ABSTRACT

Like most other autoimmune diseases, arthritis is more prevalent in the Western world than in other countries (Devereux, 2006). Although the precise reason for this difference is not understood, lifestyle is known to play a major role. Current treatments for most diseases, including arthritis, tend to be inef—cient, have side effects, and tend to be expensive (Aggarwal et al., 2006a). Natural products offer an opportunity that devoid of such disadvantages. Any treatment requires proper understanding of pathogenesis of the disease, such as arthritis. Arthritis is primarily a proin–ammatory disease. There are more than 100 different kinds of arthritides. Perhaps three of the most common occurring arthritides in the Western world are gout, osteoarthritis (OA), and rheumatoid arthritis (RA). Gout occurs in response to the presence of crystals of monosodium urate (MSU) in joints, bones, and soft tissues (Becker and Jolly, 2006; Hoskison and Wortmann, 2006; Saag and Choi, 2006). Both acute arthritis and chronic arthropathy (tophaceous gout) are considered part of gout. High serum uric acid or hyperuricemia is the necessary predisposing factor for the development of gout in which a period of hyperuricemia leads to MSU crystal deposition, reaction to which can result in acute and/or chronic in–ammation. Although hyperuricemia is a necessary predisposing

Introduction .................................................................................................................................... 295 Potential of Natural Agents Against Arthritis ................................................................................ 298

Inhibitors of TNF-α Expression ............................................................................................ 298 Inhibitors of COX-2 Expression and Activity ...................................................................... 298 Inhibitors of 5-LOX Expression and Activity ....................................................................... 298 Inhibitors of Adhesion Molecules ......................................................................................... 298 Inhibitors of NF-κB Activation .............................................................................................302

Preclinical and Clinical Studies of Natural Products Against Arthritis .........................................304 Conclusions .................................................................................................................................... 311 Acknowledgments .......................................................................................................................... 311 References ..................................................................................................................................... 311

factor, its presence does not always lead to the development of gout. Indeed, the majority of hyperuricemic patients never develop gout.