Why Use Alcohol in Herbal Liquids by James Hart of Equine Herbals
There are a range of herbal products available. Some people prefer dry herbs, but liquids are usually more effective. Herbalists have traditionally used alcohol. This article explains why alcohol is still the best. The active parts of the plants that we use are contained within the cells of the plant. To make use of these we must break down the cell walls and extract the constituents in a form that can be used by the horse (or human). Drying makes a cell wall brittle and easy to break when immersed in alcohol or other extraction liquid. However transforming the cocktail of biochemicals in the cell is a more difficult task. They vary in their solubility in water and how sensitive they are to heat. You’ll remember from your school chemistry that solubility increases with temperature. The problem though is that some delicate chemicals may be degraded by exposure to heat. For this reason most herbalists prefer to use cold extraction methods, which if done properly, involve minimal pharmaceutical processing and therefore faithfully reflect the chemical characteristics ofthe plant.
As well as producing a better and more consistent extraction liquids give several other advantages. Liquids are easily combined in formulations, they are a compact, convenient dosage form., which give considerable dosage flexibility. Liquids are readily absorbed and well-suited to patients with immature or poor digestive processes.
A Traditional and Effective Solvent
Although other liquids, such as vinegar or glycerine have been tried ethyl alcohol is still considered the best. Not only is alcohol a good solvent for the herbal active components it is also an excellent preservative. Alcohol has been used to make herbal preparations for hundreds, perhaps thousands, of years. Old texts describe steeping herbs in wine for long periods and then using the resultant liquid. With our increased knowledge of plant constituents herbalists now choose the appropriate alcohol:water mix to optimise the effectiveness of the extract. When looking at extracts to purchase it is also important to recognise that not all alcohol is equal. There are of course different grades and is important that medicinal extracts are made using a good quality alcohol. The cheaper grades have too many impurities that are hard for the liver to process.
Alcohol Improves Bioavailability
Alcohol also provides a particularly effective way of maximizing the bioavailability of the actives extracted from the plant. Results of a double blind, placebo-controlled, crossover study on children with chronic obstructed airways have been reported in the Industry News section of the Zeitschrift füür Phytotherapie. The therapeutic effects of alcoholic and alcohol-free extracts of Ivy leaves (Hedera helix) were compared. Spirometric testing showed a significant improvement in lung function for both products, which was superior to conventional bronchodilators. However, it was shown that the addition of alcohol to the preparation yielded an increase in bioavailability of active components, and the dose of the alcoholfree preparation needed to be adjusted to a higher level to obtain the same effect. The mode of action seems to be that alcohol acts to keep the active components in solution after ingestion, thus facilitating their absorption into the bloodstream. Quick absorption means a faster mode of action and as we have seen requires a lower dose to be effective.. It is hard to ask a horse when his knee stops hurting but we have noticed a significant effect on ourselves and other human patients within only 15 minutes of taking Devil’s Claw extract.
A Small Amount of Alcohol Benefits Health
Some people are concerned about possible exposure to the toxic effects of alcohol, such as during pregnancy. However, these toxic effects are dose related and do not occur with the small quantities of alcohol involved in a herbal preparation. For adverse effects to occur after alcohol intake, the blood alcohol level must rise to a certain level.In human terms a 5 ml dose of herbal extract contains about as much alcohol as 1/6 of a glass of beer or wine. Such a small intake of alcohol is rapidly metabolised by the liver and consequently its effect on the blood alcohol level may not even be measurable. A much higher intake of alcohol would be required to overload the liver’s metabolizing capacity, leading to significant blood alcohol levels and subsequent adverse effects. To compare this to the effect on a horse consider the difference in weight. We usually give a horse a 20 ml dose of tincture this is actually a lower percentage of the body weight than the human dose. Mammal’s bodies are naturally conditioned to some exposure to alcohol from ripe fruit and natural fermentation of food. Refrigeration has minimized this exposure in industrialized countries, but most animals and humans, be they young or adult, have evolved and adapted to levels of alcohol intake through food which are similar to those from herbal extracts. Recent research suggests that a small amount of alcohol is actually beneficial to the health of humans. It shows that a regular intake of a small amount of alcohol lowers the risk of cardiovascular disease. This is not usually a problem in horses but we are seeing an increasing number of dogs with heart problems. So it may not be beyond the realms of possibility that small amounts of alcohol are beneficial to horses too.
Some more technical bits on Alcohol.
The alcohol we use is Ethanol or ethyl alcohol. It is a clear, colourless liquid with a characteristic, agreeable odour. In dilute aqueous solution, it has a somewhat sweet flavour, but in more concentrated solutions it has a burning taste. Ethanol, CH3CH2OH, is one of a group of chemicals called alcohols whose molecules contain a hydroxyl group, –OH, bonded to a carbon atom. Another common alcohol is methanol, CH3OH. Although apparently similar it is highly toxic and should never be consumed in even the smallest amount.
Ethanol has been made since ancient times by the fermentation of sugars. Most beverage ethanol and more than half of industrial ethanol is still made by this process. Simple sugars are the raw material. Zymase, an enzyme from yeast, changes the simple sugars into ethanol and carbon dioxide. The fermentation reaction, represented by the simple equation C6H12O6 ? 2 CH3CH2OH + 2 CO2 is actually very complex, and impure cultures of yeast produce varying amounts of other substances, including glycerin and various organic acids. In the production of beverages, such as whiskey and brandy, the impurities supply the flavour. Starches from potatoes, corn, wheat, and other plants can also be used in the production of ethanol by fermentation. However, the starches must first be broken down into simple sugars. An enzyme released by germinating barley, diastase, converts starches into sugars. Thus, the germination of barley, called malting, is the first step in brewing beer from starchy plants, such as corn and wheat. The ethanol produced by fermentation ranges in concentration from a few percent up to about 14 percent. Above about 14 percent, ethanol destroys the zymase enzyme and fermentation stops. Ethanol is normally concentrated by distillation of aqueous solutions. When an alcohol is swallowed, it passes through the stomach into the small intestine, where the ethanol is rapidly absorbed and distributed throughout the body. The ethanol enters body tissues in proportion to their water content. Therefore, more ethanol is found in the blood and the brain than in muscle or fat tissue. Most of the ethanol is processed by the liver. The alcohol dehydrogenase enzyme converts ethanol into acetaldehyde, which is itself toxic. This is destroyed almost immediately by the aldehyde dehydrogenase enzyme, which converts it to acetate ions. The hydrogen atoms represented by these equations are not unattached, but are picked up by another biologically important compound, nicotinamide-adenine dinucleotide (NAD), whose function is to carry hydrogen atoms. NAD is converted to NADH, which must be recycled to NAD for the disposal of ethanol to continue. If the amount of ethanol consumed is not great, the recycling can keep up with the disposal of ethanol. The ethanol disposal rate in a 70 kg human is about 15 mL of ethanol per hour, which corresponds to 360 mL ounces of beer, 120 mL of wine, or 30 mL of spirits.
Ethanol acts as a drug affecting the central nervous system. Its behavioural effects stem from its effects on the brain and not on the muscles or senses themselves. It is a depressant, and depending on dose, can be a mild tranquillizer or a general anaesthetic. It suppresses certain brain functions. At very low doses, it can appear to be a stimulant by suppressing certain inhibitory brain functions. However, as concentration increases, further suppression of brain functions produce the classic symptoms of intoxication: slurred speech, unsteady walk, disturbed sensory perceptions, and inability to react quickly. At very high concentrations, ethanol produces general anaesthesia; a highly intoxicated person will be asleep and very difficult to wake, and if awakened, unable to move voluntarily. Alcohol levels in the brain are difficult to measure, and so blood alcohol levels are used to assess degree of intoxication. Most people begin to show measurable mental impairment at around 0.05 percent blood alcohol. At around 0.10 percent, mental impairment will show obvious physical signs, such as an unsteady walk. Slurred speech shows up at around 0.15 percent. Unconsciousness results by 0.4 percent. Above 0.5 percent, the breathing centre of the brain or the beating action of the heart can be anaesthetized, resulting in death.
So despite the results of overuse ethanol is still the preferred extraction medium for thebest quality herbal extracts.