Effect of Artemisia absinthium and Malva sylvestris on Antioxidant Parameters and Abomasal Histopathology in Lambs Experimentally Infected with Haemonchus contortus

Simple Summary Haemonchus contortus is a blood-feeding gastrointestinal nematode (GIN) that parasitizes in the abomasum of small ruminants. Infections caused by this parasitic nematode possess a serious threat to livestock production worldwide, and with the expansion of anthelmintic resistance, there is an urgent need for more sustainable alternative controls of GIN. It is known that nutritional supplementation with medicinal plants could slow the dynamics of infection and increase the resistance of lambs to parasitic infection. The influence of medicinal plants used for control of haemonchosis on the local immune response of abomasal mucosae in GIN-infected sheep, however, has not been reported. This study aimed to evaluate the effect of diets containing wormwood (Artemisia absinthium), mallow (Malva sylvestris), or their mix, on antioxidant parameters and local immune responses in the abomasum of lambs infected with H. contortus. Treatment with the medicinal plants affected antioxidant parameters by reducing oxidative stress in the abomasal mucosa and helped trigger local immune responses. Wormwood (A. absinthium) and mallow (M. sylvestris) applied as dietary supplements may increase the resistance of lambs to GIN infections. This study evaluated the effect of Artemisia absinthium and Malva sylvestris on antioxidant response and histopathological changes in the abomasa of the Haemonchus contortus infected lambs. Twenty-four lambs were divided into four groups: unsupplemented lambs (UNS), lambs supplemented with A. absinthium (ART), lambs supplemented with M. sylvestris (MAL), and lambs supplemented with both plants (ARTMAL). Lambs were infected orally with approximately 5000 third-stage (L3) larvae of H. contortus. The experiment was conducted for 75 d (days), all animals were then slaughtered, and the abomasal tissues were examined for antioxidant parameters and histopathology. The concentration of malondialdehyde in the abomasal mucosa was lower in ARTMAL (p < 0.05), and the total antioxidant capacity was higher in MAL (p < 0.05), than in UNS. Increased mucus production was observed in the ARTMAL. The number of mast cells in UNS and ART was significantly higher than the number in MAL (p < 0.01 and p < 0.05). Plasma cell numbers were higher in ARTMAL than the number in MAL (p < 0.05). Abomasal tissue regenerated more frequently in ARTMAL. These results represent the first report of the impact of A. absinthium and M. sylvestris on antioxidant parameters and local immune responses of abomasal mucosa of lambs infected with a GIN parasite.