Detection of calprotectin and apoptotic activity within the equine colon from horses with black walnut extract-induced laminitis.

This research article explores the inflammatory response in the colons of horses that have been exposed to the black walnut extract model of equine laminitis, a hoof disease in horses. The principal focus lies in the expression of calprotectin, an inflammation marker protein, and the levels of apoptosis (cell death) in the gastrointestinal tract of these horses, providing preliminary evidence towards an early inflammatory response in the colon upon exposure to black walnut extract.

Objective and Methodology

• The objective of this study was to understand the specific role of the gastrointestinal tract, particularly the colon, in the development of the systemic inflammatory response in horses suffering from laminitis caused by black walnut extract (BWE).
• The researchers investigated the colon tissue of 19 horses, which included 7 controls without BWE exposure, 6 horses at the developmental time-point of leukopenia (DTP), and 6 horses at the onset of a specific phase of laminitis after BWE-administration.
• The team examined calprotectin expression (an inflammation marker protein) using an immunohistochemical method with MAC 387 antibody and checked the levels of epithelial and endothelial apoptosis (programmed cell death) with caspase-3 active antibody.

Findings

• The histology of the colon tissues from BWE-treated horses showed eosinophil and lymphocyte epitheliotropism, indicating inflammation.
• The DTP group had a significantly higher calprotectin score compared to the control group, suggesting a systemic inflammatory response at this stage.
• There was no significant difference in the percentage of epithelial and endothelial apoptotic cells between the groups studied.
• No correlation was found between the calprotectin score and levels of apoptosis, indicating these two processes may occur independently.

Conclusion

• The study presents initial evidence that exposure to BWE results in an early inflammatory response in the horse’s colon.
• However, further research is required to better understand the nature of the injury caused in the colonic tissue of BWE-exposed horses and its connection to the development of laminitis.