6-Methoxyflavonol glycosides with in vitro hepatoprotective activity from Chenopodium bonus-henricus roots

In Bulgarian folk medicine the roots of Chenopodium bonus-henricus L. are known as "chuven" and have been applied externally to treat skin iflammations, wounds and boils. The infusion of the drug has been also used as a mild laxative. In Bulgarian food industry the aqueous extract of the roots has been employed in production of "halva". One new, namely 6-methoxykaempferol 3-O-[β-apiofuranosyl(1→2)]-β-glucopyranosyl(1→6)-β-glucopyranoside 2, and two known flavonoid glycosides, spinacetin 3-O-[β-apiofuranosyl(1→2)]-β-glucopyranosyl(1→6)-β-glucopyranoside 1 and spinacetin 3-O-gentiobioside 3, were isolated from the roots of Chenopodium bonus-henricus L. Their structures were determined by means of spectroscopic methods (1D, 2D NMR, UV, IR, and HR-ESI-MS). Additionally, 1 and 3 significantly reduced the cellular damage caused by the hepatotoxic agent CCl₄ in rat hepatocytes and preserved cell viability and GSH level, decreased LDH leakage and reduced lipid damage. Effects were similar to those of the positive control silymarin. Control of self-toxic effects were done in a MTT based assay using HepG2 cells and revealed a statistically significant cytotoxic effects only in very high concentrations exceeding mM concentrations and an incubation time of 72h, making flavonoid glycosides with a 6-methoxykaempferol skeleton a promising and save class of hepatoprotective compounds.