Screening of endophytic fungi having ability for antioxidative and alpha-glucosidase inhibitor activities isolated from Taxus sumatrana.

Endophytic microbes are considered as an important source of natural products. They show antibiotic, anticancer, antioxidative and antidiabetic activities. Therefore, there are many reports on the isolation and bioactivity screening of endophytic fungi from various plants including Taxus species. Taxus sumatrana (Miq.) de Laub is found in Indonesia. The objective of this study is to conduct an in vitro screening of 14 endophytic fungi isolated from Taxus sumatrana having antioxidative and alpha-glucosidase inhibitor activities. Each endophytic fungus was cultured for 7 days and the fungal mycelium and medium were extracted with methanol and ethyl acetate, respectively, to produce each extract. The antioxidative activity of each extract was tested by DPPH free radical scavenging activity and beta-carotene bleaching assays, whereas antidiabetic activity was tested based on alpha-glucosidase inhibitor activity. The screening results showed that fungal mycelia of TSC 13 had the best alpha-glucosidase inhibitor activity and TSC 24 had the best antioxidative activity. Isolation of bioactive compounds from TSC 13 and TSC 24 is being conducted. This is the first report that endophytic fungi isolated from T. sumatrana exhibited anti alpha-glucosidase inhibitory and anti oxidative activities.