# Effects of Polyphenolic Extracts From Sumac, Pomegranate Peel, Indian Almond Leaves, Falsa, and Banana Bracts on Calcium Oxalate and Brushite Crystallization In Vitro

## TL;DR

This study shows that plant-based polyphenolic extracts can inhibit kidney stone formation by reducing crystal growth in laboratory tests.

## Contribution

The novel finding is that non-anthocyanin fractions from these plants show stronger inhibition of kidney stone crystal formation than anthocyanin fractions.

## Key findings

- All extracts inhibited calcium oxalate and brushite crystallization in a dose-dependent manner.
- Non-anthocyanin fractions showed stronger inhibitory effects than anthocyanin fractions.
- Molecular docking confirmed strong binding affinity of compounds to proteins involved in crystal adhesion.

## Abstract

Nephrolithiasis, or kidney stone formation, is a widespread global health concern. This study examines the effects of polyphenolic extracts, along with their anthocyanin and non‐anthocyanin fractions, from sumac fruit, pomegranate peel, almond leaves, falsa fruit, and banana bracts on the crystallization of calcium oxalate (CaC2O4·nH2O) and brushite (CaHPO4·2H2O) in vitro. The extracts were prepared through maceration in aqueous methanol and further fractionated into anthocyanin and non‐anthocyanin fractions using solid‐phase extraction. For calcium oxalate crystallization, nucleation and aggregation were monitored using a spectrophotometer in the presence and absence of these extracts and fractions. For brushite crystallization, the single diffusion gel growth method was employed. All extracts inhibited the crystallization of both calcium oxalate and brushite in a dose‐dependent manner, significantly reducing crystal number, size, and altering crystal morphology. Non‐anthocyanin fractions demonstrated a stronger inhibitory effect than anthocyanin fractions. Molecular docking studies further revealed that compounds in these fractions exhibited strong binding affinity with proteins involved in the adhesion and aggregation of calcium oxalate crystals to renal cells, supporting their antilithogenic properties. These findings suggest that these natural polyphenolic sources hold promise as potential inhibitors of kidney stone formation.

Polyphenolic extracts and their fractions from five plant sources inhibit calcium oxalate and brushite crystal formation in vitro, with non‐anthocyanin fractions showing stronger anti‐lithogenic effects supported by molecular docking.