Adaptogens

Adaptogens are defined as those herbs able to decrease the level of stress, anxiety, fatigue and tiredness in the human body (often associated with high levels of stress) [7]. In particular, adaptogens increase the ability of the human body to react and adapt to stressors [1].

History

The history of adaptogens has ancient roots. In 1947, during the Second World War, Russian pharmacologist Nikolai Lazarev was looking for natural remedies that could decrease fatigue and increase the performance of soldiers.

In particular, Lazarev discovered that the stressful events (such as those experienced by soldiers in the war) had negative and severe impacts on human health. Moreover, he noticed that the human body, when stressed, lost its balance and internal equilibrium. For this reason, Lazarev looked for something that could counteract the effects of stress and that could re-establish balance in the body. Interestingly, he found that some herbs had these properties and could improve the soldiers’ performances.

Although the contribution of Lazarev was very important, only 20 years later, at the end of the 1960s, adaptogens were well defined by Brekhman and Dardymov who specified that adaptogens have to:

• reduce stress, normalising the physiology of the human body
• have stimulant properties
• be harmless, without any side effects
• be different from the common and conventional stimulating drugs that show withdrawal effects

In fact, even if other herbs increase energy and act as stimulants, the adaptogens are unique because they do not show the negative effects often associated with the conventional drugs (i.e. psychotic symptoms) [7].

Focus on stress

Stress is a very common feature of human life that affects millions of people. If stress is not managed and controlled, it can cause severe symptoms and negative health consequences such as fatigue, tiredness, heart problems, depression, poor memory, etc. There are different types of stress that exist. They include biological, chemical, physical and emotional stress.

Several strategies are available to reduce the level of stress, such as:

• relaxing techniques
• drugs
• exercise
• adaptogens

Adaptogens are largely used in the Ayurvedic medicine and are administered during periods of high stress, also during/after convalescence [6,7].

Mechanism of action

Several studies have recently been conducted to investigate the mechanism of action of adaptogens. In particular, the scientists investigated how these products can reduce the level of stress. It was found that adaptogens act on the so-called Hypothalamic-pituitary-adrenal axis. Adaptogens regulate the nervous, immune and endocrine systems which allows them to decrease the level of stress in the body. Moreover, it also appears that adaptogens can decrease oxidative stress.

To justify the reduction in the level of fatigue and tiredness associated with the consumption of adaptogens, it has been proven that adaptogens could have an effect on the level of nitric oxide and cortisol; both substances that are produced in high doses during the periods of fatigue [7].

List of adaptogens

Even if the health claims for adaptogens have not yet been approved, different herbs are included in this category are: [8]:

• Panax ginseng
• Bacopa monnieri
• Holy basil
• Sea Buckthorn
• Tinospora cordifolia
• Nardostachys jatamansi
• Trichopus zeylanicus
• Schisandra chinensis
• Morus alba
• Ashwagandha
• Polygala tenuifolia
• Eleutherococcus senticosus (Siberian ginseng)

Focus on Panax Ginseng

Panax ginseng, also called Asian ginseng, is a perennial plant belonging to the family of Araliaceae. It was one of the first types of adaptogens used. Moreover, it is a product largely used in traditional Chinese medicine.

The adaptogenic activity of Panax ginseng is also displayed in experimental studies that have found a possible interaction between the ginseng and the hypothalamic-pituitary-adrenal axis.

It has been found that ginsenosides present in the roots seem to exhibit adaptogenic activity.

[2].

There are some health claims under consideration for Panax ginseng, such as:

• helps to promote alertness, to counteract fatigue and to promote vitality
• helps to maintain physical and mental capacities in case of weakness, tiredness and exhaustion
• contributes to the proper function of the immune system
• helps to maintain good cognitive and memory performances
• helps to maintain normal blood sugar levels as part of a healthy lifestyle
• contributes to normal blood circulation, which is associated with brain performance and reactivity
• helps to have good sexual relations

Focus on Eleutherococcus Senticosus

Eleutherococcus senticosus, also called Siberian ginseng, is one of the species belonging to the genus Ginseng and is native to Northeast Asia. Even if its relative Panax ginseng is considered the main adaptogen, E. senticosus also seems to improve cognitive functions, decrease fatigue and improve sleep [4].

The health claims under consideration for Siberian ginseng are:

• it is a tonic for the support of mental and physical capacities in case of weakness, exhaustion, tiredness, and during convalescence
• helps in cases of recovery/rehabilitation
• contributes to support the immune system
• contributes to the normal blood circulation which is associated with brain performance and reactivity
• helps the physiological sugar balance
• helps to obtain relaxation

Focus on Rhodiola Rosea

Rhodiola rosea is a flowering plant belonging to the family of Crassulaceae. It is a perennial plant that grows in cold regions of the world such as the Artic, North America, and the mountainous regions of Europe.

It is the second most common adaptogen after Panax ginseng [9], showing good potentialities to reduce both mental and the physical fatigue [1,3]. Moreover, R. rosea seems to improve cognitive performance during fatigue or stressful conditions [4].

There are some health claims under consideration for Rhodiola rosea, among which are:

• contributes to normal blood circulation which is associated with brain performance and reactivity
• contributes to optimal mental and cognitive activity
• helps the digestive health

Focus on Schisandra Chinensis

1. chinenis in Chinese literally means "five flavours berry" on the basis that its berry contains five different tastes. It is a woody plant found in Northern China and Eastern Russia. This product is considered to be an adaptogen as it shows good potentialities to reduce the symptoms of fatigue, tiredness and to enhance physical performances [3,4].

The health claims under consideration for S. chinensis are:

• it is a tonic
• contributes to the recovery of physical and mental well-being
• helps with physical and mental resistance

Focus on Withania Somnifera

1. somnifera, also called ashwagandha, is a herb largely used in Ayurvedic medicine. It is considered to be an adaptogen. In fact, it shows good potentiality, in comparison to a placebo, to reduce the level of anxiety and stress [5].

Some health claims currently under consideration are present for this species, among which are:

• helps to maintain physical and mental capacity in case of weakness, exhaustion, and tiredness
• it is a nerve tonic
• supports in periods of high stress and anxiousness
• contributes to optimal relaxation
• beneficially affects the cardiovascular system
• supports the onset of sleep
• helps to maintain optimal stamina, energy, and vitality