CYP2E1 inhibition and NF_κB Signaling Pathway are Involved in the Protective Molecular Effect of Origanum floribundum against Acetaminophen-induced acute Hepatotoxicity in Rats

Abstract

The present study aimed to estimate the potential and the molecular mechanism of the hydro-ethanolic extract of O.floribundum against acetaminophen (AC) induced hepatotoxicity. Four groups of female Wistar rats (n=6) was formed to study the hepatoprotective effect of O.floribundum extract against acetaminophen overdose (2 g/kg): Groups N and AC received orally tap water for 03 days and Groups O. floribundum + AC and N+O.floribundum: received orally O. floribundum extract (400 mg/kg). After 1hour (h) of the last dose administered, the paracetamol solution (2 g/kg) is administered orally for group AC and O. floribundum + AC. The hydroethanolic extract of O. floribundum shows strong antioxidant activity "in-vitro". After 24 h, a single dose of acetaminophen increased significantly serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and the activity of alkaline phosphatase (ALP) significantly and decreased total protein and albumin levels compared to the normal group. These alterations are confirmed by histological observations with inflammation markers (congestion, inflammatory cells infiltration). These observed effects are mainly due to the over-expression of the CYP2E1 and NF_ κ B genes marked in this study by quantitative RT-PCR. Also, acetaminophen overdose leads to activation of the mitochondrial permeability transition (MPT). leading to hepatocyte necrosis. Pretreatment with O.floribundum before acetaminophen administration removes all previously observed biochemical, histological. and mitochondrial manifestations. These results suggest that O.floribundum has a potent antioxidant power and an interesting hepatoprotective activity against acetaminophen toxicity partly due to the inhibition of CYP2E1 and NF_ κ B genes expression.

Keywords: CYP2E1; NF_κB; Origanum floribundum; acetaminophen; oxidative stress.

Figure 1

Effect of O. floribundum extract on liver histological changes following AC toxicity in rats: (A) control group showing the normal structure of the liver, (A') normal portal space of control group with veins and arteries of regular structure; (B, B", B'"): AC treated groups with massive Porto-centrilobular necrosis. Swollen hepatocytes (B") hepatocyte with nuclear pyknosis (B") inflammatory cells infiltration for (B'’’), B’: portal space of AC treated group with piecemeal necrosis, Figure C: O. floribundum +AC pretreated group showing sub-normal architecture, Figure C’: normal portal space of O floribundum+AC pretreated group Figure D: normal liver for O. floribundum pretreated group, Figure D’: normal portal space of O. floribundum group (Hematoxylin Eosin X200); X400 for figure B”’. CV: centrilobulare vein; C: congestion; P: pyknos; PN: pieacemeal necrosis; N: necrosis; SC: swelling cell, IC: inflammatory cells

Figure 2

(A and B) Study of the CYP2E1 and NF-_KB genes expression by qRT-PCR in the liver rat

Figure 3

effect of O. floribundum on liver glycogen content in different treated groups