Medicinal Value of the Root, Stem Pith and Flower of Tongtuomu (Rice Paper Plant)
The root, stem pith and flower of Tongtuomu (Tetrapanax papyriferum) of the Araliaceae family can all be used as medicine. Its root is called Tonghuagen, its stem pith is called Tongcao, and its flower is called Tonghuahua. Tongcao is a very common Chinese herb, but Tonghuagen and Tonghuahua are relatively rare. In fact their actions are very similar to Tongcao's, and they are far easier to harvest than Tongcao, so they are cheaper.
Tongcao is also called Baitongcao, Tonghua, Tongtuomu and Congcao; it is white and hollow. It clears heat and promotes diuresis, and unblocks lactation. It is indicated for strangury with pain, difficult urination, edema, jaundice and warm-heat disease; it also treats scanty dark urine, postpartum insufficient milk, and female amenorrhea and leukorrhea. Tongcao gets its name from its ability both to unblock urine and to unblock milk. Li Shizhen wrote in the Bencao Gangmu: "Tongcao is white in color and cold in qi, bland in taste and light in body, so it enters the taiyin lung channel, conducts heat downward and promotes urination; it enters the yangming stomach channel, conducts qi upward and brings down milk."
Modern pharmacology shows Tongcao has a strong diuretic action; it markedly increases urinary potassium excretion in rats, with no significant effect on urinary sodium or chloride, so its diuresis is thought related to potassium excretion. Tongcao also has antipyretic and anti-inflammatory actions; its total polysaccharide extract has a clear antioxidant effect and raises serum lysozyme activity and the phagocytic function of mononuclear reticuloendothelial cells in experimental animals, raising serum hemolysin antibody levels and inhibiting allergic reactions.
Tongcao appears frequently in formulas for various urinary obstruction. The Puji Fang contains a formula called "Tongcao Yinzi" for "heat-type strangury with pain, urine as red as safflower juice," named after Tongcao: Tongcao 3 liang, Kuizi (Dongkuizi, Malva seed) 1 sheng, Huashi (Talc) 4 liang (crushed), Shiwei 2 liang, decocted in water. This disease resembles nephritis; the dose is large and the diuretic effect strong. The Zhejiang Yaoyong Zhiwu Zhi records another formula specifically for acute nephritis: Tongcao 9 g, Cheqiancao 9 g, Longdancao (Gentiana) 9 g, Qumai (Dianthus) 9 g.
The ancients commonly stewed Tongcao with pig's trotters to promote lactation; using Tongcao, or Tongcao together with Wangbuliuxing (Cowherb), to stew trotters both promote milk. Tongcao stewed with meat also treats excessive leukorrhea. Tongcao also treats menstrual irregularity in women; the Yunnan Zhongyao Xuan records a folk empirical formula for irregular menstruation: Tongcao 6 g, Dangguiwei (Angelica tail) 3 g, Taoren 12 g, Honghua 6 g, decocted in water.
The root, Tonghuagen, has actions similar to Tongcao. TCM holds that Tonghuagen clears heat and promotes diuresis, moves qi and promotes digestion, and activates blood and promotes lactation. It is indicated for edema, strangury, abdominal distension, focal accumulations, wind-damp impediment pain, irregular menstruation and galactostasis. Tonghuagen also treats lobar pneumonia and cough with profuse phlegm or bronchial asthma in the elderly; using 6-30 g alone decocted suffices. Tonghuagen also treats constipation.
Tonghuagen is a commonly used TCM herb for ascites and various edemas; when treating ascites or edema, the dose of Tonghuagen must be at least 30 g. This herb not only promotes diuresis and reduces swelling but also activates blood and resolves stasis, so for edema due to blood stasis it treats both branch and root.
Tonghuahua decocted and taken internally also treats edema. The Chongqing Yaocao records that Tonghuahua treats "scrotal sagging that does not retract."