Protective effect of dietary curcumin in Anabas testudineus (Bloch) with a special note on DNA fragmentation assay on hepatocytes and micronucleus assay on erythrocytes in vivo.

The present study was conducted to evaluate the safety of long-term dietary curcumin at doses 0.5 and 1% in Anabas testudineus employing hematological and cytological techniques. The fish were fed with curcumin-supplemented feed for 6 months. Fine blood smears were prepared and subjected to three different staining techniques. The erythrocyte micronucleus frequency (MN) and the cytometric measurements of erythrocytes were determined. Blood from the control and treated fish was subjected to the assessment of several hematological parameters. Also, DNA fragmentation assay on hepatocytes was conducted. The results showed that hemoglobin content, RBC count and hematocrit increased in the curcumin-fed fish compared to control, whereas WBC count, platelet count, mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration were unaffected. WBC/RBC ratio was lower in the case of curcumin-treated fish. The cytometric measurements revealed no change in the erythrocytes and their nuclei after curcumin treatment. DNA fragmentation assay revealed intact DNA in curcumin-fed group, ruling out the possibility of curcumin-induced DNA damage. The positive control group showed a significant increase in MN frequency compared to negative control and curcumin-fed groups. In fact, the MN frequency decreased in 1% curcumin-fed group compared to the negative control and 0.5% curcumin groups. All these indicated a state of well-being of the curcumin-treated fish. Therefore, it is concluded that curcumin could be used as a safe feed ingredient to improve the growth of finfish in aquaculture.