# Can Storage Stability and Simulated Gastrointestinal Behavior Change the Cytotoxic Effects of Concentrated Guava Leaves Extract against Human Lung Cancer Cells?

## TL;DR

This study examines how storage and digestion affect guava leaf extracts' ability to kill lung cancer cells.

## Contribution

The study identifies a concentrated guava leaf extract (C10) that maintains cytotoxicity and stability through digestion and storage.

## Key findings

- C10 and C20 extracts showed high stability for 125 days due to high TPC and antioxidant activity.
- Simulated digestion reduced TPC but retained over 70% bioactivity.
- C10 extract showed the best selectivity for lung cancer cells over healthy cells.

## Abstract

The influence of storage stability and simulated gastrointestinal behavior of different extracts of guava leaves extracts (NC: not concentrated, and C10 and C20: concentrated by nanofiltration) was evaluated based on their total phenolic compound (TPC) contents and antioxidant activity as well as on their cytotoxic effects on A549 and Vero cells. The results showed that C10 and C20 presented high stability for 125 days probably due to their high TPC contents and antioxidant activity. The simulated gastrointestinal behavior modified their TPC contents; however, after all digestion steps, the TPC values were higher than 70%, which means that they were still available to exert their bioactivities. Additionally, the cytotoxic effects of these extracts were evaluated before and after the simulated gastrointestinal behavior or under different storage conditions. C10 presented the best selectivity indices (SI) values (IC50 Vero cells/IC50 A549 cells) at both conditions suggesting that it can be considered a potential extract to be developed as a functional food due to its resistance to the gastrointestinal digestion and storage conditions tested.