Bromelain ameliorates hepatic microcirculation after warm ischemia

Area of Science:

• Hepatology
• Immunology
• Protease research

Background:

• Hepatic ischemia/reperfusion (I/R) injury is a significant clinical challenge.
• Bromelain, a protease with immunomodulatory properties, is explored as a novel therapeutic strategy.
• Understanding bromelain's effects on liver function, microcirculation, and cellular interactions is crucial.

Purpose of the Study:

• To investigate the dose-dependent effects of bromelain on hepatic I/R injury.
• To evaluate bromelain's impact on liver function markers (AST, ALT), microcirculation, and leukocyte-endothelium interactions.

Main Methods:

• A dose-response study involving 140 rats subjected to 30 minutes of normothermic hepatic ischemia.
• Intravenous administration of bromelain at doses of 0.1, 1.0, or 10 mg/kg prior to ischemia.
• Assessment of microcirculation, leukocyte-endothelium interactions, liver enzymes, apoptosis, Kupffer cell activation, endothelial damage, and eNOS expression.

Main Results:

• High-dose bromelain (10 mg/kg) exacerbated microcirculatory disturbances and cellular damage in sham-operated animals.
• In I/R injury, low-dose bromelain (0.1 mg/kg) significantly improved microcirculation, reduced leukocyte adhesion, apoptosis, and endothelial damage.
• Low-dose bromelain treatment resulted in increased eNOS expression and lower AST levels compared to untreated I/R groups.

Conclusions:

• Bromelain demonstrates potential as a therapeutic agent for hepatic I/R injury.
• A narrow therapeutic window exists for bromelain, with low doses being beneficial and high doses detrimental.
• Further research is warranted to optimize bromelain dosage for clinical application in liver I/R injury.