Use of Spirulina platensis and Curcuma longa as Nutraceuticals in Poultry

Since the banning of antibiotics in animal feeds (2006), there has been an increase in the number of studies looking for alternatives to stimulate the gut immune system. The main objective of our review article is to underline the nutraceutical properties of Curcuma longa and Spirulina platensis in the broiler chicken industry, and the experimental data were obtained by analyzing literature sources. Spirulina platensis is widely recognized as a valuable protein source, containing approximately 55–70% protein, 25% carbohydrates, essential amino acids, and 18% fatty acids. It is also rich in various vitamins like thiamin, riboflavin, pyridoxine, vitamin B12, vitamin C, gamma-linolenic acid, phycocyanins, tocopherols, chlorophyll, beta-carotenes, carotenoids, exhibiting positive effects on growth performance, gut integrity, and immunity. The anti-inflammatory effect of spirulina supplementation at different levels showed a decrease in caspase-3 and the TNF-α immunolabeling index; a reduction in IL-1β, IL-2 and IFN-γ; and an increase in the expression of the anti-inflammatory cytokine IL-4. Spirulina inhibits the synthesis of cytokines IL-1, IL-6, and TNF-gamma in addition to the activities of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) enzymes. Turmeric also positively influences the growth, egg production, and overall health of chickens. Curcumin, the most potent component of turmeric, possesses additional pharmacological activities, including hepatoprotective, immunostimulant, and anticancer effects. Its immunomodulatory properties greatly enhance the immune system response, acting as a natural antibiotic against pathogens and decreasing levels of proinflammatory interleukins IL-1β, IL-6, IL-2, IL-18, and TNF-α.