# Effect of freeze-pressure regulated extraction technology on the physicochemical properties and pharmacological activities of guizhi extract

## TL;DR

A new freeze-pressure extraction method improves the quality and effectiveness of herbal extracts like Gui Zhi, potentially enhancing their use in modern medicine.

## Contribution

A novel freeze-pressure regulated extraction technique is introduced, showing improved physicochemical and pharmacological properties in herbal extracts.

## Key findings

- FE extraction produced lower pH, higher zeta potential, and smaller particle size compared to traditional methods.
- FE increased cinnamaldehyde content and improved extraction of volatile and phenolic compounds.
- FE extract showed therapeutic effects by alleviating symptoms and restoring lung tissue via metabolic pathway regulation.

## Abstract

Extraction is the core process for obtaining bioactive compounds from medicinal plants. Enhancing the extraction efficiency of aromatic herbs has become a critical challenge. This study introduced a novel freeze-pressure regulated extraction (FE) technique to improve the extraction efficiency of Gui Zhi (GZ). Compared to traditional methods, FE yielded a significantly lower pH of 4.74, a higher zeta potential of −13.93 mV, and a smaller average particle size of 304.57 nm. Scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP) confirmed that FE creates larger pores and an expanded surface area, facilitating more effective compound release. HPLC analysis indicated that FE increased the cinnamaldehyde content from 348.53 to 370.20 μg/g. UPLC-MS analysis further demonstrated that FE is more effective for extracting volatile and phenolic compounds. Furthermore, the therapeutic effect of GZ extract on a wind-cold syndrome model was investigated. FE significantly alleviated symptoms and restored lung tissue integrity, through the regulation of the citric acid cycle and thiamine metabolism pathways. The findings not only support the application of FE technology in herbal extraction but also offer novel approaches for the efficient utilization of herbs like GZ in modern medicine.