Anti-UV activity of Lentinus edodes mycelia extract (LEM).

BACKGROUND: Using our recently established simple method for evaluating protective activity from ultraviolet ray injury (referred to as 'anti-UV activity'), the effectiveness of various antioxidants and plant extracts was investigated. MATERIALS AND METHODS: HSC-2 human oral squamous cell carcinoma cells were exposed to UV irradiation (wavelength: 253.7 nm, 6 J/m²) in phosphate-buffered saline (PBS(-)) containing various concentrations of samples and then incubated for 48 hours in regular culture medium to determine the viable cell number by the MTT method. RESULTS: Among the representative antioxidants, sodium ascorbate showed the most potent anti-UV activity, whereas catalase and N-acetyl-L-cysteine were inactive. Lentinus edodes mycelia extract (LEM) showed comparable anti-UV activity to sodium ascorbate. Hot water extracts of green tea and coffee, and PET-bottled of green tea extract showed slightly less, but noticeable anti-UV activity. On the other hand, hot water extracts of black tea and Jasmine tea, and PET-bottled of oolong tea, barley tea and Kohki tea were inactive. LEM was separated by gel filtration chromatography into four fractions from high to low molecular weight: polysaccharide, large and small lignin-carbohydrate complexes, and sugars. Anti-UV activity was shown by the lignin-carbohydrate fractions, but not the polysaccharide and sugar fractions. LEM, at high concentration, slightly enhanced the anti-UV activity of sodium ascorbate. CONCLUSION: LEM may be applicable as a UV-protective agent.

DNA microarray analysis of signaling pathway in macrophages stimulated by lignin-carbohydrate complex from lentinus edodes mycelia (LEM) extract.

In order to investigate the action point of lignin-carbohydrate complex (Fr4) from Lentinus edodes mycelia extract, DNA microarray analysis was performed, using mouse macrophage-like J774.1 cells. Among seven lignin-carbohydrate complex fractions, Fr4 showed the highest stimulatory activity of tumor necrosis factor production by mouse macrophage-like J774.1 cells, as well as its previously reported anti-HIV activity. Fr4 is composed of lignin precursors such as vanillic acid, syringic acid, p-coumaric acid and ferulic acid, with trace amounts of flavonoids and tannins, and negligible amount of lipopolysaccharides (LPS), confirming the authenticity of Fr4 as a lignin. DNA microarray analysis suggested that Fr4 may affect immune response-related gene expression; however, it may not affect the expression of as many genes as LPS does.

Lignin-like activity of Lentinus edodes mycelia extract (LEM).

BACKGROUND: In order to investigate the physiological role of lignin carbohydrate complex present in Lentinus edodes mycelia extract (LEM), this material was separated into seven fractions. MATERIALS AND METHODS: Three high molecular weight fractions (Frs. I-III) were prepared from the water extract by successive ethanol fractionation, dialysis and lyophilization. Four higher molecular weight fractions were prepared from the NaOH extract of the residue, followed by acid precipitation (Fr. IV) and stepwise ethanol precipitation (Frs. V-VII). RESULTS: All fractions showed higher anti-HIV activity than the water extract. Fr. IV showed the highest anti-HIV activity and most potently inhibited the NO production by LPS-stimulated mouse macrophage-like cells (RAW264.7, J774.1). ESR spectroscopy demonstrated that all fractions scavenged superoxide anion and hydroxyl radical. These properties are similar to those displayed by lignin carbohydrate complex, but not by glucans. HPLC analysis demonstrated the presence of lignin precursors, but not that of tannins, flavonoids and their related compounds. CONCLUSION: These results suggest a significant role of lignin-like substances in the expression of several important biological properties displayed by LEM.

Distribution of lignin-carbohydrate complex in plant kingdom and its functionality as alternative medicine.

Lignin-carbohydrate complexes (LCCs) are major cell wall components formed by the dehydrogenation of three monolignols, p-coumaryl, coniferyl and sinapyl alcohols. Diverse pharmacological activities of LCCs distributed into various plants were summarized. LCCs showed one order higher anti-HIV activity than tannins and flavonoids. Mechanism of anti-HIV activity induction includes the inhibition of HIV adsorption to and penetration into the cells, and inhibition of reverse transcriptase and protease. Limited digestion experiments demonstrated that a phenylpropenoid polymer, but not a sugar moiety, is important for anti-HIV activity. Dehydrogenation polymers of phenylpropenoids without carbohydrate showed higher anti-HIV activity, whereas phenylpropenoid monomers were inactive, suggesting the importance of highly polymerized structure. LCCs inhibited the plaque formation and RNA polymerase activity of influenza virus, and reduced the lethality of virus infection in mice. LCCs inhibited the plaque formation of HSV-1, and oral intake of LCC-vitamin C tablet reduced the symptoms in HSV-1-infected patients. LCCs stimulated the iodination of myeloperoxidase-positive human monocytes, neutrophiles and promyelocytic leukemia that may be involved in the bacterial killing mechanism. LCCs stimulated splenocyte proliferation, and showed both pro- and anti-inflammatory activity in activated macrophage. Preliminary DNA array analysis demonstrated the activation of the signal pathway of chemokine expression via TLR2. The molecular weight, solubility, sterilization method and association with other components during extraction step may produce diverse biological activity of LCCs. Broad and potent anti-viral activity and synergism with vitamin C suggest functionality of LCC as alternative medicine.