Introduction.

Medium-chain triglycerides (MCT) have demonstrated a wide range of neuroprotective effects, although the mechanisms still remain poorly understood. Animal models are indispensable for such research. Metabolic effects of regular diet supplementation with fats must be considered.

Methods.

Male Wistar rats aged 2.5 months received (o/g) either MCT oil (C8 & C10, 3 g/kg), lard (3 g/kg), or water (control) as a supplement to standard chow for 28 days. On the 17th day, the animals were tested in Y-maze. On the 28th day, blood was collected for biochemical testing (glucose, triglycerides, total cholesterol, HDL cholesterol). In a separate experiment, animals received 3 g/kg MCT, or lard, or water, and were then sacrificed 30 or 120 min after. Blood was collected for biochemical testing (glucose, lactate, pyruvate, acetoacetate, β-hydroxybutyrate (BHB), cholesterol, triglycerides, aspartate transaminase, alanine transaminase (ALT)).

Results and Discussion.

In the Y-maze test, the MCT-fed rats demonstrated an increased frequency of spontaneous alterations compared to both the control and lard groups, indicating improved working memory. Chronic administration of neither fat affected the blood glucose, triglycerides, total cholesterol, HDL cholesterol. Acutely, MCT supplementation elevated blood BHB, while lard did not. Lard administration increased blood triglycerides, cholesterol, and ALT, while MCT did not.

Conclusions.

Daily supplementation of standard feed with MCT led to mild intermittent ketosis and improved working memory in rats. Neither chronic nor acute MCT administration had any adverse effect on metabolic health markers. This animal model may be used to study the mechanisms of the cognitive-enhancing effects of MCT.