Jinlingzi San: A Famous Pain-Relieving Formula
Jinlingzi San is recorded in Taiping Shenghui Fang (Taiping Holy Prescriptions for Universal Relief). It is composed of equal parts (one liang each) of Chuanlianzi (Fructus Toosendan) and Yanhusuo (Rhizoma Corydalis). Because Chuanlianzi is also called Jinlingzi, the formula is named Jinlingzi San. When used, Chuanlianzi and Yanhusuo are ground together into a fine powder; each dose is 2–3 qian (6–9 g), taken mixed with wine or warm boiled water. This formula soothes the liver and drains heat, moves qi and stops pain. It is indicated for liver-qi stagnation with stagnated qi transforming into fire—distending pain in the chest and hypochondria, or hernial pain and dysmenorrhea that comes and goes, irritability and restlessness, a red tongue with yellow coating, and a wiry or rapid pulse.
Modern pharmacological research has confirmed that this formula has anti-inflammatory and analgesic effects. It reduces the number of writhing reactions induced by acetic acid in experimental mice, raises the pain threshold in the mouse hot-plate test, and inhibits the inflammatory pain response induced by the formalin-paw method in mice, showing analgesic activity. In addition, Jinlingzi San can also reduce the increased permeability of mouse abdominal capillaries caused by acetic acid and inhibit xylene-induced ear swelling.
Chuanlianzi is the fruit of Melia toosendan Sieb. et Zucc. (family Meliaceae, genus Melia) and has a certain degree of hepatotoxicity. Therefore this formula can sometimes cause abnormal liver function in patients, with elevated serum alanine aminotransferase. Patients with abnormal liver function should not use Chinese herbal formulas containing Chuanlianzi; this formula is also not suitable for children or pregnant women. The toxic component of Chuanlianzi is mainly toosendanin (chuanliansu), and its toxicity is reduced after processing. In ancient times Chuanlianzi was often processed with salt, vinegar or wine—i.e., moistened with salt water, vinegar or wine and then dried in the sun or stir-fried until yellow; it could also be stir-fried alone until the surface turned a light yellow to reduce its toxicity.
Although toosendanin is toxic, it has a good pain-relieving effect. Modern pharmacological research shows that toosendanin can block transmission at the neuromuscular junction; it is a relatively good presynaptic blocking agent at the neuromuscular synapse. Toosendanin can prolong the time before paralysis appears in the contractile response to indirect stimulation in botulism-poisoned specimens. Although there is no specific antidote for botulinum toxin poisoning, toosendanin has a good therapeutic effect on experimentally botulinum-poisoned animals.
In addition, toosendanin also has ascarid-expelling and Staphylococcus aureus-inhibiting effects. Toosendanin is a fat-soluble drug; after entering the animal body it is absorbed and distributed quickly and widely, and cleared slowly. It is mainly distributed in the liver, gallbladder and duodenum; it is also found in the spleen and kidneys, but in lower amounts, and its concentration in various parts of the brain is even lower. Therefore, when using Chuanlianzi, one must watch for cumulative poisoning and drug-induced liver injury.
Yanhusuo, also known as Yuanhu, is the tuber of Corydalis yanhusuo W. T. Wang (family Papaveraceae). It is also a specific painkiller, with an analgesic effect reaching about 40% of that of morphine. The pharmacology of Yanhusuo was introduced in a previous article by the author, "The Blood-Activating and Pain-Relieving Effects of the Papaveraceae Plants Xia Tian Wu and Yanhusuo", and will not be repeated here. The Chinese patent medicine Yuanhu Zhitong Pian sold in pharmacies is made from Yanhusuo; for simple cases of stomachache, using Yuanhu Zhitong Pian alone works very well.
It should be pointed out that neither Chuanlianzi nor Yanhusuo dissolves easily in water, so Jinlingzi San should not be converted into a decoction and boiled in water. Jinlingzi San is most effective in treating pain caused by digestive-tract diseases, such as stomachache, pain from gallbladder disease, and pain from liver disease. For pain caused by the above conditions, adding vinegar-processed Xiangfu (Rhizoma Cyperi) gives an even better analgesic effect. For pain caused by hepatobiliary disease, combining it with Xiaoyao San or Chaihu Shugan San works better than using Jinlingzi San alone. For stomachache caused by chronic atrophic gastritis, combining it with Danshen Yin or Shixiao San works better.
Some doctors have also reported that combining Jinlingzi San with Suanzaoren Tang gives good results in treating pain and insomnia caused by cardiovascular neurosis. The base formula is: Suanzaoren (Semen Ziziphi Spinosae) 15 g, Chuanxiong (Rhizoma Chuanxiong) 10 g, Zhimu (Rhizoma Anemarrhenae) 10 g, Fuling (Poria) 15 g, Gancao (Radix Glycyrrhizae) 15 g, Chuanlianzi (Fructus Toosendan) 10 g, Yanhusuo (Rhizoma Corydalis) 10 g. For severe palpitations, add Muli (Concha Ostreae) 30 g and Hupo (Succinum) 3 g; for severe insomnia, add Wuweizi (Fructus Schisandrae) 15 g and Yejiaoteng (Caulis Polygoni Multiflori) 30 g; for premature beats, add Kushen (Radix Sophorae Flavescentis) 25 g and Fangfeng (Radix Saposhnikoviae) 15 g; for aversion to cold and cold limbs, remove Zhimu and add Huangqi (Radix Astragali) 50 g and Guizhi (Ramulus Cinnamomi) 15 g; for yin deficiency with vexing heat, add Shengdi (Radix Rehmanniae) 25 g and Digupi (Cortex Lycii) 10 g. Decoct in water, one dose daily, taken once in the morning and once in the evening. According to statistics, the effective rate of this formula for cardiovascular neurosis can reach 89.2%. However, when Chuanlianzi and Yanhusuo in this formula are converted into a water decoction, the clinical efficacy is reduced.
Jinlingzi San can be used in the treatment of cancer pain, but it must be combined with other drugs according to the type of cancer pain, and it should not be used in cancer-pain patients with abnormal liver function.