Isolation of major phenolics from Launaea spinosa and their protective effect on HepG2 cells damaged with t-BHP

Context: Some Launaea species (Asteraceae) are used traditionally to treat liver oxidative stress.

Objective: The present study investigates the protective effects of isolated compounds from Launaea spinosa Sch. Bip. (Asteraceae) against oxidative stress on t-BHP-induced HepG2 cells.

Materials and methods: Major phenolic content from flowering aerial parts of L. spinosa was isolated and identified. The protective effects of isolated compounds (10 and 20?μM) against oxidative stress induced by tert-butyl hydroperoxide (t-BHP) in HepG2 cells were investigated through the measurement of aspartate aminotransferase (AST), alanine transaminase (ALT), and superoxide dismutase (SOD) levels.

Results: A new phenolic compound identified as 2,3-diferulyl R,R-(+) methyl tartrate (6), in addition to five known metabolites, esculetin (1), esculetin-7-O-d-glucoside (cichoriin) (2), fertaric acid (3), acacetin-7-O-d-glucoside (4), and acacetin-7-O-d-glucuronic acid (5), were isolated. Oxidant-induced damage by 200?μM t-BHP in HepG2 cells was inhibited by compounds 1, 4, and 5 (10 and 20?μM), or quercetin (10?μM; positive control). The protective effects of compounds 1, 4, and 5 were associated with decreasing in AST, ALT, and SOD levels. Compound 4 (20?μM) decreased the AST level from 128.5?±?13.9 to 7.9 ±1.8?U/mL. Meanwhile, compound 1 (20?μM) decreased ALT activity from 20.3?±?7.0 to 7.6?±?2.4?U/mL, while compound 5 decreased SOD levels from 41.6?±?9.0 to 28.3?±?3.4?mU/mg.

Conclusion: The major phenolic compounds isolated from L. spinosa displayed a significant cytoprotective effect against oxidative stress, leading to maintenance of the normal redox status of the cell.