781-786Young shoots or sprouts of common bamboos
are used as food in third world countries. Evidences suggest the presence of
cyanogenic glucoside like anti-thyroidal substance in bamboo shoots (BS) but
effect of prolonged BS consumption on thyroid status under conditions of varying
iodine nutriture remains unexplored. The study was undertaken to evaluate goitrogenic
content, in vitro anti thyroid peroxidase (TPO) activity and in vivo anti
thyroid potential of BS with and without extraiodide. Fresh BS contains high cyanogenic
glucoside (551 mg/kg), followed by thiocyanate (24mg/kg) and glucosinolate
(9.57mg/kg). In vitro inhibition in TPO activity was found with raw, raw
boiled and cooked extracts.
Inhibition constant (IC50) and
PTU equivalence of fresh BS were 27.5±0.77 pg and 3.27 respectively. Extra iodide
in the incubation media reduced TPO inhibition induced by BS but could not cancel
it. Thyroid weight, TPO activity and total serum thyroid hormone levels of BS fed
animals for 45 and 90 days respectively were determined and compared with controls.
Significant increase in thyroid weight as well as higher excretion of thiocyanate
and iodine along with marked decrease in thyroid peroxidase activity, T4 and T3
levels were observed in BS fed group. Chronic BS consumption gradually developed
a state of hypothyroidism. Extra iodide had reduced the anti-thyroidal effect of
BS to an extent but could not cancel it because of excessive cyanogenic glucoside,
glucosinolate and thiocyanate present in it