# Exploring techniques for extraction of silver fir (Abies alba): phytochemical composition, antioxidant activity and cell viability

## TL;DR

This paper compares methods to extract valuable compounds from silver fir, finding that subcritical water extraction at 100°C yields the most effective antioxidant-rich extracts.

## Contribution

The study identifies subcritical water extraction at 100°C as the optimal method for maximizing antioxidant activity and bioactive compounds in silver fir extracts.

## Key findings

- SWE-BA-100 extract had the highest total polyphenol content and lignan concentration.
- Bark extracts showed better antioxidant activity than branch extracts.
- All extracts were non-cytotoxic but some inhibited cell migration.

## Abstract

Silver fir (Abies alba) contains polyphenols and lignans with antioxidant and therapeutic properties. Efficient extraction methods are essential to preserve these compounds and maximize bioactivity.

To compare extraction techniques and identify the optimal method for obtaining high-quality silver fir extracts with strong antioxidant activity and minimal cytotoxicity.

Extracts from bark and branches were prepared using subcritical water extraction (SWE, 70–200 °C), supercritical CO2 extraction, and high-pressure ethanol extraction. Extracts were analyzed for total polyphenol content (TPC), lignan concentration (HPLC), antioxidant activity (DPPH and ABTS assays), and volatile profile (GC-MS). Cytotoxicity and cell migration were evaluated in HaCaT and Caco-2 cell lines via MTS and gap closure assays.

The SWE bark extract at 100 °C (SWE-BA-100) showed the highest TPC (73.8 mg GAE/g), lignan content (secoisolariciresinol 204.7 µg/mL), and antioxidant activity (DPPH: 24.2, ABTS: 32.0 mg GAE/g). Bark extracts had superior bioactive profiles compared to branches, though branch extractions gave higher yields. All extracts were non-cytotoxic. SWE-BA-100 inhibited cell migration, indicating a complex interaction between composition and cellular response.

SWE at 100 °C is a promising green method for producing potent antioxidant extracts from A. alba. Bark extracts offer strong antioxidant potential and safety for pharmaceutical, cosmetic, and nutritional uses. However, high lignan content may influence cellular behavior. Further studies should address the role of non-phenolic antioxidants and refine extraction strategies to balance efficacy and bioactivity.