Effects of Olea europaea compounds on feline intestinal cells: potential application in overweight prevention in cats

Overweight and obesity in domestic cats have significantly increased in recent years [ 1 ] with prevalence rates ranging from 11 to 63% depending on the country [ 2 ]. Recent studies show obese cats are 2-4 times more likely to develop type 2 diabetes compared to a healthy cat [ 3 ] and up to 5 times more likely for osteoarthritis. Various therapeutic recommendations for obesity exist, such as caloric restriction or increased physical activity. Unfortunately, these methods often fail to achieve sustained weight reduction over time [ 4 ]. Among new research avenues, studies highlighted the cardiovascular benefits of Olive Leaf Extracts (OLE) due to their anti-inflammatory and antioxidant properties [ 5 ], partly attributed to their polyphenolic components oleuropein and hydroxytyrosol, as well as triterpenes like maslinic acid and oleanolic acid. We assessed the cytotoxicity and barrier integrity effects of key OLE compounds on a feline intestinal epithelial cell line, as a first step in evaluating their anti-obesity potential. We first evaluated the cytotoxicity (MTT assay) of oleuropein, hydroxytyrosol, maslinic acid and oleanolic acid present in OLE, on feline intestinal cells with 24h, 48h and 72h exposures. This allowed us to determine the IC 50 , IC 50 , IC 50 , and IC 50 values for each molecule. Maslinic acid appeared to be the most cytotoxic at concentrations starting from 50 μM. We also assessed the impact of these molecules on membrane permeability by measuring TEER (Transepithelial electrical resistance). Maslinic acid and oleanolic acid reduce this integrity at 20 μM and 50 μM, respectively. kThese preliminary results suggest that certain compounds from OLE exhibit concentration-dependent cytotoxic effects and negatively impact intestinal barrier function. This should be carefully considered in evaluating their safety and therapeutic potential for feline obesity management. Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany