Bitter gourd suppresses lipopolysaccharide-induced inflammatory responses

Bitter gourd (Momordica charantia L.) is a popular tropical vegetable in Asian countries. Previously it was shown that bitter gourd placenta extract suppressed lipopolysaccharide (LPS)-induced TNF alpha production in RAW 264.7 macrophage-like cells. Here it is shown that the butanol-soluble fraction of bitter gourd placenta extract strongly suppresses LPS-induced TNF alpha production in RAW 264.7 cells. Gene expression analysis using a fibrous DNA microarray showed that the bitter gourd butanol fraction suppressed expression of various LPS-induced inflammatory genes, such as those for TNF, IL1 alpha IL1 beta, G1p2, and Ccl5. The butanol fraction significantly suppressed NF kappa B DNA binding activity and phosphorylation of p38, JNK, and ERK MAPKs. Components in the active fraction from bitter gourd were identified as 1-alpha-linolenoyl-lysophosphatidylcholine (LPC), 2-alpha-linolenoyl-LPC, 1-lynoleoyl-LPC, and 2-linoleoyl-LPC. Purified 1-alpha-linolenoyl-LPC and 1-linoleoyl-LPC suppressed the LPS-induced TNF alpha production of RAW 264.7 cells at a concentration of 10 mu g/mL.