Purpose:
To determine, in Sprague Dawley rats, the toxicity profile of the
methanol extract of
Mentha spicata, a plant used
in folklore medicine for the treatment of various forms of pain.
Methods:
The plant extract, at concentrations ranging from
100
-
0.07 mg/ml
, was used to
determine the
median lethal concentration
(
LC
50
)
based on brine shrimp lethality assay.
Artificial
sea water
served as control. Acute oral toxicity testing was carried out, according to the
Organisation for Economic Co
-
operation and Development (
OECD
)
guidelines, based on serum
biochemical analysis and
histological investigations of
liver, kidney, heart, spleen and lungs
.
Results:
The
LC
50
value of Mentha spicata was 1701 μg/ml in brine shrimp lethality assay,
indicating that the plant extract is non
-
toxic. For acute toxicity testing, administration of a single dose
of 5000 mg/kg extract to the rats did not produce toxicity, in terms of cha
nges in behaviour or
mortality. Moreover, the weight of major organs of the animals did not significantly (p > 0.05) diff
er
from those of the control group. No toxicologically significant (p > 0.05) hematological and
biochemical changes were noticed betwee
n animals treated with the plant extract and control
animals. Treatment with plant extract did not cause any morphological changes in the heart, liver,
kidney and lung tissues of the rats. Histopathological examination also did not reveal any toxicity
evid
ence in the extract
-
treated animals.
Conclusion:
The results obtained suggest that the plant extract can be classified as non
-
toxic.