Hepatoprotective activity of Erythrina × neillii leaf extract and characterization of its phytoconstituents

Abstract

Background: Natural antioxidants and anti-inflammatory agents have the ability to restore normal balance to destructed liver cells. The genus Erythrina has attracted attention for its broad spectrum of physiological activities and its rich polyphenolic and alkaloid contents.

Hypothesis/purpose: The major phytoconstituents of Erythrina × neillii, an ornamental coral tree and a hybrid between E. herbacea and E. humeana that was not previously studied, were investigated. The hepatoprotective effect and underlying mechanisms were also assessed.

Study design and methods: The main phytoconstituents in the different fractions of the alcoholic leaf extract (dichloromethane and ethyl acetate) were identified using high resolution high-performance liquid chromatography coupled with mass spectrometry (HR-HPLC-MS-MS) based on the fragmentation pattern and molecular formula of the identified compounds and on previous literature. In addition, the hepatoprotective, anti-inflammatory and antioxidant activities of three doses of E. × neillii alcoholic leaf extract (100, 250, 500 mg/kg) were investigated in methotrexate (MTX)-intoxicated rats and were compared with those of silymarin-treated rats. Liver function parameters were obtained, and a histopathological study was performed. In addition, the anti-inflammatory mediators and the antioxidant system in the liver tissues were assessed.

Results: The dichloromethane extract revealed an abundance of alkaloids (25), in addition to tentatively identifying flavone (1), flavanone (1) and three fatty acids. Additionally, thirty-six compounds belonging to different classes of phytoconstituents with a predominance of flavonoids (21), O/C-flavone and flavonol glycosides, followed by alkaloids (9), fatty acids (4) and (2), and phenolic glycoside were identified in the ethyl acetate extract. Compared with MTX, alcoholic leaf extract (500 mg/kg) ameliorated the MTX-induced alterations by improving several biochemical marker levels, fighting oxidative stress in serum and liver tissues, and decreasing inflammatory mediators; this finding was further confirmed by the histopathological study.

Conclusion: This study reveals E. × neillii, a rich source of flavonoids and alkaloids, which could be further exploited to provide a promising and safe antihepatotoxic agent source.

Keywords: Alkaloids; Antihepatotoxic; Erythrina × neillii; Flavonoids.