Plant-drug Interactions: Mechanisms and Clinical Implications of Cytochrome P450 Modulation by Common Phytochemicals

Abstract

Plant-drug interactions mediated by cytochrome P450 (CYP450) enzymes are a critical area of study owing to their potential to alter drug metabolism, efficacy, and toxicity. This review examines how common phytochemicals such as flavonoids, polyphenols, alkaloids, and terpenes modulate CYP450 activity and influence drug pharmacokinetics. Key clinical implications include changes in drug effectiveness, increased adverse effects, and therapeutic failure, as illustrated by interactions such as St. John’s Wort with CYP3A4 substrates, grapefruit juice inhibiting CYP3A4, and garlic affecting anticoagulants. Challenges in research, such as the complexity of herbal products, variability in phytochemical content, and genetic differences in CYP450 expression have been addressed. This review also outlines management strategies, including patient education, therapeutic drug monitoring, and dosage adjustments. Future research directions should emphasize the need for advanced screening methods, predictive models, and personalized medicine to optimize therapeutic outcomes and ensure patient safety. This knowledge is vital for healthcare professionals to make informed decisions and researchers to develop innovative therapeutic approaches. Continued interdisciplinary collaboration is essential to advance understanding and improve clinical guidelines for the safe use of herbal products alongside conventional medications.