Antibacterial and cytotoxic activities of endophytic fungus Diatrypella sp. MFLUCC 19-0492

Endophytic fungi are microorganisms living inside plant tissues without causing any disease symptoms in the plant. Various bioactive compounds have been produced and may be used as alternative drugs for controlling human pathogens. The aim of this work was to investigate antibacterial and cytotoxic activity potential of fungal crude extracts isolated from Barleria prionitis leaves. A total of 34 endophytic fungi were isolated. The crude ethyl acetate extracts of all fungi were preliminarily screened for their antibacterial activity. The acetate extract of isolate ANG4 showed significant antibacterial activity. This isolate was further cultured to determine its minimum inhibition concentration (MIC). The crude ethyl acetate extracts of mycelia and culture broth from isolate ANG4 were active against all tested pathogens with low MIC values rangingfrom 0.39 mg/mL to 25.00 mg/mL when compared to the crude hexane extract of its mycelia. The cytotoxic effects of all crude extracts of isolate ANG4 were also determined using tetrazolium-based colorimetric (MTT and XTT) assays against T-lymphoblast, cholangiocarcinoma, liver hepatocellular and lung carcinoma cell lines. The crude ethyl acetate extract of mycelia showed the most significant activity inhibiting T-lymphoblast and lung carcinoma cell lines with 100 and 71% respectively whereas the crude hexane extract of mycelia showed good cytotoxic activity against the T-lymphoblast cell line with 74%. The fungus ANG4 was also identified by molecular and phylogenetic methods as Diatrypella sp. MFLUCC19-0492. Therefore, this study indicates that crude extracts of Diatrypella sp. MFLUCC19-0492, isolated from B. prionitis leaves, are potential sources of novel antibacterial compounds with good cytotoxic activity.