AIM: To study the effect of polysaccharide from spirulina platensis (PSP) on the pneumocyte
apoptosis and ultrastructure
in aging mice and its functional mechanism. METHODS: Totally 50 ICR mice, aged 2 months, of either gender, were selected and divided into model group, three dosage groups with high, medium and low PSP, and control group, 10 in each. Two month old mice were fed for 11 mouths under normal condition to establish natural aging models. The 20, 40, 80 mg/kg PSP was administrated respectively to the aging mice for 6 weeks, and the apoptosis of
pulmonary histocyte and morphological changes under electron microscope were investigated with fluorescence microscope.RESULTS: Aging could induce the apoptosis of pulmonary histocyte and changes of ultrastructure of epithelial cells in pulmonary alveolus Ⅱ . PSP could
significantly inhibit apoptosis of pulmonary histocyte, decrease the number of apoptosis cells, improve the structure and function of epithelial cells in pulmonary alveolus.PSP significantly decreased apoptosis of pulmonary histocyte induced by aging. Apoptosis in the PSP high dosage group was relatively lessened, and very significantly decreased <(14.2± 2.24)% > as compared with that of model group <(23.7± 5.53)% >(t=4.672 1, P< 0.01);Apoptosis in the PSP medium and low dosage groups <(16.3 ± 3.79)% ,(19.6± 4.61)% >were significantly different from that in the model group (t=3.205 4, P< 0.01; t=1.621 9, P< 0.05); Differences of apoptosis in the PSP high and medium dosage groups and control group <(12.8± 3.54)% > had no significance (P >0.05); Differences of apoptosis in the PSP low dosage group and control group were significant (t=3.519 3, P< 0.01).CONCLUSION: PSP has ameliorating and postponing effects on the regressive changes of pulmonary histocyte in aging mice.