Sweet taste receptor inhibitors: Potential treatment for equine insulin dysregulation.
Authors: de Laat Melody Anne, Kheder Murad Hasan, Pollitt Christopher Charles, Sillence Martin Nicholas
Journal: PloS one
Summary
Hyperinsulinaemia significantly elevates laminitis risk in horses, yet effective pharmacological interventions remain limited; sweet taste receptor (T1R2/3) inhibitors show promise in other species by blunting post-prandial insulin responses to carbohydrate meals, making them candidates for managing insulin dysregulation in equines. Researchers tested two inhibitors—lactisole and *Gymnema sylvestre*—using in vitro intestinal explant tissue (measuring glucose uptake via gas chromatography-mass spectrometry) and in vivo feeding trials with ponies receiving carbohydrate-based meals across three doses in a Latin square design. *Gymnema sylvestre* demonstrated partial efficacy, reducing post-prandial blood glucose by approximately 10% and serum insulin by ~25% at the optimal dose of 10 mg/kg bodyweight, whilst lactisole showed no significant effect in vivo despite inhibiting intestinal glucose uptake by 63% in vitro; *Gymnema sylvestre* reduced glucose uptake by 73% in the tissue model. These preliminary findings suggest T1R2/3 inhibition warrants further investigation as a therapeutic avenue for insulin dysregulation and laminitis prevention, though dose optimisation, refined delivery mechanisms, and direct characterisation of sweet taste receptor activity in horses remain essential before clinical application.
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Practical Takeaways
- •Gymnema sylvestre at 10 mg/kg may help reduce insulin spikes in insulin-dysregulated horses fed carbohydrate-rich meals, though effects are modest (~25% reduction)
- •In vitro efficacy does not guarantee in vivo effectiveness (lactisole example), so clinical testing is essential before recommending new supplements
- •This is early-stage research; practitioners should await further optimization of dose/delivery methods and direct receptor testing before implementing these compounds in practice
Key Findings
- •Lactisole and Gymnema sylvestre reduced glucose uptake by equine small intestine explants by 63% and 73% respectively in vitro
- •Gymnema sylvestre reduced post-prandial blood glucose by ~10% and serum insulin by ~25% in vivo at 10 mg/kg bodyweight
- •Lactisole showed no effect on glucose or insulin concentrations in the in vivo pony study
- •Sweet taste receptor inhibitors represent a potential therapeutic approach to manage equine insulin dysregulation and prevent laminitis