Objective:
The objective of
the present study was to evaluate the acute and
sub
-chronic (
90
d;
repeated dose
) toxicity of
Withania somnifera
(ashwagandha)
extract
in rats.
Method
s:
The acute
toxicity was evaluated as per OECD (Organisation for Economic Co
-operation and Development)
guidelines 423. P
urified
ashwagandha extract (PAE)
was fed at 2000 mg/kg body weight (bw)
to overnight fasted
female
rats.
The animals were observed daily
for
clinical
signs of abnormality/mortality. After 1
4 d
, animals were sacrificed and
gross pathologic
al changes were recorded. Sub
-chronic toxicity of PAE was
studied by feeding the extract at 100, 500 and 1000 mg/kg
bw
daily to rats
as per OECD guidelines 408
. After 9
0 d
feeding
, heamatological
and
biochemical parameters
of treated rats
were compared wit
h control animals. Histopathology of all the major organs was also studied.
Result
s:
In the acute toxicity study, no mortality or clinical signs of toxicity were observed in any of the animals at maximum
recommended dose level
of 2000 mg/kg b
w;
therefore the LD50 is
>2000 mg/kg bw in rats.
The repeated administration of PAE
for 9
0 d
in rats at the maximum
dose level of
1000
mg/kg
bw
did not induce any observable toxic
effects,
when compared to its corresponding control animals.
The hematology
and biochemistr
y
profile of treated
rats was similar to control animals
and
difference
was non
-significant (p>0.05). The histopathology of
major organs of
all the control
and treated animals w
as
normal.
In this study
the NOAEL
(No Observed Adverse Effect Level) was calcu
lated as 1000
mg/kg
bw
daily for rats.
Conclusio
n:
The present study clearly indicates that
PAE
does not have any toxic effects in animals at the dose evaluated as evidenced by acute
and
sub chronic
toxicity studies in rats