Intranasal application of lentinan enhances bactericidal activity of rat alveolar macrophages against Mycobacterium tuberculosis
Markova, N.; Michailova, L.; Kussovski, V.; Jourdanova, M.; Radoucheva, T.
Die Pharmazie 60(1): 42-48
2005
ISSN/ISBN: 0031-7144 PMID: 15700777 Document Number: 587747
Lentinan is a (1-3)- beta -D-glucan isolated from the Japanese mushroom Lentinus edodes [Lentinula edodes]. To study the in vivo interaction between lentinan-stimulated alveolar macrophages and Mycobacterium tuberculosis, rats intranasally infected with 2x108 CFU were used. Before infection, animals were treated intranasally with lentinan at a dose of 1 mg/kg (administrated 3 times at 2-day intervals). Samples of broncho-alveolar lavage fluid were obtained from rats at different intervals -3, 24 and 72 h after infection. The process of phagocytosis in vivo was observed by light and electron microscopy, as well as acid phosphatase cytochemistry methods. Bactericidal activity of alveolar macrophages following the same intranasal installation of lentinan was assessed by in vitro "killing" ability test against M. tuberculosis. Nitrite production by lentinan-activated alveolar macrophages was measured 24 h after ex vivo culture of these cells. It was demonstrated that lentinan induces high level of alveolar macrophage activation manifested through enhanced bactericidal effect against M. tuberculosis, which correlates with the induction of reactive nitrogen intermediates, increased activity of lysosomal enzymes (acid phosphatase), and with effective phagolysosomal fusion followed by destruction of M. tuberculosis.