Antiradical Activity and Ferric Reducing Antioxidant Power of <i>Pleurotus pulmonarius</i>, <i>Pleurotus floridanus</i> and <i>Pleurotus sajor</i>-<i>caju</i> Formulations Extracts <i>in Vitro</i>

Abstract

Edible mushrooms, known for many years and considered as functional foods, contain a wide variety of biomolecules with nutritional and medicinal properties. Pleurotus species, especially Pleurotus pulmonarius , Pleurotus floridanus and Pleurotus sajor - caju are the most commonly consumed in Cameroon. The present work aims to study the “ in vitro ” antiradical activity and ferric reducing antioxidant power of extracts of formulations of these three species. Mushrooms were harvested in two mycicultures from Cameroon, then dried and crushed finely to obtain powders. In well-defined proportions, ten different formulations were made and their aqueous, ethanol and hydroethanol extracts prepared. These were used to determine total phenolic content by using Folin-Ciocalteu reagent method, the antioxidant activity determined by 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging activity and ferric-reducing antioxidant power (FRAP) assays, with vitamin C (ascorbic acid) as standard. The results obtained from the ten formulations, including thirty extracts, showed that all the extracts had quite significant ferric reducing power at C = 1 mg/ml, (7.35 - 26.02 mg EAA/g). They also had good percentages of DPPH radical inhibition at C = 25 mg/ml (60.40% - 77.72%) and a significant polyphenol content at C = 100 mg/ml (13.73 - 21.15 mg CE/g). The aqueous extracts had the best activities compared to the standard. In addition, a strong positive linear correlation exists between polyphenol content and the scavenging property ( R 2 = 0.9063; p = 0.0003) also with the ferric reducing test ( R 2 = 0.9253; p = 0.0001); suggesting the responsibility of these compounds for these activities. This study suggests that these mushrooms may be used as a natural source of potential antioxidants for food supplements and their consumption is strongly recommended for their beneficial effects on health through, the protection of the human body against the oxidative damage involved in the occurrence of many chronic diseases.