Pharmacokinetic Profiles of Orally Bioavailable Natural Compounds for Integration into Biomedical Cancer Drug Discovery Research

Oral drug delivery enhances patient compliance with treatment, as it is a non-invasive method of drug administration and reduces the need for travel to healthcare facilities. One approach to developing oral medications involves researching natural compounds. Numerous of these compounds have shown promising in vitro results. However, the first-pass effect after oral delivery extensively metabolises many of them, leading to poor oral bioavailability. In this article, the author reviews numerous natural compounds and identifies several that demonstrate at least 30% oral bioavailability, with at least 2 hours of half-life (t1/2). These compounds include (1) decursinol, (2) trigonelline, (3) phenethyl isothiocyanate (PEITC), (4) theobromine, (5) pterostilbene, (6) rocaglamide, (7) sinomenine, (8) sulforaphane, (9) piperine, (10) carnosic acid, (11) niazirin, (12) falcarinol, (13) acetylcorynoline, (14) gastrodin, (15) bergapten, (16) imperatorin, (17) betaine, (18) kurarinone, (19) d-limonene, and (20) usnic acid. The pharmacokinetic profiles of the compounds are listed in this article. By examining the pharmacokinetic profiles such as concentration maximum (Cmax) and t1/2 of the shortlisted compounds, researchers can design concentration to be used in in vitro experiments and predict/establish dosing regimens for preclinical studies. The researchers can incorporate these 20 orally bioavailable compounds as a screening panel to select the most suitable compound for their study. When combining a natural compound with standard chemotherapy, it is essential for researchers to thoroughly investigate potential toxicity effects, as some natural compounds are known to act as CYP3A4 inhibitors, which may influence the metabolism and clearance of chemotherapy drugs. The author believes that even more orally bioavailable compounds remain undiscovered. This article can guide researchers in their quest for orally bioavailable natural compounds. The use of proper orally bioavailable natural compounds in biomedical research is likely to encourage pharmaceutical companies to develop these compounds into viable treatments.