The dichloromethane extract of Callicarpa longissima rich in diterpenoid phenols exerts anti-inflammatory effect via inhibiting the TLR4/NF-κB signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Callicarpa longissima is a typical Yao ethnomedicine that has been used to treat arthritis in China. Our previous study found that the dichloromethane extract (DCME) of C. longissima showed anti-inflammatory activity in vitro. However, the anti-inflammatory mechanism and detailed chemical composition of DCME remain unclear, which lead to the original interest of this study. AIM OF THE STUDY: The study aimed to evaluate the anti-inflammatory properties of the DCME from C. longissima and further explore the accurate chemical components responsible for this active extract. MATERIALS AND METHODS: The anti-inflammatory activity of DCME in vivo was tested with carrageenan-induced mice paw edema model. Its anti-inflammatory mechanism was explored with LPS-stimulated RAW264.7 macrophages model. The compounds in DCME were isolated by repeated column chromatography and their structures were identified on the basis of nuclear magnetic resonance spectroscopy. The anti-inflammatory activities of the isolates in vitro were also tested by suppressing releases of inflammatory mediators (NO, IL-6 and TNF-α) in RAW264.7 macrophages model. In addition, the molecular docking analysis, which evaluated the potential interaction between the compounds and Toll-like receptor 4 (TLR4) and nuclear factor κB (NF-κB), was performed. RESULTS: DCME effectively alleviated the mice paw edema induced by carrageenan. In LPS-stimulated RAW264.7 cells, DCME significantly decreased the production of interleukin (IL)-6 and tumor necrosis factor α (TNF-α) via inhibiting their mRNA transcription, down-regulated the expression of TLR4 and myeloid differentiation factor 88, inhibited the phosphorylation of alpha inhibitor of NF-κB (IκBα), NF-κB p65, and degradation of IκBα. Twelve diterpenoid phenols were identified from DCME, and they not only showed different inhibitory effects on the production of NO, IL-6 and TNF-α in LPS-stimulated RAW264.7 cells, but also could bind to TLR4 and NF-κB as analyzed by molecular docking. CONCLUSIONS: Taken together, DCME from C. longissima could inhibit inflammatory response both in vitro and in vivo, which is mainly attributed to the synergistic effect of abundant diterpenoid phenols through inhibiting the TLR4/NF-κB signaling pathway, and might be a promising agent for the treatment of inflammatory diseases.

Structure elucidation and anti-inflammatory mechanism of difengpienol C, a new neolignan isolated from Illicium difengpi.

Illicium difengpi is well-known as its stem barks that have been widely used in the Traditional Chinese Medicine (TCM) for therapy rheumatoid arthritis and traumatic injury. To comprehensive utilization of resources, the phytochemical investigation on the branches and leaves of this plant was carried out, which led to the isolation of an undescribed neolignan along with three known lignans. Their structures were elucidated on the basis of extensive spectroscopic data and the new compound was elucidated as a neolignan possessing a dihydropyran ring formed by a unique conjugation way and named difengpienol C. Difengpienol C showed the strongest anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW264.7 cells, which powerfully inhibited nitric oxide (NO), interleukin 6 (IL-6), tumor necrosis factor α (TNF-α) production and suppressed the mRNA transcription of inducible nitric oxide synthase (iNOS), IL-6 and TNF-α. Besides, difengpienol C blocked the activation of TLR4/MyD88/NF-κB signaling pathway. Therefore, difengpienol C might be a potent agent for anti-inflammatory drug development, and the non-traditional medicinal parts of Illicium difengpi can be identified as the source of natural anti-inflammatory molecules.

Anti-Inflammatory Effect of Simonsinol on Lipopolysaccharide Stimulated RAW264.7 Cells through Inactivation of NF-κB Signaling Pathway.

Simonsinol is a natural sesqui-neolignan firstly isolated from the bark of Illicium simonsii. In this study, the anti-inflammatory activity of simonsinol was investigated with a lipopolysaccharide (LPS)-stimulated murine macrophages RAW264.7 cells model. The results demonstrated that simonsinol could antagonize the effect of LPS on morphological changes of RAW264.7 cells, and decrease the production of nitric oxide (NO), tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6) in LPS-stimulated RAW264.7 cells, as determined by Griess assay and enzyme-linked immunosorbent assay (ELISA). Furthermore, simonsinol could downregulate transcription of inducible nitric oxide synthase (iNOS), TNF-α, and IL-6 as measured by reverse transcription polymerase chain reaction (RT-PCR), and inhibit phosphorylation of the alpha inhibitor of NF-κB (IκBα) as assayed by Western blot. In conclusion, these data demonstrate that simonsinol could inhibit inflammation response in LPS-stimulated RAW264.7 cells through the inactivation of the nuclear transcription factor kappa-B (NF-κB) signaling pathway.

Preparative Isolation of Piceatannol Derivatives from Passion Fruit (Passiflora edulis) Seeds by High-Speed Countercurrent Chromatography Combined with High-Performance Liquid Chromatography and Screening for α-Glucosidase Inhibitory Activities.

Passiflora edulis Sims (passion fruit) seeds are often discarded as byproducts during juice processing. In fact, the seeds are of considerable commercial value in the food and cosmetics industry because of their rich polyphenols, especially piceatannol. In this study, high-speed countercurrent chromatography (HSCCC) was applied for the separation of stilbene polyphenols from passion fruit seeds. The n-hexane-ethyl acetate-methanol-water (1:2:1:2.8, v/v) was found to be the optimum two-phase solvent for the preparation of two major stilbenes, scirpusin B (8) and piceatannol (9) with purities of 90.2% and 94.8%, respectively. In addition, a continuous semipreparative HPLC was applied to further purify the HSCCC fractions containing minor stilbenes and obtain four new piceatannol derivatives (1-4) along with three known ones (5-7). The structures of these new compounds were determined using spectroscopic methods, including NMR, high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), and circular dichroism (CD). The isolated compounds were evaluated for α-glucosidase inhibitory activities in vitro. The result suggested that all of them exhibited more significant activity than acarbose, and passiflorinol B (2) had the strongest activity, with a IC50 value of 1.7 µM.

[Studies on chemical constituents of Zhuang medicine Excoecaria venenata and their cytotoxic activity].

Fourteen compounds were isolated from 95% ethanol extract by silica gel, MCI, and ODS column chromatography. These compounds were respectively identified as quercetin (1), kaempferol (2), (+)-catechin (3), fraxin (4), protocatechuic acid (5), gallic acid (6), methyl gallate (7), ethyl gallate (8), apocynol A (9), baccatin (10), cerevisterol (11), ellagic acid (12), 3, 3',4'-tri-0-methylellagic acid(13) and N-benzoyl-L-phenylalaninyl-N-benzoyl-L-phenylalaninate(14) by analyzing their spectral data and comparing with the previously reported literatures. Except for gallic acid (6), all other compounds were isolated from this plant for the first time. Compounds 1, 2 and 6 showed moderate anti-proliferation activities on tumor cells.

A new daphnane diterpenoid from Excoecaria venenata with inhibitory effect on human leukaemia HL-60 cells.

A new daphnane diterpenoid, venenatin (1), along with six known compounds, was isolated from the aerial parts of Excoecaria venenata. The structure of 1 was elucidated on the basis of extensive spectroscopic analysis. Compound 1 exhibited growth inhibitory effect on human leukaemia HL-60 cell line with IC50 value of 28.10 µM.

A new triterpenoid saponin from the root of Croton lachnocarpus Benth.

A new triterpenoid saponin, 3-O-ß-D-xylopyranosyl spathodic acid (1), was isolated from the EtOH extract of the root of Croton lachnocarpus Benth., together with four known compounds. These compounds were characterised on the basis of their spectral data and compatible with values in the literature. Compound 1 was the first triterpenoid glucoside isolated from the genus Croton. The known compound myriaboric acid (2) showed cytotoxic activity against human hepatocellular carcinoma SMMC-7721 cell line with an IC50 value of 42.2 µM.

A cytotoxic cardenolide and a saponin from the rhizomes of Tupistra chinensis.

A new cardenolide tupichinolide (1) and a new steroidal saponin tupichinin A (2), together with seven known compounds, were isolated from the rhizomes of Tupistra chinensis. Their structures were established using spectroscopic analysis and chemical methods. Compound 1 was the first cardenolide isolated from Tupistra chinensis and exhibited potent cytotoxicity against five human cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7 and SW480.