Protective effects of Eucommia leaves leaf extract on hepatic ischemia-reperfusion injury in rats

Abstract

Objective To study the protective effect of Eucommia leaves leaf extract on hepatic ischemia-reperfusion injury (IRI) in rats. Methods 64 SD rats were randomly divided into eight groups: blank group, IRI group, Eucommia leaves water extract and ethanol extract groups (20, 40, 80 g/kg group), each group had 8 rats. The blank group and the IRI group were treated with distilled water, and the extracts of Eucommia leaves were continuously administered for 10 days at 20, 40, 80 g/kg. The other 7 groups except the blank group established a model of hepatic ischemia-reperfusion injury (ischemia 1 h, reperfusion 4 h), and the subhepatic inferior vena cava blood and ischemic liver tissues of each group were collected for detection. Results Blank group alanine aminotransferase (ALT): (143.75±23.10) U/L, aspartate aminotransferase (AST): (86.25±14.86) U/L, malondialdehyde (MDA): (0.32±0.04) μmol/gprot, tumor necrosis factor-α (TNF-α): (213.74±20.98) ng/L, interleukin-1β (IL-1β): (50.14±8.75) ng/L, high mobility group protein B1 (HMGB1): (0.73±0.22) lower than IRI group, superoxide dismutase (SOD): (267.01±23.98) U/mgprot was higher than IRI group, the difference was statistically significant (ALT: t=33.910, P<0.01; AST: t=32.900, P<0.01; MDA: t=10.550, P<0.05; TNF-α: t=18.030, P<0.01; IL-1β: t=10.310, P<0.01; HMGB1: t=5.314, P<0.01; SOD : t=8.084, P<0.01). IRI group ALT: (1 883.71±143.80) U/L, AST: (1 456.00±117.31) U/L, MDA: (0.58±0.05) μmol/gprot, TNF-α: (456.11±30.79) ng/L, IL-1β: (112.97±14.46) ng/L, HMGB1: (1.53±0.33) higher than the extract of Eucommia leaves; SOD: (175.00±19.41) U/mgprot lower than the extract of Eucommia leaves, with ethanol extract 80 g/kg group ALT: (692.50±97.17) U/L, AST: (809.13±66.24) U/L, MDA: (0.33±0.04) μmol/gprot, TNF-α: (250.41±15.55) ng/L, IL-1β: (58.81±7.80) ng/L, HMGB1: (0.68±0.23), the difference was statistically significant (ALT: t=20.250, P<0.01; AST: t=13.390, P<0.01; MDA: t=10.100, P<0.01; TNF-α: t=16.680, P<0.01; IL-1β: t=9.173, P<0.01; HMGB1: t=5.562, P<0.01; SOD: t=7.496, P<0.01). The levels of AST, TNF-α and IL-1β in the ethanol extract of Eucommia leaves 80 g/kg group were significantly lower than those in the water extract of 80 g/kg group. The difference was statistically significant (AST: t=3.942, P<0.01; TNF- α: t=2.858, P<0.05; IL-1β: t=2.514, P<0.05). Conclusion Eucommia leaves leaf extract may protect hepatic IRI by inhibiting HMGB1 expression, reducing the level of sterile inflammation and oxidative stress. Key words: Eucommia leaves leaf extract; Hepatic; Ischemia-Reperfusion Injury; Oxidative stress; Inflammation