Anti-inflammatory effects of dehydrogeijerin in LPS-stimulated murine macrophages

Phytochemical Profiling Studies of Alkaloids and Coumarins from the Australian Plant Geijera parviflora Lindl. (Rutaceae) and Their Anthelmintic and Antimicrobial Assessment

Phytochemical profiling followed by antimicrobial and anthelmintic activity evaluation of the Australian plant Geijera parviflora, known for its customary use in Indigenous Australian ceremonies and bush medicine, was performed. In the present study, seven previously reported compounds were isolated including auraptene, 6'-dehydromarmin, geiparvarin, marmin acetonide, flindersine, and two flindersine derivatives from the bark and leaves, together with a new compound, chlorogeiparvarin, formed as an artefact during the isolation procedure and isolated as a mixture with geiparvarin. Chemical profiling allowed for a qualitative and quantitative comparison of the compounds in the leaves, bark, flowers, and fruit of this plant. Subsequently, a subset of these compounds as well as crude extracts from the plant were evaluated for their antimicrobial and anthelmintic activities. Anthelmintic activity assays showed that two of the isolated compounds, auraptene and flindersine, as well as the dichloromethane and methanol crude extracts of G. parviflora, displayed significant activity against a parasitic nematode (Haemonchus contortus). This is the first report of the anthelmintic activity associated with these compounds and indicates the importance of such fundamental explorations for the discovery of bioactive phytochemicals for therapeutic application(s).

A Review of the Ethnobotanical Use, Chemistry and Pharmacological Activities of Constituents Derived from the Plant Genus Geijera (Rutaceae)

Geijera Schott is a plant genus of the Rutaceae Juss. (rue and citrus) family, comprising six species which are all native to Oceania. Of the plants belonging to this genus, the most significant species that has a customary use is Geijera parviflora, which was used by Indigenous Australians, primarily as a pain reliever. Herein, a comprehensive review of the literature published on the genus Geijera from 1930 to 2023 was conducted. This is the first review for this plant genus, and it highlights the chemical constituents reported to date, together with the range of pharmacological properties described from the various species and different parts of the plant. These properties include anti-inflammatory, anti-microbial, anti-parasitic, insect repellent, analgesic, neuroactive, and anti-cancer activities. Finally, a reflection on some of the important areas for future focused studies of this plant genus is provided.

Heme Oxygenase 1-Mediated Anti-Inflammatory Effect of Extract from the Aerial Part of Heracleum moellendorffii Hance

In this study, the anti-inflammatory effects of a methanolic extract from the aerial part of Heracleum moellendorffii Hance (HmAPE) and its underlying mechanisms were investigated. HmAPE demonstrated a significant reduction in nitric oxide production in lipopolysaccharide (LPS)-treated murine macrophage RAW264.7 cells, and HmAPE decreased the protein and mRNA expression of inducible nitric oxide synthase. Further mechanistic studies on inflammatory signaling pathways revealed that HmAPE-mediated downregulation of inflammatory gene expressions was not associated with mitogen-activated protein kinases or nuclear factor-κB signaling pathways. However, HmAPE treatment activated nuclear factor E2-related factor 2 (Nrf2) and upregulated heme oxygenase-1 (HO-1) expression, which is known to suppress pro-inflammatory cytokine production. Additionally, treatment with a selective HO-1 inhibitor, tin protoporphyrin IX, partially reversed the effects of HmAPE in LPS-treated RAW264.7 cells, indicating that HmAPE inhibited LPS-induced NO production, at least in part, through induction of Nrf2-mediated HO-1 expression. These findings suggest that HmAPE could serve as a potential edible source with anti-inflammatory properties, and further studies are required to ascertain its anti-inflammatory efficacy in vivo.

Heracleum moellendorffii roots inhibit the production of pro-inflammatory mediators through the inhibition of NF-κB and MAPK signaling, and activation of ROS/Nrf2/HO-1 signaling in LPS-stimulated RAW264.7 cells

BACKGROUND

Heracleum moellendorffii roots (HM-R) have been long treated for inflammatory diseases such as arthritis, backache and fever. However, an anti-inflammatory effect and the specific mechanism of HM-R were not yet clear. In this study, we for the first time explored the anti-inflammatory of HM-R.

METHODS

The cytotoxicity of HM-R against RAW264.7 cells was evaluated using MTT assay. The inhibition of NO and PGE₂ production by HM-R was evaluated using Griess reagent and Prostaglandin E₂ ELISA Kit, respectively. The changes in mRNA or protein level following HM-R treatment were assessed by RT-PCR and Western blot analysis, respectively.

RESULTS

HM-R dose-dependently blocked LPS-induced NO and PGE₂ production. In addition, HM-R inhibited LPS-induced overexpression of iNOS, COX-2, IL-1β and IL-6 in RAW264.7 cells. HM-R inhibited LPS-induced NF-κB signaling activation through blocking IκB-α degradation and p65 nuclear accumulation. Furthermore, HM-R inhibited MAPK signaling activation by attenuating the phosphorylation of ERK1/2, p38 and JNK. HM-R increased nuclear accumulation of Nrf2 and HO-1 expression. However, NAC reduced the increased nuclear accumulation of Nrf2 and HO-1 expression by HM-R. In HPLC analysis, falcarinol was detected from HM-R as an anti-inflammatory compound.

CONCLUSIONS

These results indicate that HM-R may exert anti-inflammatory activity by inhibiting NF-κB and MAPK signaling, and activating ROS/Nrf2/HO-1 signaling. These findings suggest that HM-R has a potential as a natural material for the development of anti-inflammatory drugs.

Anti-inflammatory effect of the six compounds isolated from Nauclea officinalis Pierrc ex Pitard, and molecular mechanism of strictosamide via suppressing the NF-κB and MAPK signaling pathway in LPS-induced RAW 264.7 macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Nauclea officinalis Pierrc ex Pitard. is a Chinese medicinal herb that contains high level of alkaloids which is the most abundant and active constituent. Strictosamide isolated from Nauclea officinalis Pierrc ex Pitard. showed significant effects on inflammatory response, compared with pumiloside, 3-epi-pumiloside, vincosamide, 3α,5α-tetrahydrodeoxycordifoline lactam and naucleamide A-10-O-β-D-glucopyranoside of this plant.

AIM OF STUDY

we investigated the biological activities of the six compounds mentioned-above, and the underlying molecular mechanism exerted by the most potent one, strictosamide.

MATERIALS AND METHODS

The effects of strictosamide and other five compounds on the inhibitory activity of nitric oxide (NO) were screened by Griess test. The contents of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in media were detected by using Enzyme-linked immunosorbent (ELISA) kits. The effects on the mRNA expression of nitric oxide synthase (iNOS), TNF-α and IL-1β of strictosamide were further investigated by RT-qPCR. Western blot assay was conducted to illustrate the effects of strictosamide on iNOS and phosphorylation of p65, inhibitor of NF-κB (IκB)-α, IκB-kinase (IKK)-α as well as p-extracellular signal-regulated kinase (ERK), p-c-jun N-terminal kinase (JNK) and p-p38 in the protein levels.

RESULTS

Strictosamide potently suppressed the productions of NO, TNF-α and IL-1β in LPS-induced RAW 264.7 macrophages, and it dose-dependently alleviated the LPS-simulated protein level of iNOS as well as the mRNA expressions of iNOS, TNF-α and IL-1β. In addition, molecular data revealed that strictosamide markedly decreased the expressions of p-p65, p-IκBα and p-IKKα. Furthermore, strictosamide significantly attenuated LPS-induced the phosphorylation of p38, ERK and JNK.

CONCLUSIONS

At present study, the results indicated that the anti-inflammatory activity of strictosamide was associated with the restraint of NO, TNF-α and IL-1β via negative regulation of both NF-κB and mitogen-activated protein kinases (MAPKs) in LPS-induced RAW 264.7 cells.

New coumarins from the roots of Angelica dahurica var. formosana cv. Chuanbaizhi and their inhibition on NO production in LPS-activated RAW264.7 cells

A new linear pyranocoumarin named (-)-hydroxydecursinol (1) and a new biscoumarin named (±)-dahuribiscoumarin (2), together with six known compounds isoimperatorin (3), imperatorin (4), phellopterin (5), isodemethylfuropinarine (6), demethylfuropinarine (7), and (+)-decursinol (8) were isolated from the 75% ethanolic extract of the roots of Angelica dahurica var. formosana cv. Chuanbaizhi. Their structures were elucidated by extensive spectroscopic techniques, including 2D NMR spectroscopy and mass spectrometry, and the structure of 2 was confirmed by single-crystal X-ray diffraction. All of the isolated compounds were evaluated for the inhibition against nitric oxide (NO) production in the lipopolysaccharide (LPS)-activated RAW264.7 macrophage cell line, and exhibited the inhibitory activity on NO production in a concentration-dependent manner. Furthermore, real-time PCR analysis revealed that compounds 2, 5-8 could significantly suppress the expression levels of inducible nitric oxide synthase mRNA in a concentration-dependent manner. And their primary structure-activity relationships of NO inhibitory effects were also briefly discussed. These compounds are potential candidates for further bioassay studies to determine their suitability as drug leads.

Chemogeography and antimicrobial activity of essential oils from Geijera parviflora and Geijera salicifolia (Rutaceae): two traditional Australian medicinal plants

Essential oils were hydrodistilled from 27 specimens of Geijera parviflora Lindl., (Rutaceae) and nine specimens of Geijera salicifolia Schott, collected over a wide geographic range in New South Wales, Queensland and South Australia. Essential oils were produced by traditional hydrodistillation and characterised using GC-MS. From one specimen a serendipitous discovery was made of bioactive coumarins dissolved in the hydrosol, which were the coumarins isopsoralen, xanthyletine and osthole. These coumarins were not present in the essential oil from that specimen. Using essential oil composition from all specimens, principal component analysis (PCA) demonstrated nine clusters for G. parviflora and three for G. salicifolia. Some clusters are representative of previously described chemotypes and some are reflective of possible chemotypes requiring more comprehensive sampling for confirmation. Thus, another three or four possible chemotypes of G. parviflora and one of G. salicifolia have been tentatively identified. Using micro-titre plate broth dilution assays, antibacterial and antifungal activity of all chemotypes was investigated. In this regard, the 'green oil' chemotype, restricted to G. parviflora, with major components linalool, geijerene/pregeijerene, 1,8-cineol and bicyclogermacrene, demonstrated the highest antimicrobial and free radical scavenging activity. Thus, in the light of traditional use reports of local analgaesia and bioactivity demonstrated in the current study, oils from select chemotypes of G. parviflora may be useful in suitably compounded lotions and creams designed for topical antimicrobial applications and local pain relief. In addition, because major components are known for insecticidal activities, such lotions may also be useful as topically applied insect repellents.

U-Bang-Haequi Tang: A Herbal Prescription that Prevents Acute Inflammation through Inhibition of NF-κB-Mediated Inducible Nitric Oxide Synthase

Since antiquity, medical herbs have been prescribed for both treatment and preventative purposes. Herbal formulas are used to reduce toxicity as well as increase efficacy in traditional Korean medicine. U-bang-haequi tang (UBT) is a herbal prescription containing Arctii fructus and Forsythia suspensa as its main components and has treated many human diseases in traditional Korean medicine. This research investigated the effects of UBT against an acute phase of inflammation. For this, we measured induction of nitric oxide (NO) and related proteins in macrophage cell line stimulated by lipopolysaccharide (LPS). Further, paw swelling was measured in carrageenan-treated rats. Carrageenan significantly induced activation of inflammatory cells and increases in paw volume, whereas oral administration of 0.3 or 1 g/kg/day of UBT inhibited the acute inflammatory response. In RAW264.7 cells, UBT inhibited mRNA and protein expression levels of iNOS. UBT treatment also blocked elevation of NO production, nuclear translocation of NF-κB, phosphorylation of Iκ-Bα induced by LPS. Moreover, UBT treatment significantly blocked the phosphorylation of p38 and c-Jun NH2-terminal kinases by LPS. In conclusion, UBT prevented both acute inflammation in rats as well as LPS-induced NO and iNOS gene expression through inhibition of NF-κB in RAW264.7 cells.