Lipoxygenase wounding

Interestingly, the release of PUFAs without subsequent action of a lipoxygenase can act as a wound-activated defense diatom in rich fresh water biofilms. This reaction could be directly associated with a chemical defense against the grazer Thamnocephalus platyurus [78]. 

Royo, J., Vancanneyt, G., Perez, A. G., Sanz, C., Stormann, K., Rosahl, S., Sanchez-Serrano, J. J. (1996). Char-aeterization of three potato lipoxygenases with distinct enzymatic activities and different organ-specific and wound-regulated expression patterns. J. Biol. Chem., 271, 21012-21019. 

Certain echinacea constituents have demonstrated anti-inflammatory properties in vitro. Inhibition of cyclooxygenase, 5-lipoxygenase, and hyaluronidase may be involved. In animals, application of Epurpurea prior to application of a topical irritant reduced both paw and ear edema. Despite these laboratory findings, randomized, controlled clinical trials involving echinacea for wound healing have not been performed in humans. 

Lipoxygenases. Lipoxygenases catalyze the peroxidation of polyunsaturated fatty acids with a cis.cis 1-4-pentadiene moiety to form conjugated diene hydroperoxides (Figure lc). Free fatty acids are formed following wounding from the deacylation of membrane... 

Additional inflammatory mediators have been detected in cutaneous tissues as a consequence of SM treatment. These include free arachidonic acid (Lefkowitz and Smith, 2002) and its cyclooxygenase (Dachir et al, 2004 Rikimaru et al, 1991) and lipoxygenase products (Tanaka et al, 1997). Furthermore, the increased capillary permeability observed would allow a variety of circulating inflammatory participants, such as complement components, kininogens, etc., to enter the dermal interstitium (Rikimaru et al, 1991). Clearly, vesicant injury involves a host of inflammatory mediators similar to those seen in other types of wounds, where individual cytokines have been singled out as potential therapeutic targets. 

The main response of plants to wounding either to mechanically injury but also by pathogen attack is activation of lipases, followed by those of lipoxygenases as outlined above. Lipoxygenases remove from PUFAs a hydrogen atom localized at a double allylically activated methylene group, forming a mesomeric radical (Scheme 2). 

Gronert K, Maheshwari N, Khan N, Hassan IR, Dunn M, Laniado Schwartzman M (2005) A role for the mouse 12/15-lipoxygenase pathway in promoting epithelial wound healing and host defense. J Biol Chem 280 15267-15278... 

Lipoxygenase activity is commonly exhibited in wounded tissues, and perhaps the strongest circumstantial evidence for a physiological function of the enzyme is in the area of wound response of plants. Earlier suggestions... 

The first route in the lipoxygenase pathway (Scheme 5) involves the cleavage of 13-hydroperoxides into 12-oxo-(9Z)-dodccenoic acid and C -aldehydes by hydroperoxide lyase, an enzyme that has been found in a large number of plants [176,184,185]. The 12-oxo-(9Z)-dodecenoic acid isomerizes readily into the more stable 12-oxo-(10 )-dodecenoic acid, which is also known as traumatin [186]. Traumatin has been reported to mimic the physiological effects seen upon wounding of plant tissue and can be converted into traumatic acid, which has... 

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