Determination of anti-inflammatory activities of standardised preparations of plant- and mushroom-based foods

Purpose

Chronic inflammatory processes contribute to the pathogenesis of many age-related diseases. In search of anti-inflammatory foods, we have systematically screened a variety of common dietary plants and mushrooms for their anti-inflammatory activity.

Methods

A selection of 115 samples was prepared by a generic food-compatible processing method involving heating. These products were tested for their anti-inflammatory activity in murine N11 microglia and RAW 264.7 macrophages, using nitric oxide (NO) and tumour necrosis factor-α (TNF-α) as pro-inflammatory readouts.

Results

Ten food samples including lime zest, English breakfast tea, honey-brown mushroom, button mushroom, oyster mushroom, cinnamon and cloves inhibited NO production in N11 microglia, with IC₅₀ values below 0.5 mg/ml. The most active samples were onion, oregano and red sweet potato, exhibiting IC₅₀ values below 0.1 mg/ml. When these ten food preparations were retested in RAW 264.7 macrophages, they all inhibited NO production similar to the results obtained in N11 microglia. In addition, English breakfast tea leaves, oyster mushroom, onion, cinnamon and button mushroom preparations suppressed TNF-α production, exhibiting IC₅₀ values below 0.5 mg/ml in RAW 264.7 macrophages.

Conclusion

In summary, anti-inflammatory activity in these food samples survived ‘cooking’. Provided that individual bioavailability allows active compounds to reach therapeutic levels in target tissues, these foods may be useful in limiting inflammation in a variety of age-related inflammatory diseases. Furthermore, these foods could be a source for the discovery of novel anti-inflammatory drugs.     

Audit of stroke care at the Institute of Neurology,National Hospital of Sri Lanka, 1994-1997

OBJECTIVE: To audit the process of stroke care. DESIGN: Retrospective case record evaluation using an audit package designed by the Royal College of Physicians of London. SETTING: Institute of Neurology, National Hospital of Sri Lanka, Colombo. PATIENTS: 263 patients with stroke admitted over a period of 3 years. MEASUREMENTS: Documentation of 60 audit items related to 13 aspects of stroke care. RESULTS: The process of care was considered 'very good' for only 11 (18.3%), and 'good' for only 9 (15%) of the audit items. Care was 'average' for 5 (8.3%), 'poor' for 9 (15%) and 'very poor' for 26 (43.3%) of the items. CONCLUSIONS: Stroke care was suboptimal in many aspects. Care related to rehabilitation oriented neurological assessments, initiation of secondary preventive measures, rehabilitation planning and discharge planning were especially deficient. Competing interests: none declared. Some of the data reported in this paper have been presented at the Annual Scientific Sessions of the Sri Lanka Medical Association, 1998.     

Magnetic resonance angiography in the management of aneurysmal subarachnoid haemorrhage: a study of 51 cases

We report preliminary experience with the use of magnetic resonance angiography (MRA) in the assessment of intracranial aneurysms. The aims of the study were to confirm that aneurysms could be detected and to assess the quality of the images with a view to early surgery if clinically indicated. We studied 51 patients with recent spontaneous subarachnoid haemorrhage with MRA, using a three-dimensional time-of-flight technique. The results of MRA were subsequently confirmed on intra-arterial digital subtraction angiography (IA-DSA) for anatomical correlation, and were considered satisfactory in 38 patients (74.5 %). In 20 patients early surgical obliteration of their aneurysm was possible on the MRA results without recourse to IA-DSA. A total of 37 aneurysms were identified in 32 patients, while the remaining 6 patients did not have an aneurysm. MRA was misinterpreted in 4 patients (7.9 %), and in 9 other patients (17.6 %) MRA was unsatisfactory due to movement artefacts. Received: 1 September 1994 Accepted: 12 May 1995     

Running for gout research

SIR, The differential diagnosis of a swollen red forefoot includesacute gouty arthritis of the first metatarsophalangeal joint(MTPJ). This is confirmed following demonstration of sodiummonourate crystals in synovial fluid or tissues. Classic riskfactors include obesity, family history, diuretic use and historicallyhigh alcohol- and purine-containing diets. We describe a case of acute podagra in a young, athletic man.Our case reinforces important risk factors and we feel providessupport for associated aetiology. A 28-yr-old rheumatology Senior House Officer     

Multisite protein phosphorylation makes a good threshold but can be a poor switch

Phosphorylation and dephosphorylation play a fundamental role in eukaryotic signaling. Some 30% of proteins are phosphorylated at any time, many on multiple sites, raising the question of how the cellular phosphorylation state is regulated. Previous work for one and two phosphorylation sites has revealed mechanisms, such as distributive phosphorylation, for switch-like regulation of maximally phosphorylated phosphoforms. These insights have led to the influential view that more phosphorylation sites leads to steeper switching, as proposed for substrates like cyclin E and the cyclin-dependent kinase inhibitor Sic1. An analytical study of the ordered distributive case reveals a more complex story. Multisite phosphorylation creates an efficient threshold: The proportion of maximally phosphorylated substrate is maintained close to 0 when the ratio of kinase to phosphatase activity lies below a suitable threshold, and this threshold increases with increasing numbers of sites, n. However, above the threshold, the response may not always abruptly switch between 0 and 1, as would be the case for an efficient switch, but may increase in a gradual manner, which becomes more hyperbolic with increasing n. Abrupt switching cannot be attributed merely to n being large. We point out that conventional measures of ultrasensitivity must be modified to discriminate between thresholding and switching; we discuss additional factors that influence switching efficiency and suggest new directions for experimental investigation.