Inhibition of Pro-inflammatory Mediators by Methanolic Extract of Opuntia monacantha Haw. (Cactaceae) in RAW 264.7 macrophages cells

Abstract

Opuntia monacantha (Cactaceae), a cochineal prickly pear with various medicinal uses and consumed widely by local community in Mexico due its nutritional value and therapeutics effects, and known as an ornamental plant in Malaysia, with limited numbers of scientific studies. The objective of this study is to clarify the anti-inflammatory activity and mechanisms of action of the cladodes of methanolic crude extract of O. monacantha (MEOM) and, phytocontituents profiling. The cladodes were extracted using methanol-maceration method and obtained the crude extract. The MEOM (12.5, 25, 50 and 100μg/mL) was tested using in-vitro models of inflammation in RAW 264.7. The MTT assay was used to evaluate cell viability and tcytotoxicity, whereby Griess assay was used to determine NO concentration inhibition activity. Furthermore, to test the inhibitory effects pro-inflammatory mediators by MEOM, we were performed the ELISA assays for PGE2, iNOs, COX-2 and TNF-α, and enzymatic assay for LOX in LPS/IFN-γ (inflammatory inducers). Finally, the chemical compounds were identified using UHPLC-Q-TOF/MS. MEOM contained anti-inflammatory properties; i) significantly did not affect the cells viability on the cytotoxicity test in dose-dependent manner, whereby, significantly reduced the NO production on the percentage of NO concentration inhibition at the all ranging of concentration of extract, respectively., ii)inhibition by MEOM, significantly in a dose-dependent manner in the LPS/IFN-γ-induced nitric oxide (NO), -PGE2, -iNOs, -COX-2, -TNF-𝛼𝛼 and -LOX production levels in RAW 264.7, respectively. According to the library of UHPLC-MS spectra, it has been identified the MEOM contain 22 potential active compounds. The strongest peak identified as isoliquiritin, a flavonoid glycoside compound revealed the anti-inflammatory activity. The findings are in agreements to the traditional uses that consumed safely to treat of pain and inflammation with minimum and/or no side effects.