Description
Ergoloid, also known as dihydroergotoxine mesylate, is a mixture of the ergot alkaloids dihydroergocornine, dihydroergocrystine, and dihydroergocryptine. It blocks reflex vasodilation and vasoconstriction induced by norepinephrine in dogs when injected into the kidney at a dose of 0.15 mg. Ergoloid blocks norepinephrine-induced cAMP production in rat brain cortical homogenates
ex vivo in a dose-dependent manner. It also acts as an erectogenic agent in rats. Formulations containing ergoloid have been used in the treatment of migraine headaches and vascular dementias.
Uses
Cognition adjuvant. Dihydroergotoxine mesylate binds with high affinity to GABAA receptor Cl- channel. Interacts with central dopaminergic, serotonergic and adrenergic (a1) receptors. Exhibits antirproliferative activity in vitro. Displays cognition-enhancing, anticonvulsant and sedative activity in vivo. Dihydroergotoxine mesylate is a substrate of GABA Receptor.
Definition
ChEBI: Dihydroergotoxine mesylate is a mixture of hydrogenated ergot alkaloids consisting of the methanesulfonic acid salts of dihydroergocornine (R = CHMe2), dihydroergocristine (R = CH2Ph), and alpha- and beta-dihydroer ocryptine (R = CH2CHMe2 and CH(Me)Et, respectively). It is used for the symptomatic treatment of mild to moderate dementia in the elderly, although its value is not established.
brand name
Alkergot (Sandoz); Circanol(3M Pharmaceuticals); Deapril (Bristol-Myers Squibb);Gerimal (Watson); Hydergine (Novartis).
Biological Activity
Dihydroergotoxine mesylate is a complex of closely related alkaloid salts. Binds with high affinity to the GABAA receptor Cl- channel, producing an allosteric interaction with the benzodiazepine site. Also interacts with central dopaminergic, serotonergic and adrenergic (α1) receptors. Displays antiproliferative activity in vitro (IC50 = 18 - 38 μM in prostate cancer cells) and exhibits cognition-enhancing, anticonvulsant and sedative activity in vivo.
Pharmacology
The metabolic effects of ergoloid mesylates (Hydergine) may include enhancement of noradrenergic, dopaminergic and serotoninergic neurotransmission (Weil,1988) and reduction of free radicals. Schneider and Olin (1994) reviewed 151 reports on the use of Hydergine in senile dementia, but only 47 of these trials (31%) met strict criteria for meta-analysis. ACochrane review (Olin et al., 2001) confirmed that patients with VaD appeared to benefit more than patients with AD in terms of cognition,clinical global ratings and combined measures. However, compared with placebo, efficacy was very modest. Thus, there are no grounds to recommend its use.
