Antioxidant, antibacterial, cytotoxicity, and phytochemical potentials of fungal bioactive secondary metabolites.

Abstract

The present study focuses on antioxidant, antibacterial, phytochemical potential, and cytotoxicity of secondary metabolites from Colletotrichum gloeosporioides, Fusarium proliferatum, Alternaria arborescens, and Pestalotiopsis vismiae. The scavenging effect of fungal metabolites was determined by 2, 2-diphenyl-1-picrylhydrazyl(DPPH), H2 O2 , O2 -, and reducing power assays. Among the four fungi, A. arborescens have higher antioxidant activity of DPPH (81.12%), H2 O2 (74.83%), superoxide (75.74%), and reducing power (0.141) with standard ascorbic acid. Fungal metabolites were found to be significantly effective against all tested pathogens. A. arborescens showed significant amounts of phenolic (138.78 ± 3.70 mg/g of gallic acid equivalent), flavonoid (74.16 ± 3.58 mg/g of quercetin equivalent), as well as cytotoxicity effects in a cancer cell line (A549) with inhibitory concentration (IC50 = 35 µg/ml at 24and 48 h). The live and dead cells were analyzed by acridine orange/ethidium bromide staining methods. In addition, A. arborescens metabolites were characterized through gas chromatography-mass spectrometry analysis. The major compounds were found to be phenol, 4-(1,1,3,3-tetramethylbutyl)-, acetamide, N-(3-methylphenyl)-, dibutyl phthalate, and benzo[qr]naphtho[2,1,8,7-fghi] pentacene. The compounds were reported in A. arborescensis up to our knowledge this is the first report. Based on this study, all fungal strains have a significant bioactive capacity with A. arborescens strain exhibiting greater biological properties. Further purification and characterization of A. arborescens bioactive component could lead to an intriguing reservoir of novel pharmacological agents in the future.