Rumex nervosus changed the oxidative status of chicken caecum infected with Eimeria tenella

1 Introduction

Coccidiosis is a dangerous parasitic disease of the intracellular genus Eimeria protozoan parasite (Mehlhorn, 2014). This parasite causes injuries to the intestinal tissue leading to a reduction in feed intake and nutrient absorption, and also makes the host more susceptible to secondary bacterial infections (Morris et al. 2007). Every year, coccidiosis causes a global loss in the poultry industry of over US$ 2.4 billion (Quiroz-Castañeda and Dantán-González, 2015). Eimeria acervulina, E. tenella, E. maxima, and E. praecox are often found in broiler chickens (Hamidinejat et al., 2010).

Intensive chicken farming is based on effective coccidiosis prophylaxis with anticoccidial in-feed drugs. Because of the development of drug resistance, overuse of coccidiostats becomes less successful, resulting in poor weight gain and high feed intake (Jenkins et al., 2010; Wajiha et al., 2018), and impairing economic performance (Shirzad et al., 2011). The prophylactic use of anticoccidium chemicals as feed additives in European countries has been strictly limited since a short time (Muthamilselvan et al., 2015). Researchers are seeking to find natural product with low coast and reduced side effects against coccidiosis (Abbas et al., 2012; Bozkurt et al., 2013; Quiroz-Castañeda and Dantán-González, 2015). Because of their presumed safe, nutritious and therapeutic value, the use of natural antioxidants found in plant and other biological materials has recently attracted considerable interest (Al-Naqeb, 2015; Alhotan and Abudabos, 2019). Here, we determined the antioxidant activity of Rumex nervosus leaf extracts against coccidiosis induced by E. tenella in chickens. R. nervosus belongs to the Polygonaceae family and contains important anti-microbial phytochemicals and a set of vitamins (Al Yahya et al., 2018).

2 Materials and methods

3 Results

The analysis of R. nervosus extract using FTIR showed major bands at 3410.33 cm⁻¹, 1609.92 cm⁻¹, 1526.88 cm⁻¹, 1445.41 cm⁻¹, 1364.43 cm⁻¹, 1285.28 cm⁻¹, 1210.93 cm⁻¹, 1107.57 cm⁻¹, 1032.89 cm⁻¹, 765.22 cm⁻¹ (Fig. 1, table 1). N—H stretching was indicated by band at 3410.33 Cm⁻¹ confirming the presence of aliphatic primary amine. The band at 1609.92 implied to C⚌C stretching for the presence of α, β-unsaturated ketone. N—O stretching confirming the presence of nitro compound at 1526.88 cm⁻¹. Aromatic ester, alkyl aryl ether and aliphatic ether were present at 1285.28, 1210.93 and 1107.57 cm⁻¹, respectively. However, other compounds were present (Fig. 1, Table 1).

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Fig. 1

Infrared spectroscopy of Rumex nervosus leaf extracts.

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The non-infected chickens have significant increase in body weight when compared to the infected bird (Fig. 2). RE-challenged birds showed a significant increase in body weight compared to infected birds, especially at the 200 mg/kg RE dose showing more weight gain than the reference drug, Amprolium (Fig. 2).

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Fig. 2

Change in weight of chicken during E. tenella infection and after treatment with RE. Significance at p < 0.01 against control group (a) and against infected group (b).

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On day 6 post E. tenella infection, the feed intake was 438.40 ± 15.27 g/bird in the infected group (Fig. 3). This decrease was ameliorated by the treatment of animals with RE that reached 576.00 ± 18.48 g/bird (Fig. 3). Birds treated with Amprolium also significantly appeared with increased feed intake (Fig. 3).

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Fig. 3

Suppression of E. tenella oocysts in infected and infected-treated birds. Significance at p < 0.01 against control group (a) and against infected group (b).

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Examination of chicken faeces at day 6 post-infection revealed high number of oocysts output reaching 32.88 ± 2.46 × 10⁶ (Fig. 4). This number of oocysts significantly decreased (p ≤ 0.01) after the treatment of the infected chickens with 200 mg/kg. RE treated group appeared with better oocyst output inhibition than Amprolium treated group (Fig. 4).

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Fig. 4

Change in chicken’s feed intake during E. tenella infection and after treatment with RE. *Significance at p < 0.01 against infected group.

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Eimeriosis induced by E. tenella disrupted the oxidative status in chicken’s cecum. This was evidenced through the decrease in GSH level in the caecum of infected chickens and the significant increase of MDA and NO (Fig. 5). After treatment of chickens with RE, the oxidative status in chicken's cecum was changed where the level of GSH was 5.26 ± 0.68 mmol/g. However, the level of MDA and NO were reduced to 17.75 ± 2.54 U/g and 4.25 ± 0.55 µmol/L, respectively (Fig. 5). Comparing the results of RE group to that of the Amprolium treated group, it is clear that RE could act as an antioxidant agent with similar effects to Amprolium.

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Fig. 5

Induced changes in the level of glutathione (GSH), Nitric oxide (NO) and malondialdehyde (MDA) in chicken caecum infected with E. tenella and treated with RE. Significance at p < 0.01 against control group (a) and against infected group (b).

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4 Discussion

The development of effective agents against coccidiosis in animals is urgently needed. Today, the poultry industry is under growing pressure to reduce the use of anticoccidium drugs and the search for natural source active compounding that enhances and the immune function of animals. This study aimed to evaluate RE anticoccidial and antioxidant effect against E. tenella infection.

Animal infected with Eimeria show a significant weight loss and feed intake (Mehlhorn, 2014), due to the poor nutrient absorption and decreased immune response resulting in intestinal tissue damage (Chapman, 2014). Our finding demonstrated this weight loss following infection with E. tenella, as well as a decline in fee intake in the infected birds. This increase in weight and feed consumption could be due to the presence of certain essential compounds in the plant extract used. Ott et al. (2018) reported that β.glucans improved the decrease in weight and feed intake induced by E. tenella.

The caecum is the site of E. tenella infection where the parasite invades the caecum epithelium causing severe injuries (Mehlhorn, 2014). Different developmental stages were developed in caecum epithelium and finally oocysts were developed and go out with faeces.

In many diseases, including parasitic diseases, oxidative stress arises when the equilibrium between the process of producing free radicals and their removal process is disrupted, which is normally balanced under natural conditions, when the production of free radicals by antioxidant compounds is greater than the process of removal (Georgieva et al., 2006). Consequently, the oxidative stress occurs, the intestinal epithelial barrier and tight junctions are destroyed throughout lipid peroxidation (increased malondialdehyde) and antioxidants insult, as a result, reduced feed intake, a poor absorption of nutrients and the body weight gain decreased of the infected birds (Naidoo et al., 2008). During coccidiosis nitric oxide and other reactive oxygen species (ROS) are produced as an immunological response to Eimeria sporozoites that invade the intestinal epithelium causing inflammation. In spite, the nitric oxide and other ROSs are considered toxic cellular products for Eimerian sporozoites, but also have negative side effects on the host if not protected by an antioxidant system (Halliwell and Gutteridge, 1989).

Using antioxidants from natural sources could be beneficial for the oxidative status of the cell in the caecum inducing oxidant/antioxidant balance and lead to improvement in the oxidative damage induced by E. tenella infection (Wang et al., 2018). In our study, RE could significantly reduce the severity of the infection in caecum by ameliorating the level of lipid peroxidation by neutralizing reactive oxygen species (ROS). Like diclazoril, a common anticoccidial drug, RE was able to limit the degree of lipid peroxidation (Eraslan et al., 2004). The parasite induces a change in the caecum oxidative status and cause inflammatory cellular effects (Pourali et al., 2014). Similar results have been obtained in rodents infected with Eimeria papillata due to the increased MDA and NO levels. This may be caused by serious inflammatory response due to oxidative damage caused by eimeriosis (Al-Quraishy et al. 2019).

Our results collectively show that RE is effective agent that improved the change in weight and feed intake as well as it reduced the number of E. tenella oocysts expelled in faeces. In addition, RE may control the oxidative status of the infected birds in the caecum but studies are needed to know the mechanism of RE action on both the host and the parasite.