# Schisanhenol Alleviates Mycophenolic Acid-Induced Intestinal Epithelial Cell Barrier Damage by Activating the Nrf2/HO-1 Signaling Pathway

## TL;DR

Schisanhenol protects intestinal cells from damage caused by mycophenolic acid by reducing cell death and boosting antioxidant defenses.

## Contribution

Schisanhenol's protective mechanism against MPA-induced intestinal damage via the Nrf2/HO-1 pathway is newly identified.

## Key findings

- Sal increased cell viability and reduced apoptosis in MPA-treated Caco-2 cells.
- Sal upregulated ZO-1 and occludin, restoring tight junction proteins.
- Sal reduced ROS levels and enhanced antioxidant markers like SOD, CAT, and GSH.

## Abstract

Reactive oxygen species (ROS)-mediated apoptosis of intestinal epithelial cells and tight junction (TJ) protein loss play critical roles in mycophenolic acid (MPA)-induced disruption of intestinal epithelial barrier function, yet no effective therapeutic strategies exist. Schisanhenol (Sal), a major component of the traditional Chinese medicine Wuzhi capsule, exhibits strong antioxidant activity.

The present study aimed to investigate the protective efficacy and mechanisms of Sal against MPA-induced damage to the intestinal mechanical barrier.

Caco-2 cells were exposed to MPA (10 μM), Sal (5, 10, and 25 μM), or ML385 (2 μM) for 24 hours. Cell viability was measured via a Cell Counting Kit-8 (CCK-8) assay. The expression of apoptosis-related and TJ proteins was evaluated through Western blot analysis. Flow cytometry was used to quantify the percentage of apoptotic Caco-2 cells. Immunofluorescence assays were performed to assess the localization of TJ proteins. Intracellular ROS levels were measured using H2DCFDA staining. Oxidative and antioxidative biomarker levels were quantified using specific assay kits.

Sal significantly increased the viability of MPA-treated cells. It also upregulated Bcl-2 expression and reduced apoptosis. Furthermore, Sal increased the expression of the TJ proteins ZO-1 and occludin. Additionally, Sal upregulated the MPA-mediated decrease in Nrf2/HO-1 expression, reduced intracellular ROS accumulation, and increased the levels of antioxidants, including SOD, CAT, and GSH. However, ML385 partially abrogated the protective effects of Sal.

Schisanhenol alleviates MPA-induced intestinal mechanical barrier damage via modulation of the Nrf2 signaling pathway, highlighting its antioxidant and antiapoptotic properties.