Study on the metabolism of natural sesquiterpene lactones in human liver microsomes using LC-Q-TOF-MS/MS.

Sesquiterpene lactones are naturally occurring, highly active -specialised metabolites, which are biosynthesized by important medicinal plants, fulfilling many functions. The in vitro metabolism of parthenolide (1), grosheimin (2), carbetolide C (3), 8α-O-(3,4-dihydroxy--methylenebutanoyloxy)-dehydromelitensin (4) and arteludovicinolide A (5) was examined using human liver microsomes. Phase I, phase II (glucuronidation), as well as combined phase I + II metabolism were studied. Metabolites were identified via liquid chromatography-high resolution quadrupole time-of-flight mass spectrometry. Monohydroxylated, hydrated, carboxylated, methylated derivatives, together with corresponding monoglucuronides were detected, suggesting that the metabolism of sesquiterpene lactones is changeable due to structural features and scaffold diversity, though the lactone ring is the main site of metabolism.

Phytochemical Characterization of Phitosia crocifolia, a Monotypic Representative of Greek Flora.

Within the large Compositae family, Phitosia is considered a monotypic genus of the Greek flora, with its only species P. crocifolia (Boiss. & Heldr.) Kamari & Greuter growing wild with limited distribution, exclusively on the mountains Taigetos and Parnonas in Peloponnese. P. crocifolia's chemical profile was obtained, herein, for the first time and led to the isolation of 20 compounds, thirteen of which were characterized as sesquiterpene lactones and the rest mainly as phenolic derivatives. The isolates 1: -3, 5:  - 7: and 11:  - 13: represent new chemical structures. Compounds 2: and 3: especially are substituted with a pentose moiety, a rare phenomenon in sesquiterpene lactone backbones. A series of spectrometric and spectroscopic techniques were used to elucidate their structures. The relative configurations of the unreported compounds were established via extensive analysis of NMR spectroscopic and HRESIMS data, assisted by CD spectroscopic measurements. Throughout the entire isolation procedure, selected fractions rich in sesquiterpene lactones were tested against HeLa cancerous cell line for their cytotoxic effects with the lowest IC50 values being 18.84 µg/mL. Accordingly, among the tested isolates, compounds 5: and 9: exerted IC50 values of 13.5 µM and 11.4 µM, respectively.

A Bio-Guided Screening for Antioxidant, Anti-Inflammatory and Hypolipidemic Potential Supported by Non-Targeted Metabolomic Analysis of Crepis spp.

This study was designed to evaluate the chemical fingerprints and the antioxidant, anti-inflammatory and hypolipidemic activity of selected Crepis species collected in Greece, namely, C. commutata, C. dioscoridis, C. foetida, C. heldreichiana, C. incana, C. rubra, and Phitosia crocifolia (formerly known as Crepis crocifolia). For the phytochemical analyses, sample measurements were carried out by using nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography coupled with mass spectrometry (LC-MS). Τhe extracts were evaluated both in vitro (radical scavenging activity: DPPH assay and total phenolic content: Folin-Ciocalteu) and in vivo (paw edema reduction and hypolipidemic activity: experimental mouse protocols). Among the tested extracts, C. incana presented the highest gallic acid equivalents (GAE) (0.0834 mg/mL) and the highest antioxidant activity (IC50 = 0.07 mg/mL) in vitro, as well as the highest anti-inflammatory activity with 32% edema reduction in vivo. Moreover, in the hypolipidemic protocol, the same extract increased plasma total antioxidant capacity (TAC) by 48.7%, and decreased cholesterol (41.3%) as well as triglycerides (37.2%). According to fractionation of the extract and the phytochemical results, this biological effect may be associated with the rich phenolic composition; caffeoyl tartaric acid derivatives (cichoric and caftaric acid) are regarded as the most prominent bioactive specialized metabolites. The present study contributes to the knowledge regarding the phytochemical and pharmacological profile of Crepis spp.

Hypericum Essential Oils-Composition and Bioactivities: An Update (2012-2022).

Hypericum genus, considered to comprise over 500 species that exhibit cosmopolitan distribution, has attracted human interest since ancient times. The present review aims to provide and summarize the recent literature (2012-2022) on the essential oils of the title genus. Research articles were collected from various scientific databases such as PubMed, ScienceDirect, Reaxys, and Google Scholar. Scientific reports related to the chemical composition, as well as the in vitro and in vivo pharmacological activities, are presented, also including a brief outlook of the potential relationship between traditional uses and Hypericum essential oils bioactivity.

In vitro cytotoxic and anti-inflammatory activities of sesquiterpene lactones from Centaurea papposa (Coss.) Greuter.

In the pursuit of highly active specialized metabolites from endemic plants, Centaurea papposa (Coss.) Greuter, an endemic plant in Algeria and Tunisia, was investigated and afforded eleven sesquiterpene lactones (1-11). Cytotoxic evaluation of these compounds using the in vitro MTT assay on three human cancerous cell lines (HeLa, SK-MEL-28 and HepG2), revealed that isolates 4, 8 and 9 (IC50 ≤ 10 µM) could be potential anti-cancer drugs for cervical cancer according to the National Cancer Institute. Further evaluation of the in vitro anti-inflammatory activity showed that compounds 1 and 4 inhibited the TNF-α induced ICAM-1 expression in HMEC-1 endothelial cells at a maximum of 21% and 2% of the control (IC50 values 21.9 and 5.7 µM, respectively). The Michael reactions of the α-methylene-γ-lactone ring seem to be responsible for the strong activity, while no toxicity was observed in the HMEC-1 cells in all the range of tested concentrations (6.25-50.0 µM).

Macrocyclic Diterpenoid Constituents of Euphorbia deflexa, an Endemic Spurge from Greece.

Euphorbia deflexa, an endemic spurge from Greece, was investigated for the occurrence of its diterpene constituents. Through continuous monitoring by 1H NMR, 22 diterpenoids were isolated, including 16 previously undescribed compounds (euphodeflexins A-P), which belong to the jatrophane, ingenane, segetane, and pepluane diterpene types. Their chemical structures were elucidated through a combination of HRESIMS, NMR spectroscopy, and X-ray data. The isolated diterpenoids were tested against a panel of human cancer cell lines, as well as against two bacterial strains. Compounds 1, 13, and 17 were active against the HeLa cell line with IC50 values 9.9, 9.8, and 5.8 µM, respectively.

Cajamolides A-N: Cytotoxic and anti-inflammatory sesquiterpene lactones from Calea jamaicensis.

In the search for bioactive compounds from natural sources against cancer and inflammation, Calea jamaicensis (L.) L., a plant endemic to Panama, was investigated. Using multiple chromatographic steps, seventeen sesquiterpene lactones together with nine chromene derivatives were isolated from the non-polar extract of the plant. Among them, fourteen sesquiterpene lactones and three chromanes are described herein for the first time. Structure elucidation was achieved by extensive spectroscopic analysis and comparison with reported data. The isolated sesquiterpene lactones were tested against HeLa, SK-MEL-28 and HePG2 cancerous cell lines for their cytotoxic effects, as well as in the ICAM-1 assay for their anti-inflammatory potential. This study revealed strong cytotoxic agents on the one hand and strong inhibitors on the other. The compounds inhibited the TNF-α induced ICAM-1 expression on the endothelial HMEC-1 cells in a dose-dependent manner and with no toxicity observed on this non-cancerous cell line. In addition to the well-known cytotoxic activities of sesquiterpene lactones, further exploration may offer a novel therapeutic approach to cope with inflammatory diseases and the genus Calea may serve as a biobank for the isolation of potential phytopharmaceuticals, which could be utilized as leads in drug discovery and therapy.

Prenylated Acylphloroglucinols from Hypericum jovis with Anti-inflammatory Potential.

Thirteen prenylated acylphloroglucinols (1: -13: ), including 2 previously undescribed compounds (1: ) and (2: ), were isolated from Hypericum jovis. Their structures were elucidated by high-field NMR spectroscopy. The isolated prenylated acylphloroglucinols were evaluated for their anti-inflammatory effects in vitro through the reduction of the intercellular adhesion molecule 1 expression induced by TNF-α in the human microvascular endothelial cells 1 cell line. Compounds 3, 5, 6, 8,: and 12: significantly reduced intercellular adhesion molecule 1 expression in a concentration-dependent manner with IC50 values of 16.9, 34.4, 4.0, 3.2, and 7.7 µM, respectively. In addition, compound 12: showed notable inhibitory activity on the formation of cyclooxygenase-1- and 12-lipoxygenase-derived inflammatory mediators in an ex vivo cyclooxygenase-lipoxygenase assay. Eleven further constituents were isolated (14: -24: ), including the rare quercetin 3-O-(2-O-acetyl)-arabinofuranoside (18: ).

The genus Genista L.: A rich source of bioactive flavonoids.

The genus Genista L. (family Fabaceae, subfamily Papilionoideae), with its cosmopolitan distribution, has attracted the human interest since ancient times, as it is used in folk medicine and mainly in the Mediterranean area for the treatment of respiratory diseases, rheumatic disorders, diabetes and ulcer, while it is also well known for its yellow pigment. The chemical composition of the Genista species revealed the presence of more than 108 flavonoids. Isoflavones, belonging to the group of phytoestrogens, are important secondary metabolites of the genus. The extracts of the Genista species may act as important source of bioactive phytochemicals for the treatment of many human ailments, mainly inflammation and pain, estrogen related pathology, hyperglycaemia, cancer and microbial infections. Therefore, the present review summarizes and discusses the flavonoid derivatives from the genus Genista, together with their structural features and pharmacological properties, aiming to highlight the recent advances in current knowledge on Genista species as a source of bioactive flavonoids.

Cytotoxicity and Anti-cancer Activity of the Genus Achillea L.

BACKGROUND: The genus Achillea L. is rich in bioactive sesquiterpenes and flavonoids; most of the studied species exhibit several biological activities and are used as emmenagogue, wound healing and analgesic agents. Some species are also used in local folklore medicine. OBJECTIVE: Following a literature survey, we discuss the anti-cancer properties of Achillea species, taking into consideration ethnopharmacological data on their use in traditional medicine for the treatment of cancer. In addition, we screened extracts and isolated secondary metabolites from A. coarctata for cytotoxicity, upon information based on local traditional medicine. The plant was collected in Kozani (Northern Greece), where it is locally used for treating gastrointestinal disorders, including stomach cancer. METHODS: A selection of the relevant data was performed through a search in PubMed, Scopus, Google Scholar and Science Direct databases. In addition, extracts and isolated compounds from A. coarctata were tested for their in vitro activity against the human cancer cell lines MCF-7 and HeLa. CONCLUSION: The genus Achillea L. is a valuable source of bioactive secondary metabolites. The most significant outcome of the investigation of medicinal plants is the documentation and the assessment of the traditional information and its use and perspectives in the light of modern pharmacology.

Preparation, chemical characterization and determination of crocetin's pharmacokinetics after oral and intravenous administration of saffron (Crocus sativus L.) aqueous extract to C57/BL6J mice.

OBJECTIVES: To prepare a lyophilized saffron aqueous extract (SFE) and determine its chemical profile and serum and tissue pharmacokinetics after intravenous and oral administration to C57/Bl6J mice. METHODS: Lyophilized SFE was prepared, characterized using semi-preparative HPLC and NMR analysis, and stability studies at room temperature, and was quantified for crocin content with an HPLC-PDA method. After intravenous and oral administration of SFE (60 mg/kg, reconstituted with water for injection) to C57/Bl6J mice, crocetin (derived from in vivo crocin hydrolysis) serum and tissue levels (unconjugated and total) were measured with an HPLC-PDA method and subjected to compartmental and non-compartmental PK analysis. KEY FINDINGS: Saffron aqueous extract was rich in all-trans-crocin (27.8 ± 0.1% w/w) and stable for more than 15 months. One-compartment PK model described crocetin's (unconjugated) kinetics after intravenous administration of SFE, while a first-order kinetic parameter described the rate of crocetin biotransformation to crocetin metabolite (conjugated). Α οne-compartment PK model with first-order absorption described crocetin and crocetin's metabolite kinetics after SFE oral administration. Relative oral bioavailability was calculated at 1.17 for total crocetin. Tissue NCA PK analysis revealed extensive crocetin distribution to liver and kidneys. CONCLUSIONS: SFE is a stable lyophilized extract rich in all-trans-crocin. The PK study allowed the estimation of basic PK parameters and the bioavailability of SFE's main bioactive component, crocetin, after peros administration.