Isolation and cytotoxic activities of undescribed iridoid and xanthone glycosides from Centaurium erythraea Rafn. (Gentianaceae).

Centaurium erythraea Rafn. (Gentianaceae) is used in internal traditional therapy as an anthelmintic, hypotensive, antipyretic, and antidiabetic. It is used externally for the treatment of wounds. Ursolic acid, maslinic acid, secologanin, secologanin dimethyl acetal, centauroside A, erythraeaxanthone I, erythraeaxanthone II, and demethyleustomin were isolated from aerial parts of Centaurium erythraea and were identified using spectroscopic methods, including NMR and mass spectrometry. The cytotoxic potency of undescribed compounds was evaluated by the XTT assay against human breast cancer MCF-7, MDA-MB-453 and mouse fibroblast 3T3-L1 cell lines. Erythraeaxanthone II was found to have the most potent cytotoxic activity.

Phytochemical properties, biological activities and medicinal use of Centaurium erythraea Rafn.

ETHNOPHARMACOLOGICAL RELEVANCE: Centaurium erythraea is an important medicinal plant in many countries, e.g. Morocco, Algeria, Italy, Spain, Portugal, and countries of Balkan Peninsula. It is used in folk medicine to treat various illnesses. It is also used as an antiapoplectic, anticoagulant, anticholagogue, antipneumonic, hematocathartic, and as a hypotensive agent. AIM OF THE REVIEW: In this review, previous reports on the taxonomy, botanical description, geographic distribution, ethnomedicinal applications, phytochemistry, pharmacological properties, and toxicity of Centaurium erythraea were critically summarized. MATERIALS AND METHODS: Scientific search engines including PubMed, ScienceDirect, SpringerLink, Web of Science, Scopus, Wiley Online, SciFinder, and Google Scholar were consulted to collect data on C. erythraea. The data presented in this work summarized the main reports on C. erythraea phytochemical compounds, ethnomedicinal uses, and pharmacological activities. RESULTS: C. erythraea is used in traditional medicine to treat various diseases such as diabetes, fever, rhinitis, stomach ailments, urinary tract infections, dyspeptic complaints, loss of appetite, and hemorrhoids, and as diuretic. The essential oils and extracts of C. erythraea exhibited numerous biological properties such as antibacterial, antioxidant, antifungal, antileishmanial, anticancer, antidiabetic, anti-inflammatory, insecticidal, diuretic, gastroprotective, hepatoprotective, dermatoprotective, neuroprotective, and inhibitory agent for larval development. Phytochemical characterization of C. erythraea revealed the presence of several classes of secondary metabolites such as xanthonoids, terpenoids, flavonoids, phenolic acids, and fatty acids. CONCLUSIONS: Ethnomedicinal studies demonstrated the use of C. erythraea for the treatment of various disorders. Pharmacological reports showed that C. erythraea especially its aerial parts and roots exhibited potent, and beneficial activities. These findings confirmed the link between the traditional medicinal use and the results of the scientific biological experiments. Considering these results, further investigation using diverse in vivo pharmacological assays are strongly recommended to validate the results of its traditional use. Toxicological tests and pharmacokinetic studies are also required to validate the safety and efficacy of C. erythraea and its bioactive contents.

Centaurium erythraea extract improves survival and functionality of pancreatic beta-cells in diabetes through multiple routes of action.

ETHNOPHARMACOLOGICAL RELEVANCE: Centaurium erythraea Rafn (CE) is used as a traditional medicinal plant in Serbia to treat different ailments due to its antidiabetic, antipyretic, antiflatulent and detoxification effects. AIM OF THE STUDY: Elucidation of the mechanisms that underlie the antioxidant and pro-survival effects of the CE extract (CEE) in beta-cells and pancreatic islets from streptozotocin (STZ)-treated diabetic rats. MATERIAL AND METHODS: Diabetes was induced in rats by multiple applications of low doses of STZ (40 mg/kg intraperitoneally (i.p.), for five consecutive days). CEE (100 mg/kg) was administered orally, in the pre-treated group for two weeks before diabetes induction, during the treatments with STZ and for four weeks after diabetes onset, and in the post-treatment group for four weeks after diabetes induction. The impact of CEE on diabetic islets was estimated by histological and immunohistochemical examination of the pancreas. Molecular mechanisms of the effects of CEE were also analyzed in insulinoma Rin-5F cells treated with STZ (12 mM) and CEE (0.25 mg/mL). Oxidative stress was evaluated by assessing the levels of DNA damage, lipid peroxidation, protein S-glutathionylation and enzymatic activities and expression of CAT, MnSOD, CuZnSOD, GPx and GR in beta-cells. The presence and activities of the redox-sensitive and islet-enriched regulatory proteins were also analyzed. RESULTS: Treatment with CEE ameliorated the insulin level and glycemic control in STZ-induced diabetic rats by improving the structural and functional properties of pancreatic islets through multiple routes of action. The disturbance of islet morphology and islet cell contents in diabetes was reduced by the CEE treatment and was associated with a protective effect of CEE on the levels of insulin, GLUT-2 and p-Akt in diabetic islets. The antioxidant effect of CEE on STZ-treated beta-cells was displayed as reduced DNA damage, lipid peroxidation, protein S-glutathionylation and alleviation of STZ-induced disruption in MnSOD, CuZnSOD and CAT enzyme activities. The oxidative stress-induced disturbance of the transcriptional regulation of CAT, MnSOD, CuZnSOD, GPx and GR enzymes in beta-cells was improved after the CEE treatment, and was observed as readjustment of the presence and activities of redox-sensitive NFκB-p65, FOXO3A, Sp1 and Nrf-2 transcription factors. The observed CEE-mediated induction of proliferative and pro-survival pathways and insulin expression/secretion after STZ-induced oxidative stress in beta-cells could be partially attributed to a fine-tuned modulation of the activities of pro-survival Akt, ERK and p38 kinases and islet-enriched Pdx-1 and MafA regulatory factors. CONCLUSIONS: The results of this study provide evidence that CEE improves the structural and functional properties of pancreatic beta-cells by correcting the endogenous antioxidant regulatory mechanisms and by promoting proliferative and pro-survival pathways in beta-cells.

Centaurium erythraea methanol extract protects red blood cells from oxidative damage in streptozotocin-induced diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Centaurium erythraea Rafn (CE) is a traditional medicinal herb in Serbia with antidiabetic, digestive, antipyretic and antiflatulent effects AIM OF THE STUDY: To investigate the potential protective effects of the methanol extract of the aerial parts of CE against glyco-oxidative stress in red blood cells (RBCs) in rats with experimentally induced diabetes. MATERIAL AND METHODS: Diabetes was induced in Wistar rats by intraperitoneal (i.p.) injection of multiple low-dose streptozotocin (STZ) (40mg/kg, for five consecutive days), with the 1st day after the last STZ injection taken as the day of diabetes onset. The methanol extract of CE (100mg/kg) was administered orally and daily, two weeks before the first STZ injection, during the 5-day treatment with STZ, and for four weeks after the STZ injections (pre-treated group) or for four weeks after diabetes onset (post-treated group). The effect of CE extract administration on the redox status of RBCs was evaluated by assessing lipid peroxidation, the ratio of reduced/oxidized glutathione (GSH/GSSG), the level of S-glutathionylated proteins (GSSP) and the enzymatic activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) in RBCs four weeks after diabetes onset. The major biochemical parameters of diabetes, protein glycation/glycosylation of erythrocytes and parameters which correlate with their aggregation and deformability were also evaluated. RESULTS: Daily application of CE extract to STZ-induced diabetic rats provided important antidiabetic effects, observed in both pre-treated and post-treated groups of diabetic rats as elevated serum insulin concentration, reduction of blood glucose and glycated hemoglobin concentrations and an improved lipid profile. Antioxidant effects of CE extract were detected in RBCs of diabetic rats and observed as decreased lipid peroxidation and ameliorated oxidative damage as a result of increased SOD, CAT and GR activities, an improved GSH/GSSG ratio and reduced GSSP levels. Moreover, the CE extract protected RBC proteins from hyperglycemia-induced damage by reducing non-enzymatic glycation and enzymatic glycosylation processes. CE extract was more effective when applied before diabetes induction (pre-treated group). CONCLUSIONS: The results of this study show that the Centaurium erythraea methanol extract protects RBCs in diabetic animals from oxidative damage. They provide additional support for the application of this traditionally used plant in diabetes management.