Orally co-administrated oleo-gum resin of Commiphora myrrha decreases the bioavailability of cyclosporine A in rats.

Cyclosporine A is a narrow therapeutic indexed immunosuppressant used after organ transplantation. Several herbs have been reported to alter its pharmacokinetics. Myrrh, dried oleogum resin obtained from Commiphora myrrha (Burseraceae) has been used for many common ailments. The present study was carried out to investigate the effect of myrrh on the pharmacokinetics of cyclosporine A. The rats of the control group received 60 mg/kg, p.o. cyclosporine A, and blood samples were collected at predetermined time intervals. Rats of the test group were treated with an aqueous suspension of myrrh (380 mg/kg p.o.) for eight days and on 8th day a single dose of cyclosporine A was administered to the treated group after 1 h of myrrh administration. Blood samples were drawn at predetermined time points and the drug was analyzed in whole blood by using H-Class UPLC-TQD. Pharmacokinetic profiles of control and test group were compared. Statistically significant differences were observed between the pharmacokinetic parameters of control and treated groups. In the myrrh treated group, the AUC(0-t) and C(max) of cyclosporine A was decreased by about 45% and 48%, respectively. The time to reach maximum concentration (T(max)) remained almost unchanged in both groups. Results indicated that the bioavailability of cyclosporine A was reduced by about 45% when co-administered with myrrh. This observation suggests that concurrent consumption of myrrh and cyclosporine A should be avoided. To confirm the clinical relevance of these findings, P-gp and CYP3A based molecular investigations can be performed along with a well-planned clinical study.