Echinacea purpurea against neuropathic pain: Alkamides versus polyphenols efficacy

Chemotherapy-induced neuropathy represents the main dose-limiting toxicity of several anticancer drugs, such as oxaliplatin, leading to chronic pain and an impairment of the quality of life. Echinacea purpurea n-hexane extract (EP₄ -R_E ; rich in alkamides) and butanolic extract (EP₄ -R_BU ; rich in polyphenols) have been characterized and tested in an in vivo model of oxaliplatin-induced neuropathic pain, addressing the endocannabinoid system with alkamides and counteracting the redox imbalance with polyphenols. Thermal hypersensitivity was evaluated by the Cold Plate test. EP₄ -R_E showed a dose-dependent anti-hyperalgesic profile. The extract was more effective than its main constituent, dodeca-2 E,4 E,8Z,10 E/Z-tetraenoic acid isobutylamide (18 mg kg^-1 , twofold to equimolar EP₄ -R_E 30 mg kg^-1 ), suggesting a synergy with other extract constituents. Administration of cannabinoid type 2 (CB2) receptor-selective antagonist completely blocked the anti-allodynic effect of EP₄ -R_E , differently from the antagonism of CB1 receptors. EP₄ -R_BU (30 mg kg^-1 ) exhibited anti-neuropathic properties too. The effect was mainly exerted by chicoric acid, which administered alone (123 μg kg^-1 , equimolar to EP₄ -R_BU 30 mg kg^-1 ) completely reverted oxaliplatin-induced allodynia. A synergy between different polyphenols in the extract had not been highlighted. Echinacea extracts have therapeutic potential in the treatment of neuropathic pain, through both alkamides CB2-selective activity and polyphenols protective properties.

The influence of Echinacea purpurea leaf microbiota on chicoric acid level

The controversial anti-proliferative effects of Echinacea purpurea (L.) Moench (Asteraceae) might be related to different plant metabolites contained in plant samples, extracts and products. The influence of bacterial endophytes on the synthesis of bioactive compounds in the medicinal plants has been previously demonstrated but there are only few studies addressing anticancer effects and mechanisms of E. purpurea extracts following endophytic colonization. The present study aimed to test and compare the lactate dehydrogenase (LDH) inhibition potential of n-hexane and methanol extracts from in vitro endophyte non-inoculated and inoculated E. purpurea plants. An in vitro model was previously set up to perform the infection of axenic E. purpurea plants with bacterial endophytic strains isolated from E. purpurea aerial part. Only methanol extracts showed LDH5 inhibition, in particular the richest in chicoric acid and most strongly inhibiting extract was obtained from inoculated stem and leaves of E. purpurea (IC₅₀ = 0.9 mg/ml). Chicoric acid showed an IC₅₀ value (66.7 µM) in enzymatic assays better than that of the reference compound galloflavin. Modeling studies were carried out to suggest the putative interaction mode of chicoric acid in the enzyme active site. This in vitro model on plant-bacterial interaction may lead to obtain extracts from plants enriched in bioactive compounds and it is a new approach for the discovery of novel anticancer compounds.

Reproductive and developmental toxicity study of caffeic acid in mice

Caffeic acid is an antioxidant commonly used to promote hematopoiesis and hemostasis. However, little is known about its systemic safety profile in reproduction and development. Here, we focused on the reproductive and developmental toxicity of caffeic acid in F0 female mice and F1 offspring. In the three-segment study, the F0 female mice were continuously exposed to 0, 0.15, 5 or 150 mg/kg/day of caffeic acid by gavage. We found that 5 mg/kg/day and 150 mg/kg/day of caffeic acid affected implantation of embryos when administered before gestation day 6. In addition, 150 mg/kg/day of caffeic acid affected fetal weight gain. No maternal toxicity, fetal teratogenesis or post-natal effects on pup development were observed. The no-observed-adverse-effect-level was 0.15 mg/kg/day for pregnant mice under the conditions of this study.

Identification of antioxidant phenolic compounds in feverfew (Tanacetum parthenium) by HPLC-ESI-MS/MS and NMR

Antioxidant polyphenolic acids in the medicinal herb feverfew (Tanacetum parthenium) were isolated through in vitro bioassay-orientated antioxidant tests in response to 1,1-diphenyl-2-picrylhydrazyl (DPPH*) free radical scavenging and Fe(2+)-chelating activities. Purification of the active compounds and their structural elucidation involved a variety of techniques including open-column chromatography, HPLC, GC-MS, LC-MS and NMR. Major compounds with potent DPPH* scavenging activities were characterised as 3,5-, 4,5- and 3,4-di-O-caffeoylquinic acids (DCQAs). This is the first report of DCQAs found in feverfew.

Current literature in mass spectrometry

In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of mass spectrometry. Each bibliography is divided into 11 sections: 1 Books, Reviews & Symposia; 2 Instrumental Techniques & Methods; 3 Gas Phase Ion Chemistry; 4 Biology/Biochemistry: Amino Acids, Peptides & Proteins; Carbohydrates; Lipids; Nucleic Acids; 5 Pharmacology/Toxicology; 6 Natural Products; 7 Analysis of Organic Compounds; 8 Analysis of Inorganics/Organometallics; 9 Surface Analysis; 10 Environmental Analysis; 11 Elemental Analysis. Within each section, articles are listed in alphabetical order with respect to author (4 Weeks journals - Search completed at 12th. Jan. 2005).