Evaluation of the nutritional composition and antioxidant activity of Bjerkandera adusta

Abstract Bjerkandera adusta, a globally distributed fungus, is commonly used in the nutritional practices of the East Asian population. In this study, we evaluated the nutritional composition of the lyophilized mycelium of B. adusta as well as the phenolic composition and antioxidant activity of its extracts. The mycelium exhibited moisture (7.97 %), ash (3.27 %), and fiber (5.31 %) content values similar to the established values reported in the available literature. In addition, a high protein (9.32 %) and carbohydrate (63.45 %) content was shown, with a low lipid (1.36 %) content. The energy value per 100 g sample of mycelium was 1445.85 kJ. The results obtained indicated a statistically significant variation (p < 0.05) in the phenolic composition (81.84-110.96 mg gallic acid equivalents (GAE) per g of extract), free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity (IC50 29.05-340.46 µg·mL-1), phosphomolybdenum antioxidant content (34.89-55.64 %), reduction of ferricyanide ion (66.55-69.4 %), and thiobarbituric acid reactive substance (TBARS) values (44.66-133.03 %). These results are unprecedented for this species and emphasize its nutraceutical potential.

Avaliação da atividade antioxidante e antimicrobiana do extrato etanólico bruto e frações orgânicas obtidas a partir da casca do caule da espécie Guettarda uruguensis Cham, & Scthdl, (Rubiaceae) / Assessment of the antioxidant and antimicrobial activity of the crude ethanolic extract and organic fractions obtained from the stem bark of the specie Guettarda uruguensis Cham. & Scthdl. (Rubiaceae)

Este trabalho teve como objetivo avaliar o potencial antioxidante e antimicrobiano do extrato bruto e frações obtidas das cascas do caule da espécie Guettarda uruguensis, Os ensaios antioxidantes indicaram alto potencial antioxidante, No ensaio de redução de fosfomolibdênio, a fração acetato de etila apresentou atividade antioxidante de 41,67% em relação ao padrão de ácido ascórbico e superou em 35,21% a atividade do padrão rutina, No ensaio de redução do DPPH (2,2-diphenyl-1-picrylhydrazyl), a fração acetato de etila apresentou um IC50 de 10,91 µg mL-1, valor próximo ao do ácido ascórbico (IC50 = 4,78 µg mL-1) e da rutina (IC50 = 6,62 µg mL-1), Pelo ensaio de TBA (acido tiobabitúrico) o extrato bruto (IA = 71,48%) e a fração hexano (IA = 47,85%) apresentaram índices superiores ao controle de BHT (butil hidroxi tolueno) (IA = 42,66), Através do ensaio de microdiluição em placas, foi observado que o extrato bruto e frações apresentaram atividade antimicrobiana, O estudo fitoquímico qualitativo revelou a presença de alcaloides, cumarinas, esteroides e/ou triterpenos, heterosídeos saponínicos, taninos e aminogrupos...

This main purpose of this study was to evaluate the antimicrobial and antioxidant effects of the crude extract and fractions obtained from the stem bark of the plant species. The antioxidant assays indicated high antioxidant capacity. In the reduction assay of the phosphomolybdenum, the ethyl acetate fraction showed antioxidant activity of 41.67% compared to standard ascorbic acid and exceeded in 35.21% the activity of the standard rutin. In the reduction assay of the DPPH (2,2-diphenyl-1-picrylhydrazyl), the ethyl acetate fraction showed an IC50 of 10.91 µg mL-1, equivalent to the ascorbic acid (IC50 = 4.78 µg mL-1) and rutin (IC50 = 6.62 µg mL-1). By the TBA (thiobarbituric acid) assay the crude extract (IA = 71.48%) and hexane fraction (IA = 47.85%) had an index higher than the control of BHT (butyl hydroxy toluene) (IA = 42.675). Through of assay of microdilution on plates was verified that the crude extract and fractions showed antimicrobial activity. The qualitative phytochemical study revealed the presence of alkaloids, coumarins, steroids and/or triterpenoids, saponin glycosides, tannins and amino groups...