Ophiopogon root (Radix Ophiopogonis) prevents ultra-structural damage by SO2 in an epithelial injury model for studies of mucociliary transport

We studied the action of the herb, Ophiopogon root (OR) in a epithelial injury model, hypothesizing that it may have beneficial effects on mucociliary transport following injury to the palate induced by sodium metabisulphite (MB) which releases SO(2) on contact with water. OR (extract from 1g of root/ml)-incubated palates and non-incubated palates were compared to assess the effect of MB on mucociliary clearance on the bull frog palate. MB 10(-1) M, acutely increased mucociliary clearance time (MCT) by 254.5 +/- 57.3% in untreated and 243.3 +/- 98.5% in OR-incubated palates, (over all significance assessed by one-way ANOVA, F = 12.82, p < 0.001, df = 8,54 for MB and F = 10.56, p < 0.001, df = 8,54 for OR). MCT returned to normal during recovery in OR-treated palates following MB. In untreated palates, MCT did not return to control values during a similar recovery period. ANOVA comparing MCTs in the recovery period in untreated vs OR-treated palates was significantly different (F = 2.92, p < 0.03, df = 5,36). SEM images of epithelial tissue, analyzed by morphometry, showed a 25 +/- 12% loss of ciliated cells in untreated palates and little or no damage to cilia in OR-treated palates. Intact groups of ciliated cells were found in SEM micrographs of mucus from MB-treated palates. We conclude that the loss of cilia or ciliated cells prevented full recovery of MCT after MB in untreated palates. In OR-incubated palates, mucociliary transport was completely restored within 20 min after topical application of MB, possibly through a protective action on the extra-cellular matrix.