Delphinine is a toxic alkaloid

Alkaloid

Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...

 ( 1.5 mg/kg approx) found in plants from the Delphinium

Delphinium

Delphinium is a genus of about 300 species of perennial flowering plants in the buttercup family Ranunculaceae, native throughout the Northern Hemisphere and also on the high mountains of tropical Africa. The common name, larkspur, is shared with the closely related genus Consolida...

family. It is related in structure and has similar effects to aconitine

Aconitine

Aconitine is a highly poisonous alkaloid derived from various aconite species.-Uses:...

, acting as an allosteric modulator of voltage gated sodium channels, and producing hypotension

Hypotension

In physiology and medicine, hypotension is abnormally low blood pressure, especially in the arteries of the systemic circulation. It is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the...

, bradycardia

Bradycardia

Bradycardia , in the context of adult medicine, is the resting heart rate of under 60 beats per minute, though it is seldom symptomatic until the rate drops below 50 beat/min. It may cause cardiac arrest in some patients, because those with bradycardia may not be pumping enough oxygen to their heart...

 and cardiac arrythmia. These effects make it highly poisonous, but in very small doses it has some uses in herbal medicine.