Chemical fingerprinting of Equisetum arvense L. using HPTLC densitometry and HPLC.

Equisetum arvense L. is a herbaceous medicinal plant, commonly known as horsetail, whose extracts have been reported to possess diuretic and haemostatic properties. The aim of this study was to evaluate the use of fingerprint chromatographic methods on commercially available raw materials or preparations of E. arvense L. in order to ascertain their quality and identify possible adulterants using HPLC and HPTLC densitometry. Two chromatographic methods were used to determine the chemical fingerprints of E. arvense and other allied species. The first was based on HPTLC identification followed by densitometric measurement at 350 nm. The second was based on HPLC separation. The ease of sample preparation and the possibility of simultaneous analysis of several samples in a short time make HPTLC a method of choice for the comprehensive quality evaluation of herbal products.

Plants and parts of plants used in food supplements: an approach to their safety assessments.

In Italy most herbal products are sold as food supplements and are subject only to food law. A list of about 1200 plants authorised for use in food supplements has been compiled by the Italian Ministry of Health. In order to review and possibly improve the Ministry's list an ad hoc working group of Istituto Superiore di Sanità was requested to provide a technical and scientific opinion on plant safety. The listed plants were evaluated on the basis of their use in food, therapeutic activity, human toxicity and in no-alimentary fields. Toxicity was also assessed and plant limitations to use in food supplements were defined.

Polyketides from Eleutherine bulbosa.

Four new polyketides, (R)-4-hydroxyeleutherin, eleuthone, eleutherinol-8-O-ß-D-glucoside and isoeleuthoside C (dihydroisoeleutherin-5-O-ß-D-gentiobioside) were isolated from the bulbs of Eleutherine bulbosa, to join eleutherin, isoeleutherin, eleutherinol, eleutherol, eleuthoside B (eleutherol-4-O-ß-D-gentiobioside), eleuthoside C (dihydroeleutherin-5-O-ß-D-gentiobioside), hongconin (4-oxodihydroisoeleutherin) and elecanacin, which have already been isolated from the same plant. The structures of the new polyketides, based on oxydated cyclic systems, have been elucidated by chemical and spectroscopic methods.

The plant alkaloid voacamine induces apoptosis-independent autophagic cell death on both sensitive and multidrug resistant human osteosarcoma cells.

In our previous studies, the bisindolic alkaloid voacamine (VOA), isolated from the plant Peschiera fuchsiaefolia, proved to exert a chemosensitizing effect on cultured multidrug resistant (MDR) osteosarcoma cells exposed to doxorubicin (DOX). In particular, VOA was capable of inhibiting P-glycoprotein action in a competitive way, thus explaining the enhancement of the cytotoxic effect induced by DOX on MDR cells. Afterwards, preliminary observations suggested that such an enhancement did not involve the apoptotic process but was due instead to the induction of autophagic cell death. The results of the present investigation demonstrate that the plant alkaloid VOA is an autophagy inducer able to exert apoptosis-independent cytotoxic effect on both wild-type and MDR tumor cells. In fact, under treatment condition causing about 50 percent of cell death, no evidence of apoptosis could be revealed by microscopical observations, Annexin V-FITC labeling and analysis of PARP cleavage, whereas the same cells underwent apoptosis when treated with apoptosis inducers, such as doxorubicin and staurosporine. Conversely, VOA-induced autophagy was clearly evidentiated by electron microscopy observations, monodansylcadaverine staining, LC3 expression, and conversion. These results were confirmed by the analysis of the modulating effects of the pretreatment with autophagy inhibitors prior to VOA administration. In addition, transfection of osteosarcoma cells with siRNA against ATG genes reduced VOA cytotoxicity. In conclusion, considering the very debated dual role of autophagy in cancer cells (protective or lethal, pro- or anti- apoptotic) our findings seem to demonstrate, at least in vitro, that a natural product able to induce autophagy can be effective against drug resistant tumors, either used alone or in association with conventional chemotherapeutics.

Chemical fingerprinting of Lawsonia inermis L. using HPLC, HPTLC and densitometry.

INTRODUCTION: Lawsonia inermis L. is a natural red colouring agent, commonly named "Henna", which is used to dye skin and hair. The aim of this study was to evaluate the quality of L. inermis that is commercially available as a raw plant material or preparation in order to guarantee good quality products. OBJECTIVE: To develop a simple protocol for the qualification of different samples labelled as L. inermis by using the HPTLC densitometry method and to identify possible adulterations with other plants. METHODOLOGY: Samples of leaves of L. inermis were extracted with methanol. Two chromatographic methods were developed to determine the chemical fingerprinting of L. inermis. The first was based on HPTLC identification followed by densitometric measurements at 337 nm. The second was based on RP-HPLC separation with gradient elution and photodiode array detection at 337 nm. Samples of Cassia obovata Collad., and Indigofera tinctoria L., were treated in the same way. RESULTS: The simplicity of the sample preparation, and the possibility of analysing several samples of herbal products simultaneously in a short time, make HPTLC the method of choice. The HPTLC method was feasible for the comprehensive quality evaluation of herbal products. From the comparison of their "fingerprint", it was possible to detect substitution of plants that are different from those declared on the label. CONCLUSION: The HPTLC may be used as a rapid method by which to control the quality of raw plant materials and formulations based on the title plant.

Oligomeric secoiridoid glucosides from Jasminum abyssinicum.

From the root bark of Jasminum abyssinicum (Oleaceae) collected in Congo was isolated tree oligomeric secoiridoid glucosides named craigosides A-C. The three compounds are esters of a cyclopentanoid monoterpene with an iridane skeleton, esterified with three, two and two, respectively, units of oleoside 11-methyl ester. The structures were elucidated by spectroscopic methods and chemical correlations.

[Herbal drugs: from traditional use to regulation]. / Le droghe vegetali: dall'uso tradizionale alla normativa.

Herbal preparations have been used for centuries as the main therapeutic means. In Italy there is an ancient tradition of using herbal remedies, which became extremely important from the 16th to the 18th century. Nowadays multinational companies invest great resources on herbal drugs and preparations. This article focuses on herbal medicines, herbal products, and food supplements. Moreover the European legislation on traditional medicinal plants and food supplements is analysed and discussed.

Prenylated isoflavonoids from Millettia pervilleana.

From the root bark of Millettia pervilleana, which had shown significant cytotoxic activity, a 3-phenylcoumarin, named pervilleanine, two new pterocarpans, pervilline and pervillinine, and one known, emoroidocarpan, were isolated in addition to rotenone and 3alpha-hydroxyrotenone. The anticancer activity of two previously isolated isoflavanones, pervilleanone and 3'-O-demethylpervilleanone is reported.