Studies on Hypotensive Effect of Some Extracts of Cortex Mori Radicis produced in China and Japan

Abstract

The toxicity and blood pressure effects of cortex mori radicis C (Chinese product)and J (Japanese product) were examined in rabbits and mice. The results obtained were as follows:
( 1 ) Small doses of cortex mori radicis extract have a sedative effect on mice. The oral toxic doses in mice are 4.3g/kg (C) and 7.5g/kg (J). The lethal doses in mice are >6.7g/kg (C) and >11.0g/kg (J).
( 2 ) Crude cortex mori radicis extracts and cation exchange resin treated extracts are more toxic than anion extracts.
( 3 ) These cortex mori radicis extracts were found to decrease the blood pressure of rabbits 30 to 60 minutes after stomach administration through an orally inserted, tube. The effect was slow but certain and continued for 2 to 3 hours. The minimum hypotensive effect on blood pressure was revealed in doses of about 50 mg/kg.
( 4 ) The degree of toxicity of cortex mori radicis might be parallel to the decrease of blood pressure. The C extracts were more toxic than the J extracts, the former decreasing the blood pressure more sharply than the latter.
( 5 ) The blood pressure effects were completely counteracted by atropine in some cases but in the other cases there was little or no recovery. It is also recognized that the active component antagonized by atropine is more abundant in C than in J.