Hoodia

There is a single published report concerning the pharmacology of Hoodia and P57. Intracerebroventricular injection of P57 into male rats reduced food intake 50% to 60% over a 24-hour period. Similar experiments with the aglycone or a second analog had no effect, nor did intraperitoneal injections of P57. P57 was inactive against Na/K adenosine triphosphatase (ATPase), despite having a structure  hoodia with some similarity to the cardiac glycosides found in the same hoodia  plant family. Investigators detected an increase in hypothalamic adenosine triphosphate (ATP) content for rats on a normal diet when P57 was administered intracerebroventricularly. Hypothalamic ATP levels dropped in untreated rats fed a hypocaloric diet; P57 reversed this reduction. Thus, it appears that P57 may operate through normalization of hypothalamic ATP levels to hoodia  produce anorexia.