EFFECT OF AQUEOUS EXTRACT OF CRYPTOLEPIS SANGUINOLENTA ADMINISTRATION ON THE METABOLISM OF CHLOROQUINE VIA CYTOCHROME P450 ISOZYMES

Concurrent administration of herbal medicines and conventional drugs is a common practice globally, especially as the patronage of medicinal plants increases across the world. This study aimed to determine the effect of Cryptolepis sanguinolenta administration on the metabolism of chloroquine by evaluating specific Cytochrome P450 isozymes. Reconstituted freeze dried Cryptolepis sanguinolenta was administered to male Sprague-Dawley rats in drinking water for 2 weeks at a dose of 36mg/kg, followed by a single dose of chloroquine (15mg/kg). All the animals were sacrificed by cervical dislocation after 24 h of final drug administration, and the liver was excised for hepatic microsomes preparation. Using the microsomes, the PNPH, AmD and NOD activities were determined as a measure of CYP2E1, CYP2B1 and CYP1A activities, respectively. The study showed that concurrent administration of chloroquine and Cryptolepis sanguinolenta impaired the CYP-mediated metabolism of chloroquine due to competitive inhibition of CYP2B1 by C. sanguinolenta. However, concurrent administration of chloroquine and Cryptolepissanguinolenta showed no significant effect on CYP2E1 and CYP1A. Patients should be advised on the clinical consequence of concurrent administering Cryptolepis sanguinolenta-based herbal products and chloroquine.