PRELIMINARY RESEARCH REGARDING THE THERAPEUTIC USES OF URTICA DIOICA L. NOTE I. THE POLYPHENOLS EVALUATION
The use of stinging nettle leaves for the treatment of diabetes mellitus without a scientific evaluation, persuaded us to study them, in order to obtain pharmacological active extracts. According to scientific data, polyphenols are known as HMG-CoA reductase inhibitors and have potent anti-glycation activity. These compounds are the main active principles in the Urticae folium. The aim of this study was to evaluate the polyphenols’content (polyphenolcarboxilic acids = PPCA, and flavonoids) of stinging nettle leaves, harvested from culture and wild flora, originated from Racari, Dambovita district, Romania. Spectrophotometric and chromatographic methods were used. A new HPLC method for the identification and quantification of caffeic and chlorogenic acids from Urticae folium was also developed. The highest contents of polyphenolcarboxilic acids (expressed as % of chlorogenic acid) and flavonoids (expressed as % of rutin) were found in the leaves of wild nettles harvested in the month of March (4.2295% chlorogenic acid and 0.6237% rutin). The polyphenols’ content is slightly lower than the ones mentioned in the scientific literature. The content of PPCA decreases from March till September, both in wild and cultivated samples. The variation of the flavonoids’content differs with the origin of raw material (culture or spontaneus flora). The new HPLC method for polyphenols’analysis is reproductible. Rezumat Utilizarea tradiţională a produsului Urticae folium in diabet, fără o justificare stiintifica a acţiunii precum si menţionarea flavonelor si acizilor fenolcarboxilici (compusii majoritari) ca inhibitori ai HMG-CoA reductazei si ai proceselor de glicozilare si lipoxidare avansată, ne‐au determinat să abordăm cercetarea acestora, in vederea valorificării terapeutice sub formă de extracte selective. In acest scop am derulat o cercetare spectrofotometrică si cromatografică (HPLC) pentru a pune in evidenţă polifenolii prezenţi in frunzele de urzică recoltate din flora spontană si de cultură, din localitatea Răcari, judeţul Dâmboviţa. De asemenea, ne-am propus să separăm acizii cafeic si clorogenic si să-i determinăm cantitativ printr-o nouă metodă HPLC/UV.
LC/MS ANALYSIS OF ISOFLAVONES FROM FABACEAE SPECIES EXTRACTS
In order to find new sources of phytoestrogens, we analyzed the isoflavones from different extracts obtained from species belonging to the Fabaceae family within the Romanian spontaneous flora: Trifolium pratense, T. repens, Genistella sagittalis, Cytisus nigricans, Medicago lupulina and Melilotus officinalis. The qualitative and quantitative analyses were performed by LC/MS. The hydroalcoholic extracts were obtained from dried blooming aerial parts by sonication at 60 ˚C for 30 minutes. The studied extracts contain free isoflavones and isoflavon glycosides. In the Trifolium pratense, Trifolium repens and Genistella sagittalis there were found high concentration of heterosides: daidzin, genistin and ononin. The Cytisus nigricans contains just 270.6 ng/mL of ononin. Medicago lupulina and Melilotus officinalis contain low amounts of genistin (246.7 ng/mL respectively 567.2 ng/mL). Free isoflavones were identified in Trifolium pratense: daidzein (859.8 ng/mL), genistein (1423 ng/mL) and formononetin (9165.8 ng/mL) respectively in Genistella sagittalis: daidzein (549.7 ng/mL), genistin (9024.6 ng/mL), formononetin (839.5 ng/mL). As a result, of all the analyzed extracts, the ones obtained from Trifolium pratense, Trifolium repens and Genistella sagittalis are the most valuable from the point of view of their free, as well as glycosilated isoflavones content. Rezumat
A peptide muscarinic toxin from the Green Mamba venom shows agonist-like action in an inhibitory avoidance learning task.
A peptide, muscarinic toxin 2 (MTX2), isolated from Dendroaspis angusticeps venom was previously shown to displace the specific binding of [3H]pirenzepine, a muscarinic M1 receptor ligand, from rat brain synaptosomal membranes. We have tested MTX2 for muscarinic agonist or antagonist actions in an inhibitory avoidance task in rats. Infusion of the muscarinic receptor antagonist scopolamine into the hippocampus of rats immediately after the training period produced amnesia, whereas the muscarinic agonist oxotremorine increased retention. When MTX2 was injected into the hippocampus of rats after the inhibitory avoidance task, it caused memory facilitation, which could be suppressed by the concomitant infusion of scopolamine. Hence, in this test, MTX2 showed muscarinic receptor agonist-like actions, which are probably mediated by the M1 subtype of muscarinic acetylcholine receptors.