Metabolomic fingerprinting of plant extracts.

The standardization and quality control of plant extracts is an important topic, in particular, when such extracts are used for medicinal purposes. Consequently, the development of fast and effective analytical methods for metabolomic fingerprinting of plant extracts is of high interest. In this investigation, electrospray mass spectrometry (ESI-MS) and (1)H NMR techniques were employed with further statistical analyses of the acquired data. The results showed that negative ion mode ESI-MS is particularly effective for characterization of plant extracts. Different samples of the same species appear well-clustered and separated from the other species. To verify the effectiveness of the method, two other batches of extracts from a species, in which the principal components were already identified (Cynara scolymus), were analyzed, and the components that were verified by the principal component analysis (PCA) were found to be within the region identified as characteristic of Cynara Scolymus extracts. The data from extracts of the other species were well separated from those pertaining to the species previously characterized. Only the case of a species that was strictly correlated from a botanical point of view, with extracts that were previously analyzed, showed overlapping.

The pressor hyperresponsiveness to phenylephrine unmasks sympathetic hypofunction in migraine.

The pressor responsiveness to phenylephrine, an almost pure agonist of peripheral alpha-1-adrenoceptors, was studied in 32 migraine patients in headache-free intervals. Eighteen healthy volunteers served as a control group. Fourteen patients and 14 controls also underwent the tilt test. The following observations were made: (1) the pressor response to phenylephrine was significantly greater and longer lasting in patients than in controls; (2) the reflex decrease of heart rate did not differ in the two groups; (3) a normal orthostatic increase of blood pressure and heart rate occurred in migraineurs with hyperresponsiveness to phenylephrine. These findings suggest a supersensitivity of vascular adrenoceptors which is compatible with a chronic adrenergic deficiency in migraineurs. Since patients did not show an orthostatic hypotension in attack-free periods, the compensatory character of receptoral supersensitivity and the possible mechanisms of cardiovascular dysautonomia, which may occur during migraineous attack, were discussed.

Pupillary and vascular effects of calcium antagonists in migraine.

In migraine patients the effect of calcium antagonists (flunarizine, verapamil and nifedipine) on both venous and pupillary neuromuscular functions, as well as on blood pressure have been evaluated. A single oral dose of flunarizine (10 mg) and verapamil infusion (50 micrograms/ml/min) increased venous compliance. Verapamil also counteracted dose-dependent dopamine induced venoconstriction. Nifedipine (10 mg orally) reduced mean arterial pressure in upright position in migraineurs but not in controls. In addition, chronic treatment with flunarizine (10 mg for 2 weeks) induced a transient miotic effect and a reduction of tyramine induced mydriasis. These findings demonstrated that calcium antagonists affect vascular and extravascular structures. It is postulated that, in migraine, calcium entry blockers may prevent exaggerated responses to catecholaminergic stimulation.

Morphine eye-drops reduce homatropine induced mydriasis in man.

In 7 healthy volunteers 4% morphine eye-drops, when administered to one eye, caused a miosis limited to that eye. In 7 other healthy volunteers morphine was administered into one eye after bilateral instillation of 0.5% homatropine ophthalmic drops; the eye treated with morphine and homatropine showed a mydriasis less intense than the other eye treated only with homatropine. It is suggested that topical morphine locally affects sympathetic function by inhibiting noradrenaline release into the iris neuromuscular junction.

Does lithium balance the neuronal bilateral asymmetries in cluster headache?

Pupil size was measured using a pupillograph, and an asymmetric responsiveness to tyramine, instilled bilaterally, was observed in asymptomatic cluster headache patients. Relatives of cluster headache patients showed an anisocoric mydriasis to tyramine, too. This asymmetry was caused by a less marked mydriatic response of one side which, in the cluster headache sufferers, corresponds to the symptomatic side. After three months of treatment with lithium carbonate (900 mg/die), a bilateral decrease of pupil size was noted, possibly due to a reduced sympathergic tone. After six months of continued treatment an unknown mechanism, likely adaptive in nature, attenuated the effect of lithium on pupil size. Lithium also induced a symmetric response to tyramine by increasing tyramine mydriasis on the symptomatic pupil while reducing it on the asymptomatic pupil. It is postulated that lithium improves cluster headache by correcting abnormal bilateral asymmetries in central neuronal systems which regulate autonomic function and pain sensitivity of the structures involved in the cluster attack.