Tests for anti-inflammatory activity

TESTS FOR ANTI-INFLAMMATORY ACTIVITY The number of tests that have been devised for measuring the anti-inflammatory activity of compounds is legion. Those described below have been chosen largely for their ability to show diverse types of anti-inflammatory activity, preference being given to those which are in common use and are therefore referred to most often in the section on anti-inflammatory compounds later in this review. In addition, a number of techniques that may not be widely used, but which show certain important facets of inflammation, have been included. 

Spector and Willoughby, in reviewing techniques for anti-inflammatory testing, emphasize that inflammation is a series of physiological events occurring in orderly sequence, that no drug is equally effective in suppressing all aspects of it, and that some act on only one particular component of the reaction. 

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Limonene and essential oils containing limonene have been tested for anti-inflammatory activity in the mouse model of pleurisy induced by zymosan and lipopolysaccharide (LPS), and assayed for immun-oregulatory activity by measurement of the inhibition of nitric oxide (NO) and production of the cytokines, interferon-y and IL-4. Limonene and the oils, when administered orally, were able to inhibit the LPS-induced inflammation including cell migration. Limonene was also effective in inhibiting production of NO, and produced a significant inhibition of interferon-y and IL-4 production. 

In the section on tests for anti-inflammatory activity, reasons have been given for considering that the anti-inflammatory activity of some flavines is a non-specific effect. 

Fig. (4). Curcumin and semi-synthetic curcumin analogs tested for anti-inflammatory activity [11, 12]...

Numerous medicinal plants and natural compounds have been tested for anti-inflammatory activities using these models, despite their having the disadvantage of variable biological response. In addition, large quantities of pure compounds must be administered to a large number of animals in order to construct dose response-curves. However, natural products are often isolated in small quantities, which makes it necessary to analyse their activity with in vitro tests, employing cells or enzymatic systems, where only 2-5 mg of the product is necessary. 

Index for anti-inflammatory activity. Model acute inflammation, method Carragennan induced edema, test animal albino rats, number of animals per group 6, route of administration oral, standard phenylbutazone (100 mgkg ), test compounds lOOmgkg ... 

Primary screening data correlated with the in vivo results. Four selected hits, when tested on a carrageenan induced rat paw edema model of acute inflammation and were bioavailable and pharmacologically active, reducing swelling of the paw (data not shown here). The efficacies of the extracts were measured by calculating the reduction in swelling as compared to the vehicle-treated control. Aspirin was used as a positive control for anti-inflammatory activity. These observations validated the potential use of the hits discovered in the RT-PCR assay for the in vivo anti-inflammatory applications. 

Anti-inflammatory Compounds.—Claims for anti-inflammatory activity of alkaloids appear in the literature from time to time, but in view of the difficulties connected with the testing of such compounds, positive results should be viewed with caution. Recently it has been stated that cryogenine from Heimia salicifolia (Lythraceae) has anti-inflammatory activity. Lythraceae have been investigated broadly during recent years, probably because of an early claim that these alkaloids have hallucinogenic properties. The structure (31) has been proposed for cryogenine. ... 

Bucher has described a test for anti-inflammatory compounds which involves the intraperitoneal injection of talc into guinea-pigs to produce peritonitis. One of the behavioural manifestations of this is inhibition of gnawing activity, which is restored to normal by various analgesic and antipyretic substances, especially pyrazolones. Phenylbutazone and amidopyrine are both active in doses as low as 5 mg/kg subcutaneously. Acetylsali-cylic acid is also active, but prednisolone affects the response only when given in high doses. This test was used to demonstrate anti-inflammatory activity in a series of pyrazolones in which the usual 3-methyl group is replaced by alkylsulphonamido radicals . The most active compound XXXI) is equal in efficacy to phenylbutazone. 

Table 6.3. Cu(II)2(acetate)4 was found to be active in the initial test (carrageenan paw oedema) for anti-inflammatory activity, but inactive in the two follow-up anti-inflammatory screens (cotton wad granuloma and polyarthritis). Cupric chloride had no activity in any of these models of inflammation. Ligands such as anthranilic acid and 3,5-diisopropylsalicylic acid (3,5-DIPS) which were anticipated to be inactive were found to be so. However, their copper complexes were found to be potent anti-inflammatory agents in all three models of inflammation. These observations supported the notion that complexed copper is a more active anti-inflammatory form of copper and led to the suggestion that copper complexes of active anti-inflammatory agents might be more active than their parent anti-inflammatory drugs.

Further, [2.2]paracyclophane-4-acetic acid, a potential drug candidate tested for its anti-inflammatory activity (NSAID could be resolved on the 0-9-(tert-butylcarbamoyl)quinine-based CSP with a = 1.12 Rs = 2.6) and elution order (R)-(-)- before (5)-(- -)-enantiomer [125]. Samples that were assessed to be enan-tiomerically pure by an enantioselective H-NMR spectroscopic method contained 6% and 8% enantiomeric impurity in S- and/ -enantiomers, respectively. This clearly reveals that enantioselective HPLC is a more powerful technique than NMR-methods to assess stereoisomeric purity, in particular, if the enantiomeric impurity amounts to less than 10%. 

As an example, suppose that it is known to experts in the field that an extract from the plant Clusia criuva has anti-inflammatory activity. Therefore, a specialist in the subject would be led to test other species of the genus Clusia for the same biological activity (anti-inflammatory). Nevertheless, a way to prove inventive step would be to demonstrate that the species of interest, for example Clusia rosea, presents an unexpected technical effect. In other words, while the species Clusia criuva has an undesirable side effect associated with its anti-inflammatory action, such... 

Hydrochlorides of dibenzazonines 14b, 106,107, and 108 have been tested by Pecherer and Brossi (29) for analgesic and anti-inflammatory activity, antiappetite and blood pressure effects, and activity against a series of infections. The alkaloid protostephanine (3) exerts a moderately strong and persistent hypotensive effect. Most of the other compounds show some central nervous activity. Independent studies have also found CNS activity for compounds 107, 109, and 110, all of which behave as hypotensive agents (30). 

Direct tests for adrenal steroid activity are at the entry level of endocrine safety pharmacology, such activities are usually expressed by a feedback regulation at the pituitary level, changing the ACTH response, or by one of the multiple biological effects of the adrenal steroid hormones ranging from anti-inflammatory to immunosuppressive activity (Schimmer and Parker 1995). 

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