Abstract: One aspect of the present invention is a method of treating a condition or disease associated with the activity of a multidrug transporter protein comprising administering to a mammal with a condition or disease associated with the activity of a multidrug transporter protein an effective quantity of a purine derivative or analogue, a tetrahydroindolone derivative or analogue, or a pyrimidine derivative or analogue. If the compound is a purine derivative, the purine moiety can be guanine or hypoxanthine. A particularly preferred bifunctional purine derivative is N-4-carboxyphenyl-3-(6-oxohydropurin-9-yl) propanamide. Methods according to the present invention can be used to treat cancer, a microbial or parasitic infection, HIV, infection, or a condition associated with inflammation such as asthma or rheumatic disease.

Abstract: The present invention is directed to a method of inducing neurogenesis by administering to a mammal an effective quantity of a compound that induces neurogenesis, where neurogenesis includes proliferation of neural stem and progenitor cells, differentiation of these cells into neurons, and/or survival of these new neurons. In general, the compound comprises three moieties, A, L, and B, covalently linked. A can be a purine, tetrahydroindolone, or pyrimidine; L is a linker, while B is a moiety that promotes absorption of the compound. A particularly preferred compound is N4-[[3-(6-oxo-1,6-dihydropurin-9-yl)-1-oxopropyl] amino] benzoic acid (also known as AIT-082 or leteprinim potassium). Another aspect of the invention is pharmaceutical compositions for inducing neurogenesis.