A new eudesmane type sesquiterpene from Inula viscosa

Sesquiterpene lactones from Sonchus palustris L. (Asteraceae, Cichorieae)

Seven previously undescribed sesquiterpene lactones, three known sesquiterpene lactones (ixerin D, 15-p-hydroxyphenylacetyllactucin, and 15-p-hydroxyphenylacetyllactucin-8-sulfate), and two known quinic acid derivatives (3-O-feruloylquinic acid and 3,5-di-O-caffeoylquinic acid) were isolated from Sonchus palustris L. roots. Four formerly undescribed compounds were elucidated to be 3β,14-dihydroxycostunolide-3-O-β-D-glucopyranosyl-(2-O-p-hydroxyphenylacetyl)-14-O-p-hydroxyphenylacetate, 15-p-methoxyphenylacetyllactucin, 15-p-methoxyphenylacetyllactucin-8-sulfate, and 8-p-hydroxyphenylacetyllactucin-15-sulfate. Additionally, three undescribed conjugates of lactucin and a eudesmanolide type sesquiterpenic acid, sonchpalustrin, 4″-O-methylsonchpalustrin, and isosonchpalustrin, were characterized. The structures of the newly discovered natural products were elucidated using 1D and 2D NMR spectroscopy and UHPLC-HRMS. 15-p-Hydroxyphenylacetyllactucin and 15-p-methoxyphenylacetyllactucin showed significant in vitro cytotoxicity against CEM and BJ cells with IC₅₀ values ranging from 3.9 to 9.8 μM. Compounds 3 and 4 showed also strong anti-inflammatory activity in vitro.

Isolation of insecticidal components in Inula salsoloides Ostenf. and characterisation of their activities

The ethanol extract from Inula salsoloides (Turcz.) Ostenf was found to cause high mortality against Plutella xylostella L. (Lepidoptera: Plutellidae). The active components were isolated and identified. Two compounds were obtained and identified to be inulasalsolin and taraxasterol. Both compounds showed anti-feedant effects against third instar larvae of P. xylostella with AFC₅₀ of 0.030 and 0.053 mg/mL and insecticidal activities with LC₅₀ of 0.19 and 0.49 mg/mL, respectively. The two compounds also exhibited high toxicity to cabbage aphid, Brevicoryne brassicae L. (Hemiptera: Aphididae) with LC₅₀ values of 0.021 and 0.098 mg/mL. This is the first report on the study of insecticidal components of I. salsoloides and their activity against insects.

Inula Viscosa Extracts Induces Telomere Shortening and Apoptosis in Cancer Cells and Overcome Drug Resistance

Telomerase is activated in human papillomavirus (HPV) positive cervical cancer and targeting telomeres offers a novel anticancer therapeutic strategy. In this study, the telomere targeting properties, the cytotoxic as well as the pro-apoptotic effects of hexane (IV-HE) and dichloromethane (IV-DF) fractions from Inula viscosa L. extracts were investigated on human cervical HeLa and SiHa cancer cells. Our data demonstrate that IV-HE and IV-DF extracts were able to inhibit cell growth in HeLa and SiHa cells in a dose-dependent manner and studied resistant cell lines exhibited a resistance factor less than 2 when treated with the extracts. IV-HE and IV-DF extracts were able to inhibit telomerase activity and to induce telomere shortening as shown by telomeric repeat amplification protocol and TTAGGG telomere length assay, respectively. The sensitivity of fibroblasts to the extracts was increased when telomerase was expressed. Finally, IV-HE and IV-DF were able to induce apoptosis as evidenced by an increase in annexin-V labeling and caspase-3 activity. This study provides the first evidence that the IV-HE and IV-DF extracts from Inula viscosa L. target telomeres induce apoptosis and overcome drug resistance in tumor cells. Future studies will focus on the identification of the molecules involved in the anticancer activity.

Inula sesquiterpenoids: structural diversity, cytotoxicity and anti-tumor activity

INTRODUCTION

The plants of the genus Inula (Asteraceae) are widely distributed throughout Europe, Africa and Asia, and many of these plants have long been used in folk medicine. This genus is a rich source of sesquiterpenoids, which exhibit a wide range of biological activities. Recently, a series of bioactive sesquiterpenoid dimers, with unusual carbon skeletons, have been reported and these have gathered considerable interest.

AREAS COVERED

This article systematically reviews sesquiterpenoids isolated from the genus Inula that have appeared in literature up to August 2013, critically highlighting their anti-tumoral activities and relevant mechanistic insights. The authors also discuss the initial structure-activity relationships for the cytotoxic and anti-tumoral activities of the Inula sesquiterpenoids. Finally, the authors discuss the challenges and potential applications of these sesquiterpenoids in the future.

EXPERT OPINION

Cytotoxic and anti-tumor activities of Inula sesquiterpenoids have been extensively studied since the 1970s. One promising compound, Japonicone A, a dimeric sesquiterpene lactone from traditional herb Inula japonica, has displayed potent in vitro and in vivo anti-tumor activity against Burkitt's lymphoma. Additionally, acetylbritannilactone is thought to be capable of suppressing the abnormal vascular smooth muscle cell proliferation, with the induction of apoptosis in vivo and in vitro. In this regard, it may be worthwhile further investigating acetylbritannilactone in patients with vascular restenosis. Furthermore, given the anti-inflammatory property of britanin, clinical studies on chronic bronchitis and asthma, using the ethanol extract of I. japonica, are currently underway in South Korea. However, despite demonstrating good therapeutic effects, additional pharmacological and toxicological studies are still needed.

Dittrichia Viscosa L. Greuter: Phytochemistry and Biological Activity

Dittrichia viscosa is a plant widely distributed in the Mediterranean region. This species and its components present a broad range of biological activities (for example, anti-inflammatory, antifungal, antiulcer, antiviral, antiparasitic), which are reviewed. Extracts of the species are particularly rich in terpenoids, in particular eudesmane acids, notably ilicic acid (45) and α-costic acid (44). Flavonoids are also abundant, especially during flowering.

Antiviral activity of some Tunisian medicinal plants against Herpes simplex virus type 1

Fifteen species of Tunisian traditional medicinal plants, belonging to 10 families, were selected for this study. They were Inula viscosa (L.) Ait and Reichardia tingitana (L.) Roth ssp. discolor (Pom.) Batt. (Asteraceae), Mesembryanthemum cristallinum L. and M. nodiflorum L. (Aizoaceae), Arthrocnemum indicum (Willd.) Moq., Atriplex inflata Muell., A. parvifolia Lowe var. ifiniensis (Caball) Maire, and Salicornia fruticosa L. (Chenopodiaceae), Cistus monspeliensis L. (Cistaceae), Juniperus phoenicea L. (Cupressaceae), Erica multiflora L. (Ericaceae), Frankenia pulverulenta L. (Frankeniaceae), Hypericum crispum L. (Hypericaceae), Plantago coronopus L. ssp. eu-coronopus Pilger var. vulgaris G.G. (Plantaginaceae) and Zygophyllum album L. (Zygophyllaceae). Fifty extracts prepared from those plants were screened in order to assay their antiviral activity against Herpes simplex virus type 1 (HSV-1), using neutral red incorporation. Extracts from eight plants among these 15 showed some degree of antiviral activity, while the methanolic extract of E. multiflora was highly active with EC(50) of 132.6 microg mL(-1). These results corroborate that medicinal plants from Tunisia can be a rich source of potential antiviral compounds.

Evaluation of the wound healing effect of some Jordanian traditional medicinal plants formulated in Pluronic F127 using mice (Mus musculus)

The wound healing effect of the aqueous extracts of Inula viscosa, Ajuga chia, Rubia taenifolia and Parieteria diffusa, and the oil of Laurus nobilis, dispersed in water, were examined. The 10% (w/w) Pluronic F127 (PF127) was added to the applied preparations, in order to modify the aqueous extracts viscosity, and to stabilize the oil dispersion. A full thickness wound was made in the dorsal area of the mice. The wounds were treated with the different preparations with 12h intervals for four times in two successive days. For 16 days, the wounds were visually observed, photographically documented and the wound area was measured. After day 16, the animals were sacrificed and the histology of the wound area was examined. The best wound healing activity was observed with the extract of Inula viscosa, followed by Parieteria diffusa, Laurus nobilis, Ajuga chia and the least active extract was that of Rubia taenifolia.

Eudesmane sesquiterpenoids from the Asteraceae family

This review covers the structures and biological activities of eudesmane-type sesquiterpenoids from the plants of the Asteraceae family. Biosynthetic studies or chemical syntheses leading to the revision of structures or stereochemistries have also been included, and 593 references are cited.