Tongguangsan: Anti-Cancer and Swelling-Reducing Herb of the Yunnan-Guizhou Region
Tongguangsan is the stem, leaf and root of Marsdenia tenacissima of the Asclepiadaceae family, a common folk medicinal herb in Yunnan and Guizhou. The earliest record of Tongguansan is in the Diannan Bencao, written by Lan Mao, a Songming native of Yunnan in the Ming dynasty. The Diannan Bencao records that Tongguansan "unblocks lactation, promotes diuresis, resolves phlegm and clears fire"; using Tongguansan and Banlangen (Isatis root) each 3 qian (9 g), decocted in water, treats sore throat and toothache.
Traditional TCM holds that Tongguansan mainly clears heat and resolves toxin, stops cough and calms wheezing, unblocks lactation and fights cancer. It is indicated for sore throat, lung-heat cough and wheezing, damp-heat jaundice, difficult urination, galactostasis, boils and carbuncles, and cancerous swelling. Modern pharmacological research has found that Tongguansan has anti-tumor and cough-relieving, asthma-calming actions.
Modern pharmacology shows that an intravenous injection prepared from the stems of Tongguansan has a marked anti-tumor action: its inhibition rate against rat Walker 256 carcinosarcoma is 61.6%; against mouse sarcoma S180, cervical cancer U14, liver cancer HSC and Ehrlich ascites carcinoma EAC it is 59.7%, 66.0%, 43.6% and 56.7% respectively; by intramuscular injection the inhibition is 53.5% for S180, 34.0% for HSC and 70.8% for EAC. At 20 g (crude drug)/kg subcutaneously for 10 days, inhibition is 45.5% for EAC, 52.1% for L1210, 56.1% for reticulum cell sarcoma, 54.6% for HSC and 48.9% for S180.
Thus Tongguansan is a broad-spectrum anti-cancer herb. The Quanguo Zhongcaoyao Huibian records that using Tongguansan 9-120 g, decocted in water for over 3 hours and divided into three doses, treats esophageal cancer, cardiac cancer, cervical cancer and Hodgkin lymphoma. The Changjian Kang'ai Zhongcaoyao records using Tongguansan 15 g and Hujiao (pepper) 4 g decocted; or ground to powder, 1.5 g each time three times daily; or the fresh Tongguansan decocted for washing, or mixed with two Hulu leaves and a few pepper corns, mashed and applied externally, to treat cancerous swelling.
Tongguansan also has some cough-relieving and asthma-calming action. Pharmacological experiments show that the total glycosides, hydrolysates and saponified products of Tongguansan all have a marked anti-asthmatic effect, directly relaxing the smooth muscle of isolated guinea-pig organs and antagonizing histamine. Tongguangsan glycosides also have some phlegm-resolving and cough-suppressing action. Clinically, using Tongguansansu in patients with asthmatic chronic bronchitis, the lymphocyte transformation rate rose markedly and serum IgG fell.
The Yunnan Zhongcaoyao records that Tongguansan "clears heat and resolves toxin, stops cough and calms wheezing, disperses nodules and stops pain. It treats gastroenteritis, stomach pain, jaundice hepatitis, infantile malnutrition, stomatitis, cough, bronchitis, asthma, boils and carbuncles."
Although Tongguansan has an anti-cancer action, because it is a regional herb, apart from Yunnan and Guizhou it is not widely used elsewhere; its range is not broad, and most pharmacies nationwide do not stock it.