To know nutritional status of TF-1, an isolated compound from the leaves of Thalictrum foliolosum DC, male albino rats were divided into two groups. First group of animals took normal diet while the second group took a mixture of normal diet and TF-1. In both the two groups growth of rats was checked. On 20th and 40th day of experiment blood pyruvate level was measured and intestine of rats were assayed for pyruvate dehydrogenase and transketolase activity. It was found out that growth of rats which took TF-1 with normal diet was stunted. Rats developed symptom of anorexia and became weak. Blood pyruvate level was increased and intestinal pyrvate dehydrogenase as well as transketolase activities were found decreased. As transketolase is a thiamine dependent enzyme and key enzyme in pentose phosphate pathway for production of NADPH and pentose sugar for synthesis of nucleic acids, compound TF-1 may exert activity by inactivating endogenous thiamine.