Diterpenoids from the seeds of Euphorbia lathyris and their effects on microglial nitric oxide production

Four lathyrane diterpenoids from the seeds of Euphorbia lathyris

Four new diterpenoids, including three secolathyrane diterpenoids (1-3) and one lathyrane diterpenoid (4), together with seven known diterpenoids, were obtained in the shelled seeds of Euphorbia lathyris. In particular, 1-3 possess a rare split ring structure, and currently only one compound with the same skeleton has been identified in E. lathyris. Compound 4 furnishes an unprecedented oxygen bridge structure. The structures were identified using various spectral techniques, including NMR, HR-ESI-MS, single-crystal X-ray diffraction and calculated electronic circular dichroism (ECD). The biosynthetic pathway of 1-4 was inferred. Furthermore, the cytotoxic activities of all compounds (1-11) were measured on three human tumor cells. New compounds 2 and 3 showed moderate cytotoxic activities against U937 cells with IC50 values of 22.18 and 25.41 μM, respectively.

Anti-Inflammatory and Cytotoxic Compounds Isolated from Plants of Euphorbia Genus

Euphorbia is a large genus of the Euphorbiaceae family. Around 250 species of the Euphorbia genus have been studied chemically and pharmacologically; different compounds have been isolated from these species, especially diterpenes and triterpenes. Several reports show that several species have anti-inflammatory activity, which can be attributed to the presence of diterpenes, such as abietanes, ingenanes, and lathyranes. In addition, it was found that some diterpenes isolated from different Euphorbia species have anti-cancer activity. In this review, we included compounds isolated from species of the Euphorbia genus with anti-inflammatory or cytotoxic effects published from 2018 to September 2023. The databases used for this review were Science Direct, Scopus, PubMed, Springer, and Google Scholar, using the keywords Euphorbia with anti-inflammatory or cytotoxic activity. In this review, 68 studies were collected and analyzed regarding the anti-inflammatory and anti-cancer activities of 264 compounds obtained from 36 species of the Euphorbia genus. The compounds included in this review are terpenes (95%), of which 68% are diterpenes, especially of the types ingenanes, abietanes, and triterpenes (approximately 15%).

Photo-induced scandium-catalyzed biomimetic skeleton conversion of lathyrane to naturally rare eupholathone Euphorbia diterpenes

The naturally scarce eupholathone-type euphornin E (1) was efficiently prepared from abundant lathyrane-type Euphorbia factor L1via a visible-light-induced Sc(OTf)3-catalyzed tandem process. Eupholathones 2 and 3 were also smoothly obtained by changing the reaction solvent. This route provides a convenient method for easily constructing scarce eupholathone- from lathyrane-type Euphorbia diterpenes, and confirms the biogenetic relationship between them from a chemical standpoint. Notably, compound 1 exhibited good anti-HIV activity.

Synthesis of Lathyrol PROTACs and Evaluation of Their Anti-Inflammatory Activities

Lathyrol is a core scaffold structure of many lathyrane diterpenoids with potent anti-inflammatory activity isolated from Euphorbia lathyrism. It was chosen as a framework to design and synthesize a series of proteolysis targeting chimeras. A total of 15 derivatives were obtained. Compound 13 exhibited inhibitory activity on LPS-induced NO production in RAW264.7 cells (IC₅₀ = 5.30 ± 1.23 μM) with low cytotoxicity. Furthermore, compound 13 significantly degraded v-maf musculoaponeurotic fibrosarcoma oncogene homologue F (MAFF) protein, a target of lathyrane diterpenoid, concentration- and time-dependently. The mechanism of action of 13 is related to activating the Keap1/Nrf2 pathway. It also inhibited the expression of NF-κB, blocked the nuclear translocation of NF-κB, and activated autophagy in LPS-induced RAW264.7 cells. Based on the results obtained, compound 13 might be a promising anti-inflammatory agent.

Phytochemical and pharmacological review of diterpenoids from the genus Euphorbia Linn (2012-2021)

ETHNOPHARMACOLOGICAL RELEVANCE

Euphorbia is one of the major genera in angiosperms, which is widely distributed all over the world, including Asia, Africa and Central and South America. The roots or tubers of Euphorbia are famous for medicinal purposes, especially in China. Many of them, such as Euphorbia pekinensis Rupr, Euphorbia fischeriana Steud and Euphorbia Kansui S.L.Liou ex S.B.Ho. . are used as Chinese herbal medicines.

AIM OF THE STUDY

This paper reviews the diterpenoids isolated from the genus Euphorbia species and the pharmacological activities of these compounds to evaluate its traditional use and potential future development.

MATERIALS AND METHODS

Information on the studies of the genus Euphorbia Linn was collected from scientific journals, books and reports via library and electronic data search (Scifinder, Web of Science, PubMed, Elsevier, Scopus, Google Scholar, Springer, Science Direct, Wiley, ACS, CNKI and Kew Plants of the Word Online). Meanwhile, it was also obtained from published works of material medica, folk records, ethnophmacological literatures, Ph.D. and Masters dissertations.

RESULTS

Known as the main constituents of the genus Euphorbia Linn, Diterpenoids possess many pharmacological properties such as anti-inflammation, antiviral activities and cytotoxicity. To date, various types of diterpenoids were identified from this genus, including isopimarane, rosane, abietane, ent-kaurane, ent-atisane. cembrane, casbane, lathyrane, myrsinane, jatropholane, tigliane, ingenane, jatrophane, paraliane, pepluane, and euphoractin.

CONCLUSIONS

This review describes 14 types of diterpenoid isolated from 45 Euphorbia species from 2012 to 2021, a total of 615 compounds. Among them, mainly include jatrophane (171), lathyrane (92), myrsinane (62), abietane (70), ent-atisane (36), ent-kaurane (7), tigliane (26) and ingenane (19). The possible biological pathways of these compounds were presumed. At the same time, more than 10 biological activities of these compounds were summarized, such as anti-inflammation, antiviral activities and cytotoxicity.

Integrated Analysis of Transcriptome and microRNA Profile Reveals the Toxicity of Euphorbia Factors toward Human Colon Adenocarcinoma Cell Line Caco-2

Euphorbia factors, lathyrane-type diterpenoids isolated from the medical herb Euphorbia lathyris L. (Euphorbiaceae), have been associated with intestinal irritation toxicity, but the mechanisms underlying this phenomenon are still unknown. The objective of this study was to evaluate the transcriptome and miRNA profiles of human colon adenocarcinoma Caco-2 cells in response to Euphorbia factors L1 (EFL1) and EFL2. Whole transcriptomes of mRNA and microRNA (miRNA) were obtained using second generation high-throughput sequencing technology in response to 200 μM EFL treatment for 72 h, and the differentially expressed genes and metabolism pathway were enriched. Gene structure changes were analyzed by comparing them with reference genome sequences. After 72 h of treatment, 16 miRNAs and 154 mRNAs were differently expressed between the EFL1 group and the control group, and 47 miRNAs and 1101 mRNAs were differentially expressed between the EFL2 group and the control. Using clusters of orthologous protein enrichment, the sequenced mRNAs were shown to be mainly involved in transcription, post-translational modification, protein turnover, chaperones, signal transduction mechanisms, intracellular trafficking, secretion, vesicular transport, and the cytoskeleton. The differentially expressed mRNA functions and pathways were enriched in transmembrane transport, T cell extravasation, the IL-17 signaling pathway, apoptosis, and the cell cycle. The differentially expressed miRNA EFLs caused changes in the structure of the gene, including alternative splicing, insertion and deletion, and single nucleotide polymorphisms. This study reveals the underlying mechanism responsible for the toxicity of EFLs in intestinal cells based on transcriptome and miRNA profiles of gene expression and structure.

Euphorbia diterpenoids: isolation, structure, bioactivity, biosynthesis, and synthesis (2013-2021)

Covering: 2013 to 2021As the characteristic metabolites of Euphorbia plants, Euphorbia diterpenoids have always been a hot topic in related science communities due to their intriguing structures and broad bioactivities. In this review, we intent to provide an in-depth and extensive coverage of Euphorbia diterpenoids reported from 2013 to the end of 2021, including 997 new Euphorbia diterpenoids and 78 known ones with latest progress. Multiple aspects will be summarized, including their occurrences, chemical structures, bioactivities, and syntheses, in which the structure-activity relationship and biosynthesis of this class will be discussed for the first time.

Pharmacological Potential of Lathyrane-Type Diterpenoids from Phytochemical Sources

Lathyrane diterpenoids are one of the primary types of secondary metabolites present in the genus Euphorbia and one of the largest groups of diterpenes. They are characterized by having a highly oxygenated tricyclic system of 5, 11 and 3 members. These natural products and some synthetic derivatives have shown numerous interesting biological activities with clinical potential against various diseases, such as cytotoxic activity against cancer cell lines, multi-drug resistance reversal, antiviral properties, anti-inflammatory activity and their capability to induce proliferation or differentiation into neurons of neural progenitor cells. The structure of the lathyrane skeleton could be considered privileged because its framework is able to direct functional groups in a well-defined space. The favorable arrangement of these makes interaction possible with more than one target. This review aims to highlight the evidence of lathyranes as privileged structures in medicinal chemistry. Chemical structures of bioactive compounds, the evaluation of biological properties of natural and semisynthetic derivatives, and the exploration of the mechanisms of action as well as target identification and some aspects of their targeted delivery are discussed.

Characterization of diterpene metabolism in rats with ingestion of seed products from Euphorbia lathyris L. (Semen Euphorbiae and Semen Euphorbiae Pulveratum) using UHPLC-Q-Exactive MS

Previous pharmacological studies have indicated that diterpenoids are the primary effective chemical cluster in the seeds of Euphorbia lathyris L. The seed products are used in traditional Chinese medicine in the forms of Semen Euphorbiae (SE) and Semen Euphorbiae Pulveratum (SEP). However, the metabolism of the plant's diterpenoids has not well elucidated, which means that the in vivo metabolites products have not been identified. In the current study, the physiological metabolites of six diterpenes (Euphorbia factor L₁ (L1), L₂ (L2), L₃ (L3), L_7a (L7a), L_7b (L7b), and L₈ (L8) were screened in feces and urine of rats after oral administration of SE and SEP, using UHPLC-Q-Exactive MS. A total of 22 metabolites were detected in feces and eight in urine, indicating that the major elimination route of diterpenoids is via the colon. Hydrolysis, methylation and glucuronidation served as be the primary metabolic pathways of these diterpenoids. To sum up, this study contributed toward the elucidated of new metabolites and metabolic pathways of SE and SEP, and the new chemical identities can be used to guide further pharmacokinetic studies.

Diterpenoids from the seeds of Euphorbia lathyris and their anti-inflammatory activity

Twelve previously undescribed diterpenoids, euplarisans A-L (1-12), including one premyrsinane and eleven lathyranes, along with ten known analogues 13-22 were isolated from the seeds of Euphorbia lathyris. Their chemical structures were delineated by spectroscopic analysis and single-crystal X-ray diffraction. Interestingly, both 5 and 6 possessed an unusual trans-gem-dimethylcyclopropane as structural features and compound 8 was elucidated as premyrsinane-type diterpenoid. Meanwhile, a plausible biogenetic pathway for compounds 1-12 was proposed. In the anti-inflammatory bioassay, compounds 1, 2, 4, 13, 16, and 18 markedly inhibited the nitric oxide production in LPS-induced RAW264.7 macrophage cells. Compound 1 showed a more remarkable anti-inflammatory effect than others. It inhibited the generation of inflammatory cytokines (IL-1β, IL-6, and TNF-α) and also obviously decreased the expression of iNOS, COX-2, and p-IκBα in a dose-dependent manner. The structure-activity relationships (SARs) of these diterpenoids were also discussed.