Ganoderma lucidum as a cosmeceutical: antiradical potential and inhibitory effect on hyperpigmentation and skin extracellular matrix degradation enzymes

Three different polysaccharide extracts of a wild European source of the mushroom Ganoderma lucidum were screened for their free radical-blocking potential, which could strengthen the skin's barrier function, and provide a skin-lightening effect via potential inhibition of tyrosinase. The anti-collagenase and anti-elastase activities, which can help to restore skin elasticity and tensile strength, were also evaluated for the three extracts. Carbohydrates were the most abundant components of the extracts, followed by smaller quantities of proteins, phenols and flavonoids. The glucan fraction represented between 48% and 61% of carbohydrate content in all three extracts. None of the analyzed extracts showed overt toxicity to spontaneously-transformed immortal human keratinocytes (HaCaT) at concentrations up to 2 mg/mL, and displayed superior scavenging ability on 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The hot water crude polysaccharide extract (HWCP) and partially purified fraction (HWPP) were found to be effective inhibitors of lipid peroxidation (LPx), with an almost two-fold increased inhibition of LPx compared with ascorbic acid (EC50 = 1.65 +/- 0.08 mg/mL), a common additive in cosmeceutical formulations and used at mg levels. Among the investigated extracts, HWCP showed the strongest inhibition potential on tyrosinase and skin extracellular matrix (ECM) degradation enzymes. These diverse functionalities indicate that G. lucidum may represent a promising source of natural cosmeceutical ingredients