Functional components in Luffa cylindrica and their effects on anti-inflammation of macrophage cells

► Phenolics, oleanolic acid, carotenoid and chlorophyll were found in Luffa. ► Luffa peel contained a higher amount of functional components than pulp. ► Luffa peel was superior to Luffa pulp in anti-inflammation of RAW 264.7 cells. ► Ethyl acetate extract of Luffa peel decreased the production of NO and IL-6. ► Ethyl acetate extract of Luffa peel inhibited the expression of iNOS and p-IκBα. The objectives of this study were to determine the distribution of functional components in peel and pulp of Luffa cylindrica and evaluate their anti-inflammatory activity on RAW 264.7 murine macrophage cells. Phenolics and flavonoids were present in abundant amounts in aqueous extract of peel, but in ethyl acetate extracts of peel, oleanolic acid, carotenoids and chlorophylls dominated. Both ethanol and ethyl acetate extracts in peel and pulp decreased production of nitric oxide in LPS-induced RAW 264.7 cells, whereas the ethanol extract mitigated secretion of prostaglandin E2. Furthermore, all the extracts significantly inhibited IL-6 production, but remained ineffective in retarding generation of IL-1β and TNF-α. Ethyl acetate extract of peel reduced expression of inducible nitric oxide synthase, but enhanced expression of cyclooxygenase 2. Both ethyl acetate extracts of peel and pulp mitigated expression of p-IκBα, while the latter attenuated expression of p-ERK, and all the extracts failed to inhibit JNK phosphorylation.