Nowadays, everyone has moments when they need to take medicines either because of sickness or just to prevent disease development and stay healthy longer. How many pills are to be taken is always a very important question. Every drug label contains information about dosing and an intake rate. Also, physicians must make very precise prescriptions explaining patients how many, how often, and when they have to take the drugs, supplements, or herbal extracts prescribed. This is a good solution for that problem as almost nobody likes to break a physician’s recommendation. But sometimes it is not so simple.
Very often we do not get enough information about how to take remedies or supplements we choose for our health. Good examples is the dietary supplements with herbal extracts inside. Generally, herbs contain natural active compounds acting just the same way as officially approved drugs. But recommendations for the use of dietary supplements are not so straight and may vary significantly for different brands. Then it is up to a person to decide how much of an herbal extract he or she needs or wants to take. And this question is really tough.
The amount of active substances necessary for the beneficial effects in the human body is a crucial part of pharmacology as well as the entire medical science. The quantity of active substance getting into a human body is termed as “dose”. There are several different types of doses being used in pharmacology. We can define effective, toxic, and lethal doses depending on the consequences they lead to. We can calculate single and multiple (or course) doses. Very frequently we use such terms as lowest, average, and highest doses depending on how strong is the effect exerted by an active compound. And here is the tricky point leading to many mistakes.
In our lives we got used to a simple correlation: the more is at the quantity of something the bigger, or larger, or stronger is the result. That is why many people think that the more amount of drug or herbal extract we consume the stronger benefits we get. But this is not always true.
The important part of the drugs’ mechanism of action is their influence on special targets located in organs and tissues throughout the body. They are named receptors. Drug active compound affects these structures and thus induces some alterations of functions regulated by these receptors. If we take a very tiny amount of drug, it can affect only a few receptors and its effect would be barely noticed. If we take a higher dose of a drug, the more receptors would be affected and involved in this process, and we can see the real effect. But there is no direct correlation between the number of receptors influenced by a drug and the effect we observe. Our body contains a much higher number of receptors that we need for the body to function. They are named “spare receptors”. If a drug or an herbal extract affects too many receptors the effect increases but slower than expected. If drug active substance affects all receptors of a certain type fitting this drug structure, the effect is not going to increase anymore. In this case, we can increase the dose but it would not result in the effect getting stronger. Generally, the correlation between the dose and the effect looks like these curves below.
Of course, not all drugs are so safe that we can consume them in amounts as much as we want with no bad consequences. Many drugs must be taken only with doctor prescription because they can induce toxic effects and even death if consumed in high doses. Even herbal extracts may contain such dangerous compounds. But the marketing of these substances is strictly regulated by the government and FDA and it is not possible to get it without special permission. So, if you can buy a drug or an herbal extract supplement in the nearby store or online, you can be sure that it is generally safe.
Nevertheless, recommendations for the use of any drug or dietary supplement should be strictly followed. And this is also important for the herbal extract pills. And that is why. Herbs contain many different substances, and generally, each of these substances affects several types of targets in the body. And thus, they induce many various effects, similar or opposite to each other, depending on the dose, health status, physiological peculiarities, and many other factors. So, various doses of the herbal extracts may exert different effects. Commonly known drug aspirin is a good example of such a phenomenon. Doses of aspirin lower than 100 mg taken by an average adult man prevent platelet aggregation in blood. So, the blood becomes more diluted and that is helpful for heart disease prevention. Doses of aspirin higher than 100 mg activate platelet aggregation in blood via the different mechanism, and this influence is opposite to the previous one. So, there is no effect at all. That is why aspirin is low doses is very much helpful for prevention of the heart disease, but its higher doses are useless from this point of view. Such a phenomenon is termed “hormesis”.
Term “Hormesis” comes from Greek hórmēsis “rapid motion, eagerness”. It refers to some benefits caused by only the low doses of active compounds in humans or animals. The higher doses provoke no effect or even the opposite effect. So-called hormetic substances are very useful if taken in small amounts but they may be useless or sometimes dangerous if taken in higher doses. Generally, the correlation between dose and effect they induce looks like this plot below.
This correlation may vary, but there is always a decrease of efficacy corresponding to the increase of a dose.
Mechanisms of the hormesis phenomenon are not completely understood. They may be linked to
– many substances in an herbal extract exerting opposites effects in human;
– multiple targets controlling opposite functions in the body;
– different resistance of several similar but not the same types of receptors controlling the same functions;
– different affinity of different types of receptors to an active compound;
– other complicated intracellular mechanisms differently reacting to active molecules.
Hormesis is not so typical of officially approved drugs because of the strict regulations of the drug discovery and development procedures requiring a full understanding of the active molecule behavior in the human body. Herbs and herbal extracts very often cause a hormesis phenomenon.
Active compounds contained by herbs are complex and affect multiple targets and pathways. One of the interesting herbs with hormetic characteristics is Schisandra chinensis. This herb is helpful for the brain. It helps it function better because of pronounced stimulating activity and protects it from severe chronic diseases related to the degeneration of the neuronal network. Schisandra seeds contain a group of lignans termed schisandrins. The most active is gamma-Schisandrin. This is a typical hormetic agent with predominating cytoprotective effects at low concentrations and no effects occurring at high concentrations. It was shown in research studies that 15 mg schisandrin B given to healthy male subjects is an effective dose. Higher doses do not induce brain-protecting influence.
It should be noted that Schisandra’s herbal extract is pretty safe. A single oral dose of 0.8 g/kg (i.e. about 50 g) or multiple doses (200 mg/kg × 30) do not cause any toxic signs in humans. But at the same time, they do not have health benefits for the nervous system. To cause this effect it should be taken in very low doses.
Many people try to get this remedy and take it in high doses thinking it is healthier and here they make a crucial mistake. Only low doses are helpful and only low doses keep the brain working perfectly for long years.
Of course, Schisandra is not the only herbal extract with hormetic activity. Almost all adaptogen herbs function the same way. Therefore, recommendations for their use labeled on each bottle with adaptogens inside should be followed. Moreover, sometimes these recommendations have to be carefully analyzed. Only smart thinking can help to keep our brain functioning better and longer.