Phenolics of Botanical Origin for the Control of Coccidiosis in Poultry

Eimeria are the absolute intestinal parasites belonging to phylum Apicomplexa, causing the intestinal disease known as coccidiosis. It is a lethal disease that affects a large variety of animals and birds including cattle, camel, goats, sheep, poultry, etc. causing severe devastation and mortalities. Controlling poultry coccidiosis by the means of preventive and prophylactic use of chemical drugs is currently being practiced on a commercial scale. Regardless of a history of successful use of these drugs, resistance and public health concerns demand their alternatives. Several alternatives including vaccination, organic acids and botanicals, are being suggested. Several preparations of botanicals have been experimented and found useful, but exact compound identification is a question of interest for scientists. Phenolic compounds are among the most abundant phytochemicals found in diverse structural forms comprising mainly phenolic acids, tannins, flavonoids, and others. Research states that they have the potential to control coccidiosis because of their direct and indirect anticoccidial activities. Phenolics have been reported to control coccidiosis by targeting Eimeria species directly and reducing the damages by antioxidant, immunomodulatory, and anti-inflammatory properties. Phenolics kill Eimeria by engulfing schizonts, rupturing the cell membrane of sporozoites, and inhibiting growth by stopping ATP synthesis mechanisms and other pathways depending on their chemical nature and the subgroup of phenolic compounds. Because of the high potential of being oxidized; they capture the reactive species produced because of cell rupture during rapid schizogony and immune invasion. Phenolics give negative feedback to several inflammatory mediators and reduce the inflammatory destruction of the gut, hence minimizing the loss. Regardless of these activities, phenolics have some drawbacks i.e., they reduce nutrient uptake, disturb carbohydrate disturbance, have cytotoxic effects, and undefined long-term response. Extensive research is needed to investigate the proper anticoccidial compound and reduce the side effects of phenolics to manage coccidiosis in an accurate, rapid, and safe way.