Intensive tilapia farming makes it sensitive to various stress factors, such as heat stress, one of the major consequences of global warming. Although Nile tilapia can tolerate a wide range of temperatures, water temperatures above the optimal range suppress the immune system and impair its antioxidant response.
A team of researchers from the National Institute of Oceanography and Fisheries (NIOF) studied the effects of dietary supplementation with curcumin and nano-curcumin on the growth, immunity, and resistance to heat stress of Nile tilapia (Oreochromis niloticus).
Curcumin (Curcuma longa)
Curcumin is a yellow-orange hydrophobic bioactive herbal ingredient and polyphenolic compound extracted from turmeric (Curcuma longa).
The main active components of curcumin are diferuloylmethane (77%), demethoxycurcumin (17%) and bisdemethoxycurcumin (6%).
Surprisingly, curcumin possesses antiviral, antifungal, anti-inflammatory, antioxidant, and anticancer properties.
Several studies have demonstrated the beneficial effects of curcumin as a potential immunostimulant and antioxidant candidate in the diets of various fish species.
Recently, nano-curcumin has been developed to avoid the poor release properties of curcumin and enhance its therapeutic effects. Unlike curcumin, which forms lumps due to its low solubility in water, nano-curcumin dissolves completely in an aqueous medium and does not form lumps.
According to the study results, feeding Nile tilapia diets containing curcumin leads to better growth results, compared to the control diet.
Furthermore, the study strongly reveals the superiority of nano-curcumin over its free form in enhancing the growth of Nile tilapia.
“The results revealed the superiority of nano-curcumin over its free form in increasing growth performance, with the best result obtained at CN100 (100 mg kg-1 of diet), followed by CN 200”, the researchers report.
They also highlight that lower doses of nano-curcumin can increase the growth performance of Nile tilapia and provide the same effects as higher doses of curcumin.
Protective effects of curcumin
“Despite the protective effects of curcumin against liver damage in this study at a moderate concentration (100 mg kg-1 of diet), adverse effects appear at higher concentrations (200 mg kg-1 of diet)”, researchers point out.
According to the study results, the levels of liver enzyme activities, such as ALT and AST, were decreased in the nanocurcumin-fed groups of fish, before or after heat stress, and to some extent in the curcimin-fed groups. , thus demonstrating the advantage of using nano-curcumin.
“Nanocurcumin is more effective than its free form in increasing resistance to heat stress, inducing innate immunity, reducing stress indicators and promoting growth performance of Nile tilapia with the best concentration at 100 mg kg-1 of diet,” they conclude.
Reference (free access)
Abdel-Ghany, H.M., El-Sisy, D.M. & Salem, M.ES. A comparative study of effects of curcumin and its nanoparticles on the growth, immunity and heat stress resistance of Nile tilapia (Oreochromis niloticus). Sci Rep 13, 2523 (2023). https://doi.org/10.1038/s41598-023-29343-z