Dietary Supplementation of Calendula officinalis Counteracts the Oxidative Stress and Liver Damage Resulted from Aflatoxin

Abstract

This study was conducted to evaluate the total phenolic compounds, the antioxidant properties, and the hepatorenoprotective potential of Calendula officinalis extract against aflatoxins (AFs-) induced liver damage. Six groups of male Sprague-Dawley rats were treated for 6 weeks included the control; the group fed AFs-contaminated diet (2.5 mg/kg diet); the groups treated orally with Calendula extract at low (CA1) and high (CA2) doses (500 and 1000 mg/kg b.w); the groups treated orally with CA1 and CA2 one week before and during AFs treatment for other five weeks. The results showed that the ethanol extract contained higher phenolic compounds and posses higher 1,1-diphenyl 1-2-picryl hydrazyl (DPPH) radical scavenging activity than the aqueous extract. Animals fed AFs-contaminated diet showed significant disturbances in serum biochemical parameters, inflammatory cytokines, and the histological and histochemical pictures of the liver accompanied by a significant increase in malondialdehyde (MDA) and a significant decrease in superoxide dismutase (SOD) and glutathione peroxidase (GPx) in liver. Calendula extract succeeded to improve the biochemical parameters, inflammatory cytokines, decreased the oxidative stress, and improved the histological pictures in the liver of rats fed AFs-contaminated diet in a dose-dependent manner. It could be concluded that Calendula extract has potential hepatoprotective effects against AFs due to its antioxidant properties and radical scavenging activity.

Figure 1

Effect of the treatment with ethanol extract of Calendula on food intake of rats fed AFs-contaminated diet during the experimental period (AFs: aflatoxins; CE1: low dose of Calendula extract (500 mg/kg b.w); CE2: high dose of Calendula extract (1000 mg/kg b.w)).

Figure 2

Effect of the treatment with ethanol extract of Calendula on body weight of rats fed AFs-contaminated diet during the experimental period (AFs: aflatoxins; CE1: low dose of Calendula extract (500 mg/kg b.w); CE2: high dose of Calendula extract (1000 mg/kg b.w)).

Figure 3

A photomicrograph in liver section from (a) a control rat branching and anatomizing cords radiating from the central vein CV. The hepatocytes that are having vesicular nuclei and some binucleated cells are separated by sinusoids lined by flat endothelial cell and kupfer cells, (b) a rat fed AFs-contaminated diet showing hepatocytes necrosis (N) and apoptosis (yellow arrows), and fibrosis around the blood vessels (F). (c) A rat treated; with CE1 or CE2 showing the normal hepatocytes with vesicular nuclei and evident mononuclear cellular infiltration around the central vein (d) a rat fed AFs-contaminated diet and treated with CE1 showing marked improvement in hepatocytes architecture; no vacuoles or fatty droplets were detected. Some cells have eosinophilic cytoplasm and deeply stained nuclei around the central and portal vein areas (arrows), and mononuclear cellular infiltration are scattered around the portal tracts. (e) A rat fed AFs-contaminated diet and treated with CE2 showing normal histological picture with few fatty degeneration and interstitial hemorrhage around the central vein.

Figure 4

Photomicrographs in liver sections stained with Periodic-Sheif reagent-stain (PAS) for glycogen demonstration from (a) control rats showing a strong reaction of PAS, (b) rats fed AFs-contaminated diet showing a weak reaction in the damaged cell while a strong reaction in intact cells, (c) rats treated with CE1 or CE2 showing different types of reaction as well as strong reaction around the central vein and weak reaction around portal vein of hepatocytes, (d) rats fed with AFs contaminated diet treated with CE1 showing that weak reaction in some damaged cells which scattered in all the section and (e) rats fed with AFs contaminated diet and treated with CE2 showing marked improvement, although low reaction in hepatocytes were still demonstrated (PAS reaction ×100).