Radical scavenging potency, HPLC profiling and phylogenetic analysis of endophytic fungi isolated from selected medicinal plants of saudi arabia

The inhibitory effects of endophytic metabolites on glycated proteins under non-communicable disease conditions: A review

Protein glycation in human body is closely linked to the onset/progression of diabetes associated complications. These glycated proteins are commonly known as advanced glycation end products (AGEs). Recent literature has also highlighted the involvement of AGEs in other non-communicable diseases (NCDs) such as cardiovascular, cancer, and Alzheimer's diseases and explored the impact of plant metabolites on AGEs formation. However, the significance of endophytic metabolites against AGEs has recently garnered attention but has not been thoroughly summarized thus far. Therefore, the objective of this review is to provide a comprehensive overview of the importance of endophytic metabolites in combating AGEs under NCDs conditions. Additionally, this review aims to elucidate the processes of AGEs formation, absorption, metabolism, and their harmful effects. Collectively, endophytic metabolites play a crucial role in modulating signaling pathways and enhancing the digestibility properties of gut microbiota (GM) by targeting on AGEs/RAGE (receptor for AGEs) axis. Furthermore, these metabolites exhibit anti-AGEs activities similar to those derived from host plants, but at a lower cost and higher production rate. The use of endophytes as a source of such metabolites offers a risk-free and sustainable approach that holds substantial potential for the treatment and management of NCDs.

The hidden treasures in endophytic fungi: a comprehensive review on the diversity of fungal bioactive metabolites, usual analytical methodologies, and applications

This review provides a comprehensive overview of the key aspects of the natural metabolite production by endophytic fungi, which has attracted significant attention due to its diverse biological activities and wide range of applications. Synthesized by various fungal species, these metabolites encompass compounds with therapeutic, agricultural, and commercial significance. We delved into strategies and advancements aimed at optimizing fungal metabolite production. Fungal cultivation, especially by Aspergillus, Penicillium, and Fusarium, plays a pivotal role in metabolite biosynthesis, and researchers have explored both submerged and solid-state cultivation processes to harness the full potential of fungal species. Nutrient optimization, pH, and temperature control are critical factors in ensuring high yields of the targeted bioactive metabolites especially for scaling up processes. Analytical methods that includes High-Performance Liquid Chromatography (HPLC), Liquid Chromatography-Mass Spectrometry (LC-MS), Gas Chromatography-Mass Spectrometry (GC-MS), Nuclear Magnetic Resonance (NMR), and Mass Spectrometry (MS), are indispensable for the identification and quantification of the compounds. Moreover, genetic engineering and metabolic pathway manipulation have emerged as powerful tools to enhance metabolite production and develop novel fungal strains with increased yields. Regulation and control mechanisms at the genetic, epigenetic, and metabolic levels are explored to fine-tune the biosynthesis of fungal metabolites. Ongoing research aims to overcome the complexity of the steps involved to ensure the efficient production and utilization of fungal metabolites.

Anti-Staphylococcal, Anti-Candida, and Free-Radical Scavenging Potential of Soil Fungal Metabolites: A Study Supported by Phenolic Characterization and Molecular Docking Analysis

Staphylococcus and Candida are recognized as causative agents in numerous diseases, and the rise of multidrug-resistant strains emphasizes the need to explore natural sources, such as fungi, for effective antimicrobial agents. This study aims to assess the in vitro anti-staphylococcal and anti-candidal potential of ethyl acetate extracts from various soil-derived fungal isolates. The investigation includes isolating and identifying fungal strains as well as determining their antioxidative activities, characterizing their phenolic substances through HPLC analysis, and conducting in silico molecular docking assessments of the phenolics' binding affinities to the target proteins, Staphylococcus aureus tyrosyl-tRNA synthetase and Candida albicans secreted aspartic protease 2. Out of nine fungal species tested, two highly potent isolates were identified through ITS ribosomal gene sequencing: Aspergillus terreus AUMC 15447 and A. nidulans AUMC 15444. Results indicated that A. terreus AUMC 15447 and A. nidulans AUMC 15444 extracts effectively inhibited S. aureus (concentration range: 25-0.39 mg/mL), with the A. nidulans AUMC 15444 extract demonstrating significant suppression of Candida spp. (concentration range: 3.125-0.39 mg/mL). The A. terreus AUMC 15447 extract exhibited an IC50 of 0.47 mg/mL toward DPPH radical-scavenging activity. HPLC analysis of the fungal extracts, employing 18 standards, revealed varying degrees of detected phenolics in terms of their presence and quantities. Docking investigations highlighted rutin as a potent inhibitor, showing high affinity (-16.43 kcal/mol and -12.35 kcal/mol) for S. aureus tyrosyl-tRNA synthetase and C. albicans secreted aspartic protease 2, respectively. The findings suggest that fungal metabolites, particularly phenolics, hold significant promise for the development of safe medications to combat pathogenic infections.

Endophytic fungi mediates production of bioactive secondary metabolites via modulation of genes involved in key metabolic pathways and their contribution in different biotechnological sector

Endophytic fungi stimulate the production of an enormous number of bioactive metabolites in medicinal plants and affect the different steps of biosynthetic pathways of these secondary metabolites. Endophytic fungi possess a number of biosynthetic gene clusters that possess genes for various enzymes, transcription factors, etc., in their genome responsible for the production of secondary metabolites. Additionally, endophytic fungi also modulate the expression of various genes responsible for the synthesis of key enzymes involved in metabolic pathways of such as HMGR, DXR, etc. involved in the production of a large number of phenolic compounds as well as regulate the expression of genes involved in the production of alkaloids and terpenoids in different plants. This review aims to provide a comprehensive overview of gene expression related to endophytes and their impact on metabolic pathways. Additionally, this review will emphasize the studies done to isolate these secondary metabolites from endophytic fungi in large quantities and assess their bioactivity. Due to ease in synthesis of secondary metabolites and their huge application in the medical industry, these bioactive metabolites are now being extracted from strains of these endophytic fungi commercially. Apart from their application in the pharmaceutical industry, most of these metabolites extracted from endophytic fungi also possess plant growth-promoting ability, bioremediation potential, novel bio control agents, sources of anti-oxidants, etc. The review will comprehensively shed a light on the biotechnological application of these fungal metabolites at the industrial level.

Identification of geographical origins of Radix Paeoniae Alba using hyperspectral imaging with deep learning-based fusion approaches

The Radix Paeoniae Alba (Baishao) is a traditional Chinese medicine (TCM) with numerous clinical and nutritional benefits. Rapid and accurate identification of the geographical origins of Baishao is crucial for planters, traders and consumers. Hyperspectral imaging (HSI) was used in this study to acquire spectral images of Baishao samples from its two sides. Convolutional neural network (CNN) and attention mechanism was used to distinguish the origins of Baishao using spectra extracted from one side. The data-level and feature-level deep fusion models were proposed using information from both sides of the samples. CNN models outperformed the conventional machine learning methods in classifying Baishao origins. The generalized Gradient-weighted Class Activation Mapping (Grad-CAM++) was utilized to visualize and identify important wavelengths that significantly contribute to model performance. The overall results illustrated that HSI combined with deep learning strategies was effective in identifying the geographical origins of Baishao, having good prospects of real-world applications.

In vitro phytochemical analysis and antibacterial and antifungal efficacy assessment of ethanolic and aqueous extracts of Rumex nervosus leaves against selected bacteria and fungi

Background and Aim

Scientists are interested in identifying natural antibiotic substitutes that are effective against drug-resistant pathogenic microbes and spoilage fungi to counter pathogens and reduce the major public health problem of antibiotic residues in animal products. This study aimed to evaluate the antimicrobial activity of Rumex nervosus leaves (RNLs) as a medicinal herb against four bacterial and two fungal strains using absolute ethanol, 50% ethanol, and aqueous extracts.

Materials and Methods

The antimicrobial activities of various RNL extracts against selected microbes were evaluated using the disk diffusion antibiotic susceptibility test, minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs), minimum fungicidal concentrations, and the poisoned food technique.

Results

The absolute ethanol RNL extract showed the best bacteriostatic/bactericidal activity against Salmonella Typhimurium, Escherichia coli, and Staphylococcus aureus (MIC/MBC: 0.20/0.40, 0.20/0.40, and 0.32/0.65 mg/mL, respectively). The diameter of the zone of inhibition was larger (p < 0.05) for the 100% ethanol RNL extract (8.17 mm) against Salmonella Typhimurium, the 50% ethanol-RNL extract (11.5 mm) against E. coli, and the aqueous RNL extract (14.0 mm) against S. aureus than for any other bacterial isolate. The aqueous RNL extract strongly (p < 0.0001) inhibited the mycelial growth of Aspergillus fumigatus (100%) and Aspergillus niger (81.4%) compared with the control.

Conclusion

The results of this study suggest that RNL is a promising new natural antimicrobial agent for food preservation. To date, most research on the antimicrobial properties of natural herbs has been conducted in vitro, with few exceptions in vivo and intervention-based research.

Resveratrol biosynthesis, optimization, induction, bio-transformation and bio-degradation in mycoendophytes

Resveratrol (3,4,5-trihydroxystilbene) is a naturally occurring polyphenolic stilbene compound produced by certain plant species in response to biotic and abiotic factors. Resveratrol has sparked a lot of interest due to its unique structure and approved therapeutic properties for the prevention and treatment of many diseases such as neurological disease, cardiovascular disease, diabetes, inflammation, cancer, and Alzheimer's disease. Over the last few decades, many studies have focused on the production of resveratrol from various natural sources and the optimization of large-scale production. Endophytic fungi isolated from various types of grapevines and Polygonum cuspidatum, the primary plant sources of resveratrol, demonstrated intriguing resveratrol-producing ability. Due to the increasing demand for resveratrol, one active area of research is the use of endophytic fungi and metabolic engineering techniques for resveratrol's large-scale production. The current review addresses an overview of endophytic fungi as a source for production, as well as biosynthesis pathways and relevant genes incorporated in resveratrol biosynthesis. Various approaches for optimizing resveratrol production from endophytic fungi, as well as their bio-transformation and bio-degradation, are explained in detail.