(3β,16α)-3,16-Dihydroxypregn-5-en-20-one from the Twigs of Euonymus alatus (Thunb.) Sieb. Exerts Anti-Inflammatory Effects in LPS-Stimulated RAW-264.7 Macrophages

Abstract

To discover new pharmacologically active natural products, here, we performed the phytochemical analysis of a Korean medicinal plant. Euonymus alatus (Thunb.) Sieb. is a traditional medicinal plant that has been used as a remedy for various diseases in Asian countries. In particular, the cork cambium on the twigs of E. alatus has been used to treat dysmenorrhea, tumors, diabetes, and wound. Phytochemical analysis of the methanolic extract of E. alatus twigs led to the isolation of a sterol, which was identified as (3β,16α)-3,16-dihydroxypregn-5-en-20-one (1) by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy and high-resolution electrospray ionization mass spectrometry. The stereochemistry of 1 was established with nuclear Overhauser effect spectroscopy (NOESY) analysis and comparison of electronic circular dichroism (ECD) data. To the best of our knowledge, the isolation of compound 1 from nature is first reported here, as well as the complete and revised NMR data assignment of 1. In lipopolysaccharide (LPS)-stimulated RAW-264.7 macrophages, compound 1 significantly inhibited nitric oxide (NO) production at an IC50 value of 12.54 ± 0.05 μM as well as the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Moreover, the pre-treatment with compound 1 attenuated the LPS-induced phosphorylation of nuclear factor kappa B (NF-κB) p65 through the inhibition of the phosphorylation of IκB kinase alpha (IKKα), IKKβ, and inhibitor of kappa B alpha (IκBα). Compound 1 also inhibited the LPS-induced phosphorylation of p38, c-Jun NH2-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK). Taken together, compound 1 may serve as an anti-inflammatory constituent of E. alatus twigs and its anti-inflammatory property is thought to be associated with the inhibition of NO production via suppression of iNOS and COX-2 expression through inhibition of IKKα/β, I-κBα and NF-κB p65 activation and downregulation of p38, JNK, and ERK mitogen-activated protein kinase signal pathways in RAW 264.7 macrophages. These findings also provide experimental evidence that compound 1 identified from E. alatus twigs could be a candidate for an anti-inflammatory agent.

Euonymus alatus Leaf Extract Attenuates Effects of Aging on Oxidative Stress, Neuroinflammation, and Cognitive Impairment

“…Studies have shown that kaemferol and its derivatives reduce cholinesterase activity, prevent microglial activation, remove amyloid fibrils, and safeguard the blood-brain barrier [45]. In LPS-stimulated RAW264.7 cells and BV2 microglia cells, triterpenes (abruslactone A and demethylregelin), caffeic acid, and chlorogenic acid extracted from EA leaves and twigs are known to contribute to anti-inflammatory effects [29,46]. In addition, it was discovered that the anti-inflammatory properties of quercetin and kaemferol in EA also inhibited inflammatory mediators, including COX-2 and nitric oxide synthase [47].…”

Euonymus alatus (Thunb.) Siebold Prevents Osteoclast Differentiation and Osteoporosis

“…Moreover, the cork cambium of its twigs and wings, known as ‘Gui-jun-woo’, has historically been attributed to various functions, including enhancing blood circulation, alleviating pain, eliminating stagnant blood, and treating dysmenorrhea in past dynasties. [ 14 , 15 , 16 , 17 , 18 , 19 ]. In the RiHuaZi BenCao, another well-known traditional Chinese medicine (TCM) classic, E. alatus was recorded as a drug with the function of modulating gynecological diseases [ 19 ].…”

“…In the RiHuaZi BenCao, another well-known traditional Chinese medicine (TCM) classic, E. alatus was recorded as a drug with the function of modulating gynecological diseases [ 19 ]. Furthermore, recent studies have substantiated the effects of E. alatus , including its efficacy in treating rheumatoid arthritis, its immune-modulating characteristics, its benefits in managing hyperglycemia and diabetic retinopathy, along with its anti-inflammatory attributes [ 14 , 15 , 16 , 17 , 19 , 20 ]. Despite these findings, the potential impact of E. alatus on bone metabolism and bone loss remains uninvestigated.…”

ShenmaYizhi Decoction Improves the Mitochondrial Structure in the Brain and Ameliorates Cognitive Impairment in VCI Rats via the AMPK/UCP2 Signaling Pathway

“…), 59 in the form of sesquiterpenes, including sesquiterpene alkaloids, triterpenes, flavonoids, and phenolic compounds, such as β-sitosterol, aromadendrin, and alatamine. 24,60 Many compounds have been isolated from Ligusticum chuanxiong Hort, 61 including ligustilide, tetramethyl pyrazine (TMP), and ferulic acid. 25 Previous animal experiments conducted by our research group have shown that SMYZD exerts a significant effect on the treatment of dementia.…”