# Rutin–chitooligosaccharide complex: Comprehensive evaluation of its anti-inflammatory and analgesic properties in vitro and in vivo

## TL;DR

This study shows that a complex made of rutin and chitooligosaccharide has strong anti-inflammatory and pain-relieving effects in both lab and animal models.

## Contribution

The novel contribution is the comprehensive evaluation of rutin–chitooligosaccharide complex's anti-inflammatory and analgesic properties in vitro and in vivo.

## Key findings

- R-COS significantly reduced pro-inflammatory factors in LPS-stimulated RAW 264.7 cells without affecting cell viability.
- R-COS exhibited protective effects on zebrafish embryos by inhibiting pro-inflammatory factors like COX-2 and iNOS.
- R-COS showed analgesic activity in zebrafish by reducing pain-like behavior induced by acetic acid.

## Abstract

This study investigated the potential anti-inflammatory and analgesic effects of the rutin–chitooligosaccharide (R-COS) complex both in vitro and in vivo. Initially, the cytotoxicity of R-COS was assessed in RAW 264.7 cells using an MTT assay. Subsequently, an inflammatory study was conducted where R-COS demonstrated a significant reduction in various pro-inflammatory factors (nitric oxide [NO], prostaglandin E2, tumor necrosis factor-α, interleukin-6, interleukin-1, inducible nitric oxide synthase [iNOS], and cyclooxygenase [COX-2]) in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells without compromising cell viability. Furthermore, in vivo analysis showcased the protective effect of R-COS on zebrafish embryos exposed to inflammatory stress induced by LPS. R-COS exhibited inhibition against pro-inflammatory factors, specifically COX-2 and iNOS. Notably, R-COS played a modulatory role in calcitonin gene-related peptide and NO levels in zebrafish, reducing the expression of pro-inflammatory factors. Additionally, the study observed analgesic activity in zebrafish treated with R-COS, which mitigated pain-like behavior triggered by acetic acid. Overall, these findings highlight the potential of R-COS, derived from chitosan, as a promising anti-inflammatory agent with broad applications in healthcare and tissue engineering.