive metabolites using ethyl acetate were tested as antimicrobial, anticancer, antiviral and antioxidant agents. Results showed reasonable activities. GC-MS was used to recognize the active components in the ethyl acetate extract, showing that the major compound was the Dodecanamine, N,N-Dimethyl with RT 11.95, molecular weight 213, area % (55.46) and molecular formula C14H31N.

Multi-functional bioactive secondary metabolites derived from endophytic fungi of marine algal origin

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Marine algae of Kerala coastline are rich in endophytic fungal biodiversity

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Fungal isolates displayed promising antibacterial, antioxidant and cytotoxic activity

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Gas Chromatography based identification assisted in further metabolite discovery

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Various non-therapeutic applications reported earlier also adds to the significance.

Endophytic fungi from marine macroalgae are endowed with various pharmacologically active metabolites. This study mined, identified and screened endophytic fungi (EF) isolated from marine algae from the west coast of South India for screening anticancer, antioxidant and antimicrobial secondary metabolite producers. Five EF isolated from sampled marine algae were identified using morphology and ITS based identification as Grammothele fuligo, Rigidoporus vinctus, Cystobasidium minutum, Candida railenensis and Pichia kudriavzevii. After culturing 20 days on PDA medium, the ethyl acetate extracts of Cystobasidium minutum showed potent antimicrobial activity against P. aeruginosa with an IC₅₀ value of 458.7 ± 1.021 µg/mL whereas Pichia kudriavzevii extracts showed promising antioxidant activity (IC₅₀ value of 65.78 ± 1.082 µg/mL, 38.74 ± 1.040 µg/mL and 32.01 ± 1.018 µg/mL for DPPH assay, ABTS assay and FRAP assay respectively) and high cytotoxic activity against MG63 cell line (IC₅₀ = 145.1 ± 1.086 µg/mL, no activity against U87 cells). The phytochemical screening of the extracts unveiled the existence of diverse groups of secondary metabolites. Further, Gas Chromatography Mass Spectroscopy (GC-MS) analysis of the extract revealed the presence of compounds that are known to be antibacterial, antioxidant and cytotoxic. These results indicate that marine derived endophytes could be potent sources for multi-functional bioactive compounds and may find prospective application in pharmaceutical industry.

Phytochemical screening and antioxidant and antimicrobial activities of crude extracts of different filamentous fungi

Five filamentous fungal strains that grew in different whey-based media under submerged fermentation were investigated for antioxidant properties and phytochemicals. Phytochemical analysis revealed the presence of alkaloids, tannin, flavonoids, glycosides, phenols, saponins, and terpenes in the crude intra- and extracellular ethyl acetate extracts of different strains. All fungal extracts exhibited effective antioxidant activities in terms of TPC, TFC, DPPH, FRAP, ABTS, reducing power, and metal chelating capacity. The activities of intracellular extracts were higher than the extracellular metabolites. Fermentation media with sugar and salt supplementation significantly influenced antioxidant production. Aspergillus niger in glucose-supplemented whey medium was found to exhibit the highest antioxidant properties. The antimicrobial activity of A. niger and Penicillium expansum extracts by microtiter plate assay showed a promising result against some pathogenic bacterial strains. Chromatographic analysis of the fungal extracts revealed the presence of chlorogenic acid, trans-cinnamic acid, ferulic acid quercetin, myricetin, kaempferol, and catechin which are known for their antioxidant properties. Accumulation of nutrients in fungal biomass under constraint environment produces secondary metabolites which has demonstrated efficacy towards alleviation of several degenerative diseases. The antioxidative enriched phytochemicals present in these five different fungal strains will provide a breakthrough in the utilisation of whey as inexpensive source of substrate for the growth of these fungi. Moreover, phytochemicals could be utilized as therapeutic agents in a cost-effective and environmentally friendly manner.

Biochar, Compost, and Biochar-Compost Blend Applications Modulate Growth, Photosynthesis, Osmolytes, and Antioxidant System of Medicinal Plant Alpinia zerumbet

Alpinia zerumbet (Zingiberaceae) is a unique ornamental and medicinal plant primarily used in food ingredients and traditional medicine. While organic amendments such as biochar (BC) and compost (Co) have been demonstrated to improve plant productivity, no studies have examined their effects on the growth, physiology, and secondary metabolites of A. zerumbet. This study evaluated the impact of the amendment of BC, Co, or a biochar and compost mixture (BC+Co) on modifying and improving the growth, photosynthesis, antioxidant status, and secondary metabolism of A. zerumbet grown on sandy loam soil. The morpho-physiological and biochemical investigation revealed variation in the response of A. zerumbet to organic amendments. The amendment of BC and BC+Co significantly increased net photosynthetic rates of plants by more than 28%, chlorophyll a and b contents by 92 and 78%, respectively, and carboxylation efficiency by 50% compared with those grown in the sandy loam soil without amendment. Furthermore, the amendment significantly decreased plant oxidative stress, measured as leaf free proline and glycine betaine. Enzymatic antioxidant activity, total phenols, and flavonoids also varied in their response to the organic amendments. In conclusion, this study shows that BC and/or Co amendments are an efficient and sustainable method for improving the metabolite contents and reducing oxidative stress in A. zerumbet.

Antioxidants: Classification, Natural Sources, Activity/Capacity Measurements, and Usefulness for the Synthesis of Nanoparticles

Natural extracts are the source of many antioxidant substances. They have proven useful not only as supplements preventing diseases caused by oxidative stress and food additives preventing oxidation but also as system components for the production of metallic nanoparticles by the so-called green synthesis. This is important given the drastically increased demand for nanomaterials in biomedical fields. The source of ecological technology for producing nanoparticles can be plants or microorganisms (yeast, algae, cyanobacteria, fungi, and bacteria). This review presents recently published research on the green synthesis of nanoparticles. The conditions of biosynthesis and possible mechanisms of nanoparticle formation with the participation of bacteria are presented. The potential of natural extracts for biogenic synthesis depends on the content of reducing substances. The assessment of the antioxidant activity of extracts as multicomponent mixtures is still a challenge for analytical chemistry. There is still no universal test for measuring total antioxidant capacity (TAC). There are many in vitro chemical tests that quantify the antioxidant scavenging activity of free radicals and their ability to chelate metals and that reduce free radical damage. This paper presents the classification of antioxidants and non-enzymatic methods of testing antioxidant capacity in vitro, with particular emphasis on methods based on nanoparticles. Examples of recent studies on the antioxidant activity of natural extracts obtained from different species such as plants, fungi, bacteria, algae, lichens, actinomycetes were collected, giving evaluation methods, reference antioxidants, and details on the preparation of extracts.

Fungal Endophytes as Efficient Sources of Plant-Derived Bioactive Compounds and Their Prospective Applications in Natural Product Drug Discovery: Insights, Avenues, and Challenges

Fungal endophytes are well-established sources of biologically active natural compounds with many producing pharmacologically valuable specific plant-derived products. This review details typical plant-derived medicinal compounds of several classes, including alkaloids, coumarins, flavonoids, glycosides, lignans, phenylpropanoids, quinones, saponins, terpenoids, and xanthones that are produced by endophytic fungi. This review covers the studies carried out since the first report of taxol biosynthesis by endophytic Taxomyces andreanae in 1993 up to mid-2020. The article also highlights the prospects of endophyte-dependent biosynthesis of such plant-derived pharmacologically active compounds and the bottlenecks in the commercialization of this novel approach in the area of drug discovery. After recent updates in the field of 'omics' and 'one strain many compounds' (OSMAC) approach, fungal endophytes have emerged as strong unconventional source of such prized products.

Screening Fungal Endophytes Derived from Under-Explored Egyptian Marine Habitats for Antimicrobial and Antioxidant Properties in Factionalised Textiles

Marine endophytic fungi from under-explored locations are a promising source for the discovery of new bioactivities. Different endophytic fungi were isolated from plants and marine organisms collected from Wadi El-Natrun saline lakes and the Red Sea near Hurghada, Egypt. The isolated strains were grown on three different media, and their ethyl acetate crude extracts were evaluated for their antimicrobial activity against a panel of pathogenic bacteria and fungi as well as their antioxidant properties. Results showed that most of the 32 fungal isolates initially obtained possessed antimicrobial and antioxidant activities. The most potent antimicrobial extracts were applied to three different cellulose containing fabrics to add new multifunctional properties such as ultraviolet protection and antimicrobial functionality. For textile safety, the toxicity profile of the selected fungal extract was evaluated on human fibroblasts. The 21 strains displaying bioactivity were identified on molecular basis and selected for chemical screening and dereplication, which was carried out by analysis of the MS/MS data using the Global Natural Products Social Molecular Networking (GNPS) platform. The obtained molecular network revealed molecular families of compounds commonly produced by fungal strains, and in combination with manual dereplication, further previously reported metabolites were identified as well as potentially new derivatives.

Endophytic fungi from Passiflora incarnata: an antioxidant compound source

Endophytes are considered one of the most important microbial resources for obtaining biomolecules of therapeutic use. Passiflora incarnata, widely employed by the pharmaceutical industry, shows therapeutic effects on anxiety, nervousness, constipation, dyspepsia and insomnia based on their antioxidant compounds. In this study, from 315 endophytic fungi isolated from P. incarnata leaves, 60 were selected to determinate presence of chemical constituents related with antioxidant activity, based on their production of soluble pigments. The promising fungi were evaluated specifically on their potential to produce phenolic compounds, flavonoids and for antioxidant activity. Five isolates significantly produced flavonoids and phenolic compounds in the ethyl acetate and n-Butanol extracts, also saponins and high antioxidant activity against the DPPH (2.2-diphenyl-1-picrylhydrazyl) free radical. A strain of Aspergillus nidulans var. dentatus (former Emericella dentata) was able to produce tannins as well; its butanolic extract was very similar than the BHT (butylated hydroxytoluene) (94.3% × 94.32%) and Rutin (95.8%) reference substances in the DPPH radical scavenging. Similarly, a Chaetomium strain exhibited 93.6% and 94.7% of antioxidant activity in their ethyl acetate and butanolic fractions, respectively. The chromatographic analysis of the ethyl acetate fraction from the Aspergillus strain revealed the production of orcinol (3.19%). Four-methoxymethylphenol (4.79%), sorbicillin (33.59%) and ergosterol (23.08%) was produced by Trichoderma longibrachiatum and isopropenyl-1,4-dimethyl-1,2,3,3a,4,5,6,7-octahydroazulene were found in two Fusarium oxysporum strains. The phytochemical screening showed that all analyzed fungi were able to produce a kind of secondary metabolite (phenols, flavonoids, tannins and/or saponins). The study shows a great underexplored potential for industrial application of P. incarnata endophytes.

Therapeutic Response of Epimedium gandiflorum's Different Doses to Restore the Antioxidant Potential and Reproductive Hormones in Male Albino Rats

Current study was planned to explore the therapeutic response of different doses of hydroethanolic extract of Epimedium grandiflorum leaves in male albino rats. Phytochemical analysis, HPLC and FTIR spectroscopy results revealed the presence of wide range of phenolic compounds and functional groups, respectively. Further, extract not induced significant hemolysis (7.56 ± 1.297%) against PBS (3.65 ± 0.35%) as negative control; while have significant clot lysis (44 ± 5.2%) potential, exhibited DPPH (78.87 ± 5.427%) scavenging, H2O2 (31.82 ± 3.491%) scavenging, antioxidant and reducing power activities. In vivo experimentation in albino male rats' revealed that administration of different doses (50, 100, 200 mg/Kg b.w.) of extract orally for 42 days after CCl4 intoxication significantly (P < 0.05) restore the selected parameters including liver enzymes, renal profiles, and stress markers and significantly (P < 0.05) increased reproductive hormones like testosterone, luteinizing hormone, follicle stimulating hormone and prolactin while significantly (P < 0.05) decreased progesterone and estradiol toward normal in dose dependent manner. Significant (P < 0.05) improvement in the structural architecture of testicular tissue particularly in high dose group (200 mg/Kg b.w.) was also observed. Results revealed E. grandiflorum has significant therapeutic response to address the healthcare problems particularly of impotency.

Bioactive compounds from Aspergillus niger extract enhance the antioxidant activity and prevent the genotoxicity in aflatoxin B1-treated rats

This study aimed to identify the bioactive compounds of the ethyl acetate extract of Aspergillus niger SH2-EGY using GC-MS and to evaluate their protective role against aflatoxin B₁ (AFB₁)-induced oxidative stress, genotoxicity and cytotoxicity in rats. Six groups of male Sprague-Dawley rats were treated orally for 4 weeks included the control group, AFB₁-treated group (80 μg/kg b.w); fungal extract (FE)-treated groups at low (140) or high dose (280) mg/kg b.w and the groups treated with AFB₁ plus FE at the two tested doses. The GC-MS analysis identified 26 compounds. The major compounds found were 1,2,3,4,6-Penta-trimethylsilyl Glucopyranose, Fmoc-L-3-(2-Naphthyl)-alanine, D-(-)-Fructopyranose, pentakis (trimethylsilyl) ether, bis (2-ethylhexyl) phthalate, trimethylsilyl ether-glucitol, and octadecanamide, N-(2- methylpropyl)-N-nitroso. The in vivo results showed that AFB₁ significantly increased serum ALT, AST, creatinine, uric acid, urea, cholesterol, triglycerides, LDL, carcinoembryonic antigen, alpha-fetoprotein, interleukin-6, Malondialdehyde, nitric oxide, Bax, caspase-3 and P53 mRNA expression, chromosomal aberrations and DNA fragmentation. It decreased serum TP, albumin, HDL, Bcl-2 mRNA expression, hepatic and renal TAC, SOD and GPx content and induced histological changes in the liver and kidney. FE prevented these disturbances in a dosage-dependent manner. It could be concluded that A. niger SH2-EGY extract is safe a promising agent for pharmaceutical and food industries.

Phytochemical analysis and wound healing studies on ethnomedicinally important plant Malva neglecta Wallr

ETHNOPHARMACOLOGICAL RELEVENCE

The use of herbal medicines is increasing in developed countries as alternative and/or supportive therapy to conventional health care medicines. Malva neglecta Wallr. (Family: Malvaceae) has been reported as wound healing remedy in traditional medicines, however no experimental data is available on its wound healing potentials. The aim of this study was to explore phytochemistry and validate wound healing potentials of the plant using animal models.

MATERIALS AND METHODS

M. neglecta crude methanolic extract (Mn.Cme) was chemically characterized using HPLC-DAD and GCMS analysis. Acute dermal toxicity was determined in albino rats following Organization of Economic Co-operation and Development (OECD) 402 established standards. Wound healing potentials were evaluated in rats using excision wound model. Wounds (177 mm²) were made by an excision on the skin of rats which were placed individually in cages. Mn.Cme was formulated in ointment form and was applied topically onto the wound area once daily for 14 days. The wound area was measured with translucent paper and thereafter estimated on a 1 mm² graph sheet every 3rd day until epithelialization and complete wound closure was recorded. Wound contraction was calculated as a percentage of the original wound size. Antioxidant potentials were also evaluated via FRAP, DPPH and H₂O₂ free radicals scavenging assays.

RESULTS

HPLC-DAD analysis revealed 25 phenolic compounds with higher amounts of hydrotyrosol (109.3 mg/g), coumaroylhexoside (97.4 mg/g), kaempferol-3-(p-coumaroyldiglucoside)-7-glucoside (37.2 mg/g), quercetin-3-O-rutinoside (31.5 mg/g) and epicatechin-3-O-(4-O-methyl)-gallate (31.3 mg/g). In GC-MS analysis, oleic acid (19.67%), taurine (17.60%), ethylene dimercaptan (14.67%), isoeugenol (14.61%), patchoulane (10.36%), methyl 12-methyltetradecanoate (8.47%) and isopropyl myristate (7.02%) were highly abundant compounds. No sign of toxicity was observed in the acute dermal toxicity test. Our test sample (Mn.Cme) exhibited considerable wound healing tendency at all doses (1 g, 1.5 g, 2 g per 10 g of ointment base) with reduced epithelialization period in a dose-related manner. Absolute healing was observed after application of 2 g of Mn.Cme ointment. Further, Mn.Cme exhibited considerable anti-radical potential in all assays.

CONCLUSION

It may be concluded that M. neglecta possess very potent secondary metabolites which are previously reported for wound healing potentials. The plant has considerable antioxidant and wound healing properties and thus warrant further studies to uncover the molecular mechanism its wound healing potentials.

An endophytic Penicillium oxalicum isolated from Citrus limon possesses antioxidant and genoprotective potential

AIMS

This study aimed at isolating endophytic fungi from Citrus limon (L.) possessing antioxidative and genoprotective potential.

METHODS AND RESULTS

Endophytic fungi were screened for antioxidant activity using 2,2-diphenyl,1-picryl hydrazyl radical scavenging assay and maximum activity (79·70%) was exhibited by culture MP1 identified to be Penicillium oxalicum on the basis of morphological and molecular characteristics. The ethyl acetate extract of MP1 was subjected to silica column chromatography followed by LH 20 column chromatography for purification of active metabolites. The partially purified active fraction of P. oxalicum MP1 possessed good antioxidant activity as detected using various assays. It also exhibited a strong DNA damage protection potential on pUC19 plasmid DNA treated with Fenton reagent. On exposure to active fraction of MP1 significant reduction (P < 0·05) in nuclear deformities (like nuclear buds, micronuclei, nuclear ridges and binucleated cells) was observed in human lymphocytes pretreated with a toxic concentration of H₂ O₂ . In vivo genoprotectivity studies were conducted in fresh water fish Channa punctatus pretreated with a damaging compound 4-nonyl phenol. The active fraction of P. oxalicum MP1 caused a reduction of 94·7 and 66·60% in micronuclei and aberrant cell formation, respectively. A significant reduction (P < 0·05) in tail length and tail DNA parameters was also observed in comet assay.

CONCLUSION

The endophytic P. oxalicum isolated in this study has the potential to produce metabolites possessing antioxidant and genoprotective activities.

SIGNIFICANCE AND IMPACT OF THE STUDY

The isolated culture can be exploited in the field of therapeutics by virtue of its in vitro and in vivo genoprotective potential.

ANTIOXIDANT ACTIVITY of THE SECONDARY METABOLITES PRODUCED by ENDOPHYTIC FUNGI ISOLATED from JERUJU (Acanthus ilicifolius L.) PLANT

Twelve endophytic fungi were isolated from Jeruju plant. Three of which have the best antioxidant activity, namely Culvularia lunata DJS1, Diaporthe phaseolorum DJS2, and Colletotrichum siamense BJS4. The fungi can produce secondary metabolites that have the potential as antioxidant compounds. This study aims to isolate the antioxidant compound using a chromatography column and test the antioxidant activity using DPPH method. Isolation of secondary metabolites produced 40 eluates. The IC50 value of DJS111 and BJS42 eluates were 10.20 µg/ml and 20.89 µg/ml, which is an antioxidant compound with very strong activity. The IC50 value of DJS24 eluate was 54.45 µg/ml, which is strong antioxidant activity. DJS111 eluate has antioxidant activity that approaches to ascorbic acid as a standart antioxidant compound (7.76µg/ml). From TLC, DJS111 contains flavonoid compound and DJS24 and BJS42 contain terpenoid compound.