The properties of heat-clearing drugs are cold and cool. According to the therapeutic principle of "heat is cold", this kind of drugs are mainly used for various heat syndromes. The so-called heat syndrome is a very broad concept, which not only refers to fever caused by rising body temperature, but also generally refers to that although the body temperature is normal or close to normal, patients often have some symptoms of heat syndrome, such as dry mouth, dry throat, red face, red eyes, constipation in stool, short and red urine, feverish five nerves, red tongue with yellow fur and rapid pulse, all of which belong to the category of heat syndrome.
Heat syndrome can be divided into exterior heat syndrome and interior heat syndrome according to the location, nature and severity of the disease. Exterior heat syndrome is characterized by fever, but sometimes aversion to cold. Those with exterior syndrome should be treated with exterior-relieving drugs. The syndrome of internal heat is different. It is a kind of syndrome caused by exogenous pathogenic factors, or internal stagnation heat. The main clinical manifestations are fever, aversion to cold and aversion to heat, thirst, upset and bitter taste, shortness of breath, short and red urine, constipation, abdominal distension, yellow fur and red pulse, and even delirium, madness and so on.
Internal heat syndrome can be divided into two types according to its nature: excess heat and deficiency heat, and excess heat can be further divided into various types, such as energy-divided heat, blood-divided heat, damp-heat and heat-toxic ulcers. According to the differences in different types and drug properties, heat-clearing drugs are divided into the following six categories:
Clearing heat and purging gunpowder: This kind of medicine is mainly used to clear qi and divide excess heat because of its property of "cold and cold breaking fire". Commonly used drugs are gypsum, Anemarrhena asphodeloides, Gardenia, etc., and Baihu Decoction is its representative.
Drugs for clearing heat and cooling blood: mainly used for clearing away excess heat in blood. The so-called "blood heat" refers to the complications such as fever, irritability, delirium, skin rash (subcutaneous hemorrhage), bleeding, bloody stool and other hemorrhagic diseases caused by "blood heat rash". These drugs can achieve the purpose of cooling blood through their heat-clearing effect. Commonly used drugs include rhinoceros horn, radix rehmanniae, radix scrophulariae, etc., and rhinoceros horn and rehmannia decoction is its representative.
Drugs for clearing away heat and dampness: Fever caused by invasion of dampness into human body is called damp-heat, and its clinical manifestations are fever, headache, heavy body and pain, short and red urine, loose stool, yellow and greasy tongue coating, etc. Because this kind of drugs can clear away heat and dry dampness, and some drugs also have the function of detoxification, they are mainly used to treat damp-heat syndrome. Commonly used drugs include Scutellaria baicalensis Georgi, Coptidis Rhizoma, Cortex Phellodendri, etc., Xianglian Pill is the representative for treating gastrointestinal damp-heat, and Zhizi Baipi Decoction is the representative for treating damp-heat jaundice.
Clearing away heat and detoxicating: The poison here refers to "fire poison" or "heat poison" caused by intense heat, which is equivalent to high fever caused by infectious diseases and accompanying pathological changes, including various toxic reactions. A variety of purulent infections (such as sores, lung carbuncle, intestinal carbuncle, etc.), dysentery and some viral infections (such as influenza, Japanese encephalitis, etc.) all belong to the category of heat toxicity. Because this kind of medicine has the functions of clearing away heat and detoxicating, it is mainly used to treat various heat-toxic syndromes. Commonly used drugs include honeysuckle, forsythia, folium Isatidis, Radix Isatidis, Bo Gongying, etc., and Wuwei Xiaoduyin is one of its representatives.
Drugs for clearing deficiency and heat: the so-called deficiency heat refers to fever caused by deficiency of yin, yang, qi and blood in theory, but usually refers to heat syndrome caused by heat evil injuring yin. For example, in the late stage of damp-heat disease (equivalent to acute infectious disease), the symptoms of yin deficiency and fever such as dry mouth and throat, night heat and early cooling, and fever without sweat caused by heat injury, and the symptoms of afternoon fever, night sweats with red cheekbones, bone steaming and fatigue with chronic progressive wasting caused by chronic consumptive diseases (tuberculosis, etc.) are all indications of this kind of drugs. Commonly used drugs are cortex Lycii and Radix Bupleuri. Artemisia annua Biejia decoction is one of its representative prescriptions.
Heat-clearing and eyesight-improving drugs: any drug that can clear away liver heat or dispel wind heat and mainly treat liver heat and wind-heat eye diseases is called heat-clearing and eyesight-improving drugs, and is often used for eye diseases caused by liver heat disturbance. The representative drugs are cassia seed, Celosia seeds, Herba Eriocauli, etc., and the commonly used prescriptions are Celosia decoction and Gujing Longdan powder, etc.
Regarding the pharmacological effects of this kind of drugs, for a period of time, people often equate heat-clearing and detoxicating with antibacterial effects, and compare heat-clearing and detoxicating with antibiotics. However, from a large number of experimental studies at present, no Chinese herbal medicine with strong antibacterial effect in vivo and in vitro has been found in clinic. On the contrary, some Chinese herbal medicines have good curative effects on many infectious diseases, although their antibacterial effect is not strong. Therefore, it is not comprehensive enough to explain the effects of this kind of drugs simply by antibacterial effect. In recent years, pharmacological and clinical research data show that the main function of this kind of drugs may be to regulate the functional activities of the body and present a wide range of pharmacological effects. The main functions proved by modern pharmacological research are summarized as follows:
(1) antibacterial effect, most of these drugs have antibacterial effect to a certain extent, but their antibacterial range and antibacterial strength are different, such as honeysuckle, forsythia, dandelion, viola yedoensis, coptis, garlic, buckwheat, Anemarrhena, Paeonia lactiflora and houttuynia cordata, which have antibacterial effects on gram-positive bacteria (such as Staphylococcus aureus, hemolytic streptococcus, diplococcus pneumoniae, diphtheria bacillus, etc.) and. In addition, Coptidis Rhizoma, Cortex Phellodendri, Scutellariae Radix, Taraxacum, Fructus Arctii, Flos Chrysanthemi, Herba Violae, Flos Lonicerae, Radix Rehmanniae, Radix Arnebiae, etc. are also effective against a variety of skin fungi (such as Trichophyton violaceum, favus Xu Lan, Microsporum ferruginosum, etc.). At present, the effective antibacterial components are decanoyl acetaldehyde (Houttuynia cordata), β, β-dimethyl acryloyl shikonin (Arnebia euchroma), andrographolide (Andrographis paniculata), aesculin (Cortex Fraxini), protoanemonin (Pulsatilla), berberine (Rhizoma Coptidis, Cortex Phellodendri) and so on. Examination website finishing
It is worth noting that the antibacterial effect of heat-clearing drugs is not consistent with the clinical efficacy. For example, the water-soluble flavonoids of Andrographis paniculata have antibacterial effect in vitro, but the clinical efficacy is poor. On the contrary, the lactone part has no antibacterial effect in vitro, but it is effective in clinic. It can be seen that it is not enough to measure the effect of heat-clearing drugs only by antibacterial effect. In fact, many heat-clearing drugs have been found in many experimental studies, but they have obvious detoxification effect. Microbial toxin is an important factor that causes various symptoms and tissue damage in infectious diseases. Treating microbial infection with traditional Chinese medicine can often see the rapid improvement of toxic blood symptoms. Experiments show that Cortex Moutan, Rhizoma Anemarrhenae, Rhizoma Coptidis, etc. can inhibit the formation of coagulase of Staphylococcus aureus at the concentration without bacteriostatic effect, so as to weaken the virulence of bacteria and thus reduce the damage to tissues.
(2) Antiviral effect: In vitro experiments and clinical practice have proved that Flos Lonicerae, Fructus Forsythiae, Herba Houttuyniae, Rhizoma Osmundae, Scutellariae Radix, Folium Isatidis, Radix Paeoniae Rubra, Radix Isatidis, Cortex Phellodendri and Cortex Moutan have inhibitory effects on influenza virus subtype A; Flos Lonicerae, Rhizoma Belamcandae and Rhizoma Osmundae also have inhibitory effects on orphan virus (ECHO 1 1). In addition, dandelion, houttuynia cordata, andrographis paniculata and chrysanthemum indicum can also delay the cytopathic effect caused by virus.
(3) Effect on immune function: This kind of drugs can generally affect different aspects of immune function, and many heat-clearing drugs can promote the immune function of the body. Such as coptis chinensis, berberine, scutellaria baicalensis, andrographis paniculata, chrysanthemum indicum, gypsum, etc., can enhance the phagocytic function of white blood cells and reticuloendothelial system; Houttuynin can increase the concentration of properdin in the body, thus improving the nonspecific immunity to resist the invasion of the pathogen; Dandelion, garlic, coptis root and scutellaria root can also promote lymphocyte transformation rate. Baicalin, Rhizoma Coptidis and Cortex Moutan have certain inhibitory effects on allergic reaction.
(4) Antipyretic effect: Rhinoceros horn, gypsum, Anemarrhena asphodeloides, Scrophularia, Radix Paeoniae Rubra, Radix Arnebiae, Cortex Lycii, Flos Lonicerae and Folium Isatidis have obvious antipyretic effects on animal experimental fever model. Clinically, it is observed that the cooling effect of this kind of drugs on fever patients is different from that of exterior-relieving drugs, and most of them are not accompanied by obvious sweating.
(5) Anti-inflammatory effect: Acute inflammation is the main manifestation of heat syndrome, and it is also an important pathological process of acute infectious diseases. Many heat-clearing drugs have certain effects on all aspects of experimental inflammation. For example, Fructus Forsythiae can inhibit inflammatory exudation, Rhizoma Coptidis can accelerate inflammation regression, and Radix Scutellariae can resist inflammation with allergic reaction. Clinically, this kind of drugs has achieved good curative effect on acute and chronic infectious diseases, which is also closely related to anti-inflammatory effect.
(6) Other effects: Experiments have proved that Niuhuang, Gardenia, Scutellaria baicalensis Georgi and Cortex Moutan have obvious sedative or anticonvulsant effects. In addition, Radix Rehmanniae and Calculus Bovis have cardiotonic effects, Scutellariae Radix and Cortex Moutan have antihypertensive effects, Flos Lonicerae has hemostatic effects, Radix Sophorae Tonkinensis, Radix Arnebiae and Herba Taraxaci have anti-tumor effects, and Pulsatilla chinensis and Rhizoma Coptidis also have anti-amoeba effects.