Review. Drug resistance of human immunodeficiency virus and overcoming it by natural products.

Acquired immune deficiency syndrome (AIDS) caused by infection with the human immunodeficiency virus (HIV) represents a major health problem worldwide, especially in developing countries. Combinational anti-HIV therapy has largely improved patients' lives, but is not widely available in developing countries. Moreover, drug resistance is a main problem during HIV treatment. Therefore, there is a continuous need for new drugs effective against otherwise drug-resistant HIV strains. Chemical compounds from natural sources provide a large variety of potential anti-HIV compounds. The most promising natural products are discussed in this review.