Resveratrol and Montelukast Alleviate Paraquat-Induced Hepatic Injury in Mice: Modulation of Oxidative Stress, Inflammation, and Apoptosis

Abstract

Paraquat (PQ) is one of the most used herbicide worldwide. Its cytotoxicity is attributed to reactive radical generation. Resveratrol (Res) and montelukast (MK) have anti-inflammatory and antioxidant properties. The protective effects of Res, MK, or their combination against PQ-induced acute liver injury have not been investigated before. Therefore, we explored the protective potential of Res and/or MK against PQ hepatic toxicity in a mouse model. Mice were randomly assigned to five groups: group I served as the normal control and group II received a single dose of PQ (50 mg/kg, i.p.). Groups III, IV, and V received PQ plus oral Res (5 mg/kg/day), MK (10 mg/kg/day), and Res/MK combination, respectively. Res and/or MK reduced PQ-induced liver injury, evidenced by normalization of serum total protein, ALT, and AST. Res and/or MK significantly reversed PQ-induced oxidative stress markers glutathione and malondialdehyde. Res and/or MK significantly reduced PQ-induced inflammation reflected in TNF-α levels. Furthermore, Res and/or MK reversed PQ-induced apoptosis assessed by differential expression of p53, Bax, and Bcl-2. Histopathologic examination supported the biochemical findings. Although Res and MK displayed antioxidative, anti-inflammatory, and antiapoptotic activities, their combination was not always synergistic.

Figure 1

Effect of Res, MK, and Res+MK on hepatic oxidative stress markers. (a) MDA and (b) GSH levels. Data represent the mean ± SEM (n = 10–14). ∗ and ∗∗∗ mean significantly different from the control group at p < 0.05 and p < 0.001, respectively. # and ### mean significantly different from the PQ-treated group at p < 0.05 and p < 0.001, respectively.

Figure 2

Effect of Res, MK, and Res+MK on hepatic TNF-α level. Data represent the mean ± SEM (n = 10 − 14). ∗∗∗ significantly different from the control group at p < 0.001. ## and ### mean significantly different from the PQ-treated group at p < 0.01 and p < 0.001, respectively.

Figure 3

Effect of Res, MK or Res+MK on mRNA expression of Bcl-2, Bax, and p53 genes. Data represent the mean of technical duplicates of the pooled total RNA from n = 5. (a) B cell lymphoma-2 (Bcl-2), (b) Bcl-2 associated x protein (Bax), and (c) cellular tumor antigen p53 mRNA expression was detected by quantitative RT-PCR.

Figure 4

Photomicrographs of H&E stained liver sections from (a) normal control mice (64x), normal architecture of central vein (CV), and surrounding hepatocytes (h). (b) PQ group (40x): sever dilatation in portal vein (PV) with inflammatory cell infiltration (m) in the portal area surrounding the bile duct. (c) Res group (80x): dilatation of CV with diffuse Kupffer cells proliferation in between the hepatocytes (arrow). (d) MK group (40x): dilatation and congestion in the CV. (e) Res+MK group (80x): dilatation of CV with inflammatory cell infiltration in between the hepatocytes (m).