Evaluation of antidiabetic and antioxidant potential of endophytic fungi isolated from medicinal plants

Abstract

Introduction: Endophytic microorganisms residing in the tissues of the higher plants are gaining increasing importance as sources of novel therapeutic molecules. In the present study, isolation and screening of endophytes for alpha-glucosidase inhibitory and antioxidant potential was carried out which could have application in the management of diabetes mellitus (DM) and related complications. DM has become a major health concern worldwide, and development and progression of diabetic related complications are accelerated by reactive oxygen species which are generated and accumulated due to hyperglycemia. Material and Methods: Endophytic fungi were isolated from different healthy plants after surface sterilization and screened for the production of alpha-glycosidase inhibitors and antioxidant potential. Antioxidant potential was characterized using 2,2-diphenyl-1-picryl hydrazyl and ferric reducing antioxidant power assays. Total phenolic content (TPC) was estimated by Folin–Ciocalteu assay. Thin-layer chromatography-based phytochemical analysis was conducted using different visualization reagents. In a selected culture, BRY-1 identification of phenolic compounds was carried out using reversed-phase-high-performance liquid chromatography. Results: Sixty-six cultures were isolated from indigenous medicinal plants and screened for α-glucosidase inhibitors (AGI) and antioxidant potential. Majority of isolates belonged to Alternaria and Aspergillus sp. Maximum AGI activity (91.57%) was exhibited by VRJ-3, while good antioxidant potential of 92% was observed in BRY-1, BRY-2, and AZAI-12 cultures. A positive correlation was found between TPC and antioxidant potential; however, no such correlation existed between TPC and AGI. Conclusion: These studies reveal the potential of endophytic fungi as sources of pharmaceutically important molecules. AGI activity in species of Fusarium and Alternaria is being reported for the first time. These isolates can be selected and subjected to further studies to determine the nature of the components