# Pharmacological Effect of Water-Extractable (Poly)Phenolic Polysaccharide–Protein Complexes from Prunus spinosa L. Wild Fruits

## TL;DR

This paper explores the health benefits of compounds from wild blackthorn fruits, showing they can reduce cough and bronchoconstriction in guinea pigs.

## Contribution

The study identifies and characterizes water-extractable polysaccharide–protein complexes from Prunus spinosa L. with antitussive and bronchodilatory effects.

## Key findings

- Hw complex significantly suppressed citric acid-induced cough similar to codeine in guinea pigs.
- Hw reduced bronchoconstriction comparably to salbutamol in a dose-dependent manner.
- The complexes are rich in pectic polymers with specific sugar compositions and high esterification.

## Abstract

Wild fruits are distributed worldwide, but are consumed mainly in developing countries, where they are an important part of the diet. Still, in many other countries, they are consumed only locally. Blackthorn (Prunus spinosa L.) is an underutilized species rich in fibres and phenolic compounds, making it suitable as a potential functional food for supporting human health. Cold (Cw) and hot (Hw) water-extracted (poly)phenolic polysaccharide–protein complexes, differing in carbohydrate, phenolic and protein contents, were isolated from blackthorn fruits and characterized. The complexes exhibited molecular weights of 235,200 g/mol (Cw) and 218,400 g/mol (Hw), and were rich in pectic polymers containing galacturonic acid, arabinose, galactose and rhamnose, indicating a dominance of homogalacturonan (HG) [→4)-α-D-GalA(1→4)-α-D-GalA(1→]n and a low content of RGI [→2)-α-L-Rha(1→4)-α-D-GalA(1→2)-α-L-Rha(1→]n sequences associated with arabinan or arabinogalactan. Minor content of glucan, probably starch-derived, was also solubilized. Pectic polysaccharides were highly esterified and partly acetylated. Pharmacological testing was performed in male Dunkin–Hartley guinea pigs, a model with human-like airway reflexes. Both complexes affected airway defense mechanisms. Particularly, Hw significantly suppressed citric acid-induced cough, similar to codeine, and reduced bronchoconstriction comparably to salbutamol in a dose-dependent manner. These findings support further exploration of Hw as a natural antitussive and bronchodilatory agent.