On the inhibitory activities of a new boron compound and ultrasound against the mouse ascites tumour

The inhibitory effects of a new boron compound, dihydroxy (oxybiguanido) bo ron (III) hydrochloride monohydrate (HB), and ultrasound (US) of a frequenc y 25 kHz on the growth of ascites tumour in female Swiss mice were studied by monitoring the survival, weight of tumour-associated material, tumour ce ll count, serum alkaline phosphatase activity and the haematological parame ters of the treated animals. 5-Fluorouracil (5-FU), a well-known anticancer agent, was used as positive control. While HE exhibiited a very significan t antitumour action, US alone produced a small but significant inhibitory e ffect. The combination of US with HE or 5-FU produced an extra antitumour a ction as compared to the actions of these chemicals used singly. The mechan isms of action of the new boron compound (HB) and US are discussed.