Mycochemical composition and antioxidant potential of Macrolepiota africana (Heim) Heinem. (Agaricaceae), an edible mushroom from Gabon

Macrolepiota africana is a fungus used as food in Gabon for its culinary properties. However, its nutritional value, mycochemical contents, antioxidant properties and health potential still unknown. The present study investigated the phytochemicals and antioxidant properties of this mushroom species. This chemical screening was followed by a study of the antioxidant activity and a prediction of additional pharmacological activities of M. africana. Using standard methodology, the mycochemical analyses were carried out on aqueous, hydro-ethanolic and ethanolic fungi extracts. The antioxidant activity of the mushroom extracts was determined using DPPH radical scavenging assay. Apart from Digitoxigenine, flavonol and gitoxigenine that were not found in any of the extracts, all other tested mycochemical were found in atleast one of the extracts. Alkaloids, flavonoids, polyphenols, oses and holosides, proanthocyanidins and coumarins were found in all extracts at different intensity. Saponosids, sterols and triterpenes, tannins gallics, reducing sugar, anthracenosides and digitoxine were found in two extracts while tannins catechics, flavone and gitoxine were detected only in one extract. The dosage of phenolic compounds confirmed the richness of this fungus in total polyphenols, its moderate richness in proanthocyanidins, the lack of flavonoids in the aqueous extract and the moderate richness of the hydro-ethanolic and ethanolic extracts in flavonoids. Regarding the antioxidant activities, the results obtained for the DPPH trapping test showed that the different extracts had low to moderate antioxidant activity with antioxidant activity index (IAA) ranged 0.29 to 0.97 respectively in aqueous and ethanolic extracts. The presence of these mycochemical compounds along with the identified antioxidant activities shows that this M. africana have some pharmacological potential.