A Queensland, Australia, research team has found that the herb gymnema sylvestre, also known as Australian cowplant, could be useful in reducing laminitis risk in ponies with hyperinsulinemia, according to Horsetalk. Hyperinsulinemia is a condition in which an excess of insulin is produced in response to glucose and is a risk factor for laminitis.

The research team, led by Melody Anne de Laat, tested lactisole and gymnema sylvestre, sweet-taste or T1R2/3 receptor inhibitors, to determine how effective they were in reducing glucose uptake in the small intestine. Their study was published June 29, 2018, by PLOS One. 

De Laat and her team first tested the effect of lactisole and gymnema sylvestre on glucose uptake in sections of the small intestine in horses that were euthanized (for reasons unrelated to the study). They found that in samples tested with lactisole, the glucose uptake reduced 63%, and in samples tested with gymnema sylvestre, it reduced 73%.

In the next phase of the study, de Laat’s team tested the inhibitors on eight different live, overweight ponies. They tested three different dose amounts and fed the ponies a diet of wheat bran soaked in glucose and water.

Lactisole did not affect glucose and insulin concentrations in any of the doses. Gymnema sylvestre reduced blood glucose by 10% and serum insulin by 25%  in seven of the ponies and was most effective at a dose of 10 mg/kg to body weight.

Gymnema sylvestre did not alter the maximum glucose concentration but did seem to decrease the maximum insulin level, although there was a significant amount of variation between the ponies.

More research is needed to determine why lactisole was so effective in the laboratory setting and not in a live trial, according to the research team.

The findings indicate that T1R2/3 inhibitors could be useful for preventing laminitis, but further research is needed to determine what dose and delivery method is most effective. This research will function as a baseline for further studies on the effectiveness of using T1R2/3 inhibitors to prevent laminitis.

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