Immunochemical Cross-Reactivity of ß-Glucan in the Medicinal Plant, Sasa veitchii (Japanese Folk Medicine Kumazasa), and Medicinal Mushrooms.

Fungal ß-glucan is a representative pathogen-associated molecular pattern from mushroom, yeast, and fungi and stimulates innate as well as acquired immune systems. This ß-glucan is widely applied in functional food to enhance immunity. Humans and animals generally become sensitized to this ß-glucan and gradually produce specific antibodies to ß-glucans. The extracts of plants have been used as folk medicine and are reported to possess various biological activities that are beneficial for human health, such as antitumor, antiallergic, and anti-inflammatory activities. In the present study, the immunochemical cross-reactivity of Sasa extract and fungal ß-glucan was analyzed. We found that the anti-ß-glucan antibody in human sera strongly cross-reacted with the Sasa extract. This result strongly suggested that plant extracts modulate the immunostimulating effects of medicinal mushrooms. The cooperative effects of plants and mushrooms may be an important issue for functional foods.

Specificity of the Immunomodulating Activity of Sasa veitchii (Japanese Folk Medicine Kumazasa) to Fungal Polysaccharides.

Many plant extracts are used as well-known folk medicines and exhibit various biological activities that are beneficial to human health. These extracts contain polysaccharides, and some are pathogen-associated molecular patterns (PAMPs) that stimulate innate as well as acquired immune systems. In the present study, the cooperative effects of PAMPs and bamboo water-soluble methanol precipitation (BWMP) in a macromolecular fraction of the hot water extract of Sasa veitchii (in Japanese folk medicine, known as Kumazasa; family Poaceae) were analyzed in vitro using the spleen or bone marrow cells of mice. The splenocytes of male DBA/2 and C57BL/6 mice were cultured with BWMP in the presence or absence of PAMPs, and responses were assessed by measuring cytokines. BWMP inhibited the production of interferon gamma (IFN-γ) by not only toll like receptors (TLRs), but also the C-type lectin receptors (CLRs) dectin-1 and dectin-2. BWMP also inhibited the autologous production of IFN-γ in the splenocyte culture. These results suggested that BWMP may inhibit the signaling pathways of PAMPs, but not ligand-receptor interactions. In contrast, BWMP did not inhibit the production of cytokines by dendritic cells. These results indicated that the inhibition of IFN-γ by BWMP was mediated through the cell-to-cell interactions of splenic cells during cultivation.

Kinetic study of Sasa veitchii extract as a radical scavenger and an antioxidant.

UNLABELLED: We examined the free radical scavenging activity of Sasa veitchii extract (Hoshi's Striped Bamboo Extract(®), HSBE), well known in folk medicine as an efficient drug and antioxidant in detail. To evaluate the free radical scavenging activity of HSBE, its reactivity as hydrogen atom donor toward the 1, 1-diphenyl-2-picrylhydrazyl has been measured using stopped-flow spectrophotometry. It was found that the second-order rate constant, k(2), obtained at 25 °C was 1.4 (g/L)(-1) s(-1) for HSBE. To compare different chain-breaking antioxidants quantitatively, we obtained the second-order rate constant, k(2)', on the molar basis of active hydroxyl groups in the tested substances. As a result, the k(2)' values for HSBE, 6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid (Trolox), caffeic acid, and (+)-catechin were 2.6 × 10(3), 2.0 × 10(3), 2.3 × 10(2), and 6.0 × 10(2) M(-1) s(-1), respectively. These results show that HSBE and Trolox exerted the same free radical scavenging activity under these conditions. In addition, HSBE significantly inhibited the oxidation of methyl linoleate micelles in aqueous dispersions at 30 °C and its antioxidant activity (k(inh)) was more effective than those of caffeic acid and (+)-catechin. This is the first study on bamboo extracts in the context of radical scavenging activity that reports kinetic results. PRACTICAL APPLICATION: We determined the stoichiometric number and the rate constants of bamboo extracts using the method that was devised in determining the antioxidant activity of mixtures. This is the first study of bamboo extracts as an antioxidant that reports the stoichiometric and kinetic results.

Effect of Sasa veitchii extract on immunostimulating activity of ß-glucan (SCG) from culinary-medicinal mushroom Sparassis crispa Wulf.:Fr. (higher Basidiomycetes).

Fungal ß-glucan is a representative pathogen-associated microbial pattern (PAMP) from mushroom, yeast, and fungi, and stimulates innate as well as acquired immune systems. It is a widely used functional food to enhance immunity. Such plant extracts have been known as folk medicines and reported to show various biological activities beneficial to human health, such as anti-tumor, anti-allergic, and anti-inflammatory activities. In the present study, the cooperative effect of bamboo water-soluble methanol precipitation (BWMP), a macromolecular fraction of the hot-water extract of Sasa veitchii (Japanese folk medicine Kumazasa), and the ß-glucan from the medicinal mushroom Sparassis crispa (SCG) was analyzed in vitro using DBA/2 mice. The splenocytes from male DBA/2 mice were cultured with BWMP in the presence of SCG, and the responses were assessed by measuring cytokines. BWMP suppressed IFN-γ and GM-CSF production by SCG, but not TNF-α production. To analyze the specificity of the reaction, similar experiments were conducted with BWMP in the presence of bacterial lipopolysaccharide (LPS); however, none of the cytokines were inhibited. Cytokine production of splenocytes by SCG was suggested to be largely dependent on the binding of lymphocytes with dendritic cells. Functions of BWMP were also analyzed by mixed lymphocyte reaction, and IFN-γ production was suppressed. These findings suggested that BWMP modulated the cell-to-cell contact induced by SCG and inhibited cytokine production. It is strongly suggested that the plant extracts modulate the immunostimulating effects of medicinal mushrooms. Cooperative effects of plants and mushrooms would be an important issue for functional foods.