Physiological mechanisms of appetite regulation
The hypothalamus is responsible for regulating feeding behavior, housing two interconnected centers: the hunger center and the satiety center.
Neurotransmitter regulation plays an important role:
- Noradrenergic transmission: stimulation of this pathway leads to inhibition of the hunger center.
- Serotonergic transmission: stimulation activates the satiety center.
Disruptions in these links serve as targets for pharmacological intervention.
Classification of agents affecting appetite
Modern pharmacology distinguishes two main groups of drugs that purposefully alter feeding behavior:
- Appetite stimulants — used in case of decreased or lost appetite to activate digestive processes.
- Appetite suppressants (anorectic agents) — used to correct excess body weight.
Bitters (Amara) and herbal raw materials
The group of appetite-stimulating agents is compositionally divided into bitters (Amara) and essential oil-containing preparations.
Herbal raw materials of the Amara group include:
- Sweetflag rhizome (Rhizomata Calami);
- Dandelion root (Radix Taraxaci);
- Wormwood herb (Herba Absinthii).
The active substances here are glycosides possessing a specific bitter taste.
Mechanism of action and pharmacodynamics of bitters
According to the classical teachings of I.P. Pavlov, the mechanism of action of bitters is as follows:
- Irritation of taste receptors located on the oral mucosa.
- Reflex enhancement of digestive gland secretion.
Pharmacodynamic features:
- The effect manifests exclusively during food intake, as it is precisely food-related secretion that is stimulated.
- By principle, the action is analogous to traditional aperitifs.
- The drugs must be taken 15–20 minutes before meals.
Agents containing essential oils
In addition to pure bitters, complex herbal remedies are used to stimulate appetite. A prominent representative is the combined preparation «Altalex» based on diluted ethanol.
Its composition includes a complex mixture of essential oils: peppermint, lemon balm, fennel, nutmeg, clove, thyme, pine needle, anise, sage, cinnamon, and lavender.
Pharmacological effects of the drug:
- Stimulation of appetite and gastric juice secretion;
- Bile secretion;
- Spasmolytic action;
- Sedative effect.
Bitters (Amara): wormwood, calamus, and dandelion are taken 15 minutes before meals to stimulate taste receptors and trigger digestion.
Class and exam questions
Where are the appetite regulation centers localized?
Appetite regulation is carried out in the hypothalamus, where the hunger center and satiety center are located.
What is the mechanism of action of bitters (Amara) according to I.P. Pavlov?
The mechanism consists in irritating the taste receptors of the oral mucosa and reflexively enhancing the secretion of digestive glands.
When does the pharmacodynamic action of herbal bitters manifest?
The action of bitters manifests exclusively against the background of food intake, as they affect stimulated secretion.
What pharmacological effects does the preparation «Altalex» exert?
«Altalex» stimulates appetite, gastric juice secretion, and bile flow, and also exerts spasmolytic and sedative effects.
What else to study on this topic
- The role of noradrenergic and serotonergic systems in appetite regulation
- Classification of anorectic agents
- Pharmacodynamics of essential oils in gastrointestinal diseases
- The effect of alcoholic and non-alcoholic aperitifs on gastric secretion
- Indications and contraindications for prescribing herbal bitters
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