Sammo 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 relative to the positive control.