The Anticancer Effects of Donglingcao (Rabdosia rubescens)
Donglingcao (Rabdosia rubescens) is the whole herb of Isodon rubescens, a plant of the Lamiaceae family. It is a folk remedy commonly used by esophageal cancer patients in the Linzhou region of Henan Province. Because it showed some efficacy, it was discovered by researchers dispatched to Linzhou by China's health authorities; scientific research and clinical trials confirmed its anticancer effect, and it was listed as an adjunctive oncological medication.
Chinese medicine considers Donglingcao to be warm in nature and acrid in taste, with the effects of clearing heat and detoxifying, activating blood and relieving pain. It is used mainly for sore throat, colds with headache, tracheitis, chronic hepatitis, rheumatic pain, and snake and insect bites. The Compendium of Chinese Herbal Medicine entry on Donglingcao records: "Clinical observation of crude whole-herb preparations shows a certain palliative effect on esophageal cancer, cardiac cancer, liver cancer, breast cancer, and rectal cancer; it also prevents and treats side effects of radiotherapy, and can treat acute and chronic pharyngitis, tonsillitis, mumps, tracheitis, and chronic persistent hepatitis."
Modern pharmacological research shows that oridonin (rubescensin A) and rubescensin B contained in Donglingcao both have antitumor effects. Oridonin inhibits the proliferation of lung cancer SPC-A-1 cells and induces apoptosis, downregulating Bcl-2 expression while upregulating Bax protein expression. It also inhibits the growth of human nasopharyngeal carcinoma CNE-2 cells and induces their apoptosis and necrosis. In vitro, it has anti-proliferative and apoptosis-inducing effects on the leukemia HPB-ALL cell line. In addition, oridonin can inhibit the growth of multiple myeloma, acute lymphoblastic leukemia, and adult T-cell leukemia cells. Scholars have also found that oridonin is effective against the proliferation of human prostate cancer DU-145 and LNCaP cells, breast cancer MCF-7 cells, ovarian cancer A2780 and PTX10 cells, and cervical cancer HeLa cells.
Oridonin has a strong killing effect on the human hepatoma BEL-7401 cell line and human esophageal cancer 109 cells, and can enable some experimental animals to survive long-term. It can also induce apoptosis in human gallbladder carcinoma GBC-SD cells and inhibit the growth of human skin carcinoma A431 cells and melanoma K1735M2 cells.
Rubescensin B, on the other hand, has clear antitumor effects on Ehrlich ascites carcinoma, hepatoma, and sarcoma S180 ascites-type carcinoma, and can prolong survival in L615 leukemia. It significantly inhibits proliferation of the human myeloma cell lines K562 and HL-60 and induces apoptosis.
Thus Donglingcao is a broad-spectrum anticancer Chinese herb, and inexpensive, giving it a high cost-performance ratio as an adjunctive anticancer agent.
Besides its anticancer action, Donglingcao also boosts immunity, improves vascular function, and has antibacterial effects. Its toxicity is low, essentially nontoxic. Prepared slices of Donglingcao are rarely found in ordinary Chinese pharmacies, but Donglingcao tablets made from the herb are available in many places.