Antioxidant and antityrosinase activities of various extracts from the fruiting bodies of Lentinus lepideus.

Lentinus lepideus is an edible mushroom currently available in Korea. The acetone, methanol and hot water extracts were prepared and assayed for their antioxidant and antityrosinase inhibitory activities. The hot water extract showed the strongest ß-carotene-linoleic acid inhibition compared to the other extracts. At 8 mg/mL, the methanolic extract showed a high reducing power of 1.21. The acetone and methanol extracts were more effective in scavenging DPPH radicals than the hot water extract. The strongest chelating effect was obtained from the methanolic extract. Xanthine oxidase and tyrosinase inhibitory activities of the acetonic, methanol and hot water extracts increased with increasing concentration. Gallic acid, chlorogenic acid, vanillin, naringin, naringenin, formononetin, and biochanin-A were detected in the acetonitrile and hydrochloric acid (5:1) solvent extract. This study suggests that fruiting bodies of L. lepideus can potentially be used as a readily accessible source of natural antioxidants.

Immunomodulating and Antitumor Activities of Panellus serotinus Polysaccharides.

This study was initiated in order to investigate the anticancer and immunomodulating activities of crude polysaccharides extracted in methanol, neutral saline, and hot water (hereinafter referred to as Fr. MeOH, Fr. NaCl, and Fr. HW, respectively) from the fruiting bodies of Panellus serotinus. Content of ß-glucan and protein in Fr. MeOH, Fr. NaCl, and Fr. HW extracts of P. serotinus ranged from 22.92~28.52 g/100 g and 3.24~3.68 g/100 g, respectively. In vitro cytotoxicity tests, none of the various fractions of crude polysaccharides were cytotoxic against sarcoma 180, HT-29, NIH3T3, and RAW 264.7 cell lines at the tested concentration. Intraperitoneal injection with crude polysaccharides resulted in a life prolongation effect of 23.53~44.71% in mice previously inoculated with sarcoma 180. Treatment with Fr. HW resulted in an increase in the numbers of spleen cells by 1.3 fold at the concentration of 50 µg/mL compared with control. Treatment with Fr. NaCl resulted in improvement of the immuno-potentiating activity of B lymphocytes by increasing the alkaline phosphatase activity by 1.4 fold, compared with control, at the concentration of 200 µg/mL. Among the three fractions, maximum nitric oxide (13.48 µM) was recorded at 500 µg/mL in Fr. HW. Production of tumor necrosis factor alpha, interleukin-1ß, and interleukin-6 was significantly higher, compared to the positive control, concanavalin A, at the tested concentration. Therefore, treatment with crude polysaccharides extracted from the fruiting body of P. serotinus could result in improvement of antitumor activity.

Anticancer and Immunopotentiating Activities of Crude Polysaccharides from Pleurotus nebrodensis on Mouse Sarcoma 180.

Pleurotus nebrodensis is an edible and commercially available mushroom in Korea. This study was conducted in order to evaluate the anticancer and immunopotentiating activities of crude polysaccharides, extracted in methanol, neutral saline, and hot water (hereafter referred to as Fr. MeOH, Fr. NaCl, and Fr. HW, respectively) from the fruiting bodies of P. nebrodensis. ß-Glucan and protein contents in Fr. MeOH, Fr. NaCl, and Fr. HW extracts of P. nebrodensis ranged from 23.79~36.63 g/100 g and 4.45~6.12 g/100 g, respectively. Crude polysaccharides were not cytotoxic against sarcoma 180, HT-29, NIH3T3, and RAW 264.7 cell lines at a range of 10~2,000 µg/mL. Intraperitoneal injection with crude polysaccharides resulted in a life prolongation effect of 11.76~27.06% in mice previously inoculated with sarcoma 180. Treatment with Fr. NaCl resulted in an increase in the numbers of spleen cells by 1.49 fold at the concentration of 50 µg/mL, compared with control. Fr. HW improved the immuno-potentiating activity of B lymphocytes through an increase in alkaline phosphatase activity by 1.65 fold, compared with control at 200 µg/mL. Maximum production of nitric oxide (14.3 µM) was recorded in the Fr. NaCl fraction at 200 µg/mL. Production of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) was significantly higher, compared to control, and IL-6 production was highest, in contrast to TNF-α, IL-1ß, and positive control, concanavalin at the tested concentration of the various fractions. Results of the current study suggest that polysaccharides extracted from P. nebrodensis have a strong anticancer effect and may be useful as an ingredient of biopharmaceutical products for treatment of cancer.

Assessment of Antioxidant and Phenolic Compound Concentrations as well as Xanthine Oxidase and Tyrosinase Inhibitory Properties of Different Extracts of Pleurotus citrinopileatus Fruiting Bodies.

Cellular damage caused by reactive oxygen species has been implicated in several diseases, thus establishing a significant role for antioxidants in maintaining human health. Acetone, methanol, and hot water extracts of Pleurotus citrinopileatus were evaluated for their antioxidant activities against ß-carotene-linoleic acid and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, reducing power, ferrous ion-chelating abilities, and xanthine oxidase inhibitory activities. In addition, the tyrosinase inhibitory effects and phenolic compound contents of the extracts were also analyzed. Methanol and acetone extracts of P. citrinopileatus showed stronger inhibition of ß-carotene-linoleic acid compared to the hot water extract. Methanol extract (8 mg/mL) showed a significantly high reducing power of 2.92 compared to the other extracts. The hot water extract was more effective than the acetone and methanole extracts for scavenging DPPH radicals. The strongest chelating effect (92.72%) was obtained with 1.0 mg/mL of acetone extract. High performance liquid chromatography analysis detected eight phenolic compounds, including gallic acid, protocatechuic acid, chlorogenic acid, ferulic acid, naringenin, hesperetin, formononetin, and biochanin-A, in an acetonitrile and hydrochloric acid (5 : 1) solvent extract. Xanthine oxidase and tyrosinase inhibitory activities of the acetone, methanol, and hot water extracts increased with increasing concentration. This study suggests that fruiting bodies of P. citrinopileatus can potentially be used as a readily accessible source of natural antioxidants.

Appraisal of Antihyperlipidemic Activities of Lentinus lepideus in Hypercholesterolemic Rats.

The wild edible mushroom, Lentinus lepideus has recently been cultivated for commercial use in Korea. While the mushroom has been widely used for nutritional and medicinal purposes, the possible anti-hyperlipidemic action is unclear. The effects of dietary L. lepideus on plasma and feces biochemical and on the liver histological status were investigated in hypercholesterolemic rats. Six-wk-old female Sprague-Dawley albino rats were divided into three groups of 10 rats each. Biochemical and histological examinations were performed. A diet containing 5% L. lepideus fruiting bodies reduced plasma total cholesterol, triglyceride, low-density lipoprotein, total lipid, phospholipids, and the ratio of low-density to high-density lipoprotein. Body weight was reduced. The diet did not adversely affect plasma biochemical and enzyme profiles. L. lepideus reduced significantly plasma ß- and pre-ß-lipoprotein, while α-lipoprotein content was increased. A histological study of hepatic cells by conventional hematoxylin-eosin and oil red O staining revealed normal findings for mushroom-fed hypercholesterolemic rats. The present study suggests that a diet supplemented with L. lepideus can provide health benefits by acting on the atherogenic lipid profile in hypercholesterolemic rats.

Antioxidant Activities and Tyrosinase Inhibitory Effects of Different Extracts from Pleurotus ostreatus Fruiting Bodies.

We evaluated the antioxidant activity and tyrosinase inhibitory effects of Pleurotus ostreatus fruiting bodies extracted with acetone, methanol, and hot water. The antioxidant activities were tested against ß-carotene-linoleic acid, reducing power, 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity, and ferrous chelating ability. Furthermore, phenolic acid and flavonoid contents were also analyzed. The methanol extract showed the strongest ß-carotene-linoleic acid inhibition as compared to the other exracts. The acetone extract (8 mg/mL) showed a significantly high reducing power of 1.54 than the other extracts. The acetone extract was more effective than other extracts for scavenging on 1,1-diphenyl-2-picrylhydrazyl radicals. The strongest chelating effect (85.66%) was obtained from the acetone extract at 1.0 mg/mL. The antioxidant activities of the extracts from the P. ostreatus fruiting bodies increased with increasing concentration. A high performance liquid chromatography analysis detected seven phenolic compounds, including gallic acid, protocatechuic acid, chlorogenic acid, naringenin, hesperetin, formononetin, and biochanin-A in an acetonitrile and 0.1 N hydrochloric acid (5: 1) solvent extract. The total phenolic compound concentration was 188 µg/g. Tyrosinase inhibition of the acetone, methanol, and hot water P. ostreatus extracts increased with increasing concentration. The results revealed that the methanol extract had good tyrosinase inhibitory ability, whereas the acetone and hot water extracts showed moderate activity at the concentrations tested. The results suggested that P. ostreatus may have potential as a natural antioxidant.

New record of the genus calyptella from Korea.

Calyptella capula is reported for the first time in Korea. It was found in spring in Chungcheongbuk-do, central Korea, growing in a dead stalk of Sesamum indicum. A description and molecular phylogenetic analyses are reported.

Occurrence of Internal Stipe Necrosis of Cultivated Mushrooms (Agaricus bisporus) Caused by Ewingella americana in Korea.

The internal stipe necrosis of cultivated mushrooms (Agaricus bisporus) is caused by the bacterium Ewingella americana, a species of the Enterobacteriaceae. Recently, Ewingella americana was isolated from cultivated white button mushrooms in Korea evidencing symptoms of internal stipe browning. Its symptoms are visible only at harvest, and appear as a variable browning reaction in the center of the stipes. From these lesions, we isolated one bacterial strain (designated CH4). Inoculation of the bacterial isolate into mushroom sporocarps yielded the characteristic browning symptoms that were distinguishable from those of the bacterial soft rot that is well known to mushroom growers. The results of Gram stain, flagellal staining, and biochemical tests identified these isolates as E. americana. This was verified by pathogenicity, physiological and biochemical characteristics, and the results of an analysis of the 16S rRNA gene sequences and the fatty acids profile. This is the first report of the isolation of E. americana from cultivated white button mushrooms in Korea.

Changes of Enzyme Activities and Compositions of Abnormal Fruiting Bodies Grown under Artificial Environmental Conditions in Pleurotus ostreatus.

This study investigated the biochemical changes of abnormal fruiting bodies grown under artificial environmental conditions in P. ostreatus. Abnormal mushroom growth during cultivation damages the production of good quality mushroom. This study showed that different environmental conditions produced morphological changes in the fruiting bodies of P. ostreatus. The fruiting bodies with morphological changes were collected and examined for differences in biochemical properties, enzyme activities, and carbohydrates composition. The enzyme activities assay showed that glucanase and chitinase activities decreased when the temperature was below or above the optimum cultivation temperature for P. ostreatus. The biochemical compositions of the abnormal mushroom were significantly different from the normal fruiting bodies. It was suggested that the changes in the biochemical composition of abnormal mushroom were caused by the unfavorable environmental conditions during mushroom cultivation.