Anti-inflammatory Effects of Chloroform Soluble Fraction from Perilla frutescens Britton Leaves Produced by Radiation Breeding in RAW264.7 Cells

The present study aimed to determine the anti-inflammatory effects of each solvent fraction of a mutant Perilla frutescens produced by radiation breeding. Following extraction with 80% methanol, P. frutescens was fractionated in the order of hexane, chloroform, ethyl acetate, and butanol; the chloroform fraction exhibited less cytotoxicity, the greatest inhibitory effect on the production of nitric oxide (NO), and the highest rate of inhibition on the generation of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and interferon-β (IFN-β). The chloroform fraction also suppressed the mRNA and protein levels of inducible nitric oxide synthase (iNOS) and reduced the activation of nuclear factor-κB (NF-κB) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Finally, the presence of corosolic acid in the chloroform fraction was identified. Taken together, the present findings indicate that the chloroform fraction obtained from mutant P. frutescens inhibited NO production in LPS-stimulated RAW264.7 cells via the suppression of iNOS expression and the inactivation of NF-κB.