Fruiting body, spores and in vitro produced mycelium of Ganoderma lucidum from Northeast Portugal: A comparative study of the antioxidant potential of phenolic and polysaccharidic extracts

Abstract

Abbreviations CATCatalase DAD Diode array detector DPPH 2,2-Diphenyl-1-picrylhydrazyl EC 50Extract concentration providing 50% antioxidant activity or 0.5 absorbance in the reducing power assay FB Fruiting body GAE Gallic acid equivalents GPx Glutathione peroxidase GSH Reduced glutathioneHPLC High-performance liquid chromatography IS Internal standard M Mycelium MMN Melin-Norkans medium MS Mass spectrometry PDA Potato dextrose agar medium PE Polysaccharides equivalents Ph Phenolic extract Ps Polysaccharidic extract RI Refraction index RSA Radical scavenging activity S Spores SOD Superoxide dismutaseTBARS Thiobarbituric acid reactive substances v/v ml/100 ml w/v g/100 ml ABSTRACTGanoderma lucidum is one of the most extensively studied mushrooms due to its medicinal properties. Herein, a systematic study was carried out in order to compare the antioxidant activity of phenolic and polysaccharidic extracts from fruiting body, spores and mycelium, obtained in three different culture media, of G. lucidum from NortheastPortugal. Phenolic extracts were characterized using high-performance liquid chromatography coupled to photodiode array detection, while polysaccharidic extracts were hydrolysed and further characterized using HPLC and refraction index detection.In general, the phenolic extracts (Ph) proved to have higher antioxidant potential than their corresponding polysaccharidic extracts (Ps). Amongst phenolic extracts, FB-Ph provided the highest antioxidant activity (EC 50 ≤ 0.6 mg/ml) and the highest content in total phenolics (~29 mg GAE/g extract) and phenolic acids (p-hydroxybenzoic and pcoumaric acids). S-Ps was the polysaccharidic extract with the best antioxidant activity (EC 50 ≤ 2 mg/ml); nevertheless, the highest levels of total phenolics were obtained in FB-PS (~56 mg GAE/g extract), while the highest levels of total polysaccharides (~14 mg PE/g extract) and individual sugars were observed in mycelia obtained from solid culture media, M-PDA-Ps and M-sMMN-Ps. The free radical scavenging properties, reducing power and lipid peroxidation inhibition of G. lucidum seemed to be correlated with phenolic compounds mostly in a free form, but also linked to polysaccharides.

Chemical features of Ganoderma polysaccharides with antioxidant, antitumor and antimicrobial activities

“…The antioxidant activity of crude polysaccharidic extracts obtained from Ganoderma sp., have been recently described (Shi et al, 2010;Yang et al, 2010;Heleno et al, 2012;Kozarski et al, 2012;Zhao et al, 2012;Pan et al, 2013).…”

“…The above mentioned genus has been widely studied regarding its bioactive properties (Paterson, 2006;Nie et al, 2013), including antibacterial, antioxidant, antitumor and other effects (Wang et al, 1997;Wasser, 2002;Heleno et al, 2012;Li et al, 2012;Heleno et al, 2013;Popović et al, 2013;Zhonghui et al, 2013). The beneficial health properties of Ganoderma species are attributed to a wide variety of bioactive components, such as polysaccharides, triterpenes, sterols, lectins and other proteins Ferreira et al, 2010).…”

“…Other polysaccharidic extracts, also obtained from G. lucidum, displayed radicals scavenging ability, reducing power and lipid peroxidation inhibition, with the extract obtained from spores as the most effective (Heleno et al, 2012). Kozarski et al (2012) reported the antioxidant activity of polysaccharidic extracts from G. applanatum and G. lucidum namely, radicals scavenging activity, reducing power, lipid peroxidation inhibition and chelating abilities.…”

The potential of Ganoderma lucidum extracts as bioactive ingredients in topical formulations, beyond its nutritional benefits

“…Nevertheless, Yildiz et al (2015) have also detected the presence of syringic acid in the methanolic extracts from this matrix, which is consistent with results achieved in this work. Heleno et al (2012) and Stojkovic et al (2014) also reported the presence of p-coumaric and cinnamic acids in the fruiting body of G. lucidum, but differences in the extraction procedure, and used environment for mushroom maturation can justify the dissimilarity found in the achieved phenolic composition and other secondary metabolites profiles.…”

“…The phenolic composition of G. lucidum has also been widely studied and phenolic acids represent the most prominent class including chlorogenic, cinnamic, gallic, protocatechuic, p-hydroxybenzoic and p-coumaric acids. These molecules have been identified as contributors to its antioxidant, antimicrobial, antityrosinase and anti-inflammatory properties (Heleno et al, 2013(Heleno et al, , 2012Min-Young et al, 2008;Sheikh et al, 2014;Stojkovic et al, 2014). Besides all these bioactive compounds, G. lucidum nutritional composition reveals high potential to be used in the design of dietary supplements (e.g., tablets and capsules) for oral administration (Stojkovic et al, 2014).…”