Assay of antioxidant potential of two Aspergillus isolates by different methods under various physio-chemical conditions

Abstract

The objective of this work was to screen fungi isolated from soil of different areas of Punjab, India for antioxidant activity by dot blot assay and around 45% of fungal isolates demonstrated antioxidant potential.Two selected strains of Aspergillus spp (Aspergillus PR78 and Aspergillus PR66) showing quantitatively best antioxidant activity by DPPH assay were further tested for their reducing power, ferrous ion and nitric oxide ion scavenging activity, FRAP assay and total phenolic content. Different physio-chemical parameters were optimized for enhancement of the activity. This revealed stationary culture grown for 10 days at 25 o C at pH 7 to be the best for antioxidant activity. Sucrose in the medium as carbon source resulted in highest antioxidant activity. Sodium nitrate, yeast extract, and peptone were good sources of nitrogen but sodium nitrate was the best among these. The extraction of the broth culture filtrates with different solvents revealed ethyl acetate extract to possess the best antioxidant activity. The activity as expressed by ethyl acetate extract of Aspergillus PR78 was equally effective as that of commonly used antioxidant standard, ascorbic acid.

In Vitro Antioxidant Potential of Some Soil Fungi: Screening of Functional Compounds and their Purification from Penicillium citrinum

“…Using this procedure, compounds with antioxidant activity turned out to be yellow in the purple background of the plate. The intensity of the yellow color depends on the amount and nature of radical scavengers present in the extract [28].…”

In-vitro evaluation of antioxidant potential of rauwolfia vomitoria root extract and its inhibitory effect on lipid peroxidation as indication of aphrodisiac properties

“…The upper layer of solution (2.5 ml) was mixed with distilled water (2.5 ml) and ferric chloride (FeCl 3 ) (0.5 ml, 0.1%), and the absorbance of the reaction mixture was measured at 700 nm as indicative of increased reducing power. All the tests were performed in triplicate and a graph was plotted for the average of three observations [14,15].…”

Synergistic Effect of Xylose and Sucrose Enhance Accumulation of Stilbenes in Endophytic Fungus: Aspergillus stellatus

“…Carbon source promote primary metabolism and feeding with more slowly metabolizable compounds may lead to the formation of secondary products. There is usually a dilemma between achieving maximal cell growth rates and maximal production because conditions that allow fast cell growth could be unfavorable to metabolite production (Arora et al, 2010) This also proves that Czapek dox's medium is most effective for metabolite production responsible for Stilbenes production. This shows that the growth medium can also have a significant effect on secondary metabolites and enhancement of secondary metabolites can only be achieved through systematic manipulation of parameters.…”