Exploring the antioxidant potential of endophytic fungi: a review on methods for extraction and quantification of total antioxidant capacity (TAC)

Abstract

Endophytic fungi have emerged as a significant source of natural products with remarkable bioactivities. Recent research has identified numerous antioxidant molecules among the secondary metabolites of endophytic fungi. These organisms, whether unicellular or micro-multicellular, offer the potential for genetic manipulation to enhance the production of these valuable antioxidant compounds, which hold promise for promoting health, vitality, and various biotechnological applications. In this study, we provide a critical review of methods for extracting, purifying, characterizing, and estimating the total antioxidant capacity (TAC) of endophytic fungi metabolites. While many endophytes produce metabolites similar to those found in plants with established symbiotic associations, we also highlight the existence of novel metabolites with potential scientific interest. Additionally, we discuss how advancements in nanotechnology have opened new avenues for exploring nanoformulations of endophytic metabolites in future studies, offering opportunities for diverse biological and industrial applications.

Keywords: ABTS; DPPH; Endophyte solvent extracts and secondary metabolites; FRAP; ORAC; Oxidative stress; Total Phenolic content (TPC); Total flavonoid content (TFC).

Fig. 1

An illustrative description of the processes for extracting and purifying endophytic fungi metabolites from plants and the importance of its antioxidant molecules on cellular homeostasis and popular methods for estimating their total antioxidant capacity (TAC), including DPPH, FRAP, ABTS, and ORAC