2.6. CCl4-Induced Hepatotoxicity

The Wistar male rats acclimatized in the animal house were randomly grouped into 7 groups, with each group having 6 rats (42 Wistar rats) per experiment (n = 3, meaning 126 animals for the whole study). Animals were orally dosed with CCl₄as mentioned previously [22,23], and other respective concentrations of TA extracts (30, 40, and 50 mg/kg b.w.) using gastric gavage without the administration of any anesthesia agent. Group A was designated as normal, without any chemical or extract being administered. Group B was designated as the CCl₄-treated group and the animals were administered 40% CCl₄mixed in olive oil orally for 3 alternate days a week for 8 weeks. Group C was designated as 40% CCl₄mixed in olive oil and TA extract 30 mg/kg administered orally for 3 alternate days a week for 8 weeks. Group D was designated as 40% CCl₄mixed in olive oil and TA extract 40 mg/kg administered orally for 3 alternate days a week for 8 weeks. Group E was designed as 40% CCl₄mixed in olive oil and TA extract 50 mg/kg administered orally for 3 alternate days a week for 8 weeks. Group F was designated as 40% CCl₄mixed in olive oil and TA extract 60 mg/kg administered orally for 3 alternate days a week for 8 weeks. Group G was designed as 40% CCl₄mixed in olive oil and 100 mg/kg b.w. silymarin [24] administered orally for 3 alternate days a week for 8 weeks (Table 3).

To evaluate the effective dose of TA extract with the least toxicity to the animals, we intended to perform a preliminary experiment on animals. This was performed to optimize the dose of TA extract that could exhibit effective hepatoprotective activity with less deleterious effects on animals. After properly acclimatizing the animals, we categorized them randomly into seven groups, as shown in Table 3. The disease control (Group B) animals were orally administered 200 µL 40% CCl₄dissolved in olive oil for three alternate days a week for 8 weeks, whereas the control group (Group A) animals were orally administered 200 µL of vehicle. The other groups (Group C, D, E, and F) were orally administered 200 µL of 40% CCl₄dissolved in olive oil and 200 µL of TA extract with varying doses (30, 40, 50, and 60 mg/kg b.w., respectively) for three alternate days a week for 8 weeks. However, Group G animals were orally administered 200 µL of standard silymarin compound for three alternate days a week for 8 weeks; this was in addition to 200 µL of40% CCl₄dissolved in olive oil. To evaluate the effective dose in terms of the hepatoprotective effect and safe toxicity in animals, we observed the hepatoprotective activity of TA extract against CCl₄-mediated liver toxicity in a dose-dependent manner (Tables 4 and 5). Intriguingly, our results suggest that the ideal activity of TA extract was determined at 50 mg/kg b.w. (Group E), and the results were significantly compared with those of standard silymarin (Group G). When tested at 60 mg/kg b.w. (Group F), TA extract displayed toxicity-associated symptoms in animals, such as lethargy, diarrhea, muscle tremors, loss of appetite, etc., and they died before the completion of the study (Table 4 and Table 5). Collectively, the preliminary optimization results suggest that a 50 mg/kg b.w. oral dose of TA extract has the maximum hepatoprotective effect against CCl₄-mediated liver toxicity.