EFFECT OF DIETARY Houttuynia cordata LEAF EXTRACT ON STRESS MITIGATION, IMMUNOMODULATION AND EXPRESSION OF INTERLEUKIN-8 GENE IN Labeo rohita (HAMILTON, 1822)

An experiment was conducted to evaluate the stress response, immunomodulatory response and expression of Interleukin-8 gene of L. rohita (rohu) fed with H. cordata leaf extract. Four isonitrogenous (35%) and isocaloric (17 MJ DE/kg) purified diets were formulated with graded levels of H. cordata leaf extract (LE) viz. C, control (0% LE), LE-0.25 (0.25% LE), LE-0.5 (0.5% LE) and LE-1.0 (1.0% LE Fish were fed twice daily up to the satiation for sixty-days. Metabolic enzyme activities, anti-oxidative enzymes activities, haemato-immunological parameters and expression of immune gene were recorded as response parameters. Both lactate dehydrogenase and malate dehydrogenase activities in the muscle and liver were found to be significantly lower in fish fed with 1% LE compare to other dietary groups. Lower Oxidative stress enzymes (SOD and catalase) activities in gill and liver were also observed in LE-1.0 group. Lysozyme and nitroblue tetrazolium activity were observed significantly (P < 0.05) higher in fish fed with 1% LE whereas serum glucose concentration was recorded significantly lower in LE-1.0 group compared to control. Gene expression of Interleukin-8 in liver was found to be up-regulated and exhibited an increasing trend with the dietary level of leaf extract. From the present study, it can be concluded that inclusion of 1% H. cordata leaf extract in diet improves stress and immune response of L. rohita.