The anti-inflammatory active ingredients of diarylpropanes in nutmeg
Nutmeg belongs to the dried seed of Myristica fragrans, a plant in the family Myristidae. It is included in the 2015 edition of the Chinese Pharmacopoeia. Its functions and indications include warming the middle stream of qi, astringent intestines, and stopping diarrhea. It is used for spleen and stomach deficiency and cold, prolonged diarrhea, abdominal distension and pain, and vomiting when eaten less. According to literature reports, the main chemical components of nutmeg are lignin, benzofuran new lignin, and non benzofuran new lignin, while reports of diarylpropane components are relatively rare. The chemical components in nutmeg, especially the phenolic components, have a wide range of biological activities, and current activity research mainly focuses on anti-inflammatory and anti-tumor activities. In addition, there are also relevant reports on the effects on the central nervous system, such as neuroprotection, anti anxiety, antibacterial and treatment of diabetes.

Inflammation has been proven to be a common pathological mechanism in the occurrence of autoimmune disorders and diseases such as tumors. When immune cells are stimulated by inflammatory mediators and other substances, it promotes the extensive expression of nitric oxide synthase (iNOS), releases nitric oxide (NO), and triggers an immune response. Therefore, inhibiting NO production is a direct indicator for evaluating the anti-inflammatory activity of compounds.

Traditional anti-inflammatory drugs such as cyclooxygenase-2 (COX-2) inhibitors have side effects on the cardiovascular system and gastric mucosa, and there is a need to research and develop new anti-inflammatory drugs. Given the previous reports on the anti-inflammatory activity of phenolic components in nutmeg, and the limited research on the same phenolic component, diarylpropane, in order to enrich the chemical composition of diarylpropane and discover new lead compounds with anti-inflammatory activity, this study isolated, purified, and structurally identified the diarylpropane component from the ethyl acetate fraction of nutmeg fruit acetone extract, and tested the inhibitory activity of the isolated compound on NO production in mouse RAW264.7 macrophages.

This article studied the chemical composition of the ethyl acetate fraction of 70% acetone extract from nutmeg fruit. Five diarylpropane compounds were isolated and identified, among which compound 1 was a new compound. The NO generation inhibition activity test of compound 1 found that compound 1 (IC50=4.00 μ mol/L) had a significantly stronger inhibitory effect on NO generation in mouse RAW264.7 macrophages than the positive control L-NMMA (IC50=0.18 μ mol/L). The results of this study can provide a material basis for expanding the medicinal scope of traditional Chinese medicine nutmeg for anti-inflammatory purposes.