民族药马利筋内生真菌生物活性研究 postprint

Abstract: Endophytic fungi in medicinal plants have the capacity to produce bioactive compounds whose features have great identity or similarity with the phytohosts. Since Asclepias curassavica has been known to possess a broad range of biological activities, we sought to obtain the active endophytic fungi from this plant. We performed the study followed the idea of “ethnic drug-endophytic fungi-active ingredients”, and thereafter we examined the bio-activities of fungal metabolites from 168 strains of endophytic fungi isolated from A. curassavica. To evaluate the activities of anti-tumor, anti-inflammatory, anti-α-glucosidase and antioxidant in these fungi, the ethyl acetate extracts from fermentation broth of endophytic fungi were first determined using the methods of SRB, Griess, PNPG and DPPH, respectively. Furthermore, we identified the bioactive fungal strains with conserved ITS sequencing. Our results reveal 22 in 168 isolated strains have variable biological activities; and of which 9 strains have obvious antitumor effect with the IC50 values of 0.1 - 40 μg·mL-1. Further, the strain MJF-53 display prominent inhibitory effect on the release of both NO and IL-1β in Raw264.7 cell line by LPS- induction under the concentration of 2.5 μg·mL-1. There were 7 strains showing α-glucosidase inhibitory activity with the IC50 values ranging from 1.0 to 4.0 mg·mL-1, Especially, the inhibitory activity of MYF-16 and MYF-55 are close to acarbose; 19 endophytic fungi have different degrees of DPPH radical scavenging activities, among which MYF-9, MYF-19 and MJF-84 show moderate antioxidant activity with IC50 values of 13.562, 17.776 and 12.395 μg·mL-1 respectively; The ITS identification show that the 22 active strains are mainly distribute in six genera: Alternaria, Colletotrichum, Fusarium, Diaporthe, Talaromyces and Neofusicoccum. This study shows that the bioactivities of the endophytic fungi from A. curassavica are diverse, which lays a foundation for exploring new potential natural anti-tumor, anti-inflammatory, hypoglycemic and antioxidant compounds from the endophytic fungi of A. curassavica.