Grain dusts and grain plant components vary in their ability to recruit neutrophils.
Von Essen SG; O'Neill DP; Olenchok SA; Robbins RA; Rennard SI
J Toxicol Environ Health, A 1995 Dec; 46(4):425-441
The potential of grain dusts and grain plant components to induce neutrophil recruitment was examined in-vitro. Settled whole grain sorghum, corn, and soybean dusts were extracted with Hank's balanced salt solution (HBSS) and the extracts at concentrations of 10% were incubated with bovine bronchial epithelial cells (BBECs). Recruitment of neutrophils in the cells by the extracts was assessed by determining the extent of neutrophil chemotaxis using the modified blindwell technique. Similar experiments were performed with HBSS extracts of the components of the plants such as grain sorghum stems, seeds, glume, and leaves; corn stalks, seeds, glume, silk, and husks; and soybean stems, seeds, pods, and leaves. The dusts and plant parts were tested for their endotoxin content. Among the dust extracts, only grain sorghum induced significant neutrophil chemotactic activity. Grain sorghum glume and leaf extracts also significantly increased the level of neutrophil chemotactic activity. Corn plant glume, silk, and husk extracts and soybean pods and leaves induced significant neutrophil chemotaxis. Endotoxin levels in the materials varied widely, ranging from 3 nanograms per milliliter (ng/ml) in soybean seeds to 1,177,875ng/ml in corn silk extracts. The ability of the dusts and plant components to induce neutrophil recruitment was not related to their endotoxin content. The authors conclude that grain sorghum dust has greater ability than corn and soybean dusts to induce neutrophil chemotaxis. Most of the ability of grain sorghum dust to stimulate neutrophil chemotaxis resides in the glume of the plant. Although present in the plant dusts and components, endotoxin does not appear to be the only substance capable of causing neutrophilic lower respiratory tract inflammation.
NIOSH-Author; Grain-dusts; Mammalian-cells; Physiological-response; Cell-migration; Endotoxins; Lung-cells; Plant-substances; In-vitro-studies
Susanna Von Essen, MD, Associate Professor of Medicine, Pulmonary and Critical Care Medicine Section, University of Nebraska Medical Center, 600 South 42nd Street, Omaha, NE 68198-5300, USA.
Journal of Toxicology and Environmental Health, Part A: Current Issues