AbstractSammo plant which is traditionally used in Egypt for the treatment of diabetes mellitus, was administered at low and high levels (4% and 8% respectively at the expense of starch) to adult male alloxanized albino rats, to study its effect on energy metabolism. Adenosine‐5‐triphosphate (ATP) in the brain (B), liver (L) and kidneys (K) organs of alloxanized rats was significantly lowered compared with the negative control. On the other hand, adenosine‐5‐diphosphate (ADP) and adenosine‐5‐monophosphate (AMP) contents in the same organs were elevated markedly. In this connection myokinase activity in cytoplasmic and mitochondrial fractions of B, L and K organs was stimulated at control. Also, the activities of some fundamental enzymes of the oxidative pentose phosphate pathway i.e. glucose‐6‐phosphate dehydrogenase (G‐6‐PD) and 6‐phospho‐gluconate dehydrogenase (6‐PGD) in cytoplasmic and mitochondrial fractions of the same organs were markedly increased.Administration of Sammo at low and high levels reduced the consumption of ATP in B, L and K organs relative to positive control. Whereas, ADP and AMP contents were relatively reduced. Also, myokinase activity in the same organs were relatively inhibited. The activity of G‐6‐PD and 6‐PGD in cytoplasmic and mitochondrial fractions of the same organs were also decreased r