Ethanol antagonism

The definition of desired therapeutic and side effects in the case of the benzodiazepines very much depends on the clinical problem in question. The sedative and hypnotic actions are desired effects in the treatment of insomnia, but undesired effects in the treatment of anxiety disorders. Effects that are usually undesired include daytime drowsiness, potentiation of the sedative effects of ethanol, and anterograde amnesia. They are mediated via the benzodiazepine site of GABAa receptors, since they can be antagonized with flumazenil. 

Beckstead MJ, Phelan R, Mihic SJ Antagonism of inhalant and volatile anesthetic enhancement of glycine receptor function. J Biol Chem 276 24959-24964,2001 Beckstead MJ, Phelan R, Trudell JR, et al Anesthetic and ethanol effects on spontaneously opening glycine receptor channels. J Neurochem 82 1343-1351,... 

Many drugs interact with folate to affect its absorption, antagonize its biochemical activity, or increase its loss from the body. These drugs include ethanol, phenytoin, and oral contraceptives. Salicylates can compete with foUc acid for plasma protein binding. Methotrexate, a cytotoxic agent, is a folate antagonist that inhibits the biosynthesis of this coenzyme. 

We already indicated that intravenous injection of ethanol blocked the LTP induced by tetanic stimulation [18]. However, when saffron crude extracts were injected intracerebroventricularly, the blocking effect of ethanol on the LTP decreased dose-dependently [19]. Moreover, crocin prevents the ethanol-induced impairment of memory acquisition in ST and SD tests [20], From these results it is easily suggested that crocin antagonized the blocking effect of ethanol on the induction of LTP. 

An oral administration of crocin had no effect on memory acquisition in normal mice but improved the ethanol-induced impairment of learning behaviors of mice in passive avoidance performance tasks. This phenomenon resembled that of crude extract of saffron as reported previously. The tendencies of the effect between CSE and crocin are similar to each other. From these results it can be easily speculated that crocin is the most important principle in crude extract of saffron. Other crocetin glucoside esters weakly antagonized the blocking effect of ethanol on the LTP compared to crocin. 

We demonstrated for the first time that crocin selectively antagonizes the inhibitory effect of ethanol on NMDA-receptor-mediated responses in hippocampal neurons. This action of crocin may underlie the antagonism against ethanol-induced memory impairment. Crocin should be useful as a new pharmacological tool for studying the mechanism of ethanol inhibition of NMDA receptor functions. 

Crocin of 50 mg/kg ameliorated the blocking effect of ethanol on the LTP at approximately 84% compared to the control as indicated in Fig. (10). Crocetin gentiobiose glucose ester also antagonized the blocking effect of ethanol on the LTP dose-dependently. But die intensity is not so strong, about a half of crocin when compared the intensity of 50 mg/kg. On the other hand, crocetin di-glucose ester did not remove the inhibitory effect of ethanol on the LTP. 

Patynowski et al. (2002) showed that yeasts produce an unidentified inhibitory factor (maybe a toxic metabolite) that could be responsible for the inhibition of bacterial growth. These results could explain the antagonism between yeasts and malolactic bacteria, since yeasts are known to produce compounds during alcoholic fermentation such as ethanol, SO2, medium-chain fatty acids and antibacterial proteins/peptides (Weeks et al. 1969 De Oliva et al. 2004 Comitini et al. 2005 Osborne and Edwards 2007). The nature and quantity of peptides and other molecules released by yeasts are different depending on winemaking techniques and the yeast strain. 

Tourtelotte, W.W., Coon, J.M. (1949). Synergistic effect of sodium acetate and ethanole in antagonizing sodium fluoroacetate poisoning in mice. Fed. Proc. 8 339-50. 

Isopropanol is a potent central nervous system (CNS) depressant it is believed to exert this effect via a similar mechanism as ethanol by modulating ion transport at the cell membrane in excitatory and inhibitory neurons. Ethanol enhances inhibitory or antagonizes excitatory neurotransmission. The metabolite, acetone, may potentiate and lengthen the duration of CNS symptoms observed upon isopropanol exposure. Although early animal studies suggested that the CNS depressant effects of isopropanol is approximately twice that of ethanol, this increased CNS depressant activity is probably a result of the combined effects of isopropanol and acetone. 

Small doses of garlic are purported to increase the tone of smooth muscle in the gastrointestinal tract, while large doses decrease such actions (Tyler, 1993). An ethanol—chloroform extract of fresh bulb antagonized acetylcholine and prostaglandin E induced rat fundus smooth muscle contraction at a concentration of 0.002 mg/mL however, an ethanol extract of fresh garlic bulb caused rat fundus smooth muscle stimulation at a concentration of 0.016 mg/mL (Ross, 1998). 

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