Agaricus bisporus (edible mushroom lectin) inhibits ocular fibroblast proliferation and collagen lattice contraction

The edible mushroom lectin from Agaricus bisporus (ABL) has antiproliferative effects on a range of cell types. This investigation was undertaken to test whether it might have inhibitory activity on Tenon's capsule fibroblasts in in vitro models of wound healing and therefore have a use in the modification of scar formation after glaucoma surgery. Human ocular fibroblasts in monolayers and in three-dimensional collagen lattices were exposed to ABL (0-100 mug ml(-1)), Proliferation was studied by the MTS assay and by counting haematoxylin-stained cells; contraction was measured as a change in the diameter of three-dimensional collagen lattices. Toxicity was investigated using a fluorescent viability assay. FITC-labelled lectin was used to study cell binding and internalization of ABL, ABL caused a dose-dependent inhibition of proliferation and lattice contraction without significant toxicity. Proliferation was inhibited by 5-40% in the dose range 20-100 mug ml(-1) Significant inhibition of lattice contraction was achieved with 40 mug ml(-1) ABL, and at 100 mug ml(-1) contraction was completely prevented. FITC-ABL binds to the cell surface and accumulates around the nuclear envelope when internalized. These experiments have shown that ABL possesses key features required of an agent that might control scarring processes and suggest that ABL might be especially useful where subtle modification of healing is needed, Further evaluation is warranted. (C) 2002 Elsevier Science Ltd.