Antiinflammatory and antihyperalgesic activity of C-phycocyanin.
BACKGROUND
C-phycocyanin (C-PC), a biliprotein found in blue green algae, such as Spirulina platensis, is often used as a dietary nutritional supplement due to its various therapeutic values. In addition, the antiinflammatory activity of C-PC partly through inhibition of proinflammatory cytokine formation, inducible nitric oxide synthase (iNOS) and cyclooxygeanase-2 (COX-2) expression has been demonstrated in many in vitro and in vivo studies. However, whether C-PC also has antihyperalgesic activity in inflammatory nociception has not been investigated.


METHODS
Using a carrageenan-induced thermal hyperalgesia model, we evaluated the effect of C-PC on nociception by measuring paw withdrawal latency. To clarify the mechanisms involved, the expression of iNOS and COX-2 and the formation of nitrate and tumor necrosis factor-alpha (TNF-alpha) in the rat paw were determined.


RESULTS
Pre- or posttreatment with C-PC (30 or 50 mg/kg, IP) significantly attenuated carrageenan-induced inflammatory nociception and the induction of iNOS and COX-2 at the late phase, (4 h) accompanied by an inhibition of the formation of TNF-alpha, prostaglandin E(2), nitrate and myeloperoxidase activity.


CONCLUSIONS
Based on these results, it is suggested that the inhibition of NO and prostaglandin E(2) over-production through suppressing iNOS and COX-2 induction and attenuation of TNF-alpha formation and neutrophil infiltration into inflammatory sites by C-PC may contribute, at least in part, to its antihyperalgesic activity.
Shih
Chao-Ming
CM
Chia-Yi Christian Hospital, Taipei, Taiwan, Republic of China.
Cheng
Shin-Nan
SN
Wong
Chih-Shung
CS
Kuo
Yu-Ling
YL
Chou
Tz-Chong
TC
D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D002351:Carrageenan; D051546:Cyclooxygenase 2 / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D006358:Hot Temperature; D006930:Hyperalgesia / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D007249:Inflammation / Q000139:chemically induced / Q000378:metabolism / Q000517:prevention & control*; D016753:Interleukin-10 / Q000378:metabolism; D008297:Male; D020556:Neutrophil Infiltration / Q000187:drug effects; D009566:Nitrates / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects; D009195:Peroxidase / Q000378:metabolism; D010798:Phycocyanin / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000187:drug effects; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D000700:Analgesics; D000893:Anti-Inflammatory Agents; D009566:Nitrates; D014409:Tumor Necrosis Factor-alpha; D010798:Phycocyanin; D016753:Interleukin-10; D002351:Carrageenan; D009195:Peroxidase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D051546:Cyclooxygenase 2; C489691:Ptgs2 protein, rat; D015232:Dinoprostone