Possible Interaction: Carrageenan and Nitric Oxide

“… λ-carrageenan (1% w/v in 0.2 ml sterile saline) determined an intense recruitment of …) synthase and cyclooxygenase-2, thus increasing the generation of harmful autacoids such as NO and pro-inflammatory prostaglandins, PgE₂ and 6-ketoPgF(1α), increased … the local generation of IL-1β and TNF-α.”

“Conclusion:The results of … study suggest that NO activates COX-1 in … early phase of carrageenan and up-regulates COX-2 expression in the late phase in the skin, resulting in production of … and PGI2 at the site of inflammation, which would contribute to exacerbation of the inflammatory process.”

“Results Carrageenan injection resulted in increases in the concentrations of NO , PGE2, and PGI2, and these increases were completely suppressed by NG-monomethyl-l-arginine acetate.”

“The results of the current study show that carrageenan induces peripheral release of NO , the production of which is mediated by nNOS in the early phase and by both nNOS and iNOS in the late phase of carrageenan-induced inflammation.”

“Obtained results suggest that nitric oxide derived from inducible nitric oxide synthase play an inhibitory role in carrageenan produced hyperalgesia in rat.”

“The peak values at 12 hr after the LPS challenge were dependent on the dose of CAR with 1 to 5 mg, although the injection with 10 mg of CAR was adversely inhibited NO production compared with 5 mg of CAR.”

“It has also been reported that nitric oxide is positively regulated by carrageenan and negatively regulated by hyaluronan in the knee joint.”