Bitters

BITTERS (amara), substances of plant origin possessing a bitter taste and applied usually in the form of galenic preparations for disorders of digestive function. Substances of bitter taste, but possessing at the same time a sharply expressed absorptive action, such as strychnine preparations, are not included in this group. Bitters are often applied in therapy. Besides the constituent parts which give bitters their bitter taste, the latter may also contain aromatic, mucilaginous substances, also having therapeutic significance, and astringent tanning substances. According to this, B. are subdivided into purely bitter - amara pura; bitter aromatic - amara aromatica; bitter mucilaginous - amara mucilaginosa. In considering the action of B. one should bear in mind: 1) their influence on the chemistry of digestive processes, independently of the action on the mucous membranes of the digestive tract; 2) local direct impact on the mucous membranes and digestive glands; 3) reflex action; and 4) general absorptive action. 1. The impact of bitters on the chemistry of digestive processes is in general weak, expressed in a certain weakening of these processes in connection with antifermentative properties belonging not so much to the bitters themselves as to the tanning and colloidal substances encountered in them. In view of the fact that the essential oils of aromatic bitters also possess antifermentative properties, the latter usually more strongly suppress digestive enzymatic processes than amara pura. 2. The local direct impact of pure B. on the digestive organs, besides the specific stimulation of the organ of taste, which has a reflex significance for digestion, is in general weak - expressed in a certain irritation of the mucous membranes of the stomach and intestines. As a consequence is observed a certain hyperemia and after a certain time (V₂ - 1 hour.) after the introduction of B. into the stomach - acceleration of the transition of food from the stomach into the intestines, which in turn accelerates its absorption; this is also promoted by the hyperemia of the intestine. The introduction of B. into the stomach in a very large quantity has the opposite effect, delaying food in the stomach. An intensification of secretion on the part of the stomach or intestines, as well as of the large digestive glands under the influence of the direct action of B. on the mucous membranes is not observed. Aromatic bitters, as stronger irritants, prove in local action more active than pure B. Amara mucilaginosa, on the contrary, owing to the enveloping action of the mucus, irritate the mucous membranes of the digestive tract less. 3. The therapeutic significance of B. depends mainly on their specific action on the organ of taste. However, under the influence of B. reflex secretion of digestive juices does not occur, but increased reflex gastric secretion of the so-called "inflammatory" juice is observed in response to food taken after B., which is proved by experiments with simulated feeding of esophagotomized dogs, to which B. were given to chew before simulated feeding with meat. This intensification of secretion is explained by an increase in the gustatory significance of the meat or by contrast with the bitter [pleasant and unpleasant (Pavlov)] or as a result of sensitization (Borisov) of the organ of taste by a strong irritant. Another phenomenon, which depends on the reflex action of B. through the organ of taste (although here the participation of the direct local effect is also possible), is the suppression of the periodic movements of the empty stomach accompanying the sensation of hunger. 4. The absorptive action of B. is insignificant and manifests first of all in the intensification of digestive leukocytosis. This phenomenon is explained by the contraction of the milk vessels and the squeezing of leukocytes from them. The increase in the quantity of erythrocytes observed in the blood is more difficult to explain. A positive effect from the intake of B. is observed mainly in disorders of digestion when appetite is lowered and the secretion of the so-called "inflammatory" juice on food is lowered. The effect can also be obtained when the digestive glands are given an excessive task, as a result of which extraordinary irritants have to be added to the usual food irritants. From this point of view the custom of appetizers with bitter and spicy substances before excessively copious meals is understandable. In a healthy state of the digestive organs and moderate food a positive effect from the preliminary intake of bitters cannot be expected. Bitters are prescribed to patients for various dyspepsias before a meal. Preparations. - Amara pura: quassia (Lignum Quassiae), gentian (Radix Gentianae), clover (Folium Trifolii fibrini), dandelion (Radix Taraxaci) and others. As bitters are applied in small doses the preparations of cinchona bark (Cortex Chinae) and chilibuka (Strychnos nux vomica). - Amara aromatica act more strongly than pure bitters, the effect of local action on the mucous membranes of the digestive tract being more pronounced. With prolonged application they more easily cause a catarrhal state of the mucous membranes owing to their irritating properties. They include: wormwood (Herba Absynthii), orange peel (Cortex Aurantii), cascara bark (Cortex Cascarillae). - Amara mucilaginosa act simultaneously as bitters and as enveloping agents, protecting the mucous membrane. They include condurango (Cortex Condurango), containing also tanning substances, colombo (Radix Colombo), coto bark (Cortex Coto).