Inhibitory effects of cuminaldehyde on human liver cytochrome P450 enzymes

This work explored the influence of cuminaldehyde on the metabolic activity of four primary human cytochrome P450 (CYP) enzymes. Human liver microsomes (HLM) with and without cuminaldehyde were incubated with specific substrates of different CYP enzymes. The influence of cuminaldehyde on “CYP1A2, CYP2C9, CYP2D6 and CYP3A4” activities was examined. The formation of specific metabolites was analyzed by HPLC analytical methods. It was observed that cuminaldehyde appears to have a negligible influence on CYP1A2 activity. However, CYP2C9 activity was significantly and potently inhibited by cuminaldehyde at all investigated concentrations. It was found that cuminaldehyde (1 µM) inhibited the most CYP2C9 enzyme activity with 64.87 % inhibition followed by CYP3A4 (38.90 %), CYP2D6 (25.76 %) and CYP1A2 (4.99 %). Inhibition of both CYP2D6 and CYP3A4 enzyme activity was observed in response to cuminaldehyde concentrations. Findings of the current investigation indicate that herb-drug interactions are very possible when cuminaldehyde is concurrently taken with medicines predominantly metabolized by CYP2C9 and CYP3A4. Cuminaldehyde should be tested further to examine how it affects CYP2C9 and CYP3A4-metabolized drugs.