Methylxanthines are basically alkaloids that are present in elevated concentrations in beverages like tea and coffee. They are also found in chocolate. The most popular methylxanthines include caffeine, theobromine and theophilline. These compounds are present in different concentrations in tea, coffee and chocolate. While caffeine is the primary methylxanthine present in coffee, chocolate contains abundant of theobromine, wherein the ratio of caffeine theobromine varies greatly. However, typically it is higher than 1. On the other hand, the primary methylaxanthine found in tea is theophilline.
Methylxanthines are alkaloid compounds belonging to an exceptional class of drugs that are obtained from xanthine that is purine-based. Both plants and animals produce xanthine naturally. Methylxanthines like dyphylline and theophylline are used for treating obstruction of airways due to health conditions like chronic bronchitis, asthma or emphysema.
The most commonly used methylxanthine is theophylline. It is also the most well known methylxanthine. When used in low doses, this compound has anti-inflammatory, immunomodulatory and broncho-preventive effects. However, using it in higher doses is usually linked to toxicity. Theophylline is generally used in high doses for the compound's bronchodilator effect.
Experts are yet to ascertain the mechanism of methylxanthines and how they help to cure various conditions. Nevertheless, findings of various studies have revealed that they work to slow down the actions of enzyme phosphodiesterase, and antagonize receptors. When used in lower doses, it is believed that the effects of methylxanthines on histone deacetylase activity contribute to the compounds' immunomodulatory effects.
Methylxanthines work as instant stimulants which possess the ability to augment the heart rate as well as blood circulation. At the same time, these compounds are relaxants that dilate and clear the constricted blood vessels and unwind the muscular tissues. The occur naturally in caffeine and these compounds are among the main reasons why people often feel that their heart starts racing after they consume plenty of caffeinated drinks or foods. Often scientists as well as pharmaceutical manufacturers use these compounds in drugs that are meant to fight chronic obstructive pulmonary disease or COPD. In several instances, methylxanthines are capable of providing almost instant respite from blocked lungs. These compounds may also be present several kinds of inhalers meant for treating asthma and bronchitis. When used in these cases, methylxanthines help in opening up the airways, thereby making it easier to breathe.
Actually, medications that are classified as methylxanthines are derived from xanthine that is also known as purine. Simply speaking, purines are high-proteins that occur naturally in most cell parts in our body. A process called methylation converts xanthines. During methylation, methyl groups are added to purines to form alkaloids. This process can take place on its own in nature such as in the case with tea leaves and coffee berries among others. In these instances, the berries and leaves, which enclose caffeine, naturally synthesize xanthines as they mature naturally. All these take place at the cellular level - normally right at the time when a plant begins to mature. The timing of this process is such that it does not occur in young tea leaves and coffee berries. This is also the primary reason why the young tea leaves and coffee berries do not contain as much caffeine as the mature plants or the blends made from them.
Methylxanthines can also be made synthetically in laboratories. In fact, all methylxanthines used by drugs by pharmacologists are created artificially. This saves them of a lot of effort, time and money. If they had to use natural methylxanthines in drugs, scientists would have to first isolate caffeine molecules and subsequently identify and separate the naturally occurring methylxanthines. This is the main reason why scientists usually go for creating these compounds artificially in laboratories from xanthines, which are available in the nature in abundance.
Among the various applications of methylxanthine in pharmacy, it is mostly used in the form of an additive to drugs for people enduring chronic obstructive pulmonary disease (COPD). Chronic obstructive pulmonary disease is a disease related to the lungs, which basically deprives the patient's lungs of oxygen by losing access to it. In most cases, this happens because the heart of the patient is unable to pump enough blood to the lungs. While smoking has been identified as a major cause for developing this disease, COPD also occurs owing to specific genetic conditions as well as exposure to various environmental hazards. In such conditions methylxanthine can be helpful in stimulating the blood flow to the lungs and also in removing blockages in the artery. Generally, the effect of using methylxanthine is not permanent. Moreover, methylxanthine is also not considered to be a cure for COPD. Nevertheless, they can be of instant help and also an excellent short-term decision.
In addition, compounds like methylxanthine can also be very useful for people enduring emphysema, chronic obstructive lung or airway disease, and chronic bronchitis. The molecules of methylxanthine work on the constricted bronchi as well as bronchioles, thereby improving airflow and oxygen to the lungs. They also loosen up the airways, while augmenting the blood circulation by stimulating the heart and blood vessels.
Mostly for these above-mentioned reasons, methylxanthines are generally found in several asthma drugs also. In these conditions, methylxanthine is normally administered to the patient as tablets or via inhalers. This compound has an effect on the lungs, throat, heart and various vital parts of the pulmonary and bronchial systems. Methylxanthine not only speed up the response of the pulmonary system, but also help the airways to relax. This is a main reason why people who drink coffee very frequently sometimes complain of increased heart rate, mild arrhythmia and even shortness of breath.
Methylxanthines can generally be used as a stimulant. Methylated as well as non-methylated synthetic xanthines are used for this purpose. In other words, methylxanthines are used in addition to the general drugs used for treating a particular health condition. Aside from caffeine, the other compounds belonging to this group include aminophylline, theophylline, theobromine and paraxanthine. Although the molecular structure of each of the above mentioned compounds differ to some extent, all of them have a similar core and their basic characteristics too are the same.
The effects of these compounds are beneficial, especially for people enduring colds, respiratory problems or even allergies. This is the reason why such people often self-treat themselves by drinking tea or inhaling the aroma of tea leaves steeping in a kettle. In addition, they also breathe in the steam from tea. All these actions may be helpful in unwinding the airways and making it easier to breathe. While these are certainly not long-term treatments for the above mentioned conditions, they can be beneficial by providing short-term respite from the mild discomforts related to the pulmonary system. It is worth mentioning here that the International Olympic Committee (IOC) too has approved the use of these compounds for temporary relief. On the contrary, use of caffeine has not been approved by the IOC. As a result, people competing in Olympics are allowed to use methylxanthines and associated compounds to enhance their energy levels temporarily as well as accelerated adrenaline response.
Though methylxanthine has many therapeutic benefits, it also accompanies a number of side effects. Hence, it should be used cautiously. However, using methylxanthine in small doses or for short term usually does not cause any serious health risks. Since this molecule is diuretic in nature, it may cause dehydration. Therefore, people who are using it orally need to be sure that they drink lots of water.
Too much use of this compound for prolonged period may result in stress to the heart.
People suffering from gastroesophageal reflux disease (GERD) may also endure the harmful side effects from using methylxanthine and also foods containing this compound, especially drinks that contain high levels of caffeine like tea or coffee. This is also true for foods such as chocolate. This compound works to relax the esophagus and, hence, it can add to gastric reflux reactions. While taking the compound in small amounts is unlikely to cause any negative reaction, intake of larger doses of methylxanthine may result in heartburn and nausea.