Abstract:
This study is to compare and evaluate barakol content and the toxicity in S.
siamea leaf extracts (by closely copying the cooking process of Khi-lek curry) and
purified barakol. The study also analyzed and compared barakol and anthraquinone
contents in different parts of the plant (young leaves, mature leaves and young
flowers). The TLC-densitometric method was developed and validated for the analysis
of barakol in S. siamea extracts. The results indicated that 15 % ethanol was the
optimum concentration to extract barakol from S. siamea and the barakol contents in
young leaves, mature leaves and young flowers were 1.67, 0.78 and 1.44 % w/w of the
dried sample, respectively. During the cooking process by boiling with water, barakol
content was lost on the first boiling about 50 % w/w of total barakol content in fresh
leaves. Marcs (boiled leaves) from the second boiling which is the actual part
consumed as a Khi-lek curry, contained barakol content about 10 % w/w of total
barakol. Determinations of total anthraquinones in terms of rhein in dried powder
young leaves, mature leaves and young flowers were 1.31, 2.14, and 2.48 mg % fresh
weight, respectively.
The toxicity study was performed by treating barakol and various extracts
containing barakol (filtrates and marcs) of S. siamea in two rat models (normal
Sprague Dawley rats and SD rat with A-S-30D hepatomea cell transplantation [A-S-
30D rats]). Doses of barakol were assigned based on content of barakol in each extract
of S. siamea young leaves which ranged from 5.54 mg/kg/day to 83.33mg/kg/day.
According to the results of the clinical blood analysis, normal SD rats treated
with barakol ranging from 81.66 to 83.33 mg/kg/day were significantly different in
total bilirubin level from the controls (p < 0.01) whereas A-S-30D rats treated with
barakol ranging from 24.81 to 83.33 mg/kg/day showed the same results. The level of
total bilirubin in rats treated with the extracts from S. siamea leaves/powder (boiled
two times with water) was not different from the control group in both rat models (p >
0.01).The increment in the total bilirubin level in serum was also in a dose-dependent
manner with barakol content in the extracts. Barakol as a single compound showed an
obvious result on the increment of total bilirubin level about 6 times compared to the
controls.