Toxicological Influence of Aqueous Tephrosia bracteolata Leaf Extract on Haematological and Biochemical Parameters in Clarias gariepinus Juveniles

Abstract

Fish farmers traditionally explore plants to catch fish from the wild without knowing the
exact dose that would not pose a threat to the fish. The study investigated impacts of
varied concentrations (8.00, 4.00, 2.00 and 1.00ml/L and 0.00 (the control) in replicates,
using completely randomized design (CRD) and injection method, for a duration of 96hrs)
of aqueous leaf extract of Tephrosia bracteolata impacts on haematology, blood serum
biochemistry and mortality rate of Clarias gariepinus using 200 juveniles. The data were
analysed for mean, standard deviation, and Pearson’s correlation using IBM SPSS version
23. Results indicated determination of Alkaloids 52%, Saponin 31%, Flavonoids 29%,
Phenol 27%, Glucosides 18% and anthraquinone 12%; and the treatments’ LD50 was 2
mL (log concentration of 0.301). Unlike in control, levels of the PCV, Hb, RBC, and
WBC decreased as the treatments increased, with a strong and direct correlation among
the four haematological indices; the glucose levels increased while cholesterol and protein
decreased as the treatments increased, with the glucose levels having a very strong but
indirect correlation with protein and cholesterol levels. The protein level was strongly
correlated (r = 0.922, p < 0.01) with cholesterol. The study concluded that the plant
induced dose-dependent physiological stress on the experimental fish. There was no further
observation post-treatment, and cautious usage of the plant around the fish habitat and for
fish harvesting by the fish artisans is recommended.