Two Approaches for Evaluating the Effects of Galangin on the Activities and mRNA Expression of Seven CYP450.

Galangin is a marker compound of honey and Alpinia officinarum Hance that exhibits great potential for anti-microbial, anti-diabetic, anti-obesity, anti-tumour and anti-inflammatory applications. Galangin is frequently consumed in combination with common clinical drugs. Here, we evaluated the effects of galangin on cytochrome P450 (CYP)-mediated metabolism, using two different approaches, to predict drug⁻drug interactions. Male Sprague Dawley rats were administered galangin daily for 8 weeks. A "cocktail-probes" approach was employed to evaluate the activities of different CYP450 enzymes. Blood samples of seven probe drugs were analysed using liquid chromatography-tandem mass spectrometry in positive and negative electrospray-ionisation modes. Pharmacokinetic parameters were calculated to identify statistical differences. CYP mRNA-expression levels were investigated in real-time quantitative polymerase chain reaction experiments. The galangin-treated group showed significantly decreased AUC_0⁻∞ and C_max values for CYP1A2, and CYP2B3. The galangin-treated group showed significantly increased AUC_0⁻∞ and C_max values for CYP2C13 and CYP3A1. No significant influences were observed in the pharmacokinetic profiles of CYP2C11, CYP2D4 and CYP2E1. The mRNA-expression results were consistent with the pharmacokinetic results. Thus, CYP450 enzyme activities may be altered by long-term galangin administration, suggesting galangin to be a promising candidate molecule for enhancing oral drug bioavailability and chemoprevention and reversing multidrug resistance.