Phytochemical Content, Antioxidant and Cytotoxic Activities of Sedum spurium.

Sedum L. species are used for their hemostatic, antidiarrheal, antifungal, diuretic and wound healing properties, and there is growing interest in these species because of their usage in folk medicine. DPPH, SO, NO, and ABTS radical scavenging activities and protective effects against H(2)(02) induced cytotoxicity, as well as cytotoxic activities against the Hep-2 cell line of various extracts from Sedum spurium Bieb. were investigated. Besides, the total phenol, flavonoid, and flavonol contents of the extracts were determined to clarify their biological and phytochemical properties. Chromatographic studies on the most active extract led to the isolation of the major compound, identified as 2-methyl-erythritol by (1)H and (13)C NMR techniques. The EtOAc extract is found to be the most active extract in all tests. However, major compound of EtOAc extract did not possess tested activities. The EtOAC extract of S. spurium could be effective to improve antihemolytic defences of erythrocytes, and radical scavenging potential of the antioxidant mechanism. The extracts should be investigated in detail for their cytotoxic activities because of their possible pro-oxidant effects at high concentrations.

Cytotoxic compounds from endemic Arnebia purpurea.

Phytochemical studies of the roots and aerial parts of endemic Arnebia purpurea S. Erik & H. Sumbul resulted in the isolation and characterization of four naphthoquinones [isovalerylalkannin (1), α-methyl-n-butanoyl alkannin (2), acetylalkannin (3), and alkannin (4)], a triterpene derivative [3-O-acetyl-oleanolic acid (5)], a steroid [ß-sitosterol (6)], three flavonoid glycosides [isorhamnetin-3-O-rutinoside (7), kaempferol-3-O-rutinoside (8), kaempferol 3-O-(5"-acetyl) apiofuranoside 7-O-rhamnopyranoside (9)] and a phenolic acid [rosmarinic acid (10)]. 3-O-Acetyl-oleanolic acid, isorhamnetin-3-O-rutinoside, kaempferol-3-O-mrutinoside, and kaempferol 3-O-(5"-acetyl) apiofuranoside 7-O-rhamnopyranoside are reported from an Arnebia species for the first time. Cytotoxic activities on L929 murine fibrosarcoma cell line of the isolated compounds were investigated using MTT assay. Naphthoquinones (1-4) showed intermediate cytotoxic activity in comparison with the standard, doxorubicin.

Cytotoxic and antioxidative activities of Plantago lagopus L. and characterization of its bioactive compounds.

Bioactivity guided isolation and characterization of phytoconstituents from the aerial parts of Plantago lagopus L. were performed to give a new insight into the usage of Plantago species in traditional medicine. The extract showed strong radical scavenging effects against DPPH, nitric oxide (NO) and superoxide (SO) radicals comparable to that of known antioxidants 3-t-butyl-4-hydroxyanisole, ascorbic acid (vitamin C), and quercetin in addition to its cytotoxic activities against HEP-2 (human larynx epidermoid carcinoma) and RD (human rhabdomyosarcoma) cell lines based on MTT assay for growth inhibition. The gallic acid equivalent total phenolic content of the plant was found to be 79.94 mg/g dry extract. Phenylethanoid glycosides, verbascoside and calceorioside A were isolated from the most active fraction and both compounds showed strong radical scavenging activity against tested radicals and cytotoxicity against HEP-2, RD and MCF-7 (human breast adenocarcinoma) cell lines. In addition apoptotic cell death was observed in histological analysis. Taken together, these findings suggest that verbascoside and calceorioside A may be used in cancer prevention.

In vitro cytotoxic activity and structure activity relationships of iridoid glucosides derived from Veronica species.

This study was an investigation of the cytotoxic activity of iridoid glucosides, including aucubin, catalpol, 6-O-acetylcatalpol, veronicoside, catalposide, verproside, amphicoside, veratroylcatalposide, verminoside, aquaticosides B and C isolated from different Veronica species. The cytotoxic activity was determined against Hep-2 (human epidermoid carcinoma), RD (human rhabdomyosarcoma), L-20B (transgenic murine L-cells) cancer cell lines and Vero (African green monkey kidney cells) non-cancerous cell line using the MTT method. While verminoside, amphicoside and veronicoside were found to exhibit cytotoxic activity in the concentration range of 70-355 µM, acetylcatalpol, aquaticosides B and C, catalposide, veratroylcatalposide and verproside showed cytostatic activity. Apoptotic cell death was observed as the effect of verminoside in the histological analysis of the tested cell lines. In conclusion, iridoid glucosides are considered to show a biphasic effect on cancer cells that is both cytostatic and cytotoxic, depending on the chemical structure and the type of cancer cell.

Evaluation of antioxidative, protective effect against H2O2 induced cytotoxicity, and cytotoxic activities of three different Quercus species.

Quercus species are used as antidiarrheic, for the treatment of hemorrhoid, oral and anal mucosa inflammation. These tree species have been of interest to researchers because of their usage in folk medicine, consumption as food, beverage and especially usage of oak woods for construction in wine barrels. The DPPH, SO and NO radical scavenging activities, protective effect against H2O2 induced cytotoxicity as well as their cytotoxic activity against Hep-2 human larynx epidermoid carcinoma cell line of the MeOH and water extracts of the barks of Quercus cerris var. cerris, Quercusmacranthera subsp. syspirensis and Quercus aucheri were investigated for the first time. Total phenolic content of the extracts was also evaluated by Folin-Ciocalteu method. Results demonstrated that the extracts showed strong radical scavenging activity comparable to those of standard compounds. Extracts also showed good protective effect against H2O2 induced cytotoxicity on human erythrocytes comparing to ascorbic acid. On the other hand, while each extract showed dose dependent cytotoxic activity, MeOH extract of Q.macranthera subsp. syspirensis showed the strongest cytotoxicity against the tested cell line. Taken together, the results showed that Quercus species may be a promising alternative to synthetic substances as natural compound with high antioxidant and antiproliferative activities.

Iridoid content and biological activities of Veronica cuneifolia subsp. cuneifolia and V. cymbalaria.

CONTEXT: The genus Veronica L. (Plantaginaceae) is represented by 79 species, 26 of which are endemic in Turkey. Some Veronica species are used for the treatment of different inflammatory diseases and cancer in traditional medicine. In addition, chemotaxonomy of the genus is important for the reclassification of the family Plantaginaceae after different phylogenetic studies. OBJECTIVE: Veronica cuneifolia subsp. cuneifolia D. Don and V. cymbalaria Bodard were studied from the view point of iridoid glucosides which are known as chemotaxonomical markers for this genus. Radical scavenging and cytotoxic activities of the extracts were also determined in this study. MATERIAL AND METHODS: Major compounds, isolated from iridoid fractions of V. cuneifolia subsp. cuneifolia were used as the standard compounds for HPLC after determination of their structures, and investigated for their presence in iridoid fractions of V. cymbalaria. Additionally, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and SO radical scavenging and cytotoxic activities against three cancer and a noncancerous cell lines of both extract were also tested using the MTT method. RESULTS: While aucubin, catalpol, verproside, amphicoside, verminoside, and veronicoside were obtained from V. cuneifolia subsp. cuneifolia, two more iridoid glucosides, 6-O-veratroylcatalposide and 6-O-isovanilloylcatalpol, were isolated from V. cymbalaria. Comparing both species, V. cuneifolia subsp. cuneifolia showed stronger radical scavenging and cytotoxic activities than V. cymbalaria. DISCUSSION: Our results demonstrated that the iridoid contents of both species were very close to each other confirming to the chemotaxonomic studies on Veronica species and their different bioactivity range make the plants interesting from the view point of natural drug discovery research.

Chlorinated iridoid glucosides from Veronica longifolia and their antioxidant activity.

From Veronica longifolia were isolated three chlorinated iridoid glucosides, namely, asystasioside E (6) and its 6-O-esters 6a and 6b, named longifoliosides A and B, respectively. The structures of 6a and 6b were proved by analysis of their spectroscopic data and by conversion to the catalpol ester verproside (5a) or to catalpol (5), respectively. The configuration of the previously known vanilloyl analogue, urphoside B, was shown to be the 6ß-epimer (6c) of the structure originally reported. Longifoliosides A (6a) and B (6b) were found to exhibit radical-scavenging activity against nitric oxide, superoxide, and 2,2-diphenyl-1-picrylhydrazyl radicals.

Effects of two Prunella species on lymphocyte proliferation and nitric oxide production.

Water extracts of Prunella vulgaris and P. laciniata have been investigated for their immunomodulatory and antiinflammatory activities concerning their effect on the mitogenic response of murine splenocytes and nitric oxide production by murine peritoneal macrophages in vitro. It was found that both extracts stimulated the proliferation of T-lymphocytes and suppressed NO production in lipopolysaccharide-stimulated macrophages dose dependently without any cytotoxicity.

Stimulation of lymphocyte proliferation and inhibition of nitric oxide production by aqueous Urtica dioica extract.

The immunomodulatory and antiinflammatory activities of aqueous Urtica dioica extract were investigated for their effect on the mitogenic response of murine splenocytes and nitric oxide production by murine peritoneal macrophages in vitro. It was found that this extract stimulated the proliferation of T-lymphocytes and suppressed NO production in lipopolysaccharide-stimulated macrophages without affecting cell viability.

Bioassay-guided isolation of iridoid glucosides with antinociceptive and anti-inflammatory activities from Veronica anagallis-aquatica L.

Extracts obtained from the herbs of various Veronica species are used as folk remedy worldwide for the treatment of various inflammatory ailments including rheumatism. In vivo anti-inflammatory and antinociceptive activities of Veronica anagallis-aquatica L. aerial parts were investigated. Methanolic extract of the plant was shown to possess significant inhibitory activity against carrageenan-induced hind paw edema model and of p-benzoquinone-induced writhings in mice. Through bioassay-guided fractionation and isolation procedures eight compounds, aquaticoside A (1), aquaticoside B (2), aquaticoside C (3), veronicoside (4), catalposide (5), verproside (6), verminoside (7) and martynoside (8) were isolated and their structures were elucidated by spectral techniques. Catapol derivative iridoid glucosides, verproside (6) and catalposide (5), were found to possess potent antinociceptive and anti-inflammatory activities, per os without inducing any apparent acute toxicity as well as gastric damage. Results of the present study supported the utilization of the plant in Turkish folk medicine.

Acylated flavonoids and phenol glycosides from Veronica thymoides subsp. pseudocinerea.

A new acylated flavone glucoside, 3'-hydroxyscutellarein 7-O-(6''-O-protocatechuoyl)-beta-glucopyranoside (1), and a new phenol glucoside, 3,5-dihydroxyphenethyl alcohol 3-O-beta-glucopyranoside (6) were isolated from Veronica thymoides subsp. pseudocinerea together with seven known flavone, phenol and lignan glycosides; 3'-hydroxyscutellarein 7-O-(6''-O-trans-feruloyl)-beta-glucopyranoside (2), 3'-hydroxy, 6-O-methylscutellarein 7-O-beta-glucopyranoside (3), luteolin 7-O-beta-glucopyranoside (4), isoscutellarein 7-O-(6'''-O-acetyl)-beta-allopyranosyl (1''' --> 2'')-beta-glucopyranoside (5), 3,4-dihydroxyphenethyl alcohol 8-O-beta-glucopyranoside (7), benzyl alcohol 7-O-beta-xylopyranosyl (1" --> 2')-beta-glucopyranoside (8), and (+)-syringaresinol 4'-O-beta-glucopyranoside (9). Compounds 2, 3 and 7-9 were reported for the first time in the genus Veronica. The structures of the isolates were determined by means of spectroscopic (UV, IR, 1D and 2D NMR, HR ESI-MS) methods. Isolated compounds (1-7) exhibited potent radical scavenging activity against the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical.

Acylated iridoid glucosides from Veronica anagallis-aquatica.

Three new (1-3) and four known iridoid glucosides (4-7) as well as a known phenylethanoid glycoside (8) were isolated from the aerial parts of Veronica anagallis-aquatica and their structures were determined as 6'-O-benzoyl-8-epiloganic acid named aquaticoside A (1), 6'-O-p-hydroxybenzoyl-8-epiloganic acid named aquaticoside B (2), 6'-O-benzoyl-gardoside named aquaticoside C (3), veronicoside (4), catalposide (5), verproside (6), verminoside (7) and martynoside (8) on the basis of 1D and 2D NMR spectral analysis.

Iridoid glucosides from Veronica pectinata var. glandulosa.

A new highly oxygenated iridoid glucoside, urphoside B (1) was isolated from the Veronica pectinata var. glandulosa together with seven known iridoid glucosides, aucubin, catalpol, veronicoside, catalposide, verproside, amphicoside and 6-O-veratroyl catalpol. The planar as well as the stereo structures of the isolated compounds were determined by means of extensive 1D- and 2D-NMR spectroscopy and confirmed by HR-Mass.

Phenylethanoid and iridoid glycosides from Veronica persica.

A new phenylethanoid glycoside, persicoside (1) and three known phenylethanoid glycosides, acteoside (2), isoacteoside (3) and lavandulifolioside (4) were isolated from the aerial parts of Veronica persica. On the basis of spectral analyses, the structure of the new compound was elucidated to be 3,4-dihydroxy-beta-phenylethoxy-O-[beta-D-glucopyranosyl-(1-->2)]-[beta-D-glucopyranosyl-(1-->3)]-4-O-caffeoyl-beta-D-glucopyranoside. Persicoside (1) and acteoside (2) exhibited radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Beside phenylethanoid glycosides, a hexitol, dulcitol (5) and seven known iridoid glucosides, aucubin (6), veronicoside (7), amphicoside (8), 6-O-veratroyl-catalpol (9), catalposide (10), verproside (11) and verminoside (12) were isolated.

Anti-inflammatory and cytotoxic activities of five Veronica species.

Biological activities of five Veronica species (Scrophulariaceae), V. cymbalaria, V. hederifolia, V. pectinata var. glandulosa, V. persica and V. polita were studied for their anti-inflammatory and cytotoxic activities. Their methanol extracts showed both the inhibitory activity of nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated macrophages and cytotoxic activity against KB epidermoid carcinoma and B16 melanoma. When the methanol extracts were fractionated between water and chloroform, water fractions significantly inhibited NO production without any cytotoxicity, while chloroform fractions showed cytotoxicity dose-dependently. When the radical scavenging activity was determined using 2,2-diphenyl-1-picryl-hydrazyl (DPPH), water fractions of the five Veronica species scavenged free radicals effectively, suggesting that the inhibitory effect of this species on NO production was due to their radical scavenging activity. On the other hand, chloroform fractions of Veronica species except for V. cymbalaria showed similar cytotoxic activity against KB and B16 melanoma cells.