CHAPTER 1: INTRODUCTION

Transcription

1 CHAPTER 1: INTRODUCTION Rheumatoid arthritis Rheumatoid arthritis (RA) is one of the major autoimmune diseases of global prevalence 1, which is associated with systemic inflammatory disorders that are characterized by progressive joint pain, destruction and deformity of joints 2. It has worldwide prevalence of about 1% of the adult population. It affects woman more than men with an annual incidence of 3 per 10,000 adults 3-4. Recently, a self reported data by a physician-diagnosed arthritis indicated that a third of American adults had chronic joint symptoms. In the same line, it has been estimated that up to 2030, about 41 million adults aged 65 and older will have arthritis and chronic joint symptoms 5. It is accompanied by significant morbidity and mortality, depending on the severity of the disease at the beginning. The disability risk can be high as 33% and mortality by 52%, which is more frequently as a result of infection or circulatory disease. It is also expected to have a significant effect on the quality of life 6. Recently, it has been reported that micro-organism including bacteria, virus, fungi, parasites and bacterial toxin may exacerbate the inflammatory response in the joint and bone. Mycobacterium tuberculosis and Mycobacterium leprae are the most severe and most common mycobacterial cause of joint and bone disease 7. It has been proposed that there are three clinical phases of development of arthritis. First phase: In this phase inflammation induced auto-activation of the cellular and humoral immune systems occurs. Second phase: This phase has reduced phagocytic activity, sinusoid endothelial levels and multiplication in metaphases. Faculty of Pharmacy, Belgaum KLE University 1

2 Third phase: This phase produces penetrating, trauma and dissemination from acute osteomyelitic focus and also via blood stream from abscesses or infected wounds 7-8. The lipopolysaccride of the microbes are proposed to activate the macrophage in a dose dependent manner and release the cytokine interleukin (IL 1, IL 17 ) and Tumor necrosis factor (TNF-α). These cytokines alone and also in combination induce the synthesis of IL 6, IL 8 and tumor necrosis factor stimulated gene (TSG S ) by fibroblast like cells of the synovium (SFCs). The three cytokines activate the common transcription factor nuclear factor (NF-kB) in SFCs and in a variety of other cell types. NF-kB plays a role in the generation of inducible nitric oxide synthase (inos) and regulates vasodilations and transcription of cytokine. These cytokine and nitric are oxide (NO) proposed to be involved in inflammation, pain, vascular permeability and behavioral modification 9. Currently, pharmacological management of RA includes administration of non-steroidal anti-inflammatory drug (NSAID), steroids and disease modifying antirheumatic drugs (DMARD). The value of these drugs in treating RA is also limited due to their major side effects and their propensity to cause stomach ulcers, gastric bleeding and perforations. It has also been warned that their long term use may face the risk of stroke and heart attack 10. Recently, efforts have been made to use the biological agents including TNF-α, IL-1, IL-6, IL-15 and anti-cd28 mabs, anti-cd4 mabs, and anti-cd52 mabs for the management of RA alone or in combination with the existing pharmaceuticals. However, it was noticed that use of these biological agents produced severe adverse effects like multiorgan failure, life-threatening infections, increased risk of malignancies and immunogenic reactions 11. This limitation has necessitated the search for novel therapeutic products that are directed towards traditional system of medicine for the discovery of drugs that are long-acting Faculty of Pharmacy, Belgaum KLE University 2

3 anti-arthritic with minimum side effects 12. Newer complementary and alternative medicine (CAM), including herbs, are continuously being sought 13. Herbal treatments are now the most popular CAM therapy and are receiving increasing public interest. Traditional Indian Medicine (TIM) offers a variety of herbal CAM products that have been used in the treatment of patients with chronic inflammatory disorders for several decades. However, many of the plants have been validated experimentally were used in arthritis, but showed no cure. Curcuma zedoaria Rosc is commonly known as white turmeric, consists of dried pieces of rhizome 14. It is a large perennial herb with underground tuberous root-stock, growing widely in eastern Himalayas and in the moist deciduous forest of the central region of Karnataka and Kerala, also cultivated throughout India 15. Traditionally, the plant has been used as an analgesic, antiinflammatory, antiarthritic, diuretic, antiallergic, antiulcer, and antiasthmatic 16. Specially roots of Curcuma zedoaria have been used in crippling arthritis and frozen joints 17. Pharmacological evaluation on Curcuma zedoaria are reported for antimicrobial, antifungal activity, antiamoebic activity, analgesic activity, antinociceptive activity, antiallergic activity, antiulcer activity, anticancer activity, and hepatoprotective activity 18. It has been reported that some bioactive components of this plant contain bitter resin, carbohydrates, amino acid, organic acid, gum, starch sugar, steroids, terpenoids, glycosides, alkaloids, tannins and phenolic compounds 15. Scientifically a number of compounds have been isolated and reported from Curcuma zedoaria such as essential oils, starch, curcumin, furanodiene, Faculty of Pharmacy, Belgaum KLE University 3

4 furanodienone, zedorone, curzerenone, curzeone, germacrone, 13-hydroxy germacrone, dihydrocurdione, curcumenone, zedoaronediol curcumenol, phytosterols, (especially sitosterol amd stigmasterol) curcumenol, dihydrocurdione, terpenoids. A new eudesmane-type sesquiterpene, zedoarofuran, six new guaiane secoguaiane-type sesquiterpenes, 4-epicurcumenol, neocurcumenol, gajutsulactones A and B, zedoarolides, two diarylheptanoids. zedoalactone A, zedoalactone B, zedoarol, 13-hydroxygermacron, curcumanolide-a and curcumanolide-b, Ethyl aramethoxycinnamate, Urmerone, b-turmerone, epicurzerenone, curzerene, 1,8- cineole, cymene, a-phellandrene, b-eudesmol, mono sesquiterpenoids, monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpene hydrocarbons, oxygenated sesquiterpenes, terpinyl acetate, isoborneol, dehydrocurdione, b-tumerone, 1,8- cineole, zingiberene, as major constituents, 17 terpenes, 13 alcohols, 6 ketones 18. Alternative treatments based on natural plant products and herbal mixtures belong to the herbal formulation and CAM is becoming increasingly popular in India, US and other countries 13,19. However, there is scepticism about single herbal formulation and CAM products in the minds of both the public as well as the scientific community, mostly because the mechanisms of action of these products are poorly defined 20. Thus, there is a need to systemically study and define the mechanisms underlying the activity of herbal formulation. The CAM products have been used for the treatment of inflammation and arthritis diseases in folk medicine around the world for centuries. It has been well reported in literature that curcuminoid (curcumin, demethoxycurcumin and bisdemethoxycurcumin) inhibit TNF-induced NF-kB activation 21 curcumin modulates the inflammatory response by down regulating the activity of cyclooxygenase-2 (COX-2), lipoxigenase, and inducible nitric oxide synthase (inos) enzymes 22. It Inhibits the production of the inflammatory Faculty of Pharmacy, Belgaum KLE University 4

5 cytokines, tumor necrosis factor alpha (TNF-α), interleukin 1, 2, 6, 8, and 12 monocyte chemo attractant proteins (MCP), and migration inhibitory proteins; and down regulates mitogens activated and Janus kinases. COX-2 and inos inhibition are likely accomplished via curcumin suppress of nuclear factor kappa B (NF-kB) activation, is involved in inflammation, proliferation and transformation 23. Steroids block allergic reactions and reduce the symptoms of itching, swelling and redness of skin and synthesis of certain enzymes that reduced inflammation and also suppress immune system 24. One of the most effective families of natural product for their medicinal value is terpenoids have been used anti-inflammatory which reduced production of Prostaglandin E 2 (PG 2 ) and also suppress the NF-kB and inos 24. In the present study, Freund s complete adjuvant induced monoarthritis in female Wistar rats as a model of rheumatoid arthritis was used due to its relevance for the study of pathological pharmacology and on the basis of recommendation by Food Drug Administration USA 25. The commercially available Freund s complete adjuvant contains heat killed Mycobacterium butyricum suspended in mineral oil. This is injected into an intraarticular joint of rats 26. The adjuvant administered elicits characteristic changes including augmented and persistence joint swelling, increased vascular permeability, immune cell infiltration and increased blood flow after one to two weeks of arthritis induction 27, it causes minor synovial tissue proliferation and cartilage erosion. The arthritis induced by adjuvant also exhibits significant reduction of motor activity, increase itching and scratching behaviors Histologically, it also shows many features of clinical rheumatoid arthritis such as pannus formation, but does not show Faculty of Pharmacy, Belgaum KLE University 5

6 features of a severe disease such as joint ankylosis 30. The radiographic studies in adjuvant-induced animals have shown pathological bony changes similar, to the changes observed in clinical RA condition Since the advocated potential of petroleum ether, chloroform, methanol, ethanol, aqueous extracts, and its formulation of Curcuma zedoaria roots in arthritic rats was not tested rigorously by scientifically controlled experiments. This study has been used extensively to analyze the acute anti-inflammation and long lasting antiarthritic effects of root extracts of Curcuma zedoaria in adjuvant-induced arthritis in female Wistar rats and also performed the separation, purification and characterization of potent extract by TLC, column chromatography, preparative TLC, high performance thin layer chromatography, high performance liquid chromatography, UV, IR, 1 HNMR, and LCMS were performed which have been responsible for these activities. Faculty of Pharmacy, Belgaum KLE University 6