Analysis of treatment strategies of traditional Chinese medicine for COVID-19 in tropical regions based on the pathogens of dampness and heat

Xian Wang，Wen-Long Zhang，Chang Liu，Mi Li，Kai Li✉，Yi-Qiang Xie✉

School of Traditional Chinese Medicine, Hainan Medical University, Haikou 571199,China

Keywords:Pathogens of dampness and heat Tropics COVID-19 TCM Treatment strategies

ABSTRACT Objective: To summarize the treatment strategies of Traditional Chinese Medicine(TCM) for COVID-19 in tropical regions based on the pathogens of dampness and heat. Methods: For heat pathogen, analyzing heat in the superficies, lung and Yang Ming based on the different locations. Based on the progress of the disease, analyzing the stage of toxin and Qi deficiency induced by heat. For dampness pathogen, analyzing endogenous and external dampness

1. Introduction

It is a characteristic theory of TCM to treatment in accordance with local conditions. The tropical area has a low latitude position, high temperature for a long time, is mostly close to the sea, has abundant rainfall and has dampness-heat air in nature. Relevant research shows that 15-27 ℃ is the most suitable temperature for human body. If people live in high temperature environment for a long time, it is easy to induce the occurrence and development of heat pathogen [1]. The most suitable relative humidity for human body is between 30% - 60%. Affected by the location of sea and land, tropical areas are mostly close to the sea with large rainfall, humid climate, and prone to breeding of dampness pathogen [2].Every year the high dampness pathogen and heat pathogen are easily induced by the more abundant dampness and heat pathogen in the tropical

area. The latitude range of Hainan Province is 3.30 N～20.07 N and the latitude range of Hainan Island is 19 20′N～20 10′N, which belongs to tropical marine monsoon climate[3]. The team participated in the clinical treatment as the deputy leader unit of the expert group of Chinese medicine prevention and treatment of COVID-19 in Hainan Province. According to the clinical observation, syndrome of dampness-heat is a common syndrome of COVID-19 cases in Hainan Province. Therefore, the team summarized and sorted out the treatment strategies of dampness and heat pathogens in COVID-19, which is helpful to provide ideas and references for the TCM treatment of COVID-19 in tropical areas.

2. Analysis of Treatment Strategies for COVID-19 Based on the Pathogens of Heat

2.1 Identify the disease location of heat pathogen (Table 1)

Heat pathogen invades different parts of human body, causes different symptoms and suggests different location of disease and pathogenesis. Therefore, it is necessary to adopt targeted treatment according to different location of disease. The common location of disease of COVID-19 are superficies heat, syndrome of exuberance of lung heat, Yangming channel syndrome and so on. The first is superficies heat, commonly seen in the early stage of infection with Severe Acute Respiratory Syndrome Coronavirus 2(SARS-CoV-2). The wind pathogen and the heat pathogen began to invade the superficies, which affected the function of defensive Qi. The main clinical manifestations of the patients were aversion to cold with fever, swelling and pain in throat , cough, body pain and so on. The treatment is mainly clearing heat with pungent and cool-natured drugs. The drugs used to clearing-heat with pungent and cool-natured drugs, such as Jinyinhua (Flos Lonicerae), Lianqiao (Fructus Forsythiae), Sangye (Folium Mori), Juhua (Flos Chrysanthemi), Bohe (Herba Menthae) and so on were mainly used. The prescriptions of Yinqiao Powder and Sangju Decoction were needed. When location of disease is superficies ,the treatment of the disease should be based on the evacuation of heat pathogen. The medicine of bitter cold and heat clearing should not be used too early to avoid too cold. Secondly, it is the pathogenesis of syndrome of exuberance of lung heat. In clinical manifestations，syndrome of exuberance of lung heat is common in the stage of respiratory inflammation of COVID -19[4]. In clinical manifestations, there are not only signs of high fever, sweating, thirst, red tongue, yellow fur, rapid pulse and other signs of heat, but also clinical manifestations of abnormal lung function[5]，such as: cough, expectoration, air tightness and even respiratory function decline. If further damage of lung parenchyma is caused in clinical, there will be obvious imaging changes. In terms of treatment, it is necessary to clearing heat，lung governing diffusion，and lung governing purification and descending and Shigao (Gypsum Fibrosum), Huangqin (Radix Scutellariae) and other drugs can be used for clearing heat, and Mahuang (Herba Ephedrae) -Xingren (Semen Armeniacae Amarum), Suye (Folium Perillae) - Xingren (Semen Armeniacae Amarum), Sangye (FoliumMori)- Xingren (Semen Armeniacae Amarum), Jiegeng (Radix Platycodonis)- Zhike（Fructus Aurantii）and other drugs can be used for restoring lung governing diffusion，and lung governing purification and descending. The key point of the syndrome of exuberance of lung heat is the combination of clearing heat and restoring the lung governing diffusion，and lung governing purification and descending. In clinical, if we see the syndrome of exuberance of lung heat, we can only use the clearing heat method, although it can quickly reduce the fever and relieve the symptoms of fever, but it can't effectively prevent the damage of the disease to the lung. In the treatment of TCM, it can protect the lung function by combining the drugs to restore lung governing diffusion，and lung governing purification and descending. Finally, if the syndrome of exuberance of lung heat develops further, it will develop into Yangming channel syndrome, which is common in the stage of severe systemic inflammatory response caused by COVID-19. Yangming channel syndrome can be manifested as four major syndromes of Yang Ming, such as sweating, thirst, body heat, and surging pulse. In the treatment, because the heat enters into Yang Ming, the heat is extremely strong and easy to burn the body fluid, so the body fluid needs to be taken care of when clearing heat, such as Baihu Decoction with Shigao (Gypsum Fibrosum) and Zhimu (Rhizoma Anemarrhenae) to clearing heat and produce the body fluid. In the lung being connected with large intestine, if the Heat pathogen enters zang-viscera disease involving fu-viscera, it can be witnessed by Yangming fu-viscera excess. The treatment needs to combine heat-clearing method with purgation method, such as Dachengqi Decoction and Xuanbai Chengqi Decoction.

2.2 Attention should be paid to the situation of heat flourishing into poison

The concept of poison has two aspects of the content, one is the etiology and pathogenesis, Jin Dynasty Hejian Liu in the explanation of Yang poison, said the poison as "Yang hot and hyperactive extreme syndrome", Zaijing You said " Poison is the cause of the gathering and not spreading of evil spirits ", that explained the heat of the accumulation of accumulated, and depression into poison；The other is the symptom aspect, heat poisoning causes redness, swelling, heat, pain, bleeding or meat decay into pus and broken ulceration of the performance.

During the process of COVID-19, the heat pathogen was intense. In the local heat pathogen strong causes the flesh to decay into pus, clinical common COVID-19 with lung infection, cough spit a lot of pus turbid sputum, even cough hemoptysis, which is similar to the TCM lung carbuncle. [6]. On the idea of treatment, the first is to choose the medicine with the effect of clearing heat and detoxifying，such as Banlangen（Radix Isatidis），Daqingye（Folium Isatidis），Zaoxiu（Rhizoma Paridis），Huanglian（Rhizoma Coptidis），Huangqin（Radix Scutellariae），Pugongying（Herba Taraxaci）and so on. The second is to pay attention to the discharge of pus, through lung, dredge urine, dredge stool can promote the discharge of pus. It plays an important role in the treatment of the excretion of pus, which is not only the pathological product caused by the heat, but also the pathogenic factor aggravating the disease. The anatomic results of professorLiang Liu's team[7] also showed that the exudative response of COVID-19 was more obvious than that of SARS. Therefore in the treatment should pay attention to the discharge of pus matter. In the treatment process, we can choose Jiegeng（Radix Platycodonis）, Niubangzi（Fructus Arctii）to promote lung and remove phlegm and pus, Yiyiren（Semen Coicis）, Baijiangcao（Herba Patriniae）, Lugen（Rhizoma Phragmitis）, Dongguazi（Semen Benincasae）so as to achieve diuretic discharge of pus, Gualouren（Semen Trichosanthis），Dahuang（Radix et Rhizoma Rhei），Huzhang（Rhizoma Polygoni Cuspidati）to relaxing the bowels and apocenosis. Third, pay attention to the improvement of extravasated blood. The heat becomes the poison, the local stagnant, the heat poison fills in the nutrient-blood and causes the blood stasis block. Taoren（Semen Persicae）in Weijing decoction, Ruxiang（Olibanum）and Moyao (Myrrha) in Xianfang Huoming drink are all medicines to improve local stasis. Local inflammation tends to cause tissue stickiness, resulting in pulmonary fibrosis. Academician Xiaolin Tong[8] discussed that the pathological change of pulmonary fibrosis is similar to the TCM pathogenesis of blood stasis. Therefore, in its formulation for the initial diagnosis of the general prescription which have Xuchangqing（Radix Cynanchi Paniculati），Dihuang（Lumbricus）to promote blood circulation to remove meridian obstruction. Its aim is to block the course of the disease and prevent the course of the disease from developing in the direction of pulmonary fibrosis.

Table 1 Analysis of COVID-19 treatment strategies based on heat pathogenic disease location

Table 2 Analysis of the therapeutic approach of COVID-19 based on dampness pathogen.

2.3 The last against the heat evil should also be considered strong fire to exhaust Qi

Strong fire exhaust Qi was first recorded in Plain Questions· theory on Yin and Yang. It is recorded in the book that "the Qi of strong fire declines while the Qi of little fire becomes strong. Strong fire exhaust Qi , Qi exhaust less fire. Strong fire loose air, less fire produce Qi" . Zhongzi Li, Jiebin Zhang and other note experts have pointed out what is called strong fire, refers to the hyperactive Yang Qi , namely the fire of pathology. Zhongzi Li’s Abstracts of classic of internal medicine said: "the fire of hyperactivity is harmful. Therefore, if the fire is too much, the Qi will decline". It is recorded in Classified Canon that" strong fire sever Qi, so the cloud food Qi , still said the fire to eat this Qi ."

In COVID-19 the course of the disease, In the course of COVID-19, the body fluid is fried in high heat and the Qi consumption along with the fluid is caused by perspiration, which all are the causes of the depletion of human body's normal Qi. Once the normal Qi is damaged, it is unable to resist the evil Qi, resulting in the rapid development of the disease from the obvious evidence of the struggle against evil to the complex syndrome of the deficiency and solid inclusion of the resistance to evil. Clinically, similar to COVID-19 in the course of cytokine storm, respiratory failure, heart failure. In the treatment aspect, in the early treatment that needs to take care of normal Qi, such as the Baihu decoction, Zhuye Shigao decoction is the representative of clearing heat and nourishing Qi and nourishing Yin prescription, if there has been out of the syndrome, it needs to use Shengmai powder, Shenfu decoction and Huiyang emergency decoction.

3. Analysis of COVID-19 therapy based on dampness pathogen

3.1 It is necessary to distinguish between external dampness and endogenous dampness（Table 2）

For dampness disease，Zhongjing Zhang in Synopsis of Golden Chambe The syndrome of spasmodic hygrobiosis clearly put forward two kinds of treatment methods for micro-sweating and diuresis. Micro-sweating for the external dampness, diuresis for the endogenous dampness.

Surface dampness mainly refers to the body surface of dampnessinduced obstruction. After the infection with SARS-cov-2, the symptoms[9] are fatigue, body pain, dizziness and other dampness trapped surface and chest tightness, chest swelling, shortness of breath and other dampness trapped upper jiao. The main points of treatment is to release the surface of lung dehumidification, so that the damp from the surface and scattered. In the Synopsis of Golden Chamber, Ephedra decoction plus white atractylodes and Maxing Yigan decoction were selected, while in the Chapter on Damp-Heat, the taste of Huoxiang (Herba Pogostemonis), Xiangru (Herba Elsholtziae), Qianghuo (Rhizoma et Radix Notopterygii), Cangzhupi (Rhizoma Atractylodis Skin), Bohe (Herba Menthae) and Niubangzi (Fructus Arctii) were selected. External dampness in the treatment of special attention to the function of the lung, the use of more pungent-lytic powder or has the effect of dispersing and reducing lung qi drugs, through the promotion of lung function to promote the removal of dampness pathogen.

Endogenous dampness refers to that the dampness is blocked in the body, mainly in the middle jiao, and then affects the human body function. For example, some COVID-19 patients have diarrhea and other damp obstruction caused by the middle jiao, the lucid yang does not rise, turbid Yin does not fall.The main point of the treatment of endogenous dampness is to promote the transport and transformation of the spleen function, multi-purpose enliven the spleenand with aroma, invigorating spleen for eliminating dampness, dispelling dampness with pungent and warm-natured drugs, such as Huoxiang (Herba Pogostemonis), Peilan (Herba Eupatorii), Doukou(Amomum Kravanh), Sharen(Fructus Amomi), Cangzhu (Rhizoma Atractylodis), Fuling (Poria), prescription to pingwei powder as a representative. Endogenous dampness in the treatment of special attention to the function of the spleen, so the use of Baizhu (Rhizoma Atractylodis Macrocephalae), Cangzhu (Rhizoma Atractylodis), Fuling (Poria), Yiyiren (Semen Coicis) and other commonly used clearing damp drugs to achieve strengthening and transport spleen, promote the effect of the movement of the spleen qi, not only to dispel the already formed dampness pathogen, but also to prevent the accumulation of new dampness pathogen in the body.

3.2 The special disease location of dampness pathogen should be distinguished - Moyuan

Moyuan is first seen in Huangdi Neijing and Lingshu · the beginning of all diseases. It is recorded in the book that " Stay(evil qi) but do not go, pass to give up in the intestines and stomach, between the membrane of the original", Plain Questions· treatise on pain recorded that "Cold pathogen stay in the intestines and stomach, under the Moyuan, the blood flow is not unobvious" and Plain Questions· treatise on malaria recorded that " There is another day of disease, because the evil spirit close to the five viscera, in the Moyuan". The above ancient books mainly discuss the concept of disease position of Moyuan, which is basically equivalent to modern dissected mediastinum and diaphragm. Xue Xue said, "the evil qi from the top, soon to the middle jiao, so the disease more return to the original membrane" .The theory of the plague · disease source recorded that "The evil qi enters the human body from the mouth and nose. It is not in the viscera, not outside the meridian. It is not far from the surface of the body, near the stomach. It's halfsuperficies and half-interior, and it's what the Lingshu calls the Moyuan[10] ". This is a clear indication of the membrane disease in the human body, "not in the viscera, not outside the meridian" characteristics. Based on the characteristics of this disease, starting from a certain viscera or meridian in the treatment, it is impossible to effectively treat the dampness pathogen in the Moyuan. As the The theory of the plague · disease source clouds "This evil qi is not in meridian, with diaphoresis-method treatment can hurt the qi of the body surface only, febrile symptom also won't alleviate, also cannot be treated with purgative-method, because evil qi is no longer viscera, purgative-method can damage stomach Qi only, the patient can be more and more thirsty". Clinical treatment requires the use of Binlang (Betel Nut), Houpo (Cortex Magnoliae Officinalis), Caoguo (Amomum Tsao-ko)and other drugs, " Binlang (Betel Nut) can eliminate and grind latent evil qi, with conveyance and dispersion properties, can also break the miasma of lingnan region, Houpo (Cortex Magnoliae Officinalis) can break the epidemic pathogenic factor and Caoguo (Amomum Tsao-ko) has a pungent and strong smell, can dispel latent evil qi. The combined action of these three drugs can reach the root of the evil qi, dispel the evil qi away from Moyuan, and finally play the effect of avoiding filth and turbidity, so that the epidemic qi will be scattered away from Moyuan.

3.3 Dry cough with little phlegm caused by dampness’s viscosity

The clinical manifestation of phlegm and dampness in lung is phlegm[11], which is the general condition. It is mainly by dampness pathogen aggregation into sputum, sputum with cough. In clinic, but there are dampness impedes qi movement, resulting in the body fluid distribution is not free. Dampness pathogen’s viscosity causes dampness pathogen adhesion to the trachea, alveoli, it is difficult to discharge the situation, clinical manifestations will be less sputum and dry cough. Clinicians already know that dampness causes a dry cough with less phlegm, national physician master Guangxiang Hong [12] professor pointed out that dampness pathogen block cough caused by "characterized by chronic cough, sputum less, color white or color yellow or yellow-and-white, stick, not easy to produce quality and cough day and night, with chest tightness, and airway itch, breathing disorders, cough up the phlegm is comfortable, joy or thirsty would drink hot drinks, throat not unobstructed, poor appetite, loose stool, viscous uncomfortable or constipation, brown urine, red or dark red tongue, moss and greasy, thick yellow phase pulse and soggy pulse or thready and slippery pulse." COVID-19 clinical protocol (trial 7th edition)[13] according to epidemiological data, COVID-19 is characterized by dry cough. The anatomical results of professor Liang Liu's team[7] were as follows: "white foamy mucus was observed in the trachea cavity, and gelatinous mucus was observed in the right bronchus cavity. It is also proved that the dampness's viscosity causes the dampness turbidity to adhere to the body, and it is difficult to discharge.

The harm caused by dampness's viscosity makes it difficult to discharge dampness turbidity mainly has two aspects, one is that the dampness turbidity blocks the trachea and alveoli, bringing difficulties to the treatment, especially the treatment of respiratory function support. COVID-19 therapy and 7 (trial 7th version) "In the treatment of invasive mechanical ventilation advice explicitly put forward" according to the situation of airway secretions, select the closed suction phlegm, bronchoscopy, its necessary to take corresponding treatment ", and COVID-19 medical (third 3rd edition), compared to this kind of treatment for additions, explain the modern medical treatment to remove adhesion in the trachea, alveolar dampness pathogen. The second harm caused by dampness's viscosity is that it is easy to appear clinical " Back to the positive". Academician Boli Zhang [14] pointed out that the academia now basically recognized that " Back to the positive " is not a secondary infection, but was not completely cured. The lesions in COVID-19 patients were mainly small airways in the deep lung, inside the bronchioles, which contained sputum tethers wrapped around the virus. These viruses are wrapped in the sputum plug, stay in the lung deep, do not go out, so in the detection, the detection of sputum in the throat, the detection of the virus, showing that the patient's viral nucleic acid turned negative. After the patient's body slowly gets better, the lung function is slowly restored, especially the small airway, including some bronchial function is restored, and the phlegm is slowly discharged and coughed out. During the coughing process, the sputum in the deep lung comes out, which is also wrapped with the virus, showing a " Back to the positive " phenomenon.

In view of the dampness's viscosity caused by dry cough less sputum is more important to do a good differential diagnosis, must not see dry cough less sputum with heat-clearing and nourishing Yin to moistening lung drugs, need to combine the tongue coating greasy, pulse moisten and fatigue, tolerance, diarrhea and other systemic signs for comprehensive judgment. In order to reduce phlegm in dry cough caused by dampness's viscosity, we should pay attention to promoting lung and removing phlegm. Differentiation of warm diseases · upper jiao said" Taiyin warm-dampness, pathogenic factors by the surface into the interior, chest feel evil indecent and sputum, treated with XuanBi Soup". In XuanBi soup, Pipaye (Folium Eriobotryae) and Dandouchi (Semen Sojae Preparatum) dispersing lung qi, Shegan (Rhizoma Belamcandae) dry phlegm, Tongcao (Tetrapanax Papyriferus) and Yujin (Turmeric Root Tuber) combined with the benefit of eliminating dampness and diuresis, unchoking Yang for stagnation, can be aimed at the dampness's viscosity. Professor Liu Duzhou[15] for the treatment of damp and hot cough is to use sanren decoction combined with manna disinfection Dan or maxing yigan soup. Sanren decoction can promote lung and eliminate dampness and phlegm, and the herb in ganlu xiaodu micropills, Huoxiang (Herba Pogostemonis), Shichangpu (Rhizoma Acori Tatarinowii) and Maxing Yigan decoction all play a role in promoting lung and removing dampness and removing phlegm. Professor Chaozu Chen [16] pointed out in the treatment of TCM and prescriptions that Sanren decoction and ephedra can promote the lung and develop the qi mechanism, so that the qi will be under the channel, benefit the water to remove its phlegm and dampness.

The tropical region accounts for 39.8% of the total area of the world. In addition to the tropical desert climate, the tropical rain forest climate, the tropical grassland climate and the tropical monsoon climate all have the climatic characteristics of high humidity and heat[17]. Therefore, the idea of Chinese medicine treatment based on the fine differentiation of COVID-19 from the pathogenic factors of humid heat disease is of practical clinical significance in guiding the treatment of COVID-19 in tropical areas. In combination with the clinical characteristics of COVID-19, this paper summarized the treatment points of dampness-heat diseases. In clinical practice, when the pathogenic factors of dampnessheat diseases are combined with the infection, it is necessary to distinguish the difference between the severity and degree of the two diseases. Follow the principle of "In diagnosis, refer to the four diagnosis, judge the condition, and provide symptomatic treatment".