Chondroprotective and anti-inflammatory effects of sesamin

Osteoarthritis (OA) is a major disability of elderly people. Sesamin is the main compound in Sesamun indicum Linn., and it has an anti-inflammatory effect by specifically inhibiting Δ5-desaturase in polyunsaturated fatty acid biosynthesis. The chondroprotective effects of sesamin were thus studied in a porcine cartilage explant induced with interleukin-1beta (IL-1β) and in a papain-induced osteoarthritis rat model. With the porcine cartilage explant, IL-1β induced release of sulfated-glycosaminoglycan (s-GAG) and hydroxyproline release, and this induction was significantly inhibited by sesamin. This ability to inhibit these processes might be due to its ability to decrease expression of MMP-1, -3 and -13, which can degrade both PGs and type II collagen, both at the mRNA and protein levels. Interestingly, activation of MMP-3 might also be inhibited by sesamin. Moreover, in human articular chondrocytes (HACs), some pathways of IL-1β signal transduction were inhibited by sesamin: p38 and JNK. In the papain-induced OA rat model, sesamin treatment reversed the following pathological changes in OA cartilage: reduced disorganization of chondrocytes in cartilage, increased cartilage thickness, and decreased type II collagen and PGs loss. Sesamin alone might increase formation of type II collagen and PGs in the cartilage tissue of control rats. These results demonstrate that sesamin efficiently suppressed the pathological processes in an OA model. Thus, sesamin could be a potential therapeutic strategy for treatment of OA.     

Free radicals and anti-inflammatory drugs

It is widely accepted that oxygen radicals and other activated oxygen species are potent mediators or modulators of acute and chronic inflammation. They are common products of cellular metabolism, where their concentrations are controlled by different protective mechanisms such as superoxide dismutase, catalase etc. In addition to their destructive effects on various macromolecules, oxygen radicals or their products are beneficial e.g., in killing bacteria. Oxygen radicals are also closely related to arachidonic acid metabolism, prostanoids (cyclo-oxygenase pathway) and leukotrienes (lipoxygenase pathway) as well as to lipid peroxidation in general. Also, the classical mediators of inflammation, histamine and bradykinin, may be connected with the release of oxygen radicals. In addition to the earlier described inhibition of formation of prostanoids, non-steroidal anti-inflammatory drugs can inhibit production of free radicals or scavenge those already formed. Antirheumatic penicillamine and allopurinol used in the treatment of gout also act on oxygen radicals. New anti-inflammatory compounds with antioxidant properties will be developed in the near future.     

New anti-inflammatory agents

The pyrrole derivatives la, b and 2a, b were used as precursors for the preparation of N-substituted pyrrole derivatives 3a, b-9a, b and pyrrolo[2,3-d]pyrimidines 13-16. Also, all the newly prepared products were tested for anti-inflammatory activity as analogues to fenamates, and some of them revealed moderate anti-inflammatory activity compared to the standard drug indomethacin.     

Synthesis and anti-inflammatory activity of aromatic glucosinolates

Aromatic GLs are important members of the glucosinolate family of compounds because of their potential biological activity and medicinal properties. This study has shown success in the high yielding synthesis of some important aromatic GLs as well as the results of testing for anti-inflammatory properties of the synthetic GLs. 3,4-Dimethoxyphenylglucosinolate was found to be the most active anti-inflammatory of the seven glucosinolates assayed.     

Synthesis of antioxidative and anti-inflammatory drugs glucoconjugates

Glucoconjugates of (+/-)-ibuprofen, (+/-)-alpha-tocopherol (vitamin E), gentisic acid, gallic acid, 2,6-bis(tert-butyl)-4-thiophenol, and N-acetyl-L-cysteine were prepared with the objective of increasing the bioavailability of such antioxidant and anti-inflammatory drugs. The O-glucosides were synthesized using benzylated alpha-D-glucopyranosyl trichloracetimidate as glycosyl donor. For the synthesis of the S-glucosides, the glycosyl donor 1,2,3,4,6-penta-O-acetyl-beta-D-glucopyranose provided higher yields than the corresponding O-acetylated imidate.     

Synthesis and anti-inflammatory activity of indole glucosinolates

The nitronate and nitrovinyl methods to synthesize indole glucosinolates (GLs) have been investigated. The results were applied to generally the most prevalent natural indole glucosinolates to synthesize 4-methoxyglucobrassicin (MGB) and neo-glucobrassicin (NGB) in moderate overall yield for the first time. The anti-inflammatory activity of the synthetic indole GLs was determined by inhibition of TNF-α secretion in LPS-stimulated THP-1 cells. The data showed that glucobrassicin (GB) exhibited higher activity than other synthetic indolyl GLs.     

Analgesic and anti-inflammatory effects of phosphodiesterase inhibitors

The aim of the present study was to investigate the role of phosphodiesterase (PDE) enzyme inhibitors namely rolipram and theophylline in pain and inflammation in experimental animals. Rolipram, a selective PDE IV inhibitor and theophylline a nonspecific PDE inhibitor exerted dose dependent analgesic and anti-inflammatory effect against acetic acid-induced writhing in mice and carrageenan-induced paw edema in rats, respectively. Nimesulide (1, 2 mg/kg) produced significant anti-inflammatory effect. Further, nimesulide (0.5 mg/kg) potentiated analgesic effect of rolipram but it failed to modulate the anti-inflammatory effect of PDE inhibitors. Present study suggests that PDE enzymes might be playing a role in nociceptive and inflammatory responses in animals.     

Synthesis and anti-inflammatory activity of benzophenone analogues

A series of substituted benzophenone analogues has been synthesized and evaluated as orally active anti-inflammatory agents with reduced side effects. The anti-inflammatory and ulcerogenic activities of the compounds were compared with naproxen, indomethacin, and phenylbutazone. In carrageenan-induced foot pad edema assay, benzophenone analogues showed an interesting anti-inflammatory activity. In the air-pouch test, some of the analogues reduced the total number of leukocytes of the exudate, which indicates inhibition of prostaglandin production. Side effects of the compounds were examined on gastric mucosa, in the liver and stomach. None of the compounds showed significant side effects compared with nonsteroidal anti-inflammatory drugs such as indomethacin and naproxen.     

Interactions between glucocorticoids and anti-inflammatory peptides

Both pro- and anti-inflammatory mediators regulate the anti-inflammatory actions of glucocorticoids, in part by modifying the binding of glucocorticoids to specific receptors. For instance, somatostatin has been shown to increase glucocorticoid binding and signaling in macrophages. The mechanism of this regulation does not require an increased expression of glucocorticoid receptors but, rather, a stabilization of glucocorticoid receptor-associated heat shock protein 90. This is related to a decrease in calpain activity. Thus calpain inhibition may offer a new and exciting possibility for enhancing the anti-inflammatory efficiency of glucocorticoids.     

Tuberculosis and nonsteroidal anti-inflammatory drugs.

In 1980 and 1982 two case reports documented reactivation of pulmonary tuberculosis in patients who had used nonsteroidal anti-inflammatory drugs (NSAIDs). A case-control study was designed to test the hypothesis that such an association does exist. Data for 38 patients were obtained from the patients'' family physicians, and each patient was matched with a control from the same practice for age, sex, race and length of time in that practice. A statistically significant relation was found between the reactivation of tuberculosis and the use of NSAIDs. However, further research is imperative to determine whether the association is direct, indirect or secondary to an unknown factor. Physicians should keep in mind that NSAIDs are potent anti-inflammatory agents and may thus activate, spread and mask infections.