Documentation of phytochemicals, bio-toxicity and haemato-physiological responses at sub-lethal concentrations of Parthenium hysterophorus hydroethanolic extract in Cyprinus carpio : a concept of waste valorization as a phyto-ichthyotoxin

In the present study, phytoextraction of a weed plant, Parthenium hysterophorus , was performed through aqueous, alcoholic and hydroethanolic (80%) solvents followed by phytochemical profiling and evaluation of median lethal concentration (LC 50 ) of hydroethanolic extract in a freshwater fish, common carp ( Cyprinus carpio ). Haemato-physiological response was also evaluated based on LC 50 (18.99 mg L −1 ) at two sub-lethal concentrations of extract [T1: 0.379 mg L −1 (LC 50 /50), T2: 0.759 mg L −1 (LC 50 /25) and a control: devoid of extract] at three intervals (24, 48 and 96 h). The study revealed toxic constituents in extracts and the superior extraction ability of hydroethanolic solvent which was chosen for further biological characterisation, particularly on haematotoxicity. The anti-bacterial assay revealed the inhibitory capacity of the extract, whereas the phyto-haemagglutination assay, haemagglutination limit test and haemolytic activity revealed clumping, agglutination (at 1/96 th dilution) and lytic capability of extract, respectively. Later, in vivo analyses revealed a significant modulation in haemato-immunological and serum biochemical parameters upon hydroethanolic extract exposure. In conclusion, the present study emphasises locally available gajar ghas, P. hysterophorus as a non-chemical phyto-ichthyotoxin towards sustainable aquaculture.