Flavonoids immune activity

The three most widely used species of Echinacea are Echinacea purpurea, E pallida, and E angustifolia. The chemical constituents include flavonoids, lipophilic constituents (eg, alkamides, polyacetylenes), water-soluble polysaccharides, and water-soluble caffeoyl conjugates (eg, echinacoside, chicoric acid, caffeic acid). Within any marketed echinacea formulation, the relative amounts of these components are dependent upon the species used, the method of manufacture, and the plant parts used. Epurpurea has been the most widely studied in clinical trials. Although the active constituents of echinacea are not completely known, chicoric acid from E purpurea and echinacoside from E pallida and E angustifolia, as well as alkamides and polysaccharides, are most often noted as having immune-modulating properties. Most commercial formulations, however, are not standardized for any particular constituent. 

Flavonoids affect the immune system and the body s inflammatory cells. This function is partly accomplished through the effects on enzymes involved in the immune response and the generation of inflammatory cells. Balentine et al. (1999) recently reported that only the aglycon cyanidin, not the anthocyanin glycoside, showed inhibitory effects on enzymes involved in inflammatory activity. The anthocyanins can be metabolized into their glycoside-free constituents either before or after absorption in the gut and may thereby act as anti-inflammatory agents in the body. Middleton and Kandaswami (1994) stress the fact, however, that as most of these studies have been carried out as in vitro experiments, care should be taken not to draw too extensive conclusions for the in vivo actions of flavonoids. Fundamental biochemical research is needed before the mechanisms behind the diverse actions of flavonoids are fully understood. 

A native of Europe and the northwest coast of Africa, various flavonoids and triterpenes are the most active ingredients. Strong immune stimulating properties signal the treatment of cancer patients with weak immune systems. Studies show a capability to neutralize the West Nile virus. Also called elderbeny. 

The stuff that bees collect mainly from poplars and conifers is a mix of dozens of compounds, including fatty acids and flavonoids. Scientists have tested many of these for biological activity, and their tests have shown antifungal and antibacterial effects. But this certainly isn t enough to justify the claims made by propolis proponents that the substance has antibacterial effects superior to those of modern antibiotics. Some have also made the unsubstantiated claim that propolis stimulates the immune system. Others recommend using propolis to treat ulcers and skin problems caused by fungi. 

Flavonoids possess a broad spectrum of biological actions ranging from anticarcinogenic to antiinflammatory, cardioprotective, immune-modulatory, and antiviral. The mechanisms by which flavonoids cause these effects may include induction of the activity of some important enzymes while inhibiting the activity of others. Modulation of membrane function, including the activity of membrane-bound... 

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