In vivo antitumoural activity and acute toxicity study of Larrea divaricata Cav. extract

In the present work, we analysed the effect of the extract of Larrea divaricata Cav. on a mammary carcinoma chemically induced with N-nitroso-N-methylurea in female rats, The extract was administered in a dose of 25 mg/ kg, subcutaneously, beginning 20 days after tumour appearance. Of a total of 75 tumours treated with extract, a regression of 10 tumours (13%) was observed, a stabilization of 60 tumours (80%) and an increment of 5 tumours (6%), None of the 80 control tumours decreased (0%) and only 12 tumours remained static (15%). The survival time of the animals treated with the extract was significantly higher (p<0.05) than the survival time of the controls. The LD50 in females was lower than in male mice, Data indicate that the aqueous extract of Larrea divaricata Cav. could be considered tumouristatic as the extract blocked progress of the tumour. (C) 1997 John Wiley & Sons, Ltd.