carpaine

Carpaine is the major piperidine alkaloid component of papaya leaves which has been studied for potential medicinal effects. Carpaine extracted from Carica papaya trees has been reported to have diverse biological properties, such as anti-malarial, anti-inflammatory, anti-oxidant, and vasodilatory effects. Especially, Carpaine possessed significant anti-plasmodial activity in vitro (IC50 of 0.2 μM) and high selectivity towards the parasites.

Circulatory effects of carpaine were studied in Wistar male rats weighing 314 +/- 13 g, under pentobarbital (30 mg/kg) anesthesia. Increasing dosages of carpaine from 0.5 mg/kg to 2.0 mg/kg resulted in progressive decrease in systolic, diastolic, and mean arterial blood pressure. Selective autonomic nervous blockade with atropine sulfate (1 mg/kg) or propranolol hydrochloride (8 mg/kg) did not alter the circulatory response to carpaine. Carpaine, 2 mg/kg, reduced cardiac output, stroke volume, stroke work, and cardiac power, but the calculated total peripheral resistance remained unchanged. It is concluded from these results that carpaine affects the myocardium directly. The effects of carpaine may be related to its macrocyclic dilactone structure, a possible cation chelating structure.