Inflammation in any part of the body activates macrophages, which secrete more pro-inflammatory substances—driving a vicious cycle of chronic inflammation. This cycle can trigger serious diseases such as insulin resistance and atherosclerosis.
To counter this cycle, most people take non-steroidal anti-inflammatory drugs (NSAIDs) like aspirin or ibuprofen. However, long-term NSAID use causes harmful side effects such as intestinal bleeding. Finding a safer way to treat inflammation is therefore crucial.
Key Study Findings
Tsinghua University researchers investigated whether NMN (nicotinamide mononucleotide) could combat inflammation, building on previous studies showing NMN alleviates multiple diseases in rodents. They treated mouse macrophages with 500 µM NMN and observed the following:
1. Inflammation Alters Metabolite Abundance
The team measured changes in metabolites around macrophages during inflammation. Among 458 detected molecules:
- ~22% increased in abundance after inflammatory stimulation.
- ~23% decreased in abundance.
- NAD+ (nicotinamide adenine dinucleotide) levels dropped significantly with inflammation.
2. NMN Reverses Inflammatory Metabolite Profiles
Researchers treated macrophages with both NMN and LPS (lipopolysaccharide, an inflammatory inducer) to test if boosting NAD+ inhibits inflammation. Results showed:
- NMN significantly increased NAD+ levels in macrophages.
- NMN reversed the abundance of some inflammatory metabolites.
- This confirmed NMN’s ability to inhibit inflammation.
3. NMN Restores Inflammation-Related Protein Levels
To validate NMN’s anti-inflammatory effect, the team measured levels of inflammation-related proteins. After NMN treatment:
- All inflammation-related protein levels decreased.
- This further confirmed NMN alleviates the inflammatory state of macrophages.
4. NMN Inhibits NSAID-Targeted Protein Accumulation
The study also found NMN suppresses levels of COX-2 (cyclooxygenase-2)—an enzyme that causes inflammation and pain, and a well-known target of NSAIDs. By inhibiting COX-2, NMN avoids the side effects associated with NSAIDs.
Research Significance & Outlook
The study confirms NMN is an effective treatment for chronic inflammation in mice. The next step is to verify NMN’s efficacy in human macrophages.
If NMN works similarly in human macrophages, it may replace NSAIDs in the near future—providing an anti-inflammatory treatment with no side effects.
References
Liu, J., Zong, Z., Zhang, W., Chen, Y., Wang, X., Shen, J., Liu, X., Deng, H. (2021). Nicotinamide Mononucleotide Alleviates LPS-Induced Inflammation and Oxidative Stress via Decreasing COX-2 Expression in Macrophages. Frontiers in Molecular Biosciences, 8:702107. https://doi.org/10.3389/fmolb.2021.702107