Bioactivities of phenolics-rich fraction from Diaporthe arengae TATW2, an endophytic fungus from Terminalia arjuna (Roxb.)

The study demonstrated the in vitro and in vivo anti-hyperchoeterolemic activity of purified fraction of fermentation extract of endophytic fungus Diaporthe arengae TATW2 isolated from Terminalia arjuna Roxb. (Combretaceae). In vitro anti-hypercholesterolemic activity was carried out using human red blood cells (hRBCs) of healthy and hypercholesterolemic donors. Bioactive fraction of the crude extract was obtained using activity guided fractionation followed by Thin-Layer Chromatography (TLC). In vivo efficacy studies of this isolated compound were carried out using albino Wistar rats. After 24 h incubation of whole blood as well as isolated erythrocytes from hypercholesterolemic donors with 100 µg/mL of extract of TATW 2, the concentration of RBC membrane cholesterol was found to be reduced significantly (P<0.05). Bioactivity guided fractionation of crude extract followed by TLC afforded a colorless semisolid phenolic compound. In vivo efficacy studies of this isolated compound were carried out using albino Wistar rats revealed significant alteration in the serum and tissue lipid profile of the animals. Co-administration of the isolated compound at 50 mg kg−1 body weight resulted in a considerable decline in the levels of serum total cholesterol (TC), triglycerides (TG), very low density lipoproteins (VLDL) and low density lipoprotein (LDL) cholesterol in the compound treated group (group C) vis-a-vis animals fed with high fat diet (group B) and the results were comparable to the animals receiving high fat diet plus 10 mg kg−1 body weight of atorvastatin (group D). Chemical characterization of the fractionated compound using GC-HRMS chromatogram revealed one major peak at a retention time of 39.67 as well as three minor peaks. The spectra revealed three phenolic compounds identified as Benzene propionic acid, 3, 5-bis (1, 1-dimethylethyl)-4-hydroxy methyl ester; Pterin-6-carboxylic acid and 2, 6-ditert-butyl-4- phenol. Endophytic Diaporthe produces a variety of secondary metabolites, but, till date, no reports on the production of anti-hypercholesterolemic phenolic compounds. Thus, Diaporthe arengae could be a potential source of phenolic compounds with potential anti-hypercholesterolemic activity.