Rosemary extract and colitis in mice
What it found
In mice with chemically induced colitis, a daily dose of 100 mg/kg rosemary extract lowered disease activity scores and improved gut barrier integrity.
The extract's main compounds, carnosic acid and carnosol, were also measured in the blood.
What they found
Animal and lab studies
Colitis severity
Mice given 100 mg/kg rosemary extract had lower disease activity scores than untreated mice with colitis. Their stool was more solid and contained less blood.
Gut barrier
Mice with colitis had more FITC-dextran leak into the blood, showing a damaged gut barrier. Rosemary extract at 100 mg/kg reduced this leak and increased levels of the tight junction protein ZO-1.
Sestrin 2 protein
DSS exposure increased sestrin 2 protein in the gut. Rosemary extract at both 10 and 100 mg/kg prevented that increase, but sestrin 2 mRNA did not change.
Blood levels
After a single dose of 100 mg/kg rosemary extract, carnosic acid reached a maximum blood level of 54.016 µM at 0.25 hours and had a half-life of 3.5 hours. Carnosol reached 5.008 µM at 0.25 hours and had a half-life of 7.5 hours.
Lab test on cells
In HT-29 cells, a chemical that causes oxidative stress reduced ZO-1 fluorescence to 58% of control. Pre-treatment with rosemary extract rescued 67% of the lost ZO-1 intensity.
What the authors conclude
“This study suggests that RE can be an effective preventative agent against IBD.”
Also in their conclusions
- They conclude that rosemary extract can prevent colitis development in mice and improve intestinal barrier integrity.
- They note that sestrin 2 protein, which is elevated in people with ulcerative colitis, was reduced by rosemary extract.
- They say that more research is needed to fully understand how rosemary extract prevents colitis.
How it was done
The authors wanted to see if rosemary extract could prevent colitis and to understand how its compounds are handled by the body.
They gave mice a single dose of rosemary extract to measure blood levels of carnosic acid and carnosol over 24 hours. In a separate experiment, they gave mice 10 or 100 mg/kg rosemary extract daily for 10 days while also giving them a chemical (DSS) in drinking water to cause colitis.
What it can’t tell you
- These are animal and cell studies. They cannot show whether rosemary extract prevents colitis in people.
- The study cannot prove that rosemary extract would work the same way in humans as it does in mice.
Who paid
- Funding
- Funded by NIH HHS; National Institute of Food and Agriculture (from the PubMed record).
- Conflicts
- The authors declare no conflict of interest.
- Authors work at
- University of Illinois at Chicago, USA
The paper
- Title
- Pharmacokinetic Analysis of Carnosic Acid and Carnosol in Standardized Rosemary Extract and the Effect on the Disease Activity Index of DSS-Induced Colitis
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Full text
- Cite
- Veenstra JP, Vemu B, Tocmo R, Nauman MC, Johnson JJ (2021). Pharmacokinetic Analysis of Carnosic Acid and Carnosol in Standardized Rosemary Extract and the Effect on the Disease Activity Index of DSS-Induced Colitis. Nutrients. doi:10.3390/nu13030773Free full textPubMed 33673488DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error