Huang Lian (Coptis chinensis), derived from the rhizome of a perennial herb in the Ranunculaceae family, includes varieties such as Huang Lian, San Jiao Ye Huang Lian, or Yun Lian. It has a bitter taste and cold nature, primarily affecting the heart, liver, stomach, and large intestine meridians. Huang Lian is renowned for its ability to clear heat, dry dampness, purge fire, and detoxify.
In treating symptoms of heat, damp-heat, blood-heat, and heat toxins, Huang Lian demonstrates exceptional efficacy. However, beyond these well-known effects, Huang Lian possesses many other important therapeutic properties.
Damp-Heat Syndrome
The bitter and cold characteristics of Huang Lian make it particularly effective in drying dampness and purging heat, especially in treating gastrointestinal damp-heat. Here are several primary applications of Huang Lian in treating damp-heat symptoms:
1. Treatment of damp-heat obstruction, as mentioned in the Shang Han Lun regarding the San Xie Xin Tang syndrome, Huang Lian is used in combination with Ban Xia (Pinellia ternata) and Gan Jiang (Dried Ginger) to achieve a harmonizing effect on the stomach and relieve distension. In cases of severe gastrointestinal damp-heat with cholera-like vomiting and diarrhea, it can be combined with Hou Po (Magnolia Bark) and Ban Xia to create Lian Po Yin.
2. Treatment of damp-heat dysentery, Huang Lian is the first choice for treating damp-heat dysentery, showing significant inhibitory effects on pathogens such as Shigella and Vibrio cholerae. Historically, Huang Lian has been praised as the “first medicine for dysentery,” revered in medical texts throughout the ages.
3. Treatment of damp sores, which are caused by damp-heat invading the skin. Huang Lian can be taken internally with Dang Gui (Angelica sinensis) and Chi Shao (Red Peony) or externally prepared as an ointment mixed with rosin and Hai Piao Xiao (Cuttlefish Bone) for significant efficacy.
Heat Syndrome
The bitter and cold nature of Huang Lian makes it an excellent medicine for clearing and purging heat, primarily affecting the heart, liver, and stomach meridians. It excels in clearing heat, purging fire, detoxifying, and reducing swelling. It is mainly used to clear heat from the organs, such as excess heart and stomach fire or liver fire.
For patients with heart fire, Huang Lian can be used alone in decoction, as in the Tai Ping Hui Min He Ji Ju Fang with Xie Xin Tang; if the heat is intense and disturbs the spirit, it is often combined with Huang Qin (Scutellaria baicalensis) and Shan Zhi Zi (Gardenia) as in the Wai Tai Mi Yao with Huang Lian Jie Du Tang; if there is excess heart fire with kidney yin deficiency, it can be combined with Shao Yao (Peony) and E Jiao (Donkey-hide Gelatin) as in the Shang Han Lun with Huang Lian E Jiao Tang; for cases of heart fire leading to sores on the tongue or heat transferring to the small intestine, it can be combined with Zhu Ye (Bamboo Leaf) and Zhi Zi (Gardenia) as in the Yi Zong Jin Jian with Qing Xin Dao Chi San.
For patients with stomach fire, symptoms may include toothache radiating to the head and facial heat, which can be treated with Dang Gui, Sheng Di (Raw Rehmannia), and Dan Pi (Moutan Peony) as in the Lan Shi Mi Cang with Qing Wei San; for cases of stomach heat with vomiting, it is often combined with Ban Xia and Zhu Ru (Bamboo Shavings) as in the Wen Re Jing Wei with Huang Lian Ju Pi Zhu Ru Ban Xia Tang.
For patients with liver fire, symptoms often include rib-side distension and pain, which can be treated with Wu Zhu Yu (Evodia) to address liver qi transforming into fire, as in Zuo Jin Wan.
Blood Heat Syndrome
The bitter and cold nature of Huang Lian provides strong fire-purging and detoxifying effects, showing significant efficacy for bleeding disorders caused by heat forcing blood flow. It can be combined with Huang Qin and Da Huang (Rhubarb) as in the Jin Gui Yao Lue with Xie Xin Tang for treating hematemesis and epistaxis. The Bo Ji Fang records that using Huang Lian alone in powdered form, taken with water, also has this effect.
Heat Toxin Syndrome
The bitter and cold nature of Huang Lian provides strong heat-clearing and detoxifying effects, inhibiting various pathogenic bacteria, and is commonly used to treat skin conditions caused by heat toxins, especially effective for treating carbuncles. As noted in the Wai Ke Zheng Zong with Huang Lian Jiu Ku Tang, it can be combined with Jin Yin Hua (Honeysuckle) and Huang Qin for internal treatment of sores, boils, and swelling, effectively reducing swelling and alleviating pain.
Huang Lian can also be effective externally, as in the Yi Zong Jin Jian with Huang Lian Gao, made from Huang Lian and Huang Bai (Phellodendron) for external application, which is more effective when combined with internal medications.
Lowering Blood Pressure and Blood Sugar
Modern pharmacological studies indicate that Huang Lian has antihypertensive effects, with mechanisms related to the dilation of vascular smooth muscle. Clinical studies have found that Huang Lian Jie Du Tang can effectively treat patients with hypertension and insulin resistance, achieving an efficacy rate of up to 90% with continuous use for one month.
In treating hypertension with excess heart and liver fire, Huang Lian combined with Gou Teng (Uncaria) and Aloe Vera has shown an efficacy rate of over 80%.
Recent studies have also found that Huang Lian has blood sugar-lowering effects, with oral administration of Huang Lian extract at 0.4 grams three times daily for 1-3 months resulting in over 80% of patients experiencing reduced blood sugar and significant alleviation of symptoms of polyuria and polydipsia.
For early-stage diabetes patients with excess heat or insulin resistance, Ge Gen Qin Lian Tang is commonly used, showing significant blood sugar-lowering effects.
For late-stage patients with both qi and yin deficiency, Huang Lian can be combined with Huang Qi (Astragalus) and Yu Zhu (Polygonatum) to enhance blood sugar-lowering effects. Continuous use for 1-3 months gradually improves efficacy.
Eliminating Intestinal Worms
The Yao Xing Lun records that Huang Lian “kills children’s intestinal worms,” and the Ri Hua Zi Ben Cao mentions using pig stomach to steam Huang Lian into pills for treating children’s intestinal disorders. In treating pediatric malnutrition, Huang Lian can be used with a variety of spleen-strengthening and appetite-enhancing herbs to enhance efficacy, providing a bitter taste that aids digestion.
Huang Lian is typically taken internally in decoctions at a dosage of 5-10 grams, while for external use or in pills, the dosage is adjusted accordingly. However, excessive use of Huang Lian can damage stomach qi, so it should not be used in excess; patients with yin deficiency and internal heat, stomach deficiency with nausea, spleen deficiency with diarrhea, or those experiencing early morning diarrhea should use it cautiously.