Purpose: To evaluate the acute and sub-acute toxicity profile of the aqueous leaf extract of
Nymphaea lotus
L in Wistar rats.
Methods: Acute toxicity study was performed by administering a single oral dose of 5000 mg/kg body
weight of the extract to 5 rats while distilled water was given to another 5 rats (control), and the animals
were observed for 14 days. Thereafter, 50, 100 and 200 mg/kg doses of the extract were administered
to different groups of 5 rats each daily for 28 days while control received distilled water. At the end of
the experiment, the animals were sacrificed and the serum obtained was used for the assessment of
haematological and biochemical parameters. Histological examination was also performed on the liver
and kidney of the rats.
Results: The concentrations of alanine aminotransferase (42.56 U/L), aspartate aminotransferase
(126.01 U/L) and alkaline phosphatase (183.33 U/L) significantly decreased while creatinine (0.64
mg/dL) and chloride ions (94.50 mmol/L) were significantly elevated (p < 0.05) compared to those of
control following the extract treatment. Haematological parameters were not significantly different (p >
0.05) from those of control except white blood cell count (7.80 × 10
9/L), lymphocytes (5.20 %) and
monocytes (2.72 %) which were significantly elevated (p < 0.05) in the 100 and 200 mg/kg treated
groups. Histopathology did not reveal any sign of lesions or pathological changes in the organs that
could be attributed to treatment with the plant extract.
Conclusions: These results suggest that the aqueous leaf extract of Nymphaea lotus may be safe for
use at the doses tested.
