Quercetin may protect against LPS-induced inflammation

Quercetin, a flavonoid compound known for its anti-inflammatory and anti-histamine properties, may help to prevent inflammation induced by reactions to lipopolysaccharides (LPS). LPS are potent stimulators of immune reactions, so much so that they are used as adjuvants in vaccines. Do you manage patients with autoimmune disorders and impaired gut barrier function who have a bacterial or fungal gut infection? Then you're familiar with the clinical plight of needing to clear the infection but avoid amplifying the autoimmune inflammatory response by exposure to LPS and the cell walls of pathogenic organisms break down.This is certainly a complex matter of timing in case management, yet a paper recently published in the journal Thrombosis Research offers evidence that quercetin may help protect patients from autoimmune flare-ups while treating associated gut infections. The authors examined the effects of quercitin on LPS-induced disseminated intravascular coagulation (DIC), a condition that includes the activation of coagulation pathways by pro-inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor (TNF-α), 'players' in autoimmunity. The authors state:

"Quercetin is widely distributed in plants and has been reported to have effects of anti-inflammation and anti-thrombosis. In this study, we evaluated the protective effect of quercetin on LPS-induced experimental DIC in rabbits, and tried to clarify its mechanism against DIC."

They induced DIC in their study animals by LPS and observed quercetin-treated groups of several dosages, the LPS control group, a heparin control group and a saline control group for APTT, PT, and plasma levels of FIB, ALT, BUN, along with the activity of Protein C and ATIII. Quercetin had a marked protective effect:

"A continuous injection of LPS induced a gradual impairment of hemostatic parameters, a rise in plasma level of TNF-α, and damage in renal and hepatic function. The intravenous administration of quercetin significantly attenuated the increase of APTT, PT, ALT, BUN, and TNF-α, and the decrease of plasma FIB level and activity of Protein C and ATIII."

Clinical note: Caution should still be observed when treating chronic infections complicating autoimmune disorders and careful thought given to timing and the recovery of tolerance, but quercetin can be considered as part of the treatment plan when risking exposure to LPS as a consequence of antimicrobial therapy.The authors conclude:

"Quercetin may have a protective effect against LPS-induced DIC in rabbits through anti-inflammation and anticoagulation."