β-caryophyllene ameliorates hepatic ischemia reperfusion-induced injury: the involvement of Keap1/Nrf2/HO 1/NQO 1 and TLR4/NF-κB/NLRP3 signaling pathways.

Objective: Hepatic ischemia-reperfusion (H I/R) injury is a frequent clinical event during which the leading contributing players are inflammation and oxidative stress responses. β-caryophyllene (BCP), a natural bicyclic sesquiterpene, is an essential oil component of different plant species and edibles. This study aims to identify whether BCP pretreatment could avert H I/R injury with inspections of the underlying mechanisms.

Materials And Methods: Animals were devised into five groups; Sham and BCP + Sham; the animals were administered saline or BCP (200 mg/kg, orally) respectively; H I/R group, the animals were administered saline orally for 14 days before induction of H I/R; BCP100 and BCP200, the animals were administered BCP (100 and 200 mg/kg, respectively) for 14 days, followed by induction of H I/R.

Results: H I/R showed markedly increased ALT, AST, MDA, and lowered antioxidant enzyme activities, while the Nrf2/HO1/NQO1 pathway components were significantly augmented. The TLR4/NF-κB/NLRP3 elements were deterred, and subsequently, escalations in the inflammatory mediators (IL-1β, IL-6, and TNF-α), adhesion molecule ICAM-1, neutrophils infiltration (MPO), and apoptotic markers were observed. Pretreatment with BCP amplified the antioxidant enzyme activities and Keap1/Nrf2/HO1/NQO1 pathway components. BCP pretreatment lowered TLR4/NF-κB/NLRP3 pathway elements, which mitigated inflammatory mediators, ICAM-1, MPO, and apoptotic markers.

Conclusions: The protective effect of BCP against hepatic I/R induced injury might be accomplished via mitigation of oxidative stress by regulating the Keap1/Nrf2/HO1/NQO1 pathway and inhibition of the inflammatory process via manipulating the TLR4/ NF-κB/ NLRP3, reflected by inflammatory markers, neutrophils recruitment, and adhesion molecules reduction. BCP might be a potential therapeutic agent for alleviating hepatic I/R-induced injury.