*2.3. Animals and Experimental Design of the CCl4-Induced Hepatotoxicity*

To test the potential hepatoprotective effects of olive leaf extracts, experiments were conducted in six groups according to the following administration (Scheme 1): group I—negative control with administration of vehicle only (corn oil); group II—administration of carbon tetrachloride (CCl4) in corn oil 50 μL/kg [39]; group III—daily administration of fresh leaf extracts dissolved in corn oil (FLE, 30 mg/kg); group IV—daily administration of dried leaf extracts dissolved in corn oil (DLE, 30 mg/kg); group V—administration of FLE (30 mg/kg) and simultaneous treatment with CCl4 (50 μL/kg) +; group VI—administration of DLE (30 mg/kg) and simultaneous treatment with CCl4 (50 μL/kg).

**Scheme 1.** Graphical scheme summarizing the experimental design, *n*: number of rats.

The CCl4 was administered by gastric gavage twice per week (on every Tuesday and Thursday) over eight weeks. A daily pretreatment with FLE or DLE was realized 7 days before CCl4 exposure and then daily throughout the research work by gastric gavage. The rats were sacrificed at the end of eight weeks and 24 h after the last dose of the hepatotoxin.
