Diversity, bioactivities, and metabolomics of culturable endophytic fungi from the medicinal plant Ardisia crenata Sims

Abstract

Introduction Ardisia crenata Sims is an important medicinal plant in southern China, yet its industrial utilization is severely limited by unsustainable harvesting of wild resources, inconsistent active ingredient quality, and inefficiencies in conventional extraction processes. Endophytic fungi, which can produce bioactive metabolites identical or analogous to those of the host, offer a promising alternative for sustainable biomanufacturing. Methods In this study, a comprehensive screening strategy was developed to isolate and evaluate endophytic fungi from A. crenata Sims with potential applications as antioxidants, anti-hyperuricemic agents, and anti-diabetic agents. Results and discussion A total of 703 culturable endophytic fungal strains were isolated from the roots, stems, leaves, and fruits of plants collected at seven geographical locations, representing 96 genera across three phyla. Diaporthe, Colletotrichum, and Cladosporium were identified as the dominant genera, and tissue-specific colonization patterns were observed. Notably, 20 strains exhibited low ITS sequence homology, indicating that they may represent novel species. Bioactivity-guided screening revealed that strain AGYR3-6 displayed potent DPPH radical scavenging activity (96.64% at 1.0 mg/mL), comparable to that of ascorbic acid. Strain AGYL2-5 exhibited superior xanthine oxidase inhibitory activity (86.88% at 2.0 mg/mL), suggesting anti-hyperuricemic potential. For anti-diabetic activity, strain ABJR1-3 showed strong α-amylase inhibition (84.63% at 2.0 mg/mL), while strain AGYL2-6 exhibited exceptional α-glucosidase inhibition (97.31% at 2.0 mg/mL), outperforming the positive control acarbose. These findings establish a diverse endophytic fungal resource from A. crenata Sims and identify multiple candidate strains with promising bioactivities. The results highlight the potential of utilizing these endophytic fungi as microbial cell factories for the sustainable production of bioactive compounds, thereby circumventing the limitations associated with plant-based extraction and supporting the green biomanufacturing of value-added products.