Effects of coenzyme Q10 and N-acetylcysteine on experimental poisoning by paracetamol in Wistar rats

Abstract

Paracetamol (PAR) is a drug widely used in human and veterinary medicine as an analgesic and antipyretic, often involved in cases of intoxication. The most common clinical signs result from damage to red blood cells and hepatocytes, and this intoxication is considered a model for the induction of acute liver failure. In the present study, the hepatoprotective effects of coenzyme Q10 (CoQ10) and N-acetylcysteine (NAC) against experimental paracetamol (PAR) poisoning were analysed. Thirty-five adult Wistar rats (Rattus novergicus albinus) were randomly assigned to five groups, and thirty-one of these survived the treatments. Negative control group (CON-) received 1mL of 0.9% NaCl orally (PO). Other groups received 1.2g/kg of PAR (PO). Positive control group (CON+) received only PAR. NAC group received 800 mg/kg intraperitoneally (IP) of NAC 1h after the administration of PAR and at 12 h received 1mL of 0.9% NaCl, IP. The fourth group (CoQ10) received 1h and 12 h after intoxication, CoQ10 (10mg/kg IP). And the fifth group (NAC+CoQ10) received NAC (800mg/kg, IP) and CoQ10 (10mg/kg, IP). After 12 hours, the rats were euthanized and necropsied to collect liver and kidney tissues for histopathological evaluation and electronic microscopy. A single dose of PAR caused severe acute hepatitis. NAC couldn't reverse the liver and kidney damages. The group that received CoQ10 and NAC had moderate liver damage, while the group that received only CoQ10 had lower values of liver enzymes and mild liver and kidney damage. Animals that received treatment with CoQ10 or NAC+CoQ10 presented normal hepatocyte mitochondria and nuclei. Although CoQ10 couldn't reverse PAR organ damage, results indicate promising hepatoprotection in Wistar rats.

Fig 1

(A) Mean and standard deviation of haematocrit (HCT), (B) erythrocytes and (C) haemoglobin, (D) platelets (PLT), (E) total serum protein (TP), (F) albumin (ALB) of rats experimentally poisoned with paracetamol and treated with coenzyme Q10 and N-acetylcysteine. CON-: negative control; CON+ positive control; NAC group treated with N-acetylcysteine; CoQ10 group treated with coenzyme Q10; NAC+CoQ10: group treated with the association of NAC and CoQ10. Analyses performed with Tukey or Kruskal-Wallis post-test (*p<0.05; **p<0.01).

Fig 2

(A) Mean and standard deviation values of aspartate aminotransferase (AST) and (B) creatinine of rats experimentally poisoned with paracetamol and treated with coenzyme Q10 and N-acetylcysteine. CON-: negative control; CON+ positive control; NAC group treated with N-acetylcysteine; CoQ10 group treated with coenzyme Q10; NAC+CoQ10: group treated with the association of NAC and CoQ10. Analyses performed with Tukey or Kruskal-Wallis post-test (*p<0.05; **p<0.01).

Fig 3. Liver of Wistar rats.

(A) Photograph of the liver of a rat in the CON- group that received a single dose of 1mL of 0.9% NaCl PO, with normal pattern. (B) Photograph of rat liver from the CON+ group, only poisoned with paracetamol (PAR) 1.2 g/kg, PO. Multifocal and marked congestion (yellow arrow) and evidence of a marked and diffuse lobular pattern (asterisks) are visualized. (C) Photograph of the liver of a rat in the NAC group, intoxicated with PAR and treated with 800 mg/kg of NAC, with marked evidence of a diffuse lobular pattern (star) and extensive multifocal congestion (yellow arrow). (D) Photograph of rat liver from the CoQ10 group that received 10 mg/kg CoQ10, IP, showing slightly bulging edges, evidence of a moderate multifocal lobular pattern on the image (asterisks) and mild multifocal congestion (yellow arrows). (E) Photograph of the liver of the mouse from the NAC+CoQ10 group, treated with 800 mg/kg of NAC and 10 mg/kg of CoQ10, IP, without visible macroscopic changes.

Fig 4. Optical photomicrograph of liver samples from Wistar rats.

(A, B) Negative control group (CON-) presents mild hyperaemia in the centrilobular vein region (yellow arrow). (C and D) Positive control group (CON+), intoxicated with paracetamol (PAR) 1.2 g/kg, orally, presents moderate hyperaemia (yellow arrow) and necrosis and lytic haemorrhage in bridging in the centrilobular region marked (asterisk) (HE, Bar = 100 μm); (B and D) (HE, Bar = 20 μm).

Fig 5. Photomicrograph of liver tissue from Wistar rats intoxicated with 1.2 g/kg, PO, of paracetamol (PAR).

(A, B) The group that received 800mg/kg IP of N-acetylcysteine (NAC) presented marked hyperaemia (yellow arrows), necrosis of hepatocytes and haemorrhage in the centrilobular region marked in bridge (asterisks). (C, D) Group that received only 10mg/kg IP of Coenzyme Q10 (CoQ10) presented mild hyperaemia (yellow arrows) and absent hepatocyte nucleus (asterisk). (E, F) NAC + CoQ10 group, which were treated with 800 mg/kg of NAC and 10 mg/kg of CoQ10, IP and presented moderate hyperaemia (yellow arrow), mild atrophy of hepatocytes and absence of hepatocyte nucleus (asterisk). (A, C and E) (HE, Bar = 100 μm); (B, D and F) (HE, Bar = 20 μm).

Fig 6. Electron micrographs of longitudinal sections of liver tissue from rats experimentally intoxicated by paracetamol (PAR) and treated with coenzyme Q10 and N-acetylcysteine.

(A) CON- sample: emphasis on intact mitochondria (yellow star), normal hepatocyte nuclei (yellow arrow) and fat droplets; (B) CON+: fibrous tissue, degenerated mitochondria (yellow star); (C) NAC + CoQ10 group that were treated associated with NAC and CoQ10: emphasis on collagen fibers (yellow arrow) and intact mitochondria (yellow star).