Displaying posts tagged with

“antioxidant”

Antioxidant properties of several medicinal mushrooms.

Three species of medicinal mushrooms are commercially available in Taiwan, namely, Ganoderma lucidum (Ling-chih), Ganoderma tsugae (Sung-shan-ling-chih), and Coriolus versicolor (Yun-chih). Methanolic extracts were prepared from these medicinal mushrooms and their antioxidant properties studied. At 0.6 mg/mL, G. lucidum, G. lucidum antler, and G. tsugae showed an excellent antioxidant activity (2.30-6.41% of lipid peroxidation), whereas C. versicolor showed only 58.56%. At 4 mg/mL, reducing powers were in the order G. tsugae (2.38) approximately G. lucidum antler (2.28) > G. lucidum (1.62) > C. versicolor (0.79). At 0.64 mg/mL, scavenging effects on the 1,1-diphenyl-2-picrylhydrazyl radical were 67.6-74.4% for Ganoderma and 24.6% for C. versicolor. The scavenging effect of methanolic extracts from G. lucidum and G. lucidum antler on hydroxyl radical was the highest (51.2 and 52.6%) at 16 mg/mL, respectively. At 2.4 mg/mL, chelating effects on ferrous ion were in the order G. lucidum antler (67.7%) > G. lucidum (55.5%) > G. tsugae (44.8%) > C. versicolor (13.2%). Total phenols were the major naturally occurring antioxidant components found in methanolic extracts from medicinal mushrooms. Overall, G. lucidum and G. tsugae were higher in antioxidant activity, reducing power, scavenging and chelating abilities, and total phenol content.[…]

Medicinal and edible lignicolous fungi as natural sources of antioxidative and antibacterial agents.

The antioxidant activity of organic extracts of eight fungal species, Ganoderma lucidum, Ganoderma applanatum, Meripilus giganteus, Laetiporus sulphureus, Flammulina velutipes, Coriolus versicolor, Pleurotus ostreatus and Panus tigrinus, was evaluated for free radical (DPPH(·) and OH(·)) scavenging capacity and an effect on lipid peroxidation, and the antibacterial activity was tested by the agar well diffusion method. The highest DPPH(·) scavenging activity was found in the methanol extract of G. applanatum (12.5??g/mL, 82.80%) and the chloroform extract of G. lucidum (510.2??g/mL, 69.12%). The same extracts also showed the highest LP inhibition (91.83%, 85.09%) at 500??g/mL, while the methanol extracts of G. applanatum and L. sulphureus showed the highest scavenging effect on OH(·) radicals (68.47%, 57.06%, respectively) at 400??g/mL. A strong antibacterial activity against Gram-positive bacteria was also manifested. The antioxidative potencies correlated generally with the total phenol content (0.19-9.98?mg/g). The HPLC determination showed that the majority of analysed species contained gallic and protocatechic acids. Consequently, these fungi are shown to be potential sources of antioxidative and antibacterial agents. Copyright © 2010 John Wiley & Sons, Ltd.[…]

[Impact of exogenous paraquat on enzyme exudation and biochemical changes of lignin degradation fungi]

To study the effect of exogenous oxygen, we added water solution of paraquat to 7 d cultures of Coriolus versicolor for the next 148 h. Enzyme exudation and biochemiscal process were investigated on the addition of paraquat. We found that compared with the control (without paraquat), the addition of 30 micromol/L paraquat stimulated the activity of manganese dependent peroxidase (MnP), lignin peroxidase (LiP), and laccases (Lac) 7, 2.5 and 1.3 times, respectively. Also, addition of paraquat enhanced activity of superoxide dismutase (SOD) and catalase (CAT) in the first 48 h. Impact of paraquat on ligninolytic enzymes was significant than that on antioxidant enzyme. Addition of paraquat enhanced phenolic compounds and formaldehyde of cultures too. And concentration of malondialdehyde was increased in the first 24 h. The results showed that addition of paraquat promoted oxidative stress, but the antioxidant systems of the fungal strain are sufficient to prevent mycelia from oxidative stress. As exogenous oxygen, paraquat might be a useful substrate in degradation of lignocellulose.[…]