Antioxidant and Hepatoprotective Effects of Croton hypoleucus Extract in an Induced-Necrosis Model in Rats

Abstract

The aim of this study was to evaluate the antioxidant and hepatoprotective activity of Croton hypoleucus (EC). The present work reports the first pharmacological, toxicological, and antioxidant studies of EC extract on liver injury. Liver necrosis was induced by thioacetamide (TAA). Five groups were established: Croton Extract (EC), thioacetamide (TAA), Croton extract with thioacetamide (EC + TAA), vitamin E with thioacetamide (VE + TAA) and the positive control and vehicle (CT). For EC and EC + TAA, Wistar rats (n = 8) were intragastrically pre-administered for 4 days with EC (300 mg/kg.day) and on the last day, EC + TAA received a single dose of TAA (400 mg/kg). At 24 h after damage induction, animals were sacrificed. In vitro activity and gene expression of superoxide dismutase (SOD), catalase (Cat), and Nrf2 nuclear factor were measured. The results show that EC has medium antioxidant properties, with an IC₅₀ of 0.63 mg/mL and a ferric-reducing power of 279.8 µM/mg. Additionally, EC reduced hepatic damage markers at 24 h after TAA intoxication; also, it increased SOD and Cat gene expression against TAA by controlling antioxidant defense levels. Our findings demonstrated the hepatoprotective effect of EC by reducing hepatic damage markers and controlling antioxidant defense levels. Further studies are necessary to identify the mechanism of this protection.

Keywords: Croton hypoleucus; antioxidant activity; hepatoprotective effect; oxidative stress.

Figure 1

Clerodane-type diterpenoids identified in the dichloromethane fraction of EC: hypolein B (1) and Crotonpene B (2).

Figure 2

Effect of EC pretreatment on levels of (A) ALT and (B) AST analyzed by Wiener Lab equipment in the serum of rats intoxicated with a sublethal dose of thioacetamide (TAA). All data are expressed in U/L. Bars indicate the mean value with SE of two determinations (n = 8). The differences compared with the vehicle are expressed as “a”; while the differences due to TAA are expressed as “b”, p ≤ 0.05.

Figure 3

Effect of EC pretreatment on levels of (A) ALP, (B) T-Bil, and (C) D-Bil analyzed by Wiener Lab equipment in the serum of rats intoxicated with a sublethal dose of thioacetamide (TAA). In ALP, the results are expressed in U/L, while T-Bil and D-Bil are expressed in mg/dL of serum. Bars indicate the mean value with the SE of two determinations (n = 8). The differences compared with the vehicle are expressed as “a”; while the differences due to TAA are expressed as “b”, p ≤ 0.05.

Figure 3

Effect of EC pretreatment on levels of (A) ALP, (B) T-Bil, and (C) D-Bil analyzed by Wiener Lab equipment in the serum of rats intoxicated with a sublethal dose of thioacetamide (TAA). In ALP, the results are expressed in U/L, while T-Bil and D-Bil are expressed in mg/dL of serum. Bars indicate the mean value with the SE of two determinations (n = 8). The differences compared with the vehicle are expressed as “a”; while the differences due to TAA are expressed as “b”, p ≤ 0.05.

Figure 4

Effect of EC pretreatment on the levels of (A) GGT and (B) LDH analyzed by Wiener Lab equipment in the serum of rats intoxicated with a sublethal dose of thioacetamide (TAA). The results are expressed in U/L of serum. Bars indicate the mean value with the SE of two determinations (n = 8). The differences compared with the vehicle are expressed as “a”; while the differences due to TAA are expressed as “b”, p ≤ 0.05.

Figure 5

Effect of EC pretreatment on levels of (A) SOD and (B) Cat enzyme activities in rats’ liver intoxicated by a sublethal dose of thioacetamide (TAA). The results are expressed in U/mg protein. Bars indicate the mean value with the SE of two determinations (n = 8). The differences compared with the vehicle are expressed as “a”; while the differences due to TAA are expressed as “b”, p ≤ 0.05.

Figure 6

Effect of EC on (A) MnSOD, (B) CuZnSOD, (C) Cat, and (D) Nrf2 expression in homogenated liver of rats intoxicated with a sublethal dose of thioacetamide (TAA). The results are expressed in relative expression, arbitrary units (a.u.). Bars indicate the mean value with the SE of two determinations (n = 8). The differences compared with the vehicle are expressed as “a”; while the differences due to TAA are expressed as “b”, p ≤ 0.05.