Phytochemical and SAR Analyses of Limonoids in Citrus and Chinese Herbs: Their Benefits and Risks of Drug Interactions

Many beneficial effects of limonoids have reported in the literature. This paper reviews the range of limonoids that are found in nature and summarizes known beneficial effects and other relevant biochemical effects. The chemical structure and physical chemical properties (with SAR analysis) of the limonoids and a number of known P-glycoprotein substrates are also provided. The limonoids selected lie within the 3D (MW, Clogp, Hb) parameter-frame-setting of known I P-glycoprotein substrates so could potentially be substrates themselves. Based on phytochemical and SAR analyses of available literature data, it is suggested that limonoids found in citrus fruits and other Chinese herbs, when consumed in moderate amount are beneficial to health and may have preventive effect on carcinogenesis. However, due to potential interactions of limonoids with a wide range of drugs via P-glycoprotein and other drugmeetabolizing enzyme systems, it is advisable not to take citrus juices with drugs simultaneously.