Quillaja saponaria bark saponin protects Wistar rats against ferrous sulphate-induced oxidative and inflammatory liver damage

Abstract

Context: Saponins from different sources are historically reported in Chinese medicine to possess many beneficial effects. However, insufficient experimental data are available regarding the hepatoprotective potential of Quillaja bark saponin.

Objective: The protective effect of Quillaja saponaria Molina (Quillajaceae) bark triterpenoid saponin against iron-induced hepatotoxicity is compared to the standard N-acetylcysteine in adult male Wistar rats.

Materials and methods: Animals were divided into (six) groups, namely a normal control, an N-acetylcysteine control (300 mg/kg/day, p.o., 10 days), a saponin control (100 mg/kg/day, p.o., for 10 days), a hepatotoxicity control (two doses of ferrous sulphate, 30 mg/kg/day each, i.p., on 9th and 10th day), an N-acetylcysteine plus ferrous sulphate (standard treatment) and a saponin plus ferrous sulphate (test treatment) group. Hepatocyte integrity loss markers (serum ALT, AST, ALP, GGT and LDH), oxidative stress markers (hepatic MDA, GSH and NO_x), dyslipidaemic markers (serum TC and TG) and hepatocyte functioning markers (serum bilirubin and albumin) were assessed.

Results: Quillaja bark saponin decreased iron-induced elevation of ALT (reaching 57% of hepatotoxicity control), AST (66%), ALP (76%), GGT (60%), LDH (54%), MDA (65%), NO_x (77%), TC (70%), TG (54%), and total (54%), direct (54%) and indirect (54%) bilirubin, coupled with increased GSH (219%) and albumin (159%) levels. Histopathological study strongly supported biochemical estimations, while immunohistochemical study showed marked effect on eNOS and iNOS expression.

Conclusions: Quillaja bark saponin has a good hepatoprotective effect. Amelioration of oxidative stress and suppression of NOS expression, with resultant maintenance of hepatocyte integrity and functioning, may explain this beneficial effect.

Keywords: Hepatotoxicity; N-acetylcysteine; nitric oxide synthase.

Figure 1.

Effect of 10 days daily oral administration of N-acetylcysteine and saponin on hepatocyte integrity loss markers in normal rats.

Figure 2.

Effect of 10 days daily oral administration of N-acetylcysteine and saponin on nitro-oxidative stress markers in normal rats.

Figure 3.

Effect of 10 days daily oral administration of N-acetylcysteine and saponin on dyslipidaemia markers in normal rats.

Figure 4.

Effect of 10 days daily oral administration of N-acetylcysteine and saponin on functional markers in normal rats.

Figure 5.

Photomicrographs of liver section obtained from different groups (H&E; 400×), where  (A) normal control group showing normal hepatic architecture with central vein (CV) and radiating cords of normal hepatocytes (H) with central rounded vesicular nuclei and prominent nucleoli. Hepatic cords are separated by blood sinusoids (S) lined with endothelium and von Kupffer cells (blue arrow); (B) ferrous sulphate group showing dilated congested central vein (CV) with congested blood sinusoids (S). Massive fatty infiltration of hepatocytes (H) with some hepatocytes acquired the signet ring appearance (blue arrow); (C) N-acetylcysteine plus ferrous sulphate group showing congested central vein (CV). Normal hepatocytes (H) are separated by slightly dilated congested blood sinusoids (S) with activated von Kupffer cells (blue arrow). Binucleated cells (black arrow) can be seen; (D) saponin plus ferrous sulphate group showing congested central vein (CV). Normal hepatocytes (H) are separated by slightly dilated congested blood sinusoids (S) with activated von Kupffer cells (blue arrow). Binucleated cells (black arrow) can be seen.

Figure 6.

Photomicrographs of liver sections obtained from different groups (iNOS immunohistochemical stain; 400×), where (A) normal control group showing weak immunoreactivity to iNOS which appears as faint brown colour (red arrow); (B) ferrous sulphate group showing strong immunoreactivity to iNOS which appears as brown colour (red arrow) with some areas of intense immunoreactivity (yellow arrow); (C) N-acetylcysteine plus ferrous sulphate group showing mild immunoreactivity to iNOS which appears as brown colour (red arrow); (D) saponin plus ferrous sulphate group showing moderate immunoreactivity to iNOS which appears as brown colour (red arrow).

Figure 7.

A photomicrograph of liver section obtained from different groups (eNOS immunohistochemical stain; 400×), where (A) normal control group showing strong immunoreactivity to eNOS which appears as brown colour (red arrow); (B) ferrous sulphate group showing weak to negative immunoreactivity to eNOS which appears as brown colour (red arrow); (C) N-acetylcysteine plus ferrous sulphate group showing strong immunoreactivity to eNOS which appears as brown colour (red arrow) but not as normal control group; (D) saponin plus ferrous sulphate group showing moderate immunoreactivity to eNOS which appears as brown colour (red arrow).