Identification, in vitro and in vivo Antioxidant Activity, and Gastrointestinal Stability of Lignans from Silver Fir (Abies alba) Wood Extract

Abstract

Lignans are generally known for their beneficial impact on human health. In this study, we found that the water extract of silver fir (Abies alba) wood contains lignans, which constitute approximately 10% of the extract and include isolariciresinol, hydroxymatairesinol, secoisolariciresinol, lariciresinol, pinoresinol, and matairesinol. The antioxidant activity of the extract was measured by several in vitro assays and an assay in a eukaryotic cell model (yeast). The extract had greater in vitro antioxidative activity than ascorbic acid, resveratrol, or butylated hydroxytoluene (BHT) and similar antioxidative activity to epigallocatechin gallate. The intracellular antioxidant effect in the yeast gave indirect evidence that the components of the silver fir wood extract (SFWE) effectively pass through eukaryotic cell membranes and have higher in vivo antioxidative activity than ascorbic acid, resveratrol, tocopheryl succinate, or BHT and similar to epigallocatechin gallate. The in vitro gastrointestinal digestion of the lignans in the extract is not significant; therefore, it is reasonable to expect antioxidative effects from orally applied SFWE.

KEYWORDS:

• Silver fir wood
• Abies alba
• lignans
• antioxidant

ABBREVIATIONS
SFWE	=	silver fir wood extract
EGCG	=	epigalocatechin gallate
DPPH	=	1,1-diphenyl 2-picryl hidrazin
ABTS	=	2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid
TPC	=	total phenolic content
CAE	=	caffeic acid equivalents
RUE	=	rutin equivalents
BHT	=	butylated hydroxytoluene
SSF	=	simulated salivary fluid