Efficacy of dietary supplements of Glycyrrhiza glabra (Licorice) and maduramicin alone or in combination with Eimeria tenella infected chicks: A clinical study and molecular docking

Abstract

Background: Coccidiosis is one of the most economically significant poultry diseases worldwide, caused by the pathogenic Eimeria species, and is characterized by decreased weight gain (WG) and failure to grow due to malabsorption, low feed conversion rate, bloody diarrhea, and dehydration.

Aim: This study investigated the effectiveness of licorice root extract (LRE) in controlling cecal coccidiosis to determine whether its combination with maduramicin could help alleviate the pathological, biochemical, and histopathological effects of cecal coccidiosis in Sasso broiler chicks.

Methods: A total of 125 one-day-old Sasso broiler chicks were categorized into five equal groups (n = 25), each consisting of five replicates (n = 5 per replicate). G1-LE received a basal diet supplemented with LRE (3 g/kg); G2-ME received a basal diet containing maduramycin (0.5 g/kg); and G3-LME received a basal diet containing LRE and maduramicin together with the same rates. G4-E (positive control) and G5-N (negative control) received no additives in their feed. Birds in groups (G1-4) were challenged on day 14 of the experiment by orally intercropping a 1 ml suspension of Eimeria tenella sporulated oocysts.

Results: Groups of birds fed on LRE and maduramicin separately or together appeared to be in good condition where no deaths or clinical abnormalities were observed, based on the analysis of clinicopathological examination. Compared with the G4-E positive control, the dropping scoring and oocyst shedding of groups G1-LE, G2-ME, and G3-LME along the 10th-day post-challenge (dpc), as well as macroscopic and microscopic lesions scoring at the 7th dpc, was considerably lower. The dual supplementation use of LRE and maduramicin in G3-LME's reduced the harmful effects of coccidian, which appeared only as a mononuclear cellular infiltration and a small number of oocysts invading the intestinal glands. Molecular docking revealed that LRE and maduramicin interacted with E. tenella DNA polymerase, E. tenella apical membrane antigen 1, and microneme protein binding sites resulting in reduced E. tenella replication and invasion.

Conclusion: The inclusion of LRE and maduramicin, individually or in combination, in the diet might effectively mitigate the detrimental effects of coccidiosis.

Keywords: Chicken; Coccidiosis; Glycyrrhiza glabra; Licorice; Maduramicin.

Fig. 1.. Clinical and pathological findings of the cecal coccidiosis in Sasso chickens observing (i) depressed bird with ruffled feather and bloody droppings, (ii) enlarged and sausage appearance ceca, and (iii) cecal core with bloody contents.

Fig. 2.. Effect of LRE and maduramicin alone or in combination on the histopathological findings in the cecal tissues of Sasso chickens challenged with E. tenella oocysts observing (a) cecum of the control negative group showing normal intestinal villi (V) and intestinal glands (G), (H & E stain, X 20 lens). (b) Cecum of the control positive groups showed atrophied intestinal glands (G), hemorrhage (H), mononuclear cellular infiltration (black arrow) and oocyst (red arrow). (H & E stain, X 20 lens). (c) Higher magnification of showed atrophied intestinal glands (G), oocyst (red arrow) R.B. Cs in congested blood capillaries (green arrow). (H & E stain, X 40 lens). (d) cecum of birds fed on the licorice treated diet showed intestinal villi (V) with desquamated epithelial cells (d), intestinal glands (G) and some oocyst invading intestinal glands (red arrow). (H & E stain, X 20 lens). (e) Cecum of maduramicin treated groups showed normal intestinal villi (V), intestinal glands (G) with some oocyst (red arrow), congestion of blood vessels (C), mononuclear cellular infiltration either diffuse (black arrow) or nodular (yellow arrow). (H & E stain, X 20 lens). (f) Cecum of combined treated groups with licorice and maduramicin displayed little affected intestinal glands which invaded by low number of oocyst (red arrow), diffuse cellular infiltration (black arrow). (H & E stain, X 20 lens).

Fig. 3.. The ACI value was lower than 120 which means “lack of anticoccidial activity,” at 120–140 “mild effective,” at 140–160 “moderate effective” and at higher than 160 “marked effective.” The ACI is calculated according to the equation of subscripting for the sum of the lesion index (LI) and oocyst index (OI) from the sum for the percentages of survival and relative gain weight %S + %RGW) − (LI + OI) (De Pablos et al. 2010), where LI is the lesion index as the HIS multiplied by 10 and OI is the oocyst index as (OPG output of each experimental group/OPG output of the infected untreated control) × 100.

Fig. 4.. Heat map showing the effect of LRE and maduramicin alone or in combination on mean values for antioxidant and lipid profiles and liver and kidney function tests for different experimental groups.

Fig. 5.. (A) Molecular interaction of glycyrrhizin with E. tenella DNA polymerase binding site, (B) molecular interaction of soyasaponin i with E. tenella apical membrane antigen 1 (EtAMA1) binding site, and (C) molecular interaction of liquiritin apioside EtMIC3 binding site.

Fig. 6.. (A) Molecular interaction of maduramicin with E. tenella DNA polymerase binding site, (B) molecular interaction of maduramicin with E. tenella apical membrane antigen 1 (EtAMA1) binding site, and (C) molecular interaction of maduramicin with EtMIC3 binding site.