大黃
Rhubarb (Dahuang)
Pharmaceutical Name: Radix et Rhizoma rhei
Botanical Name: 1. Rheum palmatum L.. 2. Rheum officinale Baill.. 3. Rheum tanguticum Maxim. ex Balf.
Common Name: Rhubarb
Source of Earliest Record: Shennong Bencao Jing
Part Used: The roots, or rhizomes, are dug in autumn or spring. After the fibrous roots and bark have been removed, the roots are cut into pieces and dried in the sun.
Natural Properties & Taste: Bitter and cold
Meridians: Spleen, stomach, large intestine and liver
Therapeutic Effects:
1. To promote bowel movement.
2. To reduce fire and release toxins.
3. To invigorate blood.
Indications & Combinations:
1. Constipation: a) heat accumulated in constipationRhubarb (Dahuang) is used with Glauber salt (Mangxiao) in the formula Da Chengqi Tang. b) cold accumulation in constipationRhubarb (Dahuang) is used with Prepared aconite root (Fuzi) and Dried ginger (Ganjiang) in the formula Wenpi Tang. c) constipation with heat accumulation and damage to yinRhubarb (Dahuang) is used with Fresh rehmannia root (Shengdihuang), Scrophularia (Xuanshen) and Ophiopogon root (Maidong) in the formula Zengye Chengqi Tang.
2. Extravasation due to heat in the blood manifested as vomiting with blood and epistaxis, or upward attack by pathogenic fire manifested as red, painful and swollen eyes, sore throat and painful and swollen gums. These two syndromes are treated by combining Rhubarb (Dahuang), Coptis root (Huanglian) and Scutellaria root (Huangqin) in the formula Xiexin Tang.
3. Boils, carbuncles and furuncles. Rhubarb (Dahuang) is used with Peach seed (Taoren) and Moutan bark (Mudanpi).
4. Stagnation of blood manifested as amenorrhea, postpartum retention of lochia, postpartum abdominal pain, abdominal masses and traumatic injury. Rhubarb (Dahuang) is used with Chuanxiong rhizome (Chuanxiong), Peach seed (Taoren), Safflower (Honghua) and Moutan bark (Mudanpi).
Dosage: 3-12 g
Cautions & Contraindications: The raw herb is strong in moving feces. Fried with wine, the herb is good for invigorating blood. The carbonized herb is applied during hemorrhagic disease. Overboiling of the herb weakens the function of purgation. This herb is contraindicated during menstruation and pregnancy.
