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 TNFα 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 TNFα 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, IL1α, IL1β, G1p2, and Ccl5. The butanol fraction significantly suppressed NFκB DNA binding activity and phosphorylation of p38, JNK, and ERK MAPKs. Components in the active fraction from bitter gourd were identified as 1-α-linolenoyl-lysophosphatidylcholine (LPC), 2-α-linolenoyl-LPC, 1-lynoleoyl-LPC, and 2-linoleoyl-LPC. Purified 1-α-linolenoyl-LPC and 1-linoleoyl-LPC suppressed the LPS-induced TNFα production of RAW 264.7 cells at a concentration of 10 µg/mL.