# Oral Nano-Delivery of Crotoxin Modulates Experimental Ulcerative Colitis in a Mouse Model of Maximum Acute Inflammatory Response

## TL;DR

This study shows that crotoxin, when delivered via nanostructured silica, can significantly reduce symptoms of ulcerative colitis in mice.

## Contribution

The first demonstration of crotoxin incorporated into SBA-15 silica effectively treating experimental ulcerative colitis.

## Key findings

- Crotoxin incorporated into SBA-15 reduced Disease Activity Index scores by approximately 50% in mice with UC.
- Oral administration of the crotoxin–SBA-15 complex improved histopathological features of the colon in the UC model.
- The study confirms the therapeutic potential of crotoxin–SBA-15 for treating experimentally induced ulcerative colitis.

## Abstract

The incorporation of drugs into nanostructured silica has proven to be an effective strategy for delaying drug release, protecting against enzymatic degradation, and enhancing therapeutic efficacy. Specifically, crotoxin, a component derived from the venom of Crotalus durissus terrificus, exhibits notable analgesic and immunomodulatory properties. Previous studies have demonstrated that encapsulating crotoxin within SBA-15 nanostructured mesoporous silica not only reduces its toxicity and enhances its analgesic effects but also enables effective oral administration. Given its promising efficacy and the expanding interest in its application across various experimental models and potential therapeutic uses, this study aimed to conduct a detailed analysis of the physicochemical properties of crotoxin when incorporated into SBA-15 silica. Following characterization, the crotoxin–SBA-15 complex was orally administered to mice in an experimental model of ulcerative colitis (UC). The most widely adopted experimental model for studying UC involves the administration of dextran sodium sulfate (DSS) in drinking water to induce colonic inflammation in susceptible animals. In this study, we hypothesized that crotoxin incorporated into ordered mesoporous silica (SBA-15) could modulate DSS-induced UC. Crotoxin was successfully incorporated into SBA-15 and administered orally, as its physicochemical properties supported this route of delivery. Mice received the crotoxin–SBA-15 complex either at the onset of UC induction or on days 1 and 4 after DSS exposure. Seven days after the start of DSS administration, we observed a substantial reduction (approximately 50%) in Disease Activity Index (DAI) scores, accompanied by marked improvements in the histopathological features of the colon. These findings indicate for the first time that crotoxin incorporated into SBA-15 exhibits significant therapeutic potential in the treatment of experimentally induced ulcerative colitis.